Redundant God? Christian Faith in the Light of Evolution [1 ed.] 1527559475, 9781527559479

Citation preview

Redundant God? Christian Faith in the Light of Evolution

Redundant God? Christian Faith in the Light of Evolution By

David de Pomerai

Redundant God? Christian Faith in the Light of Evolution By David de Pomerai This book first published 2020 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2020 by David de Pomerai All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-5947-5 ISBN (13): 978-1-5275-5947-9

This book is dedicated to all those who taught me what love might mean: to my parents Odile and Ralph, my brother Mick, my wives Valerie, Lesley and Anne, my daughter Lauren, and those who guided my first steps in the Christian faith, opening my eyes to glimpse the breadth and length and height and depth of God’s love.

Consider the lilies, how they grow: they neither toil nor spin; yet I tell you, even Solomon in all his glory was not clothed like one of these. [Luke 12:27, NRSV].

CONTENTS

List of Illustrations .................................................................................. xi Preface .................................................................................................... xiii Part 1 Chapter 1 Of Molecules and Cells ......................................................... 2 § 1.1 Preamble: the process of science .......................................... 2 § 1.2 Cells and organisms .............................................................. 6 § 1.3 DNA and the transmission of genetic information ............... 9 § 1.4 Regulation of gene expression ............................................ 15 § 1.5 Heritable genetic variation .................................................. 22 § 1.6 Unintentional selection for pesticide resistance .................. 27 § 1.7 Evolution and the origin of life ........................................... 30 § 1.8 Reductionism in biology ..................................................... 32 Chapter 2 Speciation ............................................................................ 34 § 2.1 What is a species? ............................................................... 34 § 2.2 Geographical and climatic factors in speciation ................. 37 § 2.3 Higher-level taxonomic groupings ..................................... 39 § 2.4 Gradual evolution explains speciation and diversity .......... 44 § 2.5 Staging-posts on the way towards speciation ..................... 47 § 2.6 Opportunistic pioneers ........................................................ 51 § 2.7 Life-history strategies ......................................................... 52 § 2.8 Sexual selection and co-evolution ...................................... 54 § 2.9 Evolution—gradual or jerky? ............................................. 56 Chapter 3 Phylogeny and Convergence .............................................. 62 § 3.1 Precambrian enigmas .......................................................... 62 § 3.2 The Cambrian explosion ..................................................... 66 § 3.3 Later evolution of plants and animals ................................. 71 § 3.4 Contingency and mass extinction in the fossil record......... 74 § 3.5 Convergent evolution.......................................................... 80 § 3.6 The wider significance of convergence in evolution .......... 84 § 3.7 Co-option for novel functions ............................................. 89

viii

Contents

Chapter 4 Evolution and Development............................................... 92 § 4.1 A personal story of evo-devo .............................................. 92 § 4.2 Molecular strategies used in animal development .............. 94 § 4.3 How genes can participate in evolutionary change ............. 97 § 4.4 Oogenesis, cleavage and mosaic development ................... 97 § 4.5 Gastrulation and regulative development ......................... 101 § 4.6 Serial repetition, symmetry and polarity ........................... 104 § 4.7 Introducing segmentation in Drosophila .......................... 107 § 4.8 Subdividing the anterior/posterior axis in Drosophila ...... 109 § 4.9 Hox genes and metamere identity ..................................... 115 § 4.10 Segmentation in annelids and vertebrates ......................... 117 § 4.11 Conserved genetic modules specifying body axes ............ 124 § 4.12 Some lessons from evo-devo ............................................ 126 Chapter 5 Humanity........................................................................... 131 § 5.1 What does our genome tell us about our ancestry? ........... 131 § 5.2 What does our genome tell us about ourselves? ............... 135 § 5.3 Nature versus Nurture? ..................................................... 137 § 5.4 Ethnicity, gender and genetics .......................................... 141 § 5.5 Mind and Brain ................................................................. 145 § 5.6 Consciousness: the unitary self in a distributed brain ....... 147 § 5.7 FOXP2—a “language gene”? ........................................... 150 § 5.8 What makes humans unique? ........................................... 151 § 5.9 Development of human culture......................................... 155 § 5.10 Gene/culture co-evolution................................................. 160 § 5.11 Cultural transmission and the meme controversy ............. 162 § 5.12 An evolutionary perspective on religion ........................... 164 § 5.13 Consciousness and memes revisited ................................. 168 Part 2 Chapter 6 § 6.1 § 6.2 § 6.3 § 6.4 § 6.5 § 6.6 § 6.7 § 6.8 § 6.9

Ambiguous Histories ....................................................... 176 Introduction to Part 2 ....................................................... 177 Shostakovitch—collaborator or dissident? ...................... 178 Chevalier de Saint-Georges—the “black Mozart” ........... 179 Friedrich Wohler and the 1828 synthesis of urea ............ 180 Contemporaneous theological responses to Darwin ........ 182 The 1925 Scopes trial: evolution versus creationism....... 184 Multi-layered narratives in the Bible: Psalm 29 .............. 187 Violence and the Sacred—the work of René Girard........ 191 Doubting Thomas and Mary Magdalene ......................... 194

Redundant God? Christian Faith in the Light of Evolution

ix

Chapter 7 Key Thinkers on Evolution and Faith ............................. 199 § 7.1 How might evolution undermine Christian faith?.............. 199 § 7.2 Pierre Teilhard de Chardin (1881-1955) ............................ 202 § 7.2.1 Brief biography ............................................................... 202 § 7.2.2 Teilhard’s concept of evolution ...................................... 205 § 7.2.3 Teilhard’s mystical vision of evolution .......................... 211 § 7.3 R.J. “Sam” Berry (1934-2018) .......................................... 214 § 7.3.1 An evangelical evolutionist ............................................ 214 § 7.3.2 The Fall ........................................................................... 215 § 7.3.3 The Creation ................................................................... 217 § 7.3.4 The image of God in humanity ....................................... 219 § 7.3.5 The Virgin Birth ............................................................ 221 § 7.4 Celia Deane-Drummond (b. 1956) ................................. 224 § 7.4.1 Botany, Biotechnology and Theology ........................... 224 § 7.4.2 Wonder and Wisdom ..................................................... 229 § 7.4.3 Evolution woven into the theo-drama of salvation ........ 231 § 7.4.4 Niche construction and human/non-human interactions 233 § 7.5 Arthur Robert Peacocke (1924-2006) ............................... 235 § 7.5.1 Scientist turned theologian............................................. 235 § 7.5.2 Emergentist-Naturalistic-Panentheistic perspective....... 236 § 7.5.3 Pros and cons of Peacocke’s ENP position.................... 242 § 7.5.4 Sacrament and naturalism .............................................. 244 § 7.5.5 Evolution, the disguised friend of faith? ........................ 245 § 7.6 Four paths to faith through evolution............................... 247 Chapter 8 An Evolutionary Theology .............................................. 250 § 8.1 Scope and aims ................................................................ 251 § 8.2 God as Creator? ............................................................... 252 § 8.2.1 Theism and evolution .................................................... 252 § 8.2.2 The scriptural witness to God ........................................ 254 § 8.2.3 God, humanity and evolutionary time ........................... 255 § 8.2.4 God improvising? .......................................................... 256 § 8.2.5 A self-limited God? ....................................................... 259 § 8.2.6 A God who waits and lets be ......................................... 263 § 8.3 Jesus the Christ ................................................................. 266 § 8.3.1 Encountering Jesus: incarnation, baptism, resurrection .. 266 § 8.3.2 The divinity and kenosis of Christ .................................. 271 § 8.3.3 The kingdom announced: paradox, preaching and power .................................................................... 274 § 8.3.4 The kingdom announced: love, grace and compassion ... 280

Contents

x

§ 8.4 Trinity, communion and community ................................. 286 § 8.4.1 Biblical allusions to the Trinity ...................................... 286 § 8.4.2 Doctrine of the Trinity .................................................... 287 § 8.4.3 Trinity, community and church ...................................... 290 § 8.4.4 Flourishing in community............................................... 292 § 8.4.5 Priests of Creation? ......................................................... 294 § 8.5 A future hope? .................................................................. 296 § 8.5.1 Scriptural dreams and nightmares................................... 296 § 8.5.2 Universal salvation?........................................................ 300 Chapter 9 Evolutionism in the Pulpit ............................................. 310 § 9.1 The task of scriptural interpretation (exegesis) ................. 311 § 9.2 Rewards in this life and beyond ....................................... 314 § 9.3 A sovereign God? ............................................................ 316 § 9.4 God’s care for the non-human creation ........................... 318 § 9.5 Glory to God? .................................................................. 319 § 9.6 Evolution according to Mark ........................................... 320 § 9.6.1 Finding another way ...................................................... 320 § 9.6.2 Paradox of the sower ..................................................... 321 § 9.6.3 Children versus progeny ................................................ 322 § 9.6.4 Servanthood ................................................................... 324 § 9.6.5 Unanticipated turns of events ........................................ 326 § 9.6.6 All-consuming sacrifice ................................................. 327 § 9.6.7 Betrayal, suffering, renewal ........................................... 329 § 9.7 Evolutionary exegesis, or hermeneutics? .......................... 332 Chapter 10 § 10.1 § 10.2 § 10.3 § 10.4 § 10.5 § 10.6 § 10.7 § 10.8

Envoi: The Sixth Mass Extinction ................................. 334 Mea culpa ......................................................................... 335 Complexity—in music, biology and evolution ................. 337 A God’s-eye perspective? ................................................. 344 A path of repentance? ....................................................... 346 How might Christians help? ............................................. 355 The practice of restraint .................................................... 357 The importunate friend ..................................................... 362 Afterword.......................................................................... 363

Abbreviations ........................................................................................ 369 Bibliography.......................................................................................... 373 List of Biblical Quotations ................................................................... 411 Index ...................................................................................................... 414

LIST OF ILLUSTRATIONS

Fig. 1-1 Fig. 1-2 Fig. 1-3 Fig. 1-4 Fig. 1-5 Fig. 1-6 Fig. 1-7 Fig. 1-8 Fig. 1-9

Outline of prokaryotic versus eukaryotic cell structure ............. 7 Mitosis and Meiosis ................................................................... 8 DNA base pairs ........................................................................ 10 DNA replication (simplified) ................................................... 11 Transcription, translation and the genetic code........................ 13 DNA replication, transcription and translation ........................ 14 Jacob-Monod model for regulation of E. coli lac operon ........ 16 Looping in eukaryotic gene regulation .................................... 20 Various types of genetic mutation ........................................... 25

Fig. 2-1 Fig. 2-2 Fig. 2-3 Fig, 2-4 Fig. 2-5 Fig. 2-6 Fig. 2-7 Fig. 2-8 Fig. 2-9 Fig. 2-10 Fig. 2-11 Fig. 2-12 Fig. 2-13

British and Mediterranean orchid flowers .................. Centrefold Varieties, relatives and endemics ................................ Centrefold Macaronesian endemics .............................................. Centrefold Seasonality .................................................................. Centrefold Plant families .............................................................. Centrefold Arthropod diversity .................................................................. 42 Diversity of life ........................................................................ 42 Vertebrate diversity ................................................................. 43 Ecotypes: Three-Spine Stickleback and Rough Periwinkle ..... 50 Weeds ......................................................................... Centrefold Sexual selection and co-evolution ........................................... 56 Modern vegetables derived from Wild Cabbage ........ Centrefold Flower mutants, Evening Primrose, Lamium hybrids .. Centrefold

Fig. 3-1 Fig. 3-2 Fig. 3-3 Fig. 3-4 Fig. 3-5 Fig. 3-6 Fig. 3-7 Fig. 3-8

Precambrian rocks and fossils.................................................. 64 Early (pre-Ediacaran) emergence of some animal groups ....... 69 Cambrian chordates ................................................................. 71 Appearance of major Arthropod and Chordate groups ............ 72 The beauty of fossils ................................................................ 74 Models of evolutionary directionality ...................................... 79 Outline of vertebrate and octopus eye structures ..................... 82 Two roads not pursued—from dinosaurs to birds .................... 87

Fig. 4-1 Fig. 4-2

Cleavage ................................................................................ 100 Regulative development in sea urchin embryo ...................... 103

xii

Fig. 4-3 Fig. 4-4 Fig. 4-5 Fig. 4-6 Fig. 4-7 Fig. 4-8 Fig. 4-9

List of Illustrations

Chick forelimb development (schematic) .............................. 106 Metameres in Drosophila embryogenesis.............................. 108 Genetic control of segmentation in Drosophila ..................... 113 Hox clusters in Drosophila, Branchiostoma, Mus ................. 118 Hox and krox-20 expression in vertebrate hindbrain ............. 121 Shared features of most Bilateria ........................................... 126 ABC model of floral development ......................................... 128

Fig. 5-1 Cave paintings from the Grotte du Pech-Merle ..................... 135 Fig. 5-2 Twinning ................................................................................ 138 Fig. 5-3 Inheritance of a FOXP2 mutation in family KE .................... 150 Fig. 5-4 Neolithic artefacts .................................................................. 159 Fig. 5-5 Mozart and Dittersdorf........................................................... 173 Fig. 6-1 Eponymous organic compounds and source plants ................ 182 Fig. 6-2 Inculturation exemplified in buildings .................................... 190 Fig. 7-1 Teilhard de Chardin ................................................................ 211 Fig. 7-2 Some characteristic flowers of the Burren .............................. 234 Fig. 8-1 Improvisation in ink and paint ................................................ 258 Fig. 9-1 Orchids imitating insects ............................................. Centrefold Fig. 10.1 Arthur’s Seat and its flora ....................................... Centrefold Fig. 10-2A Complexity in music .......................................................... 340 Fig. 10-2B Genetic complexity ............................................................ 341

PREFACE

This book looks at Christian faith through the lens of evolution. As a professional biologist—and before that, as an amateur botanist since childhood—I live and breathe a discipline permeated through and through by evolution. That doesn’t make me an expert on evolutionary theory, but the evidence in favour of evolution by natural selection is overwhelming, and there is no alternative paradigm that makes coherent sense of the living world around us. Part 1 of this book reviews some of that evidence, using examples and case-studies that particularly appeal to me. Doubtless others could have been adduced, perhaps to greater effect, but this is my own selection—laced with a few personal anecdotes. I make no apology for using technical jargon-words, which are usually italicised and briefly defined at their first appearance. An extended glossary seems redundant, since interested readers can check online for more nuanced meanings of these terms. Though I have omitted many details in my chosen examples, I have tried not to oversimplify too much—since the interpretations offered are always subject to revision, expansion or occasionally disproof. Readers from faith backgrounds who may have opened this book in the hope of finding a rebuttal or alternative to evolution will be sorely disappointed. I am not trying to defend a sandcastle of faith against the surging tides of scientific materialism, but rather to ask what kind of God might be consistent with the current evolutionary world-view. My provisional answers, developed in outline through part 2 of this book, are surprisingly consonant with the kingdom teaching of Jesus in the gospels. It is this belief which allows me to keep faith as an ordained Anglican priest, ministering from a liberal theology yet preaching the good news of Jesus Christ with evangelical zeal, without denying or betraying my evolutionary convictions. To many this will seem a contradiction in terms, and doomed from the outset. Even so, I believe the attempt is worthwhile, and where I have fallen short, I trust that others will rise to the challenge and will find new ways of holding Christian faith and evolution in creative tension. Like most biologists, I use the word function as a kind of shorthand—to describe what a gene or protein or cell or organism actually does. Inevitably, such functional descriptions are incomplete; multi-functionality is the norm rather than the exception. But in common parlance, the word

xiv

Preface

function has at least two additional senses that most biologists would eschew, as noted by Daniel Dennett (2017, pp. 34-38). When applied to a human artefact, function implies both design (and thus a designer) and purpose. Despite appearances, this does not concede the core argument of the Intelligent Design (ID) school. The designs that evolve in biology, however astonishing in their intricacy and aptness, have been crafted not by some (divine) Intelligent Designer, but rather by an undirected evolutionary process of endless trial and error, with natural selection relentlessly winnowing out the failures. Whereas William Paley (1802) used design in nature to argue for a beneficent divine designer—based on the analogy of a watch and its human watchmaker—Richard Dawkins pointedly entitled one of his books “The Blind Watchmaker” (1986). Dennett (2017), for one, is more relaxed about using the language of design and even purpose in biology, so long as we remember that these are produced by undirected, non-intentional processes of evolution. And that, for many religious believers, seems to deny any notion of a divine Creator. I will return to this question and offer a few pointers in chapter 8; suffice it to note here that non-interventionist does not inevitably imply uncaring, and that the topsy-turvy world of kingdom values, to which the gospels attest, points us to a loving God who never coerces us (Oord, 2015). It is often claimed that science cannot answer “why?” questions, yet Dennett (2017, p. 38) distinguishes two senses of “why?” that science can indeed address: how did this come to be the way it is? and what is it for? Both are central to evolution, and each of these senses can illuminate the other. To take one familiar example that will be revisited in chapter 3, the function of wing feathers in (most) birds is to facilitate flight. Even in fossil precursors showing clear reptilian features, such as Archaeopteryx, a typical avian arrangement of cross-linking barbs, barbules and barbicels was already present, enabling these pennaceous feathers to act as aerodynamic vanes (for insight into the underlying biomechanics of wing feathers, see Matloff et al., 2020). But complex structures such as flight feathers could not possibly have arisen in one step. During the evolution of modern birds from theropod dinosaurs, the earliest feather-like structures were single keratin filaments, then multiple filaments, which later became attached to a central axis (plumaceous or down feathers). None of these could conceivably have served to enable flight, and most likely they functioned as insulators in thermoregulation, since birds are (and many dinosaurs were) warm-blooded; this function is still retained by the down feathers in juvenile or flightless birds. We will meet with further examples of evolutionary co-option for new functions (exaptation) later in chapter 3.

Redundant God? Christian Faith in the Light of Evolution

xv

The story of how flight feathers evolved (“came to be the way they are”) therefore implies several answers as to “what they are (and were) for”. The tale is told of a child who asks both parents where the rain comes from. Mum—who is both religious and busy—replies that “God makes the rain”. Dad, by contrast, launches into a long account of the sun’s heat, evaporation from the seas, rising air currents and the condensation of water droplets. The child returns to mum and confronts her with a slightly garbled account of where the rain really comes from; “yes”, she responds, “that’s how God makes the rain”. A wise answer, if the parents wish to avoid being played off one against the other, but equally it’s an answer that begs far too many questions. I suspect many middle-of-the-road Christians believe something similar about evolution—that it’s the process whereby God creates all the myriad varieties of living things on this planet. But is that really a sufficient answer? One underlying problem is that evolution is both indifferent to suffering and incredibly wasteful. For most organisms, only a fraction of one percent of the viable offspring produced will actually survive to adulthood and produce offspring of their own. True enough, this percentage increases significantly among those birds and mammals that carefully nurture their young—and especially so among humans. But even so, it is hard to reconcile this relentless struggle for survival with a loving God who wills only good for creation. Because of the close evolutionary ties linking humans with other animals, this cost of evolution cannot be glibly dismissed as a mere illusion, as though only human beings matter to God. Nor can we pursue an ascetic line that decries the body and its sufferings, but glories in an immaterial soul or spirit— since modern neurobiology seems inconsistent with such a dualism (see chapter 5). An impersonal God, indifferent to the suffering and wastage attendant on evolution, has only limited appeal; why would such an entity merit devotion and worship? As a Christian, what makes all the difference for me is my conviction that in Jesus, Godself enters into the pain and suffering of this world (which can also be viewed in evolutionary terms), and even suffers death on behalf of—and in solidarity with—all human beings, and perhaps all living things. I cannot prove beyond reasonable doubt that Jesus really was God incarnate, nor that he rose again from the dead, but I can at least try to outline how such a God could be interpreted in ways more consistent with an evolutionary world-view. Here I am not so much seeking to convert atheist scientists to faith (though I would ask them to read this book with an open mind), but rather to open the eyes of Christians to evolution and the hard questions it raises for theology.

xvi

Preface

It is a truism that death is an inevitable corollary of life: galaxies and stars, as well as species and individuals, all succumb to death—eventually. The second law of thermodynamics cannot be defied forever. All living organisms manage to do this temporarily by taking in energy to counteract entropy (increasing disorder)—but sooner or later errors creep in, leading to senescence and finally death. As Ecclesiastes 3:1-2 (NRSV) states: “For everything there is a season, and a time for every matter under heaven: a time to be born, and a time to die”. On our geologically active Earth, environmental change is unavoidable, and on occasion this will prove catastrophic, precipitating the demise of individuals and of whole species, or rarely mass extinctions (§ 3.4). Lucas Mix (2020) argues that most if not all of the suffering and wastefulness usually blamed on evolution is in reality caused by the attrition of entropy in all organised systems. We cannot hope for evolution to redeem itself by defying entropy; such a hope lies in the gift of God alone (§ 8.5.2) and is beyond the scope of science. The welfare of animals is a fairly recent concern, coming to the fore only since the 19th C CE, at least in Britain. Are we then projecting 21st C sensitivities onto the costliness, suffering and wastage entailed by entropy and evolution, whereas people in earlier centuries would have seen nothing untoward in this? In what ways are human sensations of suffering or pain (a useful warning system, in evolutionary terms) applicable to animals, let alone plants. or even microbes? Among higher vertebrates, comparable experiences of pain can be inferred—but is a plant wilted by drought “suffering” in any real sense? And yet, there is accumulating evidence that plant root systems are able to “communicate” via networks of mycorrhizal fungal symbionts, extending to warnings of predator or disease attack, and even sharing nutrients. This suggests unanticipated levels of co-operation and interactivity even among plants. Little wonder that many Christians are appalled by the seeming callousness of evolution—summarised in Tennyson’s eloquent phrase “nature red in tooth and claw” from his 1849 poem “In Memoriam” (McGrath, 2011, p. 167), which predated Darwin’s “Origin of Species” by a decade. Jesus came to the sheep of his fold so “that they may have life, and have it abundantly” (John 10:10, NRSV), which hardly squares with a world in which so many lives—human and especially non-human—are cut short and left unfulfilled. The question remains unanswered: where can God’s love be discerned under the harsh spotlights of entropy on the one hand and evolution on the other? I will doubtless be taken to task for making common cause with ultraDarwinists such as Daniel Dennett and Richard Dawkins, who have become bêtes noires among Christians. However, my reasons for doing so

Redundant God? Christian Faith in the Light of Evolution

xvii

are straightforward, since these authors both provide plausible Darwinian accounts of how uniquely human traits such as consciousness, free will, language and culture could have arisen through conventional evolutionary processes. Much of this is speculative, to be sure, but at least it seeks for continuities rather than discontinuities between ourselves and all other living things on this planet. The question I am pursuing here is whether such an evolutionary perspective is inevitably fatal to belief in God. If evolution is as all-embracing as its atheist proponents claim (and I believe it is), then there is no obvious necessity for a Creator, either to set the ball rolling (“light the blue touch-paper and retire to a safe distance”: the deist position) or to guide the whole process. My tentative answer is to suggest that the interfering, micro-managing, all-powerful God of traditional belief is indeed redundant, but that the forgiving, non-coercive, counter-intuitive God of love to whom Jesus bears witness in his gospel teaching is not only plausible, but is desperately needed in this beleaguered world we share. One of the most characteristic and possibly unique of human traits is our innate predilection for story-telling. Our species has been aptly dubbed Homo fabulans—“tellers and interpreters of narrative” (Currie, 1998, p. 2). Michael Dowd (2007, pp. 103-106) draws a useful distinction between day talk, based on rational evidence and facts (the very essence of science)— and night talk, couched in the allusive and emotionally charged language of myth, metaphor and poetry. The former is handled in large part by the left half of the human brain, the latter by the right half (McGilchrist, 2009). But we should not let this neat categorisation blind us to intermediate possibilities—what we might term sunset talk or dawn talk. The former draws highly selectively on facts and rationality to propose an ideology— political or religious—that tries to lead us down the narrator’s preferred path towards conclusions that do not necessarily follow from the facts. I have tried to avoid this trap, as far as possible, by separating the evolutionary science in part 1 from the more speculative theology in part 2. My hope is that this tactic comes closer to dawn talk—where a broader perspective on the facts might lead us to consider alternative possibilities, as non-exclusive ways of understanding the intricate narrative of evolution. Scientists each tell that story in slightly different ways, choosing their own personal selections of examples and illustrations, even if tinged with a flavour of whatever ideology they might adhere to (whether atheist or religious, secular or spiritual, political or philosophical). Rather different readings of the story of evolution are given by Richard Dawkins, by Stephen Jay Gould, and by Simon Conway Morris—to take just three writers who have all brought evolution to a wider readership in recent

xviii

Preface

decades. All base their arguments on the same underlying set of facts, but the examples used and the interpretations offered take the reader on quite different journeys. Even successive books by the same author offer subtle contrasts in emphasis, often with different questions or audiences in mind. There is nothing wrong in this—no one account is necessarily “correct” and the others false (despite bluster to the contrary!). All are provisional, and all may be mistaken or distorted in some respects, while also offering insights that help us glimpse afresh the sheer scope, variety and subtlety of evolution. We don’t have a complete understanding of the process, so of necessity all these accounts are partial—in both senses of the word. That is one reason why part 2 of this book explores the possibility of different readings, both of scripture and of history, that do not simply play into the tired and obsolete myth of inevitable conflict between science and faith. It is all too easy to portray evolution as a triumphal progress culminating in human beings as some sort of pinnacle or ultimate achievement—“the crown of all creation” (quoted from Eucharistic Prayer G, Archbishops Council “Common Worship”, 2000, p. 201), or as “the universe become conscious of itself” (cf. Dowd, 2007). That is far too hubristic and anthropocentric a view. We cannot presume that the universe (or multiverse) has not evolved intelligent beings elsewhere, nor indeed that humanity is the final word for evolution on planet Earth. Our singular power to reflect consciously on ourselves and on the universe around us seems to be matched only by our capacity for heedless destruction of other humans and of our environment. In some ways Homo sapiens is a misnomer for our species, since wisdom seems in short supply in many of our dealings with each other and with the natural world. It will be noted by both scientists and theologians that in part 2 of this book I treat scriptural quotations as pieces of evidence—but not, I trust, as proof texts. This somewhat cavalier approach to scripture glosses over much Biblical scholarship: textual and form criticism, and hermeneutics— of which I am aware but have no space to explore in detail. Rather, I employ the risky approach that most preachers use in a Sunday sermon— which is to take the words of one or more scriptural passages and try to unpack what they might mean for an audience in the 21st C CE, some 2000 years after they were written down. Of course, words change their meanings and associations over time, but it is dangerous to assume that in any given text there is only one clear and immutable meaning, fixed for all time. Unpeeling the many different layers of meaning and ambiguity in scripture is, to me, more fruitful, more challenging and more illuminating. To emerge after a sermon saying “I’d never thought of it that way before” can be a sincere tribute to inspirational preaching—unless of course the

Redundant God? Christian Faith in the Light of Evolution

xix

interpretation offered was so bizarre and implausible that this phrase is said with a regretful shake of the head or a dismissive shrug of the shoulders! That too can happen when preachers start riding one of their pet hobbyhorses. I am well aware that conservative Christians and biblical scholars will think this is precisely the trap I have fallen into in part 2 of this book. The world-views available to people back in the first century CE were not touched in any sense by evolution nor even by science as we currently understand it. But science and evolution so dominate contemporary culture and thinking, at least in the West, that Christians must needs accommodate to this reality—perhaps seeing things we thought we knew in a fresh light, as if for the first time. Otherwise, we retreat into alternative realities that operate by their own local rules—an option followed by fringe sects and by fundamentalist streams within all major religions. Though prevalent and superficially attractive—thanks to the apparent certainties it offers—I believe that option to be profoundly misguided and even dangerous. We all inhabit planet Earth and must husband its dwindling resources as best we can, yet many fundamentalists vehemently deny human responsibility for climate change and refuse to accept evolution or many other scientific inferences. But science and faith co-exist within the same physical reality, underlining the urgency of finding realistic contact-points between them. In terms of this book’s structure, chapter 1 offers an outline of cell and molecular biology; non-biologists may find this tough going, but without it much of the rest of part 1 will make little sense. Chapter 2 addresses the core topic of Charles Darwin’s 1859 book “The Origin of Species”, asking how diverse and distinct life-forms arise through evolution by natural selection. Chapter 3 expands this perspective through the vast epochs of geological time—focussing mainly on animals over the past 600 million years—pointing to the ominous refrain of mass extinctions that have punctuated the earth’s fossil history. Chapter 4—doubtless also daunting to non-biologists—returns to the molecular and genetic themes of chapter 1, exploring how genes co-operate to establish pattern in developing animal embryos, and the hints of “deep homology” that suggest how evolution generates endless variety and innovation by tinkering with ancient genetic modules. Chapter 5 looks at humanity from a scientific perspective, ranging widely from DNA and brains to the remarkable rise of culture that seems unique to our species. In Part 2, chapter 6 offers a selection of ambiguous histories—where digging down into apparently straightforward stories reveals unexpected layers of complexity—in music, in the history of evolution, and in biblical texts. This provides a prelude to chapter 7, where I review the thought of four very different “key thinkers” who have wrestled with the conundrums of evolution and

xx

Preface

Christian faith: the Jesuit Pierre Teilhard de Chardin, the evangelical R.J. (Sam) Berry, the Roman Catholic Celia Deane-Drummond, and the liberal Anglican Arthur Peacocke. Chapter 8 is an attempt to state my own position as clearly as I can set it out, without pretending that I have answers to every question. Chapter 9 offers a brief evolutionary exegesis of a personal selection of biblical texts, exploring how the words used (at least in modern English) can find new resonances in the light of evolution—but without suggesting that the original writers penned these phrases with any such interpretation in mind! Lastly, in chapter 10, I return to the theme of mass extinctions covered in chapter 3. Global warming—largely anthropogenic in origin—is triggering a sixth mass extinction among the myriad other species with whom we share this planet, exacerbated by expanding human populations and overexploitation of resources. Unless we can curb our greed and find the inner spiritual motivation to live more sustainably, our future looks bleak. Though this book offers a personal take on its subject-matter—its core arguments developed over many years while leading a double life as an academic biologist and ordained priest—it could not have reached fruition without the input and enthusiasm of many others. I would like to take this opportunity to thank my colleagues and friends who suggested extra reading or read chapters in draft: from the University of Nottingham, Jerzy Behnke, Ian Duce, Kate Durrant, Markus Eichhorn, Francis Gilbert and Paul Scotting; among fellow members of the Society of Ordained Scientists, David Atkinson, Pan Conrad, Tom Lindell, Colin Price, Roger Pullin, Simon Lumby, Mark Gallagher, Keith Suckling and Roger Yates; from New College at the University of Edinburgh, Michael Fuller, Mark Harris, Anja Klein and Helen Bond. Help with chapter 3 was generously provided by my geologist brother Mick, with contributions from Simon Conway Morris, Alexander Liu, Jean-Bernard Caron and Sarah Gabbott. I am particularly indebted to Adrian Armstrong, Michael Fuller and Jeff Patrick for reading through most or all of my text—pointing out omissions and non-sequiturs as well as typographical errors. This book has benefitted greatly from all their suggestions and comments. I take full responsibility for the inevitable errors, misapprehensions and omissions that remain. Most illustrations are my own, since copyright permission is such a vexed issue; readers will be left in little doubt about my enthusiasm for plants! As for diagrams, I opted for the familiarity of Powerpoint, despite its limitations. In both parts, I refer extensively to popular presentations of evolution and theology, but part 1 also draws widely on the primary scientific literature. This reflects my own background as an academic biologist, whereas I have no comparable foundation in academic theology.

Redundant God? Christian Faith in the Light of Evolution

xxi

I have endeavoured to update many of the stories I cite with the latest plottwists and question-marks from papers published in the last year or so. But I am aware that this provides no assurance of security—as only time will tell which advances will prove fruitful and which lead nowhere. Science is always provisional—aiming for verisimilitude rather than absolute truth.

PART 1

CHAPTER 1 OF MOLECULES AND CELLS

Summary § 1.1 outlines the basic reasoning, reporting and reliability of science. § 1.2 deals with cell structure, and how bacterial cells (prokaryotes) differ from those of higher organisms (eukaryotes). § 1.3 describes how genetic information is encoded in DNA, copied (by replication), and expressed via RNA (transcription) into protein (translation), using the triplet genetic code. § 1.4 compares the regulation of gene expression in bacteria (Jacob-Monod model) with the multi-level modular control systems employed in eukaryotes, using protein transcription factors, DNA looping, RNA splicing and other mechanisms. § 1.5 looks in brief at inheritance patterns from cross-breeding (Mendelian ratios), genetic mixing through recombination during gamete development, together with the various types of mutation that can alter the DNA sequence and introduce genetic novelty. § 1.6 describes how the prolonged use of pyrethroid insecticides has encouraged specific resistance mutations to emerge among target pests. § 1.7 considers the origin of life, and explores the possibility of an “RNA world” that preceded the emergence of cellular life based on DNA, RNA and proteins. Lastly, § 1.8 considers the success of scientific reductionism, but asks whether there might also be “emergent properties” of the whole that cannot readily be predicted from the properties of its component parts.

1.1 Preamble: the process of science Part 1 of this book claims to be scientific in its approach, yet many non-scientists have asserted that evolution is non-falsifiable and is therefore not truly a scientific theory. It is always risky to infer a general truth from specific instances—for instance if staking a claim that all swans are white—yet this is the way that scientists often work. Such a statement may hold true for all swans encountered in the northern hemisphere, but is immediately disproved by the occurrence of black swans in Australia. Our original sample (northern swans) was too limited in scope and diversity,

Of Molecules and Cells

3

and thus our generalisation was misleading; we need a broader zoological definition of what defines the group of birds known as swans (§ 2.3). Karl Popper proposed that science works (for the most part reliably) on the basis of falsifiability, whereby any scientific hypothesis can in principle be disproved through thorough testing of its key predictions and showing one or more of them to be demonstrably false (Popper, 1968). At first sight, evolution provides a remarkably protean and flexible explanation for the history of life on earth, with a capacity to absorb major setbacks or to find alternative explanations whenever its key tenets come under challenge. But that doesn’t mean that it is in principle unfalsifiable: when asked what evidence might disprove evolution, J.B.S. Haldane flippantly but pointedly replied “Fossil rabbits in the Precambrian”. Similarly preposterous claims (e.g. of “human footprints” among dinosaur footprints at Paluxy River) have never yet been proven scientifically, but in principle they could be. However, another philosopher of science, Thomas Kuhn, pointed out that science works mostly within over-arching paradigms that represent the accepted consensus in any given field. These paradigms are sometimes false (e.g. the phlogiston theory of combustion before the discovery of oxygen) or at least incomplete (e.g. Newtonian physics before relativity and quantum mechanics). The transition from one paradigm to another (a so-called “paradigm shift”) is a time of challenge and re-evaluation, when accepted models and explanations are brought into question and often rejected as inadequate (Kuhn, 1962). Such paradigms also feature as core assumptions that cannot be abandoned without undermining an entire programme of scientific research, in the model proposed by Imre Lakatos (1978). It is certainly true that evolution provides the current over-arching paradigm and core assumption within the biological sciences; Theodosius Dobzhansky (1973) entitled an influential essay “Nothing in biology makes sense except in the light of evolution”. But there have been opportunities aplenty for this evolutionary paradigm to be undermined if not overturned over the past half-century: the genetic code might not have proved universal (so denying the descent of all living things from a common ancestor; this chapter), and genome sequencing in a wide range of organisms might have flatly contradicted rather than broadly supported the inferred evolutionary basis for traditional taxonomy (the classification of life; chapter 2) and phylogeny (the fossil history of life; chapter 3). The application of scientific method has proved immensely successful in making sense of the world around us. It makes the tacit assumption that the universe is indeed understandable and that we can apply reason as well as observation to the process of understanding it. Many have argued that

4

Chapter 1

this has arisen primarily in the Christian West through its view of God as guarantor of natural laws (Aquinas). Scientific reasoning proceeds in two directions: first inductively, building models and hypotheses on the basis of our observations; and second deductively, making predictions of what we should expect to observe under certain (ideally experimental) conditions if our model or hypothesis is correct, and then testing those predictions. There is thus a to-and-fro process of model building and refinement driven by ever more extensive and precise experimental or field observations. This works on the basis of what Lucas Mix (2015, pp. 48-50) has termed mutual observables: if I were to conduct an experiment in my Nottingham laboratory, then the same (or very similar) results should be obtainable in a replicate experiment conducted anywhere else in the world on another occasion. Needless to say, there are several caveats to this sweeping generalisation: both experiments would need to use identical conditions, with the same materials and equipment. Another key limiting factor is statistical. Ideally one might wish to measure every single instance of a particular phenomenon, but in practice this is impossible—and we have to content ourselves with measuring a subset or sample of the total instances. This can also introduce sample bias—particularly if the sample has been selected using criteria that skew the outcome. This can often be inadvertent, but occasionally it is done deliberately. Inadequate sample size is another important limitation. If you toss a coin 5 times, it would not be especially surprising if heads turned up 4 times and tails only once. But if you tossed the same coin 100 times, an outcome of 80 heads to 20 tails would suggest the coin had been tampered with. In general, the larger the sample size, the more confident we can be that our sample is representative of the whole population, giving us tighter confidence intervals (often stated as 95% CIs). Critics claim that “evolutionary” explanations for specific adaptations often amount to little more than wishful “Just-So Stories”—on a par with Rudyard Kipling’s fanciful account of how the leopard got his spots (etc.). This is more than a little unfair; most such explanations do make testable predictions about the mechanisms or pathways by which these adaptations arose, and since most have arisen multiple times in different groups of organisms (by convergent evolution; § 3.5 and 3.6), they are both testable and in principle falsifiable. Daniel Dennett (1995) draws a useful distinction between skyhooks—instances of irreducible complexity which defy evolutionary explanation and so necessitate an Intelligent Designer— and cranes, where such complexity is built up gradually by plausible small-scale evolutionary steps. By definition, science prefers to work with cranes rather than posit a “miraculous” skyhook. Even where the latter might seem more likely at first sight, it always remains vulnerable to crane

Of Molecules and Cells

5

attack. The Intelligent Designer (Behe, 1996) is therefore liable to become an ever-shrinking “God of the gaps” (compare Behe, 2007). In practice, science works by proposing rational hypotheses and models within the prevailing paradigms, such that key predictions made by a given hypothesis or model can be tested—for preference through experiments under carefully controlled conditions—so that it can be either rejected or retained. Experimental findings consistent with the model or hypothesis can never prove its validity, since future tests might come to an opposite conclusion. But once falsified through experimental testing, any hypothesis ought to be discarded as inadequate, and alternatives (or at least modifications) sought. In practice, as pointed out by Popper (1968), scientists can waste inordinate amounts of time and effort defending a favourite “wrong” hypothesis, sometimes on the dubious grounds that it is far too good an idea not to be true! Occasionally that stubbornness pays off and a controversial hypothesis is eventually vindicated, as with Alfred Wegener’s evidence suggesting continental drift (Dudman, 2003), but far more often contrary evidence accumulates till the idea has to be jettisoned. The process of scientific publication deserves brief comment here. Scientists usually describe their findings and the methods used to obtain them in the form of a paper submitted to a scientific journal, which may be prestigious and broad in scope (like Nature or Science), or alternatively quite narrow in terms of its remit. After determining its suitability for that journal, the paper is sent out for anonymous peer review, conducted by two or more scientific experts in that field. Reviewers can accept or reject a paper outright, but the former at least is unusual. More commonly, sundry criticisms are raised, often requiring extra controls or experimental tests, or sometimes proposing an alternative interpretation, and very frequently recommending additional explanations, cuts, references or textual clarifications. Many authors acknowledge that the final published paper has been greatly improved through this peer review process, though it can all take an unconscionably long time (months to years). However, the system is only as good as the quality of its reviewers, and the time and energy they are willing to devote to this unpaid task amid the pressures of their own careers. There are cases where poor-quality papers slip through the net and get published, not to mention an acknowledged problem of fraud—ranging from selective presentation of data through to outright falsification of results. This detracts from the reputation of science, and is time-wasting for scientists trying to repeat or develop the fraudulent work, though this can often help unmask the fraudsters. Despite these problems, peer-reviewed papers should at least meet basic scientific standards of competence; however, that does not prevent biased or simply erroneous

6

Chapter 1

papers from being published. The quest for scientific novelty can lead to corners being cut, or claims may be made that are later contradicted by new data. The proper procedure in such cases is for the original authors to publish a retraction, but this isn’t always done; I did so once myself (de Pomerai et al., 2006) in Nature after identifying a key confounding factor. Science deals with repeatable observations and experiments, subject always to the technological limitations of its equipment, and viewed through the interpretative lens provided by current models and paradigms. It does not deal with absolute truths, but rather aims to provide the most accurate achievable description of reality (verisimilitude). Its conclusions are necessarily provisional and subject to revision in the light of new understanding, but it is neither arbitrary nor easily set aside as mere “interpretation”. Despite the innate conservatism and inertia of mainstream science, paradigm shifts can and do occur; during my own life, these have arisen from the advent of plate tectonics, molecular biology and genomics. Science is not wasting its time trying to paper over inadequacies in the evolutionary world-view. Likewise, the vacuous bubble of post-modern deconstructions of the whole scientific enterprise has been convincingly pricked (Sokal & Bricmont, 1998). Human societies depend on the reliable out-workings of applied science: thus antibiotics combat bacterial diseases, vaccines protect against infections, antiretroviral drugs control HIV/AIIDS (despite all rumours and conspiracy theories to the contrary!), and airliners full of trusting humans keep flying—thanks to the laws of aerodynamics.

1.2 Cells and organisms Readers may question why this book, ostensibly on evolution and Christian faith, opens with a brief primer on genes and cells. Practising biologists often assume that “everybody knows” most of what follows, at least in broad outline, but public knowledge about genes and proteins tends to be very sketchy. It is thus all too easy to miss the clear evolutionary implications of the ways in which organisms function at a molecular level. If we set aside typical viruses—which are genetic parasites rather than independent life-forms—then all living things are composed of cells. These vary in size from micrometres to centimetres—indeed the egg-yolk of a bird is in reality a single huge cell. The internal contents of a cell (cytoplasm) are separated from the external environment by a lipid bilayer membrane, within which embedded proteins control (among other things) the uptake of nutrients and other molecules, and removal of waste-products etc. Often this membrane is reinforced by an external cell wall, as for instance in plants, fungi and bacteria. The prokaryotic cells of bacteria are

Of Molecules and Cells

7

generally much smaller and simpler than those of “higher” eukaryotic organisms—which include both single-celled and multicellular forms. In unicellular prokaryotes, genetic information is carried on a circular piece of DNA (chromosome), though often this is supplemented by smaller DNA circles called plasmids that can readily transmit traits such as antibiotic resistance between bacterial cells, even across species barriers (Fig. 1-1A).

Figure 1-1. Outline of prokaryotic versus eukaryotic cell structure. Part A, prokaryotic cell with a circular DNA chromosome, small DNA plasmids, a cell wall outside the lipid bilayer membrane, and 1 or more flagellae (not present in all bacteria); this structure applies both to Bacteria and Archaea. Part B, eukaryotic cell with a membrane-bounded nucleus containing diploid linear chromosomes, and multiple mitochondria. The outer cell membrane is supported by a cell wall in plants, algae and fungi, or by a fibrous extracellular matrix in many animal cells. If drawn to scale, B would be very much larger than A.

In eukaryotic cells, the genetic material comprises several linear but vastly longer pieces of DNA that are packaged with histones and other proteins to form chromosomes; these are usually enclosed in a membranebounded nucleus (Fig. 1-1B). Most sexually reproducing eukaryotes are diploid (2N)—meaning that their nuclei contain two sets of chromosomes derived respectively from the male and female parents. Before a diploid cell divides into two, it first become tetraploid (4N) through chromosome duplication (§ 1.3 below), such that each daughter cell receives an identical diploid (2N) set of chromosomes—a process known as mitosis (Fig. 1-2A). During the development of sex cells (animal ova or sperm; plant ovules or pollen), a different type of division called meiosis reduces the number of chromosome sets from four to two to one, such that each sex cell or gamete

8

Chapter 1

carries only a haploid (N) or single set of chromosomes (Fig. 1-2B). When a new organism is reconstituted genetically via fertilisation, the fusion of male and female gamete nuclei restores the diploid 2N state (karyotype).

Figure 1-2. Mitosis and Meiosis. Part A, mitosis for diploid tissue (somatic) cells: both chromosomes (one from each parent) are duplicated, and when a cell divides, each daughter cell receives a set of chromosomes identical to the original cell. Part B, in germ-line cells that generate gametes (sex cells), a different type of division—termed meiosis—occurs: the diploid germ cells undergo chromosome duplication as in mitosis, but the number of chromosome sets is reduced from 4 to 2 to 1 (haploid) through 2 reduction divisions, meiosis 1 and 2. In addition, recombination between homologous chromosomes at the tetraploid stage ensures a mingling of genes from the paternal and maternal chromosomes (see § 1.6).

Eukaryotic cells contain a variety of other subcellular membranebounded structures termed organelles, in addition to the nucleus. These include the mitochondria in animal cells (Fig. 1-1B), and also chloroplasts in plants—both of which arose from ancient intracellular symbioses between different types of prokaryotic cell (the endosymbiont hypothesis of Lynn Margulis, 1970). Both organelles retain at least some of their own genetic information in the form of circular (sometimes linear) DNA that replicates independently of the nuclear chromosomes, though many key genes have been ceded to the nucleus. Mitochondria, derived originally IURP Į-proteobacteria, may be compared to cellular batteries, producing energy in the form of adenosine triphosphate (ATP) to fuel the complex metabolic and other activities of cells. There are many advantages, but also some disadvantages, to this endosymbiotic arrangement (Youle, 2019). Plant chloroplasts undertake photosynthesis using the green pigment

Of Molecules and Cells

9

chorophyll to harness the sun’s energy for synthesising carbohydrates (sugars) from carbon dioxide and water, while also producing oxygen (O2) in this process. One group of prokaryotes (the Cyanobacteria) evolved the ability to photosynthesise over 2 billion years ago, and members of this group gave rise to the endosymbiotic chloroplasts seen today in plant cells. Diatoms are photosynthetic unicellular algae with a silica microskeleton, but they seem to have acquired their chloroplasts secondarily through symbiosis with a unicellular red alga (Büchel, 2019). Recent analyses imply that certain eukaryotes—specifically red algae that live in extreme environments—have acquired prokaryotic gene sequences directly from bacteria, conferring traits that can enhance their survival (Pennisi, 2019a). In multicellular eukaryotes, genetically identical tissue cells become specialised for different functions, a process termed differentiation. Typical flowering plants include roots with differentiated hair cells for absorbing water and minerals from the soil, stems with xylem and phloem tissues adapted for translocating water and photosynthetic products respectively, leaves with specialised stomata to control gas exchange with the environment, and flowers that include whorls of sepals (calyx), petals (corolla), stamens (bearing male pollen) and one or more carpels (with female ovules). Differentiated cells are organised into tissues and organs that all co-operate together to constitute a single organism. In a typical vertebrate animal, specialised cell-types include those of the skin, skeletal, muscle, gut, blood and nervous systems: >200 cell-types occur in humans.

1.3 DNA and the transmission of genetic information All living organisms (again excluding some viruses) use DNA as their genetic material. DNA has a remarkable chemical structure that facilitates replication—the process whereby identical copies of the parent molecule are produced. In essence, the DNA molecule (whether linear or circular) comprises two strands with opposite orientations wound round each other —the double helix model (Watson & Crick, 1953). Each strand consists of a backbone of sugar (deoxyribose)-phosphate units, each attached to one of 4 bases designated A, G (both purines), T or C (both pyrimidines). But G on one strand is always paired with C on the other and vice versa, while T is likewise base-paired with A. Thus when the two strands of DNA separate, each can assemble an identical copy of the other by base-pairing with complementary purine or pyrimidine bases (Figs. 1-3 and 1-4); the base pairs are held together by hydrogen bonding (dashed lines in Fig. 1-3).

10

Chapter 1

Figure 1.3. DNA base pairs, showing the chemical structures of a T:A base pair (top) and of a G:C base pair (bottom). Note that the former is held together by two hydrogen bonds, the latter by three. The sugar (deoxyribose)-phosphate chains to which these 4 bases are attached run anti-parallel to each other, i.e. they have opposite 5’ to 3’ orientations (see Fig. 1-4 below), as shown by the grey arrows. The nucleoside bases are: T = Thymine; A = Adenine; C = Cytosine; G = Guanine.

James Watson, Francis Crick and Maurice Wilkins were jointly awarded the 1962 Nobel Prize in Physiology or Medicine for elucidating DNA structure (Rosalind Franklin unfortunately died too early for her crucial contributions to be recognised). Separating the two parental DNA strands and synthesising complementary daughter strands is a complex process that is catalysed by numerous proteins, notably DNA polymerases (Fig. 1-4), and—as will emerge later—this copying is not entirely error-free. But as Watson and Crick recognised in their classic 1953 paper, the doublehelical structure of the DNA molecule in itself implies this replication process, and solves at a stroke the problem of how genetic information can be passed from parent to daughter cells with high (though not 100%) fidelity. However, this information must somehow be encoded within an extended linear sequence of just 4 different bases along each DNA strand; how then can such information be extracted and used in a living organism? Ultimately, the characteristic traits that we inherit (with greater or lesser accuracy) from our parents are expressed through the medium of proteins—a very different class of macromolecule from DNA. Each protein is specified (encoded) by a stretch of DNA termed a gene. Proteins in living cells are polypeptides composed of some twenty different amino acids that are linked together through peptide bonds between the carboxyl

Of Molecules and Cells

11

Figure 1-4. DNA replication (simplified). On the left, a double-stranded DNA sequence (Roman black lettering) is in the process of being copied; as the parental strands separate, so new complementary strands (italic grey lettering) are assembled using the standard base-pairing rules, resulting in two daughter double strands (right) that are identical in sequence both to each other and to the original parental sequence. A and G denote purines, T and C pyrimidines (Fig. 1-3); 5’ and 3’ denote the opposite chemical polarities of each strand in the double helix.

group of one amino acid and the amino group of the next. Proteins can vary from a few amino acids in length to several thousands; the precise sequence of amino acids specifies the primary structure of a polypeptide. Proteins also have a polarity, from the initial free amino (N) group to the final carboxyl (C) group of the amino acid chain, and they are assembled stepwise from N to C terminus (see below). These twenty amino acids are chemically diverse—with side-groups that can be acidic (aspartic and glutamic acids) or basic (arginine, lysine), or can incorporate sulphurcontaining (methionine, cysteine) or aromatic residues (histidine, tyrosine, tryptophan). Certain amino acid sequences within the chain spontaneously assemble into common structurDO IHDWXUHV VXFK DV Į-helices or E-pleated sheets—collectively termed the secondary structure of that protein. Weaker interactions between the side-groups of amino acids—usually within the same polypeptide chain—help to establish a very precise and all-too-easily disrupted 3-D tertiary structure, which is necessary for biological activity. Many proteins function as enzymes, which act as biological catalysts to promote highly specific biochemical reactions that would otherwise be energetically unfavourable. Some proteins work in partnership with either the same (homomeric) or different (heteromeric) polypeptides; indeed, some complex enzymes may involve tens of partner proteins as subunits within a functional quaternary structure. But how can a DNA sequence using just 4 bases be translated into a protein sequence comprising 20 different amino acids? To cut a long story short, the answer lies in the triplet genetic code, whereby a group of 3 bases (or codon) specifies each amino acid. Since there are 43 = 64 possible triplet codes using A, G, C and T, it follows that this code is redundant— with several triplets coding for most of the individual amino-acids. One such codon—ATG specifying methionine—acts to initiate the synthesis of

12

Chapter 1

a polypeptide chain; three others (TAG, TAA and TGA) act as stop signals to terminate the chain. Normally, protein synthesis proceeds from an initiating methionine residue through to one of the terminating codons— although on occasion these stop signals may be ignored. However, this process of translation does not utilise the DNA genetic information directly, but rather involves an intermediate molecule called RNA. This is chemically related to DNA, although in RNA the pyrimidine U (uracil) replaces T and the sugar ribose replaces deoxyribose. RNA can readily form double-stranded structures, and even acts as genetic material in RNA retroviruses. However, it is through a linear, partly single-stranded form termed messenger or mRNA that genetic information is converted from the DNA code into a protein sequence. Each protein-coding region of the DNA (a gene) is first of all transcribed (in a 5’ to 3’ direction) into a corresponding mRNA chain, using the template strand of the DNA such that the codons in the resultant mRNA strand can be translated into the amino-acid sequence of the protein (Fig. 1-5A). RNA triplet codons use the same letter designations as DNA, but with U replacing T (Fig. 1-5B). RNA polymerase II (pol II, on which I once worked as a PhD student) is the enzyme responsible for transcribing DNA into mRNA in all eukaryotes; it is composed of multiple subunits, and only recently has its full structure been described in detail. The translation process from mRNA to protein is even more complicated, involving two further types of RNA, respectively termed ribosomal or rRNA (transcribed by pol I) and transfer or tRNAs (transcribed by pol III). In eukaryotes, the protein-assembly factories known as ribosomes are built around a framework of four ribosomal RNAs—two large (28S and 18S, distinguished by size) and two small (5.8S and 5S). The largest rRNA (28S) is a ribozyme or RNA enzyme that catalyses the formation of peptide bonds, though numerous specific ribosomal proteins are also required for ribosome function. Three of the rRNAs (18S, 5.8S, 28S) are cleaved from a single long rRNA precursor that is transcribed by pol I from ribosomal gene units, which occur in multiple copies in most genomes. The 5S rRNA is synthesised separately by pol III from multi-copy 5S rRNA genes. Transfer or tRNAs are small RNAs, also transcribed by pol III, that act as adapters. Each type of tRNA attaches to one specific amino acid, such that this is incorporated into the growing (nascent) protein chain whenever the anticodon loop of the tRNA base-pairs with a corresponding mRNA codon being read by the ribosome.

Of Molecules and Cells

13

Figure 1-5. Transcription, translation and the genetic code. Part A shows the notional transcription (upper part) and translation (lower part) of the short DNA sequence used in Figure 1.4. Though this is flanked by proper initiation (Met) and termination (Stop) codons, real mRNAs and proteins would be far longer than the 4 amino-acid sequence shown. Part B shows the genetic code used in all living organisms; each codon in the mRNA is read from left to top to right. Amino acid abbreviations: Ala, alanine; Arg, arginine, Asn, asparagine; Asp, aspartic acid; Cys, cysteine; Gln, glutamine; Glu, glutamic acid; Gly, glycine; His, histidine; Ile, isoleucine; Leu, leucine; Lys, lysine; Met, methionine; Phe, phenylalanine; Pro, proline; Ser, serine; Thr, threonine; Trp, tryptophan; Tyr, tyrosine; Val, valine.

14

Chapter 1

Figure 1-6. DNA replication, transcription and translation. Part A, replication; the 2 DNA strands are unwound, and each copied into a complementary strand by the enzyme DNA polymerase. This can only synthesise DNA in a 5’ to 3’ direction, so the leading strand is copied continuously, while the lagging strand is copied discontinuously in short segments (Okazaki fragments) that are subsequently joined by DNA ligase. Replication fork direction of travel shown by shaded arrow: ¶ĺ¶ indicates direction of DNA polymerase strand-copying with solid arrows. Part B, transcription; RNA polymerase copies the coding region of the gene into RNA, which is synthesised ¶ĺ¶ (arrow). Prokaryotic mRNAs can be translated

Of Molecules and Cells

15

directly into protein, but the presence of introns in most eukaryotic genes necessitates RNA splicing (Fig. 1-8B), prior to mRNA export from the nucleus and translation. Upstream promoter and coding regions of gene are both lightly shaded. Part C, translation; this begins at an AUG triplet codon in the mRNA, encoding methionine. Each triplet codon of bases in the mRNA is recognised by base-pairing with a complementary group of 3 bases in the anticodon loop of a tRNA, at whose 3’ end a single amino-acid (here aa5) is bound. Formation of a peptide bond between this and the preceding amino-acid residue (aa4) is catalysed by the largest rRNA, acting as a ribozyme. Arrow shows direction of ribosome travel and polypeptide synthesis (N to C terminus) along the mRNA strand.

In prokaryotes, the large ribosomal RNAs are somewhat smaller in size (23S and 16S), and 5.8S rRNA is absent. Here, 5S rRNA forms part of the long rRNA precursor that is cleaved and processed to yield the three mature rRNAs. Ribosomal genes are present in multiple copies in some bacteria, but are single-copy in others. In prokaryotes, both rRNAs and tRNAs are transcribed by the same RNA polymerase that also transcribes mRNAs. Eukaryotic mitochondria and chloroplasts each possess their own RNA polymerases that transcribe only mitochondrial or chloroplast genes; these encode both large and small rRNAs (16S and 12S in mitochondria) plus tRNAs for all 20 amino acids. The sum total of all DNA sequences present in the nucleus of a given organism is termed its nuclear genome, as distinct from its mitochondrial or chloroplast genomes. These three fundamental processes in molecular biology—namely DNA replication, transcription.of RNA from a DNA gene, and translation of an mRNA into protein—are shown diagrammatically in Fig. 1-6A, B and C.

1.4 Regulation of gene expression In 1961, Francois Jacob and Jacques Monod proposed a model for joint regulation of three genes involved in lactose metabolism in the bacterium, Escherichia coli (Jacob & Monod, 1961), work for which they were later awarded the Nobel Prize in Physiology or Medicine in 1965. These three genes (cistrons) are lacZ encoding E-galactosidase, lacY encoding Egalactoside permease and lacA encoding E-galactoside transacetylase. All 3 proteins are required at high levels in order for E. coli to use lactose as an energy source, but are not needed in its absence (when these genes are effectively shut down). In fact, all 3 genes lie next to each other on the bacterial chromosome, forming an operon which is transcribed as a single unit to produce a polycistronic mRNA. This co-ordinate regulation is achieved using a fourth gene, lacI, encoding a DNA-binding lac-repressor protein (functioning as a homotetramer). This repressor protein binds to a short DNA sequence termed the operator, located between the promoter

16

Chapter 1

(binding site for RNA polymerase) and the start or 5’ end of the first gene in the operon (lacZ). When repressor tetramers are bound to the operator, transcription of the lac operon is blocked (Fig. 1-7A). This repression is relieved only when a lactose metabolite (allolactose) binds to the repressor, reducing its binding affinity for operator DNA and allowing RNA polymerase to gain access to the promoter and initiate transcription of the lac operon (Fig. 1-7B). The lacI gene is always constitutively active, so the lac operon is only expressed when lactose (as allolactose) is present.

Figure 1-7. Jacob-Monod model for regulation of E. coli lac operon (simplified).

This elegantly simple control module for bacterial gene expression soon spawned a variety of suggested models for gene regulation in eukaryotes, which typically contain tens to thousands of times more DNA than prokaryotes. Yet although E. coli has about 4300 genes, the yeast Saccharomyces (a unicellular fungal eukaryote) has only 6600 and the fruit fly Drosophila roughly 14000. Perhaps more surprisingly, the nematode Caenorhabditis, the sea urchin Strongylocentrotus and human beings (Homo sapiens) each have around 22000 genes, while some plants (e.g. rice, Oryza sativa) have >55000. There is no necessary correlation between gene number and organism complexity, nor indeed between total DNA content and gene number. Some genomes seem to have expanded vastly without greatly increasing gene numbers (though the functions of the additional DNA, if any, remain controversial), whilst other genomes (including that of Drosophila) have become smaller and more “streamlined”

Of Molecules and Cells

17

in comparison with related organisms. More detail on genome organisation and evolution in both prokaryotes and eukaryotes can be found in Krebs et al. (2018) or other popular textbooks on genetics. In bacteria, transcription is collinear—that is to say, the DNA gene coding for a specific protein is copied directly into mRNA—which is then translated on ribosomes into protein. In eukaryotes, and to some extent in Archaea (the other vast group of prokaryotes), these two processes are far more complicated. This is caused by the presence of interruptions termed intervening sequences (or introns) within the coding sequence of a gene. In eukaryotes, introns are transcribed as part of a collinear pre-mRNA transcript, which is then edited within the nucleus by a process of RNA splicing to remove intron sequences, and the mature mRNA is exported to the cytoplasm for translation on ribosomes. Sequences flanking an intron in the pre-mRNA are recognised by small nuclear snRNAs within a spliceosome complex, using base-pairing to bridge the ends; the premRNA is cut twice and the intron excised as a lariat, then the ends of the protein-coding sequences (or exons) are rejoined to form a mature mRNA (Fig. 1-8B). Many genes contain several introns, which allows differential RNA splicing to generate multiple different mRNAs containing varying combinations of exons. In this way, a single eukaryotic gene can generate several related proteins, a feature that is especially prevalent in mammals. Since many eukaryotic (and some Archaeal) genes contain introns, it follows that these split genes are often much larger than their bacterial counterparts. The largest known human gene (DMD, mutations in which can cause Duchenne Muscular Dystrophy) spans >2.3 million base-pairs (bp) of DNA, 2.1 million of which are transcribed, with the major DMD mRNA in muscle comprising 79 exons and encoding a 3685 amino-acid protein called dystrophin. Given this prolixity of DNA, it is unsurprising to find that the sequences involved in eukaryotic gene regulation are also far less compact than the operator and promoter of the E. coli lac operon. Frequently, these regulatory sequences occur scattered across large DNA regions stretching for hundreds or thousands of base-pairs—usually 5’ to (upstream of) the start-site of the gene where transcription begins, though some such sequences can occur within introns or beyond the 3’ terminus of a transcribed gene region. Regulatory sequences that increase transcription from a gene are generally termed enhancers, while those that repress gene expression are termed silencers. Sequences lying close to the 5’ end of the gene are usually termed promoters, by analogy with bacterial precedents. One key question is how DNA-binding proteins (transcription factors, henceforth TFs) that interact with remote enhancer or silencer sites can

18

Chapter 1

influence events at the promoter, where RNA pol II must bind to initiate pre-mRNA transcription—since the rate of initiation will in large measure determine the overall level of gene expression. To cut a long story short (again), this is achieved by DNA looping, as shown in Fig. 1-8A. The socalled TATA-binding protein (TBP) interacts with core promoter sequences in most eukaryotic protein-coding genes, and has a strong affinity for the TATA(A) box sequence found in some promoters 25-35 base pairs (bp) upstream of a transcriptional start-site (by convention +1). TBP also promotes binding of RNA pol II to initiate gene transcription, as well as interacting with the activation domains of transcription factors bound to more remote enhancer or silencer sequences. Multiple TFs bound to these regulatory sites interact dynamically with promoter-bound TBP, providing flexible modular control of gene expression in response to a cell’s needs. As might be expected, there are other proteins involved in the formation and maintenance of these gene-regulatory loops, including dimers of the general TF YY1 (Weintraub et al., 2017), which interacts with both promoter and enhancer elements in mammalian cells. By contrast, dimers of the transcriptional repressor CTCF often act as a long-range insulator to mark the boundaries of a looped-out active gene region, though this is not the only possible outcome (Splinter et al., 2006). In both cases, the base of the DNA loop is stabilised by an encircling ring of cohesin, composed of 4 different proteins; this complex (Li et al., 2020) also plays a key role in both mitosis and meiosis, where it brings two different DNA molecules together (reviewed by Remeseiro & Losada, 2013). In recent years, automated DNA sequencing has allowed whole genomes to be sequenced at relatively low cost. Certain genes—notably those encoding the rRNAs—are highly conserved through evolution, such that significant sequence identity can be detected even between bacteria (such as E. coli) and humans. Aside from a clear implication of common ancestry in the distant evolutionary past, comparisons of rRNA gene sequences allow an independent assessment of the relatedness of different animal and plant groups—sometimes with surprising results (chapter 2). Transcription factor (TF) proteins are most highly conserved across their DNA-binding domains, where a domain is a section of the polypeptide chain that can fold and function relatively independently from the rest of the protein, and is often encoded by a single exon. Each class of TF has its own characteristic DNA-binding structure, such as the homeodomain (first identified in Drosophila homoeotic genes; § 4.7, 4.9), zinc-finger domains (a series of peptide loops each cross-linked at its base by a zinc atom), and paired or forkhead domains (named after Drosophila genes). Conserved DNA sequences encoding these domains (e.g. the 180 bp homeobox)

Of Molecules and Cells

19

identify families of TF genes, and multiple members of each such family may be present in a given organism’s genome. Other TF proteins function as homo- or hetero-dimers, including those with helix-loop-helix (HLH) or leucine zipper (bZIP) domains. The molecular details of DNA-binding, activation and dimerisation domains need not detain us here, but we will return to DNA-binding TFs in in chapter 4 on evo-devo. It is worth noting in passing that eukaryotic genomes can evolve quite rapidly by exon shuffling, where whole exons are lost or acquired by a gene, e.g. through recombination (§ 1.5). If each exon encodes a discrete protein domain, then its loss or gain can dramatically affect how that protein functions. Gene regulation in bacteria is by no means always as simple as the Jacob-Monod model (Fig. 1-7) might suggest, and this applies with even greater force to eukaryotes—where Fig. 1-8A represents a gross oversimplification. The DNA of the chromosomes is packaged with associated histone and non-histone proteins in the form of chromatin. Approximately 145 base pairs of core DNA are wound around a histone octamer comprising two molecules each of the H4, H3, H2A and H2B histones, with one molecule of the H1 histone associated with about 60 bp of linker DNA. This nucleosome unit is repeated every ~200 bp along the DNA, but adopts a more open conformation in regions where genes are being actively transcribed, or conversely becomes more compacted in regions of heterochromatin where genes are mostly inactive—e.g. at chromosome ends (which often consist of highly repetitive non-coding sequences). Typically, the extended length of DNA is reduced by about 6- to 7-fold in nucleosomal chromatin but only by ~2-fold in actively transcribed chromatin, and by 40-fold or more in heterochromatin. However, the importance of dynamic chromatin architecture for gene regulation has only emerged relatively recently, as reviewed e.g. by Cramer (2019) and by Stadhouders et al. (2019). In part, the distinction between transcriptionally active and inactive regions of chromatin reflects the relative levels (low in the former, high in the latter) of DNA methylation—specifically the methylation of C residues where the C is flanked on one side by a G residue (CpG sequences). The pattern of methylation depends on specific DNA methyltransferase enzymes, but once established this pattern is passed on to mitotic daughter cells by maintenance methyltransferases that recognise hemimethylated DNA (only methylated on the parental strand), and hence methylate the new daughter strand. Actively transcribed regions of chromatin with under-methylated DNA are heritable through mitosis, as are heavily methylated inactive regions. Such methylation patterns are erased incompletely during gamete formation (meiosis) and again during early embryonic development. However, some so-called imprinted genes

20

Chapter 1

Figure 1-8. Looping in eukaryotic gene regulation. Part A, DNA looping through interaction of transcription factors (TFs) bound to distant enhancer sites with TBP bound to the promoter region near the transcriptional start-site of the gene, allowing RNA pol II to initiate gene transcription. Part B, pre-mRNA splicing through base-pairing of intron ends with small nuclear snRNAs contained within spliceosome RNA-protein complexes. An initial cut is made at the 5’ end of the intron, which is linked covalently to a branchpoint within the intron prior to the 3’ cut. Intron sequences are looped out and excised as a lariat, and exon sequences are rejoined by RNA ligases to form the mature mRNA.

Of Molecules and Cells

21

retain a parent-specific pattern of methylation (either paternal or maternal) that will determine which of the 2 parental genes is active in the offspring. Over the past 20 years, it has become increasingly apparent that many different types of non-protein-coding RNA molecules also play crucial roles in regulating eukaryotic gene expression, as suggested 50 years ago in a prescient paper by Britten and Davidson (1969). Far more of the DNA genome is transcribed into nuclear RNA than is exported to the cytoplasm as protein-coding mRNAs, even making allowances for the intron transcripts lost through splicing. Short microRNAs, ~22 bases in length, were the first to be implicated in gene regulation through their ability to silence the expression of target genes by base-pairing with specific mRNAs and enhancing their degradation (RNA interference). They can also reduce levels of translation from the targeted mRNAs (Guo et al., 2010). Most of these microRNAs act negatively to reduce or repress gene expression, in contrast to the activating role proposed originally by Britten and Davidson (1969). Other classes of nuclear RNA have different modes of action, including highly expressed circular RNAs that act as “sponges” to inhibit the activity of specific microRNAs (Memczak et al., 2013; Hansen et al., 2013), thereby upregulating levels of gene expression. There are emerging regulatory roles for long non-coding (lnc) RNAs that interact with TFs or chromatin-modifylng proteins (Guttman & Rinn, 2012), though many lncRNAs also encode short peptides (Chen, J., et al., 2020). Finally, the compartmentalised organisation of eukaryotic cells affords many additional opportunities for regulating gene expression. Pre-mRNAs may be retained in an unprocessed or partially processed form within the nucleus, since the export of mature mRNAs is an active process involving complex protein-lined pores in the nuclear membrane. Once mRNAs are released into the cell cytoplasm, translation by ribosomes can be regulated through the recruitment of proteins that increase or reduce the rates of ribosome initiation or elongation. Proteins themselves can be activated or inactivated by cleavage (e.g. insulin), and by the addition or removal of methyl, acetyl and especially phosphate groups (all are post-translational modifications). Chemical modification is also used to regulate mRNA translation. During early embryo development, there is a vital changeover from utilising maternal mRNAs (transcribed from the mother’s genes and stored in the egg; § 4.4) to zygotic mRNAs transcribed from the embryo’s own genome—the maternal-to-zygotic transition (MZT). In zebrafish most maternal mRNAs carry N6-methylated A residues, whose rapid clearance in embryos involves a protein that binds N6-methyl-A (Zhao et al., 2017).

22

Chapter 1

1.5 Heritable genetic variation I hinted earlier that DNA replication processes are not always 100% accurate, and that rare errors can creep in. The same also applies to transcription and translation, but here the consequences are more local, as they affect only particular RNA or protein chains. The key point about DNA sequence errors is that they are heritable. For somatic tissue cells undergoing mitosis in higher eukaryotes, this is not a big problem, even though a proportion of the cell population will be abnormal in some respect. However, if the initial abnormality involves a malfunction of the regulatory mechanisms that normally limit cell division, the result may be a clone of proliferating cells (originating from the parent cell in which the error arose) that divide without restraint, forming a cancerous tumour. But even in this case, the effect is confined to an individual and is not passed on to descendants. This is because in animals, the germ-line cells that give rise to the gametes (so contributing genetic material to the next generation) are set aside relatively early in development, and are thereafter unaffected by replication or mutation errors (below) affecting somatic or tissue cells. Indeed, this is one reason why Lamarckian inheritance of acquired characteristics (§ 2.4) cannot occur, since there is no mechanism by which favourable traits learned or developed by an individual could be passed on to its progeny—except through cultural transmission during rearing of the young, which is seen in several animals, but par excellence in humans (chapter 5). A partial exception here is gene imprinting (above), where one of the two parental gene-copies is expressed preferentially in the offspring. However, genetic changes arising in the gametes themselves may well become manifest in the offspring. In sexually reproducing organisms, genetic variation is enhanced through the process of recombination during meiosis—the reduction divisions that generate haploid gamete cells. After chromosome doubling to 4N in germ-line cells (spermatocytes in males, primary oocytes in females), the two parental chromosomes of each kind lie close together alongside their copies, forming a tetrad. This enables exchanges of genetic material between pairs of homologous chromosomes (Fig. 1-2B), with resealing of DNA strands by DNA ligase enzymes. In this way, parental sequences become admixed within the chromosomes of each gamete, and some of these result in offspring that will inherit and express various novel combinations of grandparental genes. This is advantageous for promoting genetic variation—but at the cost of potential disruption from abnormal recombination events, or failure (non-disjunction) of the tetrad to separate properly after recombination. As a result, chromosomes may be missing or duplicated in a minority of gametes, a frequent cause of

Of Molecules and Cells

23

human developmental abnormalities. In animals, each male spermatocyte gives rise by meiosis to four haploid gametes (sperm cells), whereas in females only one cell retains the oocyte cytoplasm to become an ovum, the other products of meiosis being discarded as tiny polar bodies (Fig. 1-2B). Although DNA appears chemically stable, it is in fact under continuous assault from ionising radiation (cosmic and X-rays, as well as radioactive decay processes) and from chemical mutagens, both of which directly or indirectly attack bases and/or create strand breaks in the DNA. To counter these ongoing sources of damage, there are elaborate proof-reading mechanisms built into the machinery that replicates and repairs DNA— such that the vast majority of DNA damage is repaired accurately and causes no problems (although such repair processes do incur a metabolic cost). It is often stated, misleadingly, that chemical mutagens and ionising radiation directly damage DNA and cause mutations (base alterations) in the sequence of base pairs. Both elements of this statement are true, but omit the important intervention of DNA repair enzymes, which attempt to correct the initial damage, usually successfully. Mutations that change an AT base pair into a CG, or vice versa, generally arise from botched or unsuccessful attempts at damage repair, and these occur more frequently when the levels of DNA damage are high, e.g. following exposure to high doses of radiation or mutagens. In these circumstances, additional DNA repair enzymes are pressed into service, but they are more error-prone (e.g. the bacterial SOS system) than the systems in normal use. Single base-pair changes (point mutations) in the DNA often have little or no effect, unless they occur within regulatory or protein-coding (exon) sequences. Even in the latter case, many changes at the third codon position (Fig. 1-5B) are silent, causing no change to the encoded amino acid; alternatively, a new amino acid may have no measurable effect on structure or function in the final protein (both are termed neutral mutations). But other DNA sequence changes provide a furtther source of variation among offspring. Darwin had no idea of the genetic basis of inheritance, but correctly noted that smallscale heritable variations provide material for natural selection to work on. Notably, mutations provide genuine genetic novelty, rather than the simple reshuffling of existing genetic material that occurs during recombination. Overall, some mutations (a minority) alter the sequence of a proteincoding gene, in many cases changing just a single amino acid in the polypeptide chain (compare Fig. 1-9B with A). In population terms, the most common functional version of a gene is termed wild-type, and sequence variants are termed mutant alleles of that gene. Some mutations have no appreciable effect on protein function, but often the effects are more serious, e.g. inactivating the enzymic function(s) of that protein or

24

Chapter 1

preventing key interactions with other molecules. Such mutations are termed loss-of-function, and in genetic terms they tend to be recessive, as against the dominant wild-type allele. Since there are two copies of each gene in a diploid organism, if one of these encodes a functional wild-type protein, then the effect of a loss-of-function mutation in the second copy will be masked because some wild-type protein is still available. Individuals with one wild-type and one mutant copy of any given gene are heterozygous, whereas individuals with two copies of the same allele (whether wild-type or mutant) are homozygous. In a cross where both parents are heterozygous (Aa) for two alleles (A and a) of a particular gene, then these alleles will become assorted independently among the offspring in 4 possible combinations: one quarter of the progeny will have two copies of allele A (AA), half of them will have one copy of each allele (since aA is genetically the same as Aa), while one quarter will have two copies of allele a (aa). These are termed Mendelian segregation ratios, after their discoverer, the Augustinian monk Gregor Mendel (1866). A capitalised gene abbreviation (here A, but typically comprising 3 or more letters) normally designates a dominant and/or wild-type allele, while lower-case abbreviations (here a) usually indicate a recessive mutant allele. Thus one-quarter of the offspring in the above cross would be wildtype A/A homozygotes; these would be pure-breeding if they were crossed (selfed) amongst themselves. The same would be true for the one-quarter of recessive a/a mutant offspring, which would also be pure-breeding if selfed. The remaining 50% of A/a heterozygotes would appear as wild-type (since one wild-type A allele can provide sufficient functional protein), but these would not breed true if selfed, segregating all 3 possible genotypes (or genetic constitutions) in the same ratios as the original cross. In any individual, the particular combination of traits specified by its genotype is described as its phenotype; both terms can be used generically or in relation to a single gene. Although the term “wild-type” usually refers to the most common allele of any given gene within a population, this term is relative: different alleles may predominate in other populations of the same species.

Figure 1-9 (next page). Various types of genetic mutation. Part A, translation of the same DNA sequence as Fig. 1-5A. Part B, a point mutation of GC to AT (underlined), altering the second amino-acid from proline to leucine. Part C, a 2 bp insertion causing a frameshift mutation that alters one amino acid (valine to tryptophan) and introduces a premature stop codon. Part D, a frameshift mutation caused by a one bp deletion, altering the reading frame (valine-alanine to glutamic acid-proline) and deleting the stop codon (leading to run-on translation starting with a threonine).

Of Molecules and Cells

25

26

Chapter 1

There are many complications besetting this simple genetic model. In particular, certain types of mutation may exert a dominant (gain-offunction) effect, overriding the wild-type copy. Such mutations may affect regulatory DNA sequences, for example causing over-expression of the gene in the wrong place (ectopic expression) or at the wrong time during development—and these abnormalities cannot be suppressed by normal expression of the wild-type allele. In other instances, the level of wild-type gene expression may be crucial, such that inactivation of one copy through a loss-of-function mutation causes a marked deficit in the offspring. Mutations that generate a stop codon in the wrong place cause premature termination of the polypeptide chain (e.g. Fig. 1-9C). Conversely, altering a stop codon into one that codes for an amino-acid (Fig. 1-5D) will cause run-on translation and produce an abnormal protein with additional amino acids at its C-terminus. Insertion or deletion of one or two base-pairs within the coding sequence of a gene will result in a frameshift mutation, whereby all subsequent codons are altered, since they will be read by the ribosome in a different reading frame (Fig. 1-9C and D). The effect of a 3 base-pair insertion or deletion is usually less severe, however, as this will add or remove only a single amino acid in the final protein chain. Some mutations cause far more extensive genetic changes than do simple point mutations. Examples include major deletions or insertions of DNA, and loss or extra copies of whole chromosomes. More complicated Mendelian segregation ratios can be calculated for two different genes in combination (2-factor crosses), but these apply only when the genes are each carried on separate chromosomes. If present together on the same chromosome (termed linkage), then such gene-combinations will tend to be inherited together, since independent segregation of these genes is no longer possible. Even so, genetic recombination during meiosis will occasionally separate them during 2-factor crosses. But the more closely two genes are linked, the more rarely are they separated by recombination, a feature that was much used by early geneticists for the purpose of gene-mapping. Because single base-pair changes in DNA (caused by ionising radiation etc) occur at a fairly constant rate, one can estimate approximate times of divergence between related DNA sequences using a so-called molecular clock, though different types of DNA sequence evolve at different rates. Whereas mutations in non-coding and non-regulatory regions are largely unconstrained, base-pair changes in the exons of coding genes, or in their control elements, are more tighly constrained by a need to preserve the functionality of that sequence. Particularly useful for estimating divergence times are the ribosomal gene sequences (encoding rRNAs)—which evolve only slowly because they are essential for life—hence there are limits to the

Of Molecules and Cells

27

permissible changes that would still allow ribosomes to work efficiently. There is a great deal of hidden complexity behind this seemingly simple idea of molecular clocks, but this is not the place to delve into the technicalities and caveats that beset this field. In order to validate sequence comparisons within a group of (more or less closely) related organisms, it is necessary to include at least one more distantly related “outgroup”. This allows one to infer a rooted phylogenetic “tree”, showing which of the organisms are most closely and which more distantly related (Page & Holmes, 1998). Such molecular phylogenies assume a constant mutation rate (for that type of sequence) and descent from a common ancestor, but ignore other possibilities, e.g. horizontal gene transfer. These simplifying assumptions explain why divergence times based on molecular phylogeny can differ significantly from those inferred from fossil records (chapter 3). As a postscript to this section, it is worth mentioning one exception to the normal diploid rule that applies to chromosomes in the somatic tissue cells of plants and animals. This rule holds true for all of the autosomes, but not for the so-called sex chromosomes in one sex. In fruit flies and mammals (including humans), females are homogametic and carry two large X chromosomes, whereas males are heterogametic and carry one copy of the X chromosome and one much smaller Y chromosome. It thus follows that males are effectively haploid for genes carried on both the X and Y chromosomes—and this means that the effects of mutant alleles carried by either sex chromosome cannot be masked by wild-type alleles on a homologous chromosome. This is why men are far more susceptible to certain genetic conditions such as colour blindness (the gene for which is X-linked)—since all males carrying this allele will be colour-blind, whereas a female would have to inherit the mutant allele from both parents on each version of her X chromosome. However, XY sex determination is by no means universal; in birds and butterflies an opposite pattern is seen, with heterogametic ZW females but homogametic ZZ males. In other animal groups, sex determination is not chromosomal, but instead depends on environmental factors such as temperature. In some reptiles such as alligators, eggs incubated at low or high temperatures produce females, but those incubated at intermediate temperatures develop as males. Global warming could cause catastrophic effects on sex ratios in such species.

1.6 Unintentional selection for pesticide resistance The pesticide DDT (dichlorodiphenyltrichloromethane) was widely used as an insecticide during and following World War 2, initially in malaria control but later also in agriculture. Indiscriminate spraying led to

28

Chapter 1

widespread ecological damage, as documented vividly in Rachel Carson’s ground-breaking book “Silent Spring” (1962). Wide usage also promoted the emergence of DDT resistance among malaria-carrying mosquitoes, as first noted in India in 1959. Although DDT has long been banned for agricultural use, it continues to play an important role in malarial control programmes targeting the mosquito vector. Even before the first moves to ban DDT, several other insecticides had been developed, notably the pyrethroids based on stable synthetic versions of the naturally insecticidal pyrethrins produced by certain species of Chrysanthemum. Secondgeneration synthetic pyrethroid compounds—such as permethrin, cypermethrin and deltamethrin—have proved extraordinarily effective since they were introduced in 1974. Unfortunately, increasing numbers of pests have now developed resistance against pyrethroids, and often against DDT as well. Both classes of pesticide kill insects by interfering with the conduction of nerve impulses, specifically through binding with high affinity to the voltage-gated sodium channel (VGSC) protein that controls the flow of sodium ions into insect nerve cells. However, they bind with much lower affinity to vertebrate VGSC proteins, ensuring a good margin of safety for humans and other vertebrates exposed to these pesticides. What is remarkable is how pyrethroid-resistant mutations in unrelated insect pests involve similar or often identical amino-acid substitutions in the VGSC protein. In many cases the leucine at position 1014 in this polypeptide chain is replaced by phenylalanine (L1014F), e.g. in the housefly, peach-potato aphid and Colorado beetle, as well as at an equivalent structural position (L993F) in a cockroach. This amino-acid change is caused by a single point mutation in the VGSC gene, and confers a 10- to 20-fold increase in resistance to most pyrethroids, termed knockdown resistance (kdr mutation), as well as cross-resistance to DDT. Frequently this kdr mutation is accompanied by one of two separate point mutations termed super-kdr (skdr), either converting methionine to threonine at position 918 (M918T), or threonine to isoleucine at position 929 (T929I). The M918T mutation has been found both in fruit flies and houseflies, whereas T929I occurs in the diamondback moth and in the head louse, as does a similar change from threonine to valine at the same position (T929V) in the cat flea and tobacco whitefly. More recently, an skdr mutation (T929I) has also been found on its own in the maize weevil (Araújo et al., 2011). The conjunction of both kdr and skdr mutations confers a combined resistance of up to several thousand-fold for certain pyrethroids, meaning that double-mutant individuals can survive very high-dose applications that kill off all non-resistant pests. Thus it is easy to

Of Molecules and Cells

29

see why this combination of mutations has been selected so strongly by intensive use of pesticides targeting VGSCs (both DDT and pyrethroids). The three residues (L1014, M918 and T929) mentioned above are crucial for the binding of pyrethroids to insect VGSC proteins, such that amino-acid changes at any of these sites greatly reduce binding, hence conferring pyrethroid resistance. As a corollary, if the typical iosleucine residue at position 918 in the rat neuronal VGSC protein is mutated to methionine (I918M), then its normally low sensitivity to pyrethroids is greatly increased (Vais et al., 2000). It is only fair to add that mutations at other sites within insect VGSC genes can also confer pyrethroid resistance, e.g. in mosquito (Zhu et al., 2016). There are also other routes to pesticide resistance, including increased expression of cytochrome P450 enzymes that break down the pesticide itself. But few if any of these changes confer such high efficiency of resistance as does the combination of kdr and skdr mutations, which may explain why both have been selected so frequently (but independently) in so many disparate pest species. The fact that resistance has appeared within decades—albeit under intense selection pressure (applied unwittingly)—should remind us that evolution need not always move at a glacial pace. This also provides a clear-cut example of convergent (or, more strictly, parallel; § 3.5) evolution at the molecular level; these specific point mutations keep on getting selected because they seem to be the only ones that can generate such high levels of resistance. Examples like this help to reinforce Richard Dawkins’ (1976) genecentred view of evolution, because it is the gene mutation itself (or in this case, combination of mutations) that is selected, rather than the individual carrying that (those) mutation(s). In fact, many if not most such pesticideresistant mutations also carry an associated fitness cost; for instance, the mutated protein may function less efficiently than the wild-type version. For this reason, if the use of DDT and pyrethroids is discontinued (e.g. by switching to a different insecticide that binds to a different target), then the above-mentioned kdr and skdr mutations will decrease in frequency in the pest population, and may eventually disappear entirely because they have been outcompeted by the wild-type allele, which has no such fitness cost. A further important point concerns the likelihood of two such mutations (kdr and skdr) ocurring together. Point mutations arise in bacteria at a rate of approximately 10-10 per base-pair per cell division. If we assume, for simplicity, that a similar mutation rate applies per generation in a typical insect pest—then the chances of two specific simultaneous mutations arising in the same gene should be vanishingly improbable (10-10 x 10-10 = 10-20, i.e. one in 100 million million million individuals). But that isn’t the

30

Chapter 1

way it happens; once either the kdr or skdr mutation has appeared in an insect population (and both do occur separately), that mutation confers sufficient resistance to pyrethroids to provide a selective advantage for the mutants—hence this mutation will rapidly come to predominate in fields sprayed with pyrethroids. Within a large population of pests already carrying that first resistance mutation, it is only a matter of time before the second resistance mutation appears—conferring much greater resistance and thus an enormous selective advantage. Small functional gains from beneficial mutations will tend to accumulate over time under constant selection pressure; there is no need for them all to appear simultaneously.

1.7 Evolution and the origin of life The fact that all living cells use DNA as their genetic material, with a genetic code that is to all intents and purposes universal—despite some variations seen in non-plant mitochondria (Jukes & Osawa, 1990)—clearly implies descent from a far-distant common ancestor. Of course, Charles Darwin had no inkling of any of this when he published “The Origin of Species” (1859, republished 1998). Moreover, the same tripartite system— involving DNA, RNA and proteins—is also shared by all cellular life (for further details, see e.g. Krebs et al., 2018). It seems unlikely that DNA is the only kind of molecule that combines the requisite properties of stability and replication ability with high information content, but this remains a matter of speculation until such time as living organisms are discovered on other planets. Indeed, calculations of “chemical space” suggest that there may be very large numbers of polymer structures that could potentially encode genetic information (Henderson et al., 2019). The complex cellular apparatus needed for transcription and translation likewise displays numerous shared features (§ 1-2 to 1-6), consistent with evolution from a common ancestor, though these processes are considerably more complex in “higher” eukaryotic cells. In the Archaea, there are elements of both bacterial and eukaryotic systems, implying a probable ancestral position. None of this is intended to belittle the enormous and largely unanswered question of how the first living cells arose during the early history of life on earth—perhaps as little as half a billion years after this planet was formed. From what we can infer about the likely atmospheric conditions on the early earth, it is probable that quite complex organic compounds (including the sugars, RNA/DNA bases, lipids and amino acids required for life) could have been produced spontaneously in isolated water bodies: the so-called primordial soup. “Watery consommé” might be a better culinary analogy, since such molecules would most likely be present in

Of Molecules and Cells

31

dilute solution—unless adsorbed onto the surface of colloidal clays or else concentrated on bubbles rising from undersea hydrothermal vents. But the likelihood of simultaneously generating the entire tripartite system for DNA replication, transcription and translation (with all requisite proteins and RNAs encoded by that DNA!) seems impossibly remote—a skyhook crying out for the stepwise deployment of non-miraculous Dennett cranes. There is no shortage of ingenious speculation here, but rather less in the way of persuasive evidence. One suggestion that has achieved widespread acceptance is the proposal of an “RNA world” (Gilbert, 1986; Jeffares et. al., 1998) that preceded the evolution of the DNA-based cell from which all present-day life is descended. This idea is based on the fact that RNA conflates the tripartite system into a single molecule, since RNA itself acts as an intermediate in converting DNA information into protein structure and function, but can also act both as a genome in RNA retroviruses, and as an enzyme (ribozyme), e.g. in the catalytic function of 23S/28S rRNA. In 1989, Thomas R. Cech and Sidney Altman were jointly awarded the Nobel Prize for Chemistry for their discovery of ribozymes (Stark et al., 1978; Zaug & Cech, 1986). Recently, a ribozyme has been synthesised that can assemble a mirror-image version of itself, suggesting ways in which such RNA molecules might have been able to proliferate on a prebiotic earth (Sczepanski & Joyce, 2014). That said, the proportion of random RNA sequences capable of such self-replication is miniscule, so the chances of such a molecule appearing spontaneously in the primordial soup/consommé seem little greater than zero. One intriguing suggestion is that quantum tunnelling of protons and electrons within the molecular structure of an RNA molecule might allow it to “try out” or “search” through a vast number of alternative configurations in quantum space, nearly all of which will be incapable of self-replication. Al-Khalili and McFadden (2014, pp. 354-384) suggest that this quantum search would continue until a self-replicating configuration is achieved—at which point that entity starts to replicate and undergoes an “irreversible transition into the classical world” (ibid., p. 382) of conventional molecular biology. All three essential classes of biomolecule (amino acids, RNA precursors and lipids) can be produced simultaneously by chemical reactions involving water and just two simple compounds (hydrogen cyanide and hydrogen sulphide) that would undoubtedly have been abundant on the early earth (Service, 2015), plus phosphates concentrated in carbonate-rich soda lakes (Toner & Catling, 2020). A unified pathway for synthesising both purine and pyrimidine bases has recently been proposed (Becker et al., 2019), and prebiotic iron-catalysed reactions that mimic important biochemical cycles in living cells have also been reported (Muchowska et al., 2019). It

32

Chapter 1

is also possible that the earliest life-forms might have used a “mixed alphabet” of DNA purine and RNA pyrimidine bases (Xu et al., 2020). Thus RNA-based “life forms” may well have preceded the DNA-based organisms with which we are familiar, even though the former have left no known descendants, but only tantalising hints as to what might have existed 4 billion years ago. The RNA-world scenario can at least supply an outline sketch of some plausible cranes that might avoid the need for a skyhook. But it still remains an intriguing hypothesis, with a dearth of direct evidential support, though arguably the roles of ribosomal RNAs and tRNAs in protein synthesis represent ghostly relics of that ancient RNA world (Jeffares et al., 1998). The later appearance of DNA-based life would require first the recruitment of proteins—probably through chemical affinities between RNA codons and specific amino-acids (Yarus et al., 2009)—that could then be joined together by ribozymes into peptide chains. Those that improved the accuracy and/or speed of replication of the coding RNA would provide a selective advantage. At some stage, DNA would also need to be recruited, providing a stable and dedicated storage depot for genetic information. Lipids carrying phosphate groups at one end of the molecule (termed phospholipids) spontaneously self-assemble into bilayer membranes that separate off the interior cytoplasm of a cell from the external medium, with hydrophilic (water-attracting) phosphate groups oriented towards the watery cytoplasm and exterior, while hydrophobic (water-repelling) lipid tails are buried inside the membrane. Transmembrane proteins, embedded in these bilayers and often spanning them, allow selective communication between the inside and outside of a cell, thereby facilitating uptake of nutrients and oxygen, or export for waste products.

1.8 Reductionism in biology To conclude this chapter, I will return briefly to the practice of science. The molecular biology of gene regulation (above) is often cited as a great triumph of reductionism in biology, whereby complex systems are broken down into simpler component processes that can be analysed more easily and then pieced back together so as to understand the whole. This approach has been astoundingly successful in science, but especially in biology. Nor is its application confined to genes and cells: it can work equally well when applied to the roles of individual species in an ecosystem, or to aspects of an animal’s behaviour. Even so, reductionist is used as an insult by those wedded to a more wide-ranging holistic view of the natural world. The old adage about not seeing the wood for the trees springs to mind. The central dispute here concerns whether the behaviour of the whole can be explained

Of Molecules and Cells

33

entirely in terms of the activities of its component parts, or whether there are emergent properties characteristic of the whole system that cannot be predicted from the functioning of its various parts (whilst admitting that knowledge of those parts is always incomplete). Can genes and proteins provide a comprehensive functional description of a living cell? Can the sum total of those cells adequately specify a whole organism, or human neurons a conscious brain, or component species an entire ecosystem? In the absence of complete knowledge, such questions cannot be answered definitively. The power of reductionist approaches in science is undeniable, even if there are also additional emergent properties that cannot readily be predicted. We will return to this in part 2 below (§ 7.5.2; Clayton, 2004). Now the stage is set to introduce the topic of evolution as Darwin first envisaged it, set in the complex world of macroscopic organisms. I will deal first with the title topic of Darwin’s 1859 book in chapter 2 on speciation, then the fossil record (as well as evolutionary convergence) in chapter 3, followed by a return to more genetic and cellular themes when considering recent insights from animal development in chapter 4, and finally a thumbnail sketch of human beings in chapter 5—a roller-coaster ride through genetics, neurobiology, language, cultural evolution and finally religion—acting as a bridge into part 2 of this book.

CHAPTER 2 SPECIATION

Summary § 2.1 looks at the biological category of species, together with the genera and families into which these are grouped. § 2.2 explores how new species can arise through adaptive radiation—often on islands or in isolated populations. § 2.3 summarises the higher-level groupings into which all organisms are classified. § 2.4 outlines Darwin’s key idea of natural selection operating on variations that arise (as we now know) through mutation, and how this helps explain the great diversity of the biosphere. Since the evolution of new species is such a slow process, § 2.5 describes how distinct morphs or ecotypes can emerge within a given species, leading on to ecological and reproductive separation, as a staging post on the road to speciation. § 2.6 looks briefly at the importance of weeds and other opportunistic species, able to colonise new habitats (including cities). § 2.7 introduces the concept of lifehistory strategies, and how these can also evolve through natural selection. Key aspects of this process are described in § 2.8, exemplified by sexual selection and co-evolution of species—this last including “arms races”, e.g. between predator and prey. Finally § 2.9 asks whether evolution proceeds by gradual incremental steps, as Darwin originally envisaged, or whether more radical changes, termed “saltations”, might be needed to account for the vast diversity of living things on this planet.

2.1 What is a species? Over 60 years ago, when I was five, my mother encouraged me to start collecting (and only later photographing!) wild flowers—which required first identifying them. I still remember my childish delight at being given McClintock and Fitter’s “Collins Pocket Guide to Wild Flowers” (1956), in which plants were starred according to their rarity. It w as a real thrill to find 3-star flowers, of which rather few seemed to grow in North Devon where I then lived. So, at a very early age, I became familiar with plant

Speciation

35

families and their various particularities: the 4 petals of crucifers (now Brassicaceae), the 6 of lilies, or the strangely hooded flowers of orchids. I also became aware of “difficult” groups such as eyebrights, dandelions, hawkweeds or brambles—where multiple species all look confusingly similar to the non-expert. So where better than flowering plants to start thinking about what is meant by the term species?—a deceptively simple concept at first sight, but one that is mired in complexity and controversy. Species can be viewed either as real and discontinuous entities, or alternatively as somewhat arbitrary groupings superimposed upon a continuous flux—both in time and characteristics—of variation between similar types of organisms. A species denotes a particular kind of organism—be it animal, plant or microbe. Members of that species are normally able to interbreed sexually only with each other, unless populations are prevented from doing so by geographical barriers. That said, hybridisation between related species is common in certain plant families—notoriously so among orchids. However, the resultant hybrids are usually—though not always—infertile. Species are grouped together into genera (singular genus), whose members all display certain common features. Under the classification system devised by Carl Linnaeus in the 18th C CE (Linnaeus, 1753, 1758, 1759), each discrete species is given a two-part (binomial) Latin name—the first (capitalised) denoting the genus and the second the actual species. Once introduced and fully spelt out initially, genus names are usually abbreviated as a capital letter followed by a full stop, unless this would cause confusion. Higher level taxonomic groupings will be considered in § 2.3. Originally, the Linnaean classification system was based on morphology—the outward form and inner structure of an organism. However, recent genetic studies using rapid DNA sequencing methods have necessitated some re-evaluation of inferred relationships between species. There are cases where disparate-looking organisms turn out to be closely related genetically, while in other cases superficially similar appearances mask amazingly deep genetic differences. Consider the orchid flowers shown in Fig. 2-1 (centrefold), which are all British or Mediterranean (panels B, I, L, M, N) members of the family Orchidaceae. If we tried to classify these plants on the basis of flower appearance alone (one arbitrary feature from among many available traits), then we might come up with something like the order shown. Whilst A looks strange by any standards, it has a branched lip like that of B, which in turn shares its bifurcated lower lip with C to G and P. The flowers of H, I and Q, by contrast, have a trifid (3-pronged) lower lip, whereas J to O all share a fan-shaped lip that is rather more lobed and subdivided in K and

36

Chapter 2

L—somewhat resembling H, I and Q. In fact, Linnaean taxonomy placed A to F all in separate genera (Himantoglossum, Barlia, Neotinea, Listera, Neottia and Aceras, respectively), as was also true of Q (Anacamptis), whereas G to P were all grouped within the genus Orchis (Buttler, 1991). Recent studies of genetic relatedness among orchids have reassigned several of these species into different genera (Bateman, 2006). Thus B has joined A in Himantoglossum, D has joined E in Neottia, and F has joined Orchis. More surprisingly, M, N and O have all been moved to the genus Anacamptis to join Q, despite a lack of obvious floral similarity (Harrap & Harrap, 2009), while L and P have joined C in Neotinea. The take-home message is that appearances can be deceptive for classification purposes. A single plant species may display varied characteristics depending on its habitat, often reflecting phenotypic plasticity and/or genetic variation. Populations growing on an exposed mountain or cliff-top may appear stunted compared with their counterparts in a lush valley. Even so, they remain recognisable as members of the same species, as with the lowland and dwarf mountain forms of the Cretan Tulip, Tulipa cretica (Fig. 2-2A and B; centrefold). This local variation shades off into distinct varieties that sometimes merit sub-species status, or may even harbour sufficient genetic differences from the type-form to qualify as distinct species (e.g. among dandelions). Sometimes it is simply a matter of knowing what to look for: thus Common Gorse with its unruly clusters of large flowers (Fig. 2-2C) is readily distinguishable from the similar Western Gorse with its tighter terminal spikes of smaller flowers (Fig. 2-2D). Genetic differences resulting in new species arise commonly in isolated populations on islands. Because of their geologically recent separation from Europe, the British Isles have relatively few endemic plant species, but two of those illustrated grow on small offshore islets—the eponymous Lundy Cabbage (Coincya wrightii; Fig. 2-2E) and Lindisfarne Helleborine (Epipactis sancta; Fig. 22F). Other Coincya species occur in the north and west of the British Isles—while E. sancta is very close to, but genetically distinct from, a mainland endemic species in the same genus (E. dunensis: Fig. 2-2G). The fourth endemic shown is the Scottish Primrose (Primula scotica; Fig. 22H), which is confined to the north coast of Scotland and Orkney, but differs markedly in its flower colour and smaller habit from the related but non-endemic Birdseye Primrose (P. farinosa; Fig. 2-2I). On older, isolated island archipelagos, such as the Canaries, endemic species are rife. Two overlapping causes can be distinguished for this rich floral diversity (Bramhall & Bramhall, 2001). First, there are descendants of survivors from an earlier epoch, when luxuriant laurel forests dominated large parts of Europe until the recent Ice Ages began ~2.6 million years

Speciation

37

ago (Ma). Isolated fragments of this laurisilva persist in the Macaronesian archipelagos, mainly in Madeira and the jagged Anaga peninsula of northeastern Tenerife (Fig. 2-3A-C; centrefold); this entire ecosystem is largely extinct elsewhere. There are also many instances where certain genera are represented by numerous Macaronesian species, which are often far more diverse than their European counterparts: examples include the buglosses (Echium; Fig. 2-3E to I) and spurges (Euphorbia; Fig. 2-3J to L). The island species have resulted from local adaptive radiation, where the descendants of initial colonisers have specialised to fill a range of available ecological niches. European buglosses can grow to a metre or more (e.g. Echium vulgare; Fig. 2-3D), but these are dwarfed by their 3+ metre Canarian cousins, such as the pallid E. simplex (Fig. 2-3E), or the similar but scarlet-flowered E. wildpretii (Fig. 2-3F)—confined to the crater of Mount Teide on Tenerife. Many such Echium species are bushy in form (e.g. E. aculeatum or E. virescens; Fig. 2-3G, H), while a few are weedy (E. triste; Fig. 2-3I). A study of genetic relationships among Macaronesian Echium species suggests that they have all diversified from a common ancestor, such as the European Small-flowered Bugloss, E. parviflorum, chosen as an outgroup for DNA sequence comparisons (Bohle et al., 1996). Of the Euphorbias illustrated, both E. atropurpureum and E. regisjubae (Fig. 2-3J and K) are larger and bushier than most of their European relatives, with leaves and flowers clustered towards the tips of their thick fleshy stems. The striking E. canariensis (Fig. 2-3L) at first sight resembles an American cactus—belonging to a totally different family (Cactaceae). The same is true of its much rarer and spinier Fuerteventuran cousin E. handiensis, as well as several African Euphorbias. Though not related, both cacti and these Euphorbias show similar adaptations against drought—such as thick water-storing stems, a waxy cuticle resistant to water loss, and absent leaves. This is a case of convergent evolution— whereby similar adaptive traits have evolved independently in phyletically unrelated groups, whose last common ancestor would not have possessed any of these specialised features. Notably, true cactus flowers (superficially daisy-like; Fig. 2-3M) do not resemble those of Euphorbias (Fig. 2-3J, K). The key topic of onvergent evolution is discussed further in § 3.5 and 3.6.

2.2 Geographical and climatic factors in speciation The endemic species found on islands frequently result from adaptive radiation involving allopatric speciation—whereby isolated populations of colonising organisms become adapted over time to thrive in several new habitats, each differing in its particular biotic (organismal) and abiotic

38

Chapter 2

(climatic, geological and topographical) conditions. Genetically speaking, geographical isolation prevents colonist populations from interbreeding with their source populations, such that both groups accumulate genetic differences (through a lack of gene flow) and in time become incompatible reproductively. The diversity of Macaronesian Echiums and Euphorbias reflects a multiplicity of available habitats in that archipelago, ranging from damp forests to rocky deserts, from coastal sand dunes to a snowcapped volcano. The Lindisfarne Helleborine (Epipactis sancta; Fig. 2-2F) may exemplify an early stage in this process. As a small, geographically isolated population, it has become genetically but not (to any extent) morphologically distinct from its mainland relative and presumed progenitor, E. dunensis (Fig. 2-2G). Islands thus offer unique laboratories for observing evolutionary processes at work (reviewed e.g. by Losos and Ricklefs, 2009). Two endemic beetles have co-evolved in association with the longestablished Lundy Cabbage (Fig. 2-2E), so it is not just single species that diversify in this way. Darwin’s Galapagos finches (actually related to tanagers) provide another classic case of adaptive radiation: 14 species belonging to several genera (but all in the sub-family Geospitzidae) show specialised beak adaptations for different types of foods and niches available on the various Galapagos islands. Contrary to popular myth, Darwin’s discovery of these birds during his epic Beagle voyage did not give birth to the theory of evolution in a sudden flash of insight. In fact, it was not until he consulted with the eminent ornithologist John Gould in 1837 that their relatedness was even recognised. The genetic basis of speciation in this group has been clarified by recent DNA sequence studies (Lamichhaney et al., 2015), with evidence of extensive interbreeding during speciation, down-playing the role of reproductive isolation here. Indeed, species can also diversify whilst still sharing the same geographical area (sympatric speciation), though this would presumably have to arise within a freely-interbreeding population. Specialisation for different food sources could provide one contributory factor. Among plants, temporal changes in flowering season can similarly lead to reproductive isolation. The Mediterranean Mandrake has two forms, one with pallid flowers in spring (Mandragora officinarum, formerly M. vernalis; Fig. 2-4A, centrefold), the other with violet flowers in autumn (M. autumnalis; Fig. 2-4D). Though sometimes distinguished as separate species, many botanists contend that they are variants of a single species (M. officinarum). Among many other Mediterranean flowers, autumn- and spring-flowering forms have evolved into clearly distinct species, e.g. the spring-flowering endemic Cretan Sowbread (C. creticum; Fig. 2.-4B) and autumn-flowering Ivy-leaved Sowbread (Cyclamen hederifolium; Fig.

Speciation

39

2.4E). Though Spring and Autumn Squills (Fig. 2-4C, F) were formerly both classified in the genus Scilla, the latter has been moved into a separate genus (Prospero) of largely autumn-flowering species, implying a deeper split which is now reflected at genus rather than species or variety level. In fact, allopatric and sympatric speciation describe the two extreme ends of a spectrum, where gene flow is (initially) either zero or unrestricted. Intermediate possibilities are properly termed parapatric speciation, where diverging populations occupy adjoining geographical regions and gene flow is restricted to a greater or lesser extent (Butlin et al., 2008). Evolution on remote islands can pursue unusual, not to say bizarre, paths. One extraordinary example is afforded by the animals that dominate Christmas Island in the Indian Ocean—which are neither mammals nor even reptiles but rather a multiplicity of land crab species that only return to the sea in order to breed. Spectacular footage of these creatures featured in the first episode (“Islands”) of the Planet Earth II series narrated by Sir David Attenborough, first broadcast by the BBC in November 2016. Madagascar, one of the largest islands in the world, originally separated from India about 88 Ma. A primate species reaching the island some 54 million years ago has diversified through adaptive radiation into a hundred or more present-day endemic species and subspecies of lemurs, occupying a vast range of habitats in the absence of predation. The immensely slow fragmentation, separation and collision of continental plates through tectonic movements has also played a major role in evolutionary history, causing animal and plant populations to become isolated, and often to experience major climatic changes as they move into different latitudes. Sometimes this results in the extinction of species that are unable to adapt, opening up vacated ecological niches for opportunistic colonisers, and so promoting further adaptive radiations. All major continental land masses were once fused together as a single vast super-continent called Pangaea, lasting from c. 300 to 180 Ma before breaking up—eventually to form the continents we know today. Mountain building along the edges of colliding tectonic plates also causes gradual but drastic ecological changes, as a result of land being uplifted to higher (and therefore colder) altitudes. Mountains, especially in the tropics, are particular hotspots for biodiversity —a fact first noted by Alexander von Humboldt during his explorations at the start of the 19th C, and recently re-investigated by Rahbek et al. (2019).

2.3 Higher-level taxonomic groupings Taxonomy denotes the systematic classification of living things. So far, only species and genera have been mentioned, together with a passing

40

Chapter 2

mention of the families into which related genera are grouped. A number of traditional Linnaean plant families, such as the diverse Liliaceae, have now been subdivided into several allied families, each comprising clusters of more closely related genera. Much of this recent revision of traditional taxonomy has resulted from DNA sequence comparisons—a gigantic task which is still far from complete, and will undoubtedly necessitate further reclassifications in the future (as was true for almost half the orchid species in Fig. 2-1). Three plant families are illustrated in Fig. 2-5 (centrefold). Members of the vast family Asteraceae (formerly Compositae) in the top row are instantly recognisable by their characteristic flower structure— although the typical ray florets are not always present (e.g. Senecio vulgaris). The family Gentianaceae in the middle row is much smaller, and most of its members possess the typical 5- (or 4-) petalled gentian flowers shown in the first five panels, although Blackstonia perfoliata has more numerous petals. By contrast, the Linnaean family Scrophulariaceae in the bottom row seems far more heterogeneous in terms of floral structure, and DNA sequence comparisons have led to many of its component genera being reassigned to other families, e.g. Plantaginaceae (Olmstead, 2002). Looking at still higher-level groupings, it is perhaps clearer to turn the focus from plants to animals. Families are grouped together into orders: among insects, the 2-winged flies (Diptera) are obviously different from the 4-winged bees and ants (Hymenoptera), the butterflies and moths (Lepidoptera; Fig. 2-6C, E-H), the crickets and grasshoppers (Orthoptera), or the beetles with their hard wing casings (Coleoptera; Fig. 2-7E). These 5 orders, along with 24 others, comprise the class Hexapoda (formerly Insecta), all of which are characterised by 3 pairs of thoracic legs. Many insects develop initially as larvae (grubs or caterpillars; Fig. 2-6H), whose thoracic true legs are supplemented by extra pairs of abdominal prolegs. Metamorphosis involves radical reconstruction of the larva from imaginal discs inside the pupa, out of which emerges the adult (or imago). Other features typical of the class Hexapoda include a body that is subdivided into segments with a tough chitinous exoskeleton. These characteristics, however, are also found in several other classes, such as 8-legged spiders and scorpions (Chelicerata; formerly Arachnida, Fig. 2-6D) and two multilegged groups—the Myriapoda (centipedes, millipedes; Fig. 2-6A) and Crustacea (mainly aquatic—including lobsters, shrimps, crabs; Fig. 2-6B). Together, these classes all share a common “body plan” and are therefore grouped together into the huge phylum Arthropoda. Other important animal phyla include the Porifera (sponges), Cnidaria (corals, sea pens, jellyfish; Fig. 2-7B), Ctenophora (comb jellies), Annelida (earthworms, many marine worms; Fig. 2-7C), Nematoda (roundworms; Fig. 2-7F),

Speciation

41

Mollusca (slugs, snails, bivalves, cephalopods; Fig. 2-7D), Echinodermata (sea urchins, starfish; Fig. 2-7G) and Chordata (sea squirts, amphioxus, vertebrates; Figs. 2-7H and Fig. 2-8). Evolutionary relationships between these animal groupings, each with its own characteristic body plan, will be dealt with in the next 2 chapters. Major groups among vertebrates include the Pisces (fish, split into 5 classes; Fig. 2-8A,), Amphibia (newts, toads, salamanders; Fig. 2-8B), Reptilia (tortoises, crocodiles, snakes, lizards; Fig. 2-8C), Aves (birds; Fig. 2-8D, F-K), and Mammalia (mammals; Figs. 2-7H; 2-8E, L-P). All these animals belong to the kingdom Animalia, as distinct from Plantae or Fungi (Fig. 2-7A), each meriting kingdom status. A more controversial grouping was the “kingdom” Protista, comprising a bewildering variety of mostly single-celled organisms. However, DNA sequence evidence has shown that some of these are more closely allied to animals, and some to plants or fungi. Protists are therefore polyphyletic: they do not form a unified monophyletic group descended from a single common ancestor, but rather constitute a group with disparate origins. Equally untidy are the Algae, which are photosynthetic organisms ranging from single cells to large plant-like marine forms—the red, brown and green seaweeds, which are in fact quite different phyletically (only green algae being allied to plants). Historically algae also included Cyanobacteria (blue-green algae) as well as some protists, so algae are also polyphyletic. All of the organisms listed so far (except Cyanobacteria) are classified on the basis of subcellular structure as eukaryotes (Eukarya), whose genetic material is organised as linear chromosomes inside a membrane-bounded nucleus. The other main groups of living organisms are prokaryotes, whose DNA is usually circular but not enclosed in a nucleus (Fig. 1-1A versus B). These prokaryotes are now split into two separate domains. Familiar bacteria such as E. coli belong to the domain (Eu-) Bacteria, including photosynthetic Cyanobacteria and infectious bacteria—as well as most of those living symbiotically within the gut and those responsible for decay processes. The other prokaryotic domain comprises the Archaea (formerly Archaebacteria), which sometimes live in extreme environments such as submarine hydrothermal vents (surviving at temperatures of 90°C or more) or in toxic highly saline lakes. They often derive their energy from unusual chemical reactions, and include the methanogenic (methane-producing) bacteria found in marshes and the gut. Archaea share certain characteristics with eukaryotes, including the presence of introns in some genes (§ 1.4), and may represent much-modified descendants of the earliest living cells (Martin et al., 2014). Mysterious Archaea from ocean sediments, known as Lokiarchaeota, carry genes related to those in eukaryotes as well as classic

42

Chapter 2

Fig. 2-6. Arthropod diversity. Top row, principal classes: Myriapoda, Crustacea, Hexapoda (Insecta) and Chelicerata (Arachnida). Bottom row, a few representatives of the insect order Lepidoptera. N.B. larval caterpillar in part H, showing aposematic warning coloration (black and orange-yellow; see § 9.6.7).

Fig. 2-7. Diversity of life. A, puffball (Fungi); B, cnidarian jellyfish; C, marine polychaete annelids; D, gastropod molluscs; E, Seven-spot ladybird (insect); F, Caenorhabditis nematode (lab. culture, University of Nottingham; ~1 mm long); G, starfish (echinoderm; west Canada); H, waterbuck (vertebrate; Kenya). Referring forwards to chapter 3 (Fig. 3-2), B typifies the Cnidaria (Radiata), C and D the Lophotrochozoa, E and F the Ecdysozoa, and G and H the Deuterostomata.

Fig. 2-8. Vertebrate diversity. Top row, the 5 major classes: fish, amphibians, reptiles, birds and mammals. Middle row, ……..examples of bird diversity. Bottom row, examples of mammalian diversity.

Speciation 43

44

Chapter 2

archaeal genes (Imachi et al., 2020). Some reports describe such bacteria as developing “tentacle-like” structures when cultured under laboratory conditions (no mean achievment in itself; Lambert, 2019), suggesting a possible ancestry for more complex eukaryotic cells (Imachi et al., 2020) . Based on these fundamental genetic differences, Carl Woese proposed that living organisms should be subdivided into three huge domains— the Bacteria, Archaea and Eukarya (Woese & Fox, 1977)—with animal, plant and fungal kingdoms relegated to a subsidiary status as offshoots of the Eukarya, as also are the various groups of algae. DNA sequence evidence implies that there were only two primary domains (Bacteria and Archaea), which preceded the emergence of Eukarya by ~2 billion years. The original endosymbiosis that led to eukaryotes most likely involved a bacterial symbiont that was acquired by an archaeal host cell, thereby conferring a hybrid domain status (Williams et al., 2013). Lineweaver and Chopra (2019) give an overview of the place of Homo sapiens in the living world as currently understood, tracing our shared ancestry with other organisms. The overall diversity of life is far greater than most non-biologists realise, but much of this is microbial or microscopic, thereby escaping daily notice.

2.4 Gradual evolution explains speciation and diversity The revolutionary claim made in Charles Darwin’s “Origin of Species” (Darwin, 1859, republished 1998) is that natural selection, applied over vast spans of geological time, can account for the emergence of novel species and even of higher taxonomic groupings. This follows from the observation that organisms produce more offspring than the environment can support, and that there are variations among progeny. Natural selection will favour survival and reproduction of those variants best adaptaed to the prevailing environment, while other variants are eliminated. Darwin espoused the gradualist views of Charles Lyell, as expounded in the latter’s 3-volume “Principles of Geology” (Lyell, 1830, 1832, 1833), in opposition to popular catastrophist views holding that fossil remains of extinct creatures were relics of past geological paroxysms. These, for the religious-minded, could be reconciled with the story of Noah and the Flood in Genesis 6-9 (also in the Epic of Gilgamesh). But since the fossil record bears witness to 5 mass extinctions during the history of macroscopic life on earth (§ 3.4), Lyellian gradualism can no longer be taken for granted. Darwin had scant regard for the earlier evolutionary views of Lamarck, though not because the latter mistakenly believed that adaptation occurred through the inheritance of acquired characteristics (so too did Darwin). Lamarck had in fact proposed 2 antagonistic “forces” that drove evolution, the more

Speciation

45

important of which was a principle of directional progress (rather like an escalator from basic chemical constituents up towards the higher life forms). By contrast, acquired adaptations to local environmental conditions were merely secondary, often diverting the force of progress into dead ends. Because new life was continually emerging, all of the grades of animal and plant organisation would still be present at any one time (Lamarck’s ideas are discussed in Gould, 2002, pp. 170-192). Darwin sought instead to identify a single unifying principle underlying evolution, and by homing in on natural selection to fulfil this role, he also effectively undermined Paley’s famous watchmaker argument—whereby the intricate adaptations found throughout nature were seen as eloquent testimonials to the creativity and beneficence of an omnipotent God (Paley, 1802). Darwin himself was well aware of the scale of the mountain he had to climb—witness his own description of the Origin of Species as “one long argument” (Darwin, 1859/1998, p. 346). As stated in his Introduction (p. 1), the 1859 “Origin” was originally published as an Abstract for a much larger and more systematic treatment of the subject, which was never completed, though part of it was edited for publication over a century later (Darwin ed. Stauffer, 1975). It is of more than passing interest that Darwin himself had recourse to a second principle operating within the framework of natural selection, termed the Principle of Divergence (see Gould, 2002, pp. 224-260). In essence, this proposed a tendency for natural selection to favour extreme variants at one or both ends of a spectrum of variation. The solitary diagram that adorns the published “Origin” is found in chapter 4 on Natural Selection (Darwin, 1859/1998, p. 91), and is popularly supposed to illustrate the branching Tree of Life. However, Gould argues that it is really intended to clarify Darwin’s Principle of Divergence, since it shows new varieties (and ultimately new species) arising only when extreme variants are favoured as survivors under natural selection. In his more expansive draft (Darwin ed. Stauffer, 1975, pp. 236), a version of this same diagram is accompanied by a second, which illustrates the outcome when random variants are able to survive, and no selection pressure is imposed (ibid., p. 237). Predictably, under these conditions, species fail to diversify or to follow any particular trend; all three diagrams are reproduced by Gould (2002, pp. 242-243]. One interesting detail is that the first of Darwin’s (ed. Stauffer, 1975, p. 236) figures includes not only the well-known branching tree (resulting from survivors being selected at the extremes of variation), but also a staircase representation of unidirectional evolutionary change when only one extreme is selected; obviously this last does not lead to diversification (splitting) of species, though the original species would show progressive alterations over time, perhaps eventually

46

Chapter 2

becoming a new species. This trend is also present, but subsumed within the branching tree, in the “Origin of Species” (p. 91). So, for example, a plant facing desertification (as today in sub-Saharan Africa) might become adapted to resist drought more efficiently through spontaneous droughttolerant mutations being favoured by selection. But this would remain a unidirectional trend unless simultaneous selection was also occurring for very different mutations providing a selective advantage, say, in marshy ground beside permanent upland watercourses—eventually resulting in new species that could thrive respectively under dry and wet conditions. This is plausible for geographically isolated populations, such as invaders colonising available niches on islands, and essentially describes the underlying mechanism involved in allopatric speciation and adaptive radiation. There must be interactions between individual phenotypes and the prevailing environment for any species under selection, but the precise nature and mechanisms of these interactions have been surprisingly little studied (MacColl, 2011). One classic and frequently cited example concerns the medium-sized Galapagos ground finch, Geospiza fortis. In drought years, the seeds on which it feeds tend to be large and hard, favouring larger variants with stronger bills; conversely, in wet years the seeds are small and soft, favouring smaller bills and sizes (Gibbs & Grant, 1987). There is thus intermittent (oscillating) selection for both extremes, though these adaptations seem to be held in balance (as a balanced polymorphism) and probably do not herald the future emergence of two distinct species. Within a large inter-fertile population (as envisaged for sympatric speciation), one might expect extreme variants to interbreed mainly with the more abundant “typical” individuals, such that the average phenotype and genotype would not change appreciably (as in the second diagram in Darwin, ed. Stauffer, 1975, p. 237) in the absence of selection. This can be viewed as a “regression to the mean”, to borrow Francis Galton’s phrase. Within such a population, it is hard to see why more extreme variants would be favoured by selection over more typical individuals. Darwin himself appealed to species diversity as an underlying driver. This suggests that variants of any given species which become specialised for new ecological niches, e.g. through adaptations favouring one particular food source or microhabitat, might have a survival advantage over more generalist variants. If taken to its logical extreme, this would imply that evolution in a stable environment should favour a proliferation of species occupying ever-more specialised niches—which provides a fairly accurate description of the most biodiverse ecosystems on earth, such as rainforests or coral reefs. However, there are attendant costs in terms of intense

Speciation

47

competition for food and space. Relatively small changes involving habitat, disease or co-evolved species can then result in extinction—witness the disappearance of many tropical rainforest amphibians as a result of chytrid fungal infection, as well as habitat loss and human encroachment (Scheele et al., 2019); these extinctions also trigger knock-on declines in snake diversity (Zipkin et al., 2020). Another way in which the principle of divergence might operate for higher animals involves sexual imprinting, whereby progeny seek out mates with traits that resemble those of their parents—especially mothers—so promoting reproductive isolation (Yang et al., 2019). Interestingly, this has been demonstrated among Darwin’s finches (Grant & Grant, 2018), and also in tropical frogs (Verzijden, 2019). Extinction plays a major role in the “struggle for life” that underlies natural selection. Darwin embraced Malthus’ axiom that populations (of any organism) will expand geometrically in numbers, provided food and habitat are plentiful. But once resources become limiting, weaker members of the population will be outcompeted and in time eliminated by those better able to exploit the remaining resources—essentially summed up in the phrase “survival of the fittest”. What goes for members of a single species competing among themselves could equally apply to different (or related) species competing for overlapping resources. Darwin envisaged habitats or ecosystems as being already crowded with existing species occupying essentially all of the available niches. It follows that new species can only find a niche by displacing, out-competing and ultimately eliminating other species already occupying that niche—or else by finding a more specialised niche that had previously been under-exploited. This can account for many features of stable and biodiverse ecosystems, and could also allow more efficient or specialised new variants to displace their parental species, in part vindicating Darwin’s Principle of Divergence. However, recent ecological studies suggest a more nuanced picture, where a trend towards increasing biodiversity in tropical regions is accompanied by lower densities of most individual species. Overall, the ratio of intraspecies to inter-species competition rises by about 0.25% per decreasing degree of latitude towards the tropics (Usinowicz et al., 2017). In other words, more intense competition within each species reduces its overall population density, but there is less direct competition with other species as niches become more diversified. Adaptive radiation of cichlid fish species and genera in the great lakes of the East African Rift Valley has for many years provided an object lesson for geneticists studying speciation, and the genomic basis of this divergence is now emerging from DNA sequencing studies (Brawand et al., 2014).

48

Chapter 2

2.5 Staging posts on the way towards speciation Speciation is usually a gradual process, often taking many thousands of years, whereby different populations of an organism diversify and acquire reproductive barriers against interbreeding, as well as behavioural and/or morphological differences. It is therefore impossible to observe this entire transformation in real time, starting with a single parental species as it diversifies into distinct daughter species. However, there are intermediate stages along the way, such as the emergence of different forms (ecotypes or morphs) of a single species showing differing degrees of habitat and/or reproductive isolation—a process termed “ecological speciation” (Hendry, 2009). A classic example of this concerns the post-Ice-Age evolution of Three-Spine Sticklebacks (a fish, Gasterosteus aculeatus) into two distinct ecotypes in several lakes in British Columbia. One ecotype lives in surface waters (limnetic) and has a shallow body with multiple long gill rakers, while the other is bottom-dwelling (benthic), with a deep body and fewer, shorter gill rakers (Fig. 2-9A). These populations do not intermingle much and are essentially isolated from each other reproductively. Moreover, there is some evidence that hybrids between these ecotypes are less fit than either parental form in its preferred habitat. These two ecotypes may therefore be in the process of becoming two separate species, though obviously one cannot predict the future course of evolution here. Another difference between benthic and limnetic populations of ThreeSpine Sticklebacks is the presence of a spine on each pelvic fin in the latter (and also in marine ancestors)—where it protects against predation by other fish—but not in the former, where its presence seems to be disadvantageous because it can be grasped more easily by predatory dragonfly larvae. The molecular and genetic basis of this ecotype difference has been analysed in detail by Shapiro et al. (2004). Among the F2 offspring of crosses between a limnetic (spine-bearing) female and a benthic male (no spine), a complete range of different spine morphologies can be found—from full-size to absent. Several genetic loci seem to contribute towards this variation, but the major effect comes from a single gene called Pitx1. In benthic sticklebacks, Pitx1 is expressed normally at other sites in the body and the protein itself is not mutated. However, this protein and its mRNA are absent specifically from the hindlimb region (§ 4.6) that generates the pelvic fins. This is due to a mutation in one of the modular enhancers regulating Pitx1 expression—specifically that which activates this gene in the pelvic fin limb-buds to promote spine development. Interestingly, this same pattern of altered Pitx1 expression is seen in benthic but not in limnetic Three-Spine Stickleback populations in

Speciation

49

Iceland that have evolved quite separately since the last Ice Age. Thus favourable adaptations can evolve convergently (strictly, in parallel; § 3.5) through similar genetic changes in different populations. Molecular studies reveal that this Pitx1 enhancer is a mutational hotspot involving fragile DNA—prone to double-stranded breaks or deletions (Xie et al., 2019). Three-Spine Sticklebacks also differ in terms of their protective lateral armour plates, which restrict growth in juveniles, that are much reduced in freshwater as compared to marine populations—attributable to selection for different alleles of the Ectodysplasin gene (see Barrett et al., 2008). In his critical review of ecological speciation, Hendry (2009) suggests that other presumed examples of this process may not fulfil the necessary criteria of full ecotype separation, and may perhaps represent earlier or intermediate stages along this path. At the least, this shows how variants of a single species can become specialised for differing habitats, acquiring both morphological novelties and reproductive barriers along the way. The erection of such reproductive barriers, and whether they act at the level of incompatibility for mating or fertilisation (pre-zygotic), or at the level of inviability or sterility of the hybrids (post-zygotic), remains a challenge in our understanding of the genomics of speciation (Seehausen et al., 2014). Donkeys and horses produce viable hybrid offspring (mules or hinnies), but both are infertile and cannot reproduce. Swordtail fish interspecies hybrids often develop melanomas due to incompatible alleles (Powell et al., 2020). My second case-study is the Rough Periwinkle, Littorina saxatilis—a small mollusc that is abundant on European seashores. Pairs of distinct morphs have been described from at least three widely separated coastal regions, in the north-east of Britain, in Galicia (NW Spain) and in Sweden (Butlin et al., 2008). One morph is always smaller and relatively thinshelled, but with a wider shell aperture accommodating a larger foot (relative to the rest of the animal), allowing this mollusc to cling on to rock surfaces in surf and rough seas. This morph is termed H in Britain (Fig. 2-9 B i and ii, left), SU in Galicia and E in Sweden—but is here designated type 1. The second morph is always larger, with a much thicker shell and relatively smaller aperture—termed M in Britain (Fig. 2-9 B i and ii, right), RB in Galicia and S in Sweden, but here designated type 2; this form is more resistant to crushing and predation by crabs. In all three locations, these morphs occupy adjacent but largely separate ecological niches. In Britain type 1 (H) occurs on the upper shore whereas type 2 (M) occurs lower down on the middle shore where crabs are far more common. This vertical displacement is reversed in Galicia, where type 2 (RB) occurs among barnacles on the upper shore (but again where crabs are common),

50

Chapter 2

whereas type 1 (SU) occurs lower down the shore among mussels (Mytilus spp.)—whose close packing affords protection from crab predation. In Sweden, there is little tidal movement and the separation of habitats is horizontal rather than vertical—with type 1 (E) found on exposed rocky headlands while type 2 (S) is found in more sheltered bays where crab predation is significant. As well as morphological and habitat contrasts between morphs, there are also partial reproductive barriers. Most mating occurs assortatively, i.e. within one or the other morph, although some gene flow can occur between them in boundary zones where their habitats abut. However, the hybrid embryos are more prone to abort, suggesting an as-yet inefficient post-zygotic barrier to reproduction (Butlin et al., 2008).

Fig. 2-9. Ecotypes: Three-Spine Stickleback and Rough Periwinkle. Part A, shallow-bodied limnetic form (top) of the Three-Spine Stickleback, versus deepbodied benthic form (bottom); copyright photograph, courtesy of Dr Andrew MacColl, University of Nottingham. Part Bi/ii left, thin-shelled H form (type 1) of the Rough Periwinkle from upper shore of Lindisfarne (Northumberland, UK), contrasted with Part Bi/ii right, thicker-shelled M form (type 2) from middle shore at the same location; these shells are essentially indistinguishable when viewed from above (B i), but differ clearly when seen from below (B ii). Bars show 1 cm.

So far, geographical and phylogenetic data have been used to infer patterns of adaptive change driving the emergence of distinctive ecological morphs. But small-scale adaptive changes can also be demonstrated experimentally—not only in laboratory experments, but even in the field. Transplanting populations of anole lizards (Anolis sagrei), from one small Bahamian island to 14 others previously devoid of this species, resulted in adaptive changes over periods of 10-14 years. Changes in traits such as limb length were far more marked on islands whose vegetation differed greatly from that of the source-population island (Losos et al., 1997;

Speciation

51

Losos, 2017, pp. 155-179). Different islets act as “replicates” in these experiments, though precise conditions cannot be reproduced exactly from one to another, and many trials were terminated abruptly by hurricanes! One remarkable feature of these studies is the rapidity with which adaptive changes appear and come to predominate in a test population, giving the lie to the assumption that evolution always proceeds with glacial slowness. Moreover, these changes appear to be heritable—suggesting that they are genetic rather than adventitious consequences of phenotypic plasticity.

2.6 Opportunistic pioneers There are also advantages for species that are flexible generalists, since they can invade new habitats as these open up, when competition is much less intense. Invasive foreign weeds belong to this category, often benefitting from the absence of pests, parasites or herbivores that normally keep populations in check within their original native range. Weeds, when all is said and done, are just opportunistic plants that are particularly successful at colonising new habitats—especially disturbed ground, fields and gardens. Of those illustrated in Fig. 2-10 (centrefold), both Rosebay Willowherb (Chamaerion angustifolium; Fig. 2-10A) and the invasive fern Bracken (Pteridium aquilinum; Fig. 2-10B) have a very broad temperate distribution. In Britain, the former was confined to woodlands or gravelly watersides through the 19th and early 20th centuries CE (Step, 1930, p. 97), in spite of its ability to spread rapidly after tree-felling or fires (hence its nickname Fireweed). It ranks among the few beneficiaries of the Blitz during World War 2, when it was able to colonise large areas of derelict bomb sites in London and other major cities, and over the past 75 years it has become one of the commonest of British wild flowers. Daisy (Bellis perennis; Fig. 2-10C), Dandelion (Taraxacum officinalis; Fig. 2-10D) and Hedge Mustard (Sisymbrium officinale; Fig. 2-10E) are all European weeds that have now spread world-wide in the wake of human colonists— as likely to be seen in Asian, Australasian or American cities as in their home range. Walking round the UBC campus in Vancouver in May 2016, I spotted 15 familiar plants of European origin, including all of the above. But this traffic is not all one-way: some garden flowers introduced into Europe by plant-hunters of the 18th and 19th centuries CE have become naturalised in their adoptive countries, though only a few have become invasive (such as Rhododendron ponticum). Several North American plants from temperate forests are now becoming established in the UK, e.g. Fringecups (Tellima grandiflora; Fig. 2-10F), Salal (Gaultheria shallon; Fig. 2-10G), and more recently Youth-On-Age (Tolmia menziesii;

52

Chapter 2

Fig. 2-10H)—probably originating from garden escapes. However, several other plants shared between northern parts of Europe and America have a circumpolar distribution dating back at least to the last Ice Age. These include Twinflower (Linnaea borealis, named after Carl Linnaeus; Fig. 210I), which is rare in Scotland (leaves) but much more common in Canada (flowers). Invasive colonisers from abroad include the notorious Himalayan Balsam (Impatiens glandulifera; Fig. 2-10J), which has spread so rapidly along watercourses throughout the UK that it needs uprooting annually to give native riparian plants an opportunity to compete. Though not yet so widespread, the Australasian Pirri-pirri Bur (Acaena novaezelandiae; Fig. 2-10K) is similarly invasive in dune habitats, its hooked fruit (upper image) readily clinging to clothing. These and other introduced plants, including Rhododendron and Japanese Knotweed, have proved extraordinarily difficult to eradicate in Europe—ample witness to their tenacity. Charles Darwin had also noticed the invasiveness of alien species and especially genera (Darwin, 1859/1998, pp. 89 and 255). Mice, rats, pigeons, starlings, seagulls, foxes and grey squirrels are among the many opportunistic animals that have profited from the advantages and convenience afforded by human dwellings and city habitats in Europe and across the world. Once confined to remote hilly areas in Britain, Peregrine Falcons (Falco peregrinus) have taken to nesting in church towers and university buildings—successfully rearing chicks despite human proximity. Indian Leopards (Panthera pardus fusca) have been filmed hunting pigs by night in the streets of Mumbai (Planet Earth II, part 6, “Cities”; first broadcast by the BBC in December 2016). Rabbits (Oryctolagus cuniculus; Fig. 2-8E) were introduced to Australia in the 18th C CE, and wreaked havoc on wildlife and crops until decimated by myxomatosis in the 1950s, a disease that was caused by deliberate release of the myxoma virus. Rabbit numbers had largely recovered by the 1990s, prompting a second release programme, this time of a calicivirus causing Rabbit Haemorrhagic Disease. The introduction of commensal (e.g. rats) and domesticated species (e.g. dogs) has often had devastating effects on local biodiversity when humans first reach hitherto uninhabited lands (e.g. New Zealand), quite apart from the depredations (e.g. hunting) and habitat losses (e.g. through farming) caused by the human colonists themselves.

2.7 Life-history strategies For any organism, the pattern of resource allocation (e.g. to growth, reproduction, etc.) across its lifetime is termed its life-history strategy. Depending on the prevailing conditions, a perennial plant may sometimes

Speciation

53

invest in flowering and reproduction, or alternatively in vegetative growth without flowering. Adaptation to a particular environment can affect the nutritional, developmental and reproductive strategies adopted by an organism in order to optimise its use of available resources and maximise the numbers of surviving offspring. The classic adaptations of Galapagos “finches” to different food resources, or the seasonal flowering of different cyclamen species, were noted earlier in § 2.2. I will not attempt extensive coverage of this topic, but will confine myself to a few familiar examples. Behavioural patterns in animals—such as feeding or reproductive habits— are subject to natural selection just as much as any purely physical traits. In animals, sexual reproduction can sometimes occur at an immature or larval stage in the life cycle (neoteny). The most celebrated case is that of the axolotl (Ambystoma mexicana), which used to live in Lake Xochimilco near Mexico City, but is probably now extinct in the wild—though it is widely reared in captivity. This is a salamander that retains its aquatic larval form (essentially as an overgrown tadpole with gills) throughout life, and never naturally metamorphoses into an adult with lungs for breathing air. It can, however, be forced to do so by injections of the metamorphosis-inducing hormone thyroxin; however, this never happened in the wild, yet the axolotl larvae still reproduced successfully. Some other salamander species show partial neoteny, with larval reproduction favoured under harsh conditions when the metabolic cost of full metamorphosis to an adult may be prohibitive. Similarly, neoteny occurs in flightless Strepsipteran female insects that never undergo metamorphosis. In terms of animal nutrition, there is strong evidence that feeding strategies are finely tuned to maximise the energy value of the food ingested after hunting for suitable prey (carnivores) or plants (herbivores). These optimal foraging strategies can be modelled mathematically; both the food rewards themselves and the time plus effort required to search for food (also to catch and defend, as well as to eat and digest it) can be tallied in quantitative terms as an energy budget. To allow for survival and reproduction, this energy budget must average out as a net positive term in the long run. A concise account of such models and supporting evidence can be found in Barnard (2004, pp. 357-405). Predator and prey species can become enmeshed in an “arms race”, with improvements in predator performance (e.g. cheetah speed) becoming matched by the ability of prey (antelope) to outrun pursuers. Similarly, improved prey protection (shell or carapace) can be countered by stronger predator jaws or beaks, and plant toxins by more efficient detoxification systems in herbivores. In a similar vein, one can model the optimality of adaptations resulting in specific

54

Chapter 2

reproductive behaviours, in habitat choices and migration, in social versus solitary lifestyles, or in learning and communication (see Barnard, 2004).

2.8 Sexual selection and co-evolution “Fitness” is measured by success in passing on one’s genes to the next generation, so it is hardly surprising that various reproductive traits have been subjected to intense sexual selection in one or both sexes, affecting the structures and behaviours involved in courtship and mating. Elaborate tail feathers in male peacocks afford one obvious example (Fig. 2-11A), as do the heavy antlers borne by many male deer (Fig. 2-8M)—apart from reindeer, where antlers develop in both sexes. Because these exaggerated physical or behavioural attributes are interpreted as reliable indicators of a sexual partner’s fitness, they can become runaway evolutionary trends. Elaborate courtship displays and competitive behaviours (nest-building, or choosing and clearing a display arena) are also subject to sexual selection, as are aggressive fights between males to secure one or more females for mating. These sexually selected traits most commonly appear in males, so that females are able to choose between available males, mating only with those that appear to offer the best prospects for successful reproduction, i.e. healthy offspring with good chances of survival. It is something of a paradox that sexual selection can favour traits which are extremely costly (even disadvantageous) to males. Recent mathematical modelling suggests that genes affecting sexual choices may be carried preferentially on the sex chromosomes—with the prediction that the W chromosome in birds might be particularly effective in this respect. The W-linked genes influencing such preferences could spread selfishly among ZW females, even though the ZZ males (which have no W chromosome) might be adversely affected through selection for the exaggerated traits favoured by those preferences (see Muralidhar, 2019; accompanying commentary by Kirkpatrick, 2019). Co-evolution can occur when adaptations in one species have knock-on effects (which may be beneficial or negative) for a second (co-)dependent species, so imposing selection for complementary adaptations in the latter. Arms races between predator and prey offer clear examples of competitive co-evolution. The importance of predation for the evolution of prey species has been demonstrated in both laboratory and field experiments, with clear adaptive changes observable over the course of a few decades or even a few years. One case-study involved guppy populations living in stream pools on the island of Trinidad. In the absence of predation, these fish develop more gaudy or iridescent spot patterns—a sexually selected trait. But in pools that are influenced by introduced predators, these brightly

Speciation

55

marked fish afford too obvious a target, and dull colourations—which are better camouflaged—soon come to predominate in the guppy population (Endler, 1980). This change is accompanied by marked shifts in life-history strategy, depending on which of two predator species was introduced into previously predator-free pools: one predator targetted small and immature guppies, the other large and sexually mature fish (Reznick et al., 1990). Co-evolution of plants and their insect pollinators can lead, inter alia, to deeper flowers and longer insect mouthparts—a trend that may be carried to astonishing extremes. The 30 cm-long spur of the Madagascan Comet Orchid (Angraecum sesquipedale; Fig. 2-11B) conceals nectar at its base, with pollen at the flower mouth; this flower attracts a hawkmoth pollinator (Xanthopan morganii praedicta) with an equally long proboscis, enabling it to pollinate other flowers of the same species after feeding on its nectar. There is, however, a cost: this orchid cannot be fertilised by any other insect—although the hawkmoth does not depend solely on this orchid, as it can also exploit other food resources. This pattern is repeated in many similar cases where one species is highly specialised but its co-evolved partner is more of a generalist. Interestingly, Darwin (1862, pp. 197-203) knew of the orchid but not of the hawkmoth, and correctly predicted that a pollinator with an extraordinarily long proboscis must exist. His suggestion was finally vindicated in 1903, when Lionel Rothschild and Karl Jordan discovered a hawkmoth with these anticipated characteristics. Innumerable further examples of mutual dependency between organisms could be cited; the gigantic flower of the Titan Arum (Fig. 2-11C), transiently emits a stench of rotting flesh (whence its local Edinburgh sobriquet of “New Reekie”!) to attract the carrion flies that will ensure its pollination. Many plants are largely or wholly dependent on symbioses with specific root fungi known as mycorrhizae (recently reviewed by Tedersoo et al., 2020). Orchid seeds contain almost no food or energy reserves, hence they depend entirely on appropriate mycorrhizae in order to germinate. Often, but by no means always, there are clear benefits to both partner organisms in such associations—which are then described as mutualistic. There is often a complex 2-way flow of nutrients (especially nitrogen and phosphorus) between a mature plant and its roots’ mycorrhizal symbionts. For one category of association, namely parasitism, any benefits appear entirely one-sided. Parasites (two examples shown in Fig. 2-11D and E) obviously gain nutrients and a sheltered environment at the host’s expense, while their host suffers mild to debilitating disease—though host immune and other defensive responses will try to eliminate or at least keep the parasites in check. Levels of parasitism in turn affect patterns of host behaviour such as reproductive success and dominance hierarchies

56

Chapter 2

(Barnard & Behnke, 1990). This sets up another kind of arms-race, with the host evolving new immune strategies to control parasite numbers, creating selection pressures on the parasites to evolve more effective ways of countering or evading that immune response. Often the end result is a parasite species that is uniquely adapted to one particular host. Similar arms-races occur between hosts and other pathogens, such as bacteria or viruses. One clear example is provided by rabbits and myxoma viruses (cited in § 2.6), where parallel adaptations to this virus have been reported in geographically separated rabbit populations (Alves et al., 2019).

Figure 2-11. Sexual selection and co-evolution. Part A, Peacock (Pavo cristatus), male tail display. Part B, 30 cm spur of Madagascan Comet Orchid (Angraecum sequipedale), and Part C, Titan Arum (Amorphophallus titanum)—both flowering in hothouses of the Royal Botanic Gardens, Edinburgh. Parts D and E, 2 parasites of wood mouse: tapeworm Taenia parva (strobilocercus stage) in D, and nematode Heligmosomoides bakeri in E. Photographs A-C by author, D and E by courtesy of the copyright holder, Professor Jerzy Behnke of the University of Nottingham.

2.9 Evolution – gradual or jerky? Darwin began the “Origin of Species” (1859/1998, pp. 8-35) with a discussion of natural variation and how it has been exploited through selective breeding during the few thousand years of human agricultural history. His favourite example was the pigeon, but instead I will follow the lead of Steve Jones (2017), and simply point to the many distinct vegetable crops that have originated through selective breeding from Wild Cabbage (Brassica oleracea)—which include cabbage, kale, Brussel sprouts, kohl-rabi, broccoli and cauliflower (see Fig. 2-12, centrefold). Admittedly the selection imposed in each case is through human agency, and in modern plant breeding practice great care is taken in choosing

Speciation

57

particular plants with desirable characteristics (e.g. taste, yield, disease- or pest-resistance) for fertilisation with pollen from other plants possessing either similar or complementary traits. The extent of variation within a species is itself highly variable: all modern breeds of dogs—despite their vast range in size and physique—are ultimately descended from domesticated wolves. Generally, however, the commonest variants in a population will tend to cluster closely around the “typical” form, with greater deviations from that type becoming increasingly rare. Put more succinctly, variation for Darwin is generally small-scale and isotropic, meaning that there is no preferred direction in the types of variation found. Darwin knew nothing of the near-contemporaneous work of Gregor Mendel, who was studying patterns of inheritance for discrete traits among cultivated peas in a monastery garden at Brno (Czech Republic, now Czechia), work which was finally published in 1866 in an obscure local botanical journal (Mendel, 1866). Curiously, a copy of this paper was found, unread (with pages uncut), in Darwin’s library after his death. How different the history of biology might be had he read it! Mendel’s pioneering work was not rediscovered until the early 20th century CE, and even then its relevance to evolution was misinterpreted until much later, when Fisher (1930) showed how gene mutations could generate Darwinian microvariation via Mendelian genetics. Darwin himself favoured gradual evolutionary change through natural selection working on small variations over vast geological time-spans, but many contemporaries and successors doubted whether this would suffice to generate new species, let alone new taxa at order, class, phylum or kingdom level. Mass extinctions (§ 3.4) also disrupt any semblance of smooth progression over evolutionary time. Francis Galton (1889) suggested that new species might often arise from “sports”—that is to say, rare extreme variants which cannot readily interbreed with the type form, and so tend to inbreed among themselves. This model envisages evolution by fits and starts, rather than smooth Darwinian change over time. There are indeed rare genetic mutations that cause radical changes in body structure or life history (§ 4.7, 4.9), but most of these would be eliminated by natural selection. This is especially true for mutations that abolish or disable the activity of an important protein. Although we are only beginning to understand the genetic basis of the structural and functional changes that distinguish different ecotypes or indeed species, there is accumulating evidence that many of the underlying genetic changes may involve regulatory rather than protein-altering mutations. Because enhancers and silencers operate in a modular fashion (§ 1.4)—such that specific regulatory sites act as switches for gene

58

Chapter 2

expression in particular locations or tissues during development—it is relatively easy to modify these expression patterns by adding, deleting or mutating these sites. The functionality of the protein encoded by that gene (whose sequence remains unchanged) and its pattern of expression at other sites would not be affected by such regulatory changes. The case of Pitx1 and the pelvic fin spines of Three-Spine Sticklebacks has been described earlier; further evidence pointing in this direction is adduced in chapter 4. The term sport is used in plant and animal breeding to denote offspring that show particularly unusual features, which in some cases differ quite dramatically from the norm. Such sports are occasionally used by breeders as a basis for developing new varieties, so long as they can breed true. One contributory mechanism here is polyploidy (involving multiple sets of chromosomes), often leading to true-breeding but larger, more vigorous or high-yielding plant varieties. Thus, among modern commercial crops, potatoes are tetraploid (4N), bread-wheat hexaploid (6N) and sugar-cane octaploid (8N), as compared with their diploid (2N) wild ancestors. But in other cases, the underlying cause is a single (usually recessive) mutation that simply has a glaringly obvious effect on the phenotype, such as albinism in flowers (Fig. 2-13A, B; centrefold) or animals, due to a failure in pigment production pathways. Double sets of petals, variegated leaves or changes in plant growth habit also fall into this category, though not necessarily with simple genetics. Fig. 2-13 parts C and D show rayed and rayless variants of the pernicious weed, Ragwort (Jacobaea vulgaris), growing on dunes near Edinburgh. There is in fact a recognised rayless subspecies (J. vulgaris dunensis) that normally grows on dunes in Britain, to which the plant shown in part D could plausibly belong. However, since this was the only rayless plant among thousands carrying typical rayed flowers (part C), I suspect—albeit without any genetic proof—that it may instead have resulted from a spontaneous genetic mutation abolishing ray production. [Presumably, this would also have been true of the dunensis subspecies at some point in its past history]. All of these are small-scale Darwinian variants that just happen to look quite different even to an untutored eye, but they are not incipient new species. Indeed, Darwin gave such sports short shrift at the start of his first chapter on Variation under Domestication (1859/1998, p. 10). Later in this chapter he summarised his own view that small changes act cumulatively over time: “If selection consisted merely in separating some very distinct variety, and breeding from it, the principle would be so obvious as hardly to be worth notice; but its importance consists in the great effect produced by the

Speciation

59

accumulation, during successive generations, of differences absolutely inappreciable by an uneducated eye…”. [Darwin, 1859/1998, p. 27]

A contrary but mistaken view was championed by the Dutch botanist Hugo de Vries, who discovered a species of Evening Primrose (Oenothera lamarckiana, now O. glazioviana; Fig. 2-13E) that readily gave rise to “new species” in a single leap or “saltation” (de Vries, 1905). One of these, which de Vries named O. gigas, was indeed later shown to be a tetraploid, but O. “lamarckiana” itself later turned out to be a permanent interspecies hybrid with chromosomes linked at their ends to form rings, breeding true only in the sense that just half of its seeds are viable. Thus de Vries was misled in basing his non-adaptive model for the origin of new species on a single atypical quirk of nature, which was in no sense a representative example of how new species usually evolve. But this case is not unique, as exemplified in Lamium—a genus incuding several common weeds. Hybridisation between L. purpureum and L. amplexicaule (each 2N = 18; Figs. 2-13F, G) generated the ancestors of L. confertum and L. hybridum (Figs. 2-13H, I)—but these hybrids are polyploid (4N = 36 for L. confertum). This prevents interbreeding with either of the diploid parents, erecting a reproductive barrier that allows the hybrid species to diverge. The critiques of Darwin from Galton, de Vries and others reflect two main concerns. First is the supposed inadequacy of cumulative, small-scale variations to explain major evolutionary shifts, leading to suggestions that rare macromutations or saltations might be needed to generate these larger shifts. Richard Goldschmidt, while conceding that such macromutations would usually have negative effects on fitness (if not outright lethality), nevertheless suggested that a few might occasionally survive as “hopeful monsters”—an ill-chosen phrase that has gravely damaged his reputation ever since. Nearly a century on there is no evidence that such macromutations have contributed significantly to speciation—they would almost always be eliminated as unfit by natural selection. This led Stephen Jay Gould to quip that such monsters might be helpful scientifically, but were hopeless as individuals. In chapter 4 we will look at the functions of Hox genes and the homeodomain TFs they encode; homeotic Hox mutations in Drosophila cause striking transformations of body segments (e.g. an extra pair of wings). At first sight, these resemble Goldschmidt’s “hopeful monsters”— except that their fitness is severely compromised. However, there is still scope for regulatory mutations that subtly alter the location, timing or levels of gene expression without changing the sequence or functionality of the encoded protein. This point is emphasised by Akam (1998a) in his review of Hox genes and their role in segment identity—not as binary selector switches (either one fate or another) as initially envisaged, but

60

Chapter 2

rather allowing for gradual, incremental changes in segment patterning without requiring non-viable “hopeful monsters” as intermediates. Second, the directions of evolutionary change are to some extent channelled or constrained; certain things are simply impossible, because the requisite genetic pathways are not available. Despite the ingenuity of insectivorous plants, they lack the genes required to evolve a functional nervous system or brain. Similarly, animals cannot become photosynthetic, though certain marine species such as corals have “acquired” this ability through symbiotic algae (dinoflagellates) known as zooxanthellae. In fact, there are constraints on permissible directions of change for each taxon, imposed by its genetic resources and mode of development (ontogeny; chapter 4). Both of these underlie its anatomical characteristics, reflecting the genetic and evolutionary history of that group (phylogeny; chapter 3). Two further contentious issues will be addressed in chapter 3: first, the “punctuated equilibria” model of Eldredge and Gould (1972), as well as the contingent effects of mass extinctions on the biosphere; and second, the prevalence of evolutionary convergence, as championed by Simon Conway Morris (2003, 2015). This raises a key metaphysical issue about evolution: how significant are chance (even catastrophic) events—as opposed to predictable trends that result in similar adaptations appearing in distantly related organisms? Chapter 4 will focus on gene expression during animal development, together with evidence from “evo-devo” and the implication of deep homology among highly conserved gene circuits. There is overwhelming evidence that rising levels of atmospheric carbon dioxide (CO2) and other greenhouse gases—generated largely by human industry and transport—are causing rapid global warming and climate change, threatening innumerable species with extinction. However, ecosystems can also be endangered by well-meaning human attempts to mitigate these trends (Turner et al., 2010). We are precipitating a sixth mass extinction, and while opportunistic generalist species may be able to take advantage of this situation (Thomas, 2017), many of the specialist species whose intricate adaptations we so admire are likely to disappear forever. Some may be able to migrate to higher latitudes or altitudes by so-called habitat tracking, but eventually even these options will run out (Hoffmann & Sgro, 2011). In one sense this is hardly new; human hunting may have played a role in the extinction of mammoths and other Ice-Age megafauna, although this factor has been ruled out for African herbivores (Faith et al. 2018) that have disappeared since human ancestors first emerged there. Yet modern threats from poaching and illegal trade in horn and ivory have brought all rhinoceros species to the verge of extinction, and are also

Speciation

61

threatening elephants. Biodiversity has diminished significantly as a result of human activities such as forest clearance and farming, but rates of species loss have accelerated alarmingly in recent years. It is possible to develop landscapes that promote wildlife as well as purely human interests (Kremen & Merenlender, 2018); many advocate vast tree-planting projects across the world as our best hope for sequestering large amounts of CO2 from the atmosphere (Bastin et al., 2019), though there are limitations on the likely effectiveness of this strategy (Anderegg et al., 2020). However, there is still little sign of major international investment in these options. Already, there are signs of adaptive evolutionary changes (genetic, but building on intrinsic phenotypic plasticity) in response to the warming climate—as revealed through long-term studies of a red deer population on the island of Rum off the Scottish west coast, where the mean date for parturition (birth of new fawns) has advanced by 2 weeks over the past 4 decades (Bonnet et al., 2019). Some groups of Hudson Bay polar bears have developed a novel strategy for preying on beluga whales during the ice-free summer months when food is in short supply (BBC1, “Seven Continents, One World; North America”; broadcast December 1st 2019, narrated by Sir David Attenborough). We have come dangerously close to a tipping point where global warming becomes self-reinforcing and thus unstoppable (Steffen et al. 2018). Past mass extinction events will be outlined in the next chapter (§ 3.4), providing a grim foretaste of what we might expect. We will return to this topic in greater depth in chapter 10.

CHAPTER 3 PHYLOGENY AND CONVERGENCE

Summary § 3.1 introduces the first macroscopic fossils, dating from the Ediacaran era (635-540 Ma), most of which remain enigmatic—though fossils from the end of the Ediacaran show affinities with later animal groupings. As oulined in § 3.2, modern animal phyla emerged definitively during the Cambrian explosion starting 540 Ma, though there are some anomalous fossils from this period whose taxonomy is less certain. Essentially all of the body-plans of modern animals—including chordates—can be traced back to the Cambrian. § 3.3 offers a brief sketch of the subsequent fossil history of life on earth, including the colonisation of land. § 3.4 looks at the role of contingency in evolution (as championed by Gould), and in particular at the five mass extinctions that have interrupted the fossil record—each eliminating a large proportion of species (but fewer families or higher taxa). The likely causes of these mass extinctions are also examined, along with possible contributory facors. The topic of convergent evolution is explored in § 3.5, focussing in particular on animal eyes, whose development is initiated in most cases by utilising the same genetic module. The wider significance of convergence (as championed by Conway Morris) is discussed at greater length in § 3.6: were human beings truly inevitable? Lastly, § 3.7 uses lens crystallins to exemplify the re-purposing or co-option (exaptation) of old genes, modules and structures for novel functions during evolution—a process in which gene duplication often plays a key contributory role.

3.1 Precambrian enigmas Twenty kilometres south of Nottingham, at whose senior university I taught zoology for almost 40 years, there rises a range of low hills called Charnwood Forest. Its rolling summits are crowned with fangs of tilted rocks (Fig. 3-1A)—part sedimentary and part volcanic in origin—dating back to the Precambrian era over 560 million years ago (Ma). Until the

Phylogeny and Convergence

63

late 1950s, it was generally believed that such Precambrian sediments were devoid of macrofossils representing the remains of animals or plants, since only stromatolites and similar structures built by microbial or algal mats had been recognised in these and earlier rocks. [The earliest known stromatolites may date back to 3700 Ma; Nutman et al., 2016]. This belief was overturned when three schoolboys, climbing in a Charnwood quarry in 1957, discovered the first unequivocally Precambrian macrofossil, now named Charnia masoni (Fig. 3-1B) after its geographical origin and one of its finders—the future geologist Roger Mason. Similar fossils had earlier been found by Reginald Sprigg in the Ediacara hills of southern Australia, in rocks later dated to the late Precambrian (Spriggina; Fig. 3-1C). These fossils typify the Ediacaran assemblage, an era lasting from 635 to 541 Ma. As a prelude to the Ediacaran era there was a prolonged cold period (the Marinoan glaciation, or “Snowball Earth”), with ice extending even into the tropics. This ended about 635 Ma with a switch to high levels of atmospheric carbon dioxide and a greenhouse climate. There are possible biomarkers (organic compounds) derived from marine sponges in even older rocks, and multicellular fungal microfossils occur in sediments from 800-1000 Ma (Loron et al., 2019; Bonneville et al., 2020), but macrofossils appear only during the Ediacaran. These larger organisms are enigmatic, to say the least. Many are frond-like rangeomorphs (such as Charnia), comprising an axial stem with fractal branching patterns (Fig. 3-1B) and often a basal holdfast. Others, however, appear mat-like, disc-shaped or elongated, and often apparently segmented (e.g. Spriggina; Fig. 3-1C) but lacking appendages. Few of them bear any obvious relationship to extant groups of multicellular animals or plants. One idea suggests that many of these Ediacaran biota were constructed rather like a quilted water mattress, with an outer capsule and internal stiffening with sand (Vendobionts; Seilacher, 2007). These could even have been large, compartmentalised, single-celled protozoa—similar to present-day giant marine protists (e.g. Stannophyllum). Other suggestions include land-based, possibly lichenlike, plants (presumably photosynthetic) growing in or on the soil (Retallack, 2013), though most doubt this interpretation. Dunn et al. (2018) have reviewed the growth patterns evinced by 3 of the major groups of Ediacaran fossil biota, and conclude that they are probably metazoan animals, but cannot be clearly linked to any living animal phyla.

64

Chapter 3

Figure 3-1. Precambrian rocks and fossils. Part A, typical rock outcrop in Charnwood Forest. Leicestershire, UK (author’s photograph). Part B, holotype fossil of Charnia masoni, kept at Leicester New Walk Museum (copyright photograph by permission of Frances Dunn, Alexander Liu and the British Geological Survey). Part C, fossil Spriggina from the Ediacara Hills in S. Australia (photograph copyright Dr Alexander Liu of a specimen kept at the South Australia Museum, Adelaide). Scale bar in B shows 10 cm; that in C shows 1 cm.

The fractal branching patterns of rangeomorphs can be described mathematically as variations on a shared body plan, suggesting that these organisms belonged to a large extinct group (clade) that has no modern counterpart (Hoyal Cuthill & Conway Morris, 2014, 2017). They lived in relatively deep-water benthic environments where light penetration would be insufficient to support photosynthesis—lying on or projecting above the ocean-floor sediment and usually anchored via the holdfast. One puzzling feature of Ediacaran rangeomorphs is that they lack any trace of feeding structures, implying they may have absorbed dissolved organic compounds directly by osmosis from surrounding seawater (osmotrophy), consistent

Phylogeny and Convergence

65

with other evidence that dissolved carbon was plentiful in Precambrian oceans. Moreover, the fractal branching would maximise these organisms’ surface area to facilitate food uptake. If this interpretation is broadly correct, then depletion of such food resources at the end of the Ediacaran era might have contributed to rangeomorph extinction. However, other nutritional scenarios are also plausible, including filter feeding, phagotrophy (essentially, cells engulfing bacteria as food) and ecto- or endo-symbiotic relationships with chemosynthetic bacteria in the sediment. These bacteria might have produced energy by converting toxic sulphides into sulphates in the presence of oxygen, in which case the large surface area of rangeomorphs could have served to absorb both oxygen for and nutrients from these symbiotic bacteria (Dufour & McIlroy, 2016). Rangeomorphs such as Charnia bear a passing resemblance to sea pens (Cnidaria), but true cnidarian fossils occur not only in younger Cambrian rocks, but also perhaps in the late Ediacaran—where Haootia from 560 Ma features fine striations likely to represent muscle fibres (Liu et al., 2016). Other late Ediacaran organisms also display features suggesting affinities with present-day animal groups. Kimberella, for instance, may be related to molluscs, and was able to move and graze on microbial mats using a few teeth on its under-surface—possibly a precursor of the molluscan radula (Ivantsov, 2009). Others include Eoandromeda—perhaps an ancestor of comb jellies (Ctenophora)—and the reef-forming Cloudina, consisting of stacked calcified cones (the first signs of biomineralisation). Cloudina also possessed a through gut, suggesting bilaterian and possibly annelid affinities (Schiffbauer et al., 2020). Other Ediacaran biota remain puzzling—including apparently segmented organisms such as Dickinsonia and Spriggina (Fig. 3-1C) that superficially resemble modern arthropods or annelids, but lack any sign of lateral appendages. Yet Dickinsonia at least was clearly an animal, based on fossil traces of steroid biomarkers (Bobrovskiy et al., 2018). Recently, fossils of a segmented, worm-like, burrowing animal (Ylingia spiciformis; Chen et al., 2019) have been described from the late Ediacaran. Each segment carries 2 backwardpointing lateral lobes, which might be parapodia (suggesting annelid affinities) or even limbs (implying arthropod links). Overall, it is likely that precursors of several modern animal groups appeared in the late Ediacaran (Nama assemblage), along with tell-tale signs of feeding, burrowing and motility. However, by no means all of the claimed assignments to modern phyletic groups stand up to critical scrutiny (Dunn & Liu, 2017), and many Ediacaran fossils remain enigmatic and open to interpretation. Darwin himself conceded that the sudden appearance of animal fossils at the base of the Silurian (= modern Cambrian,

66

Chapter 3

approximately 541 to 488 Ma) poses a puzzle, if not a challenge, to his theory of evolution by natural selection: “Consequently, if my theory be true, it is indisputable that before the lowest Silurian [= Cambrian] stratum was deposited, long periods elapsed….and during those vast, yet quite unknown, periods of time, the world swarmed with living creatures.” (Darwin, 1859/1998, pp. 232-233).

The Ediacaran fossils go some way towards plugging this gap—but arguably they pose more questions than they answer, and for now their antecedents still remain shrouded mystery. Among the more enigmatic Ediacaran anomalies are what appear to be fossilised animal embryos (Hagadorn et al., 2006). However, these fossils can be interpreted in other ways, and it is difficult to account for the absence of any adult or even larval forms. But the picture is changing rapidly; new data have emerged from Siberian riverbank exposures that straddle the Ediacaran/Cambrian boundary. These imply greater continuity than was previously apparent— with some Ediacaran species surviving into the early Cambrian, and clear ancestors of some Cambrian groups already apparent in late Ediacaran strata (see e.g. Zhu et al., 2017; Wood, 2019; Wood et al., 2019). The fuse leading up to the Cambrian explosion (§ 3.2) was lit during the Ediacaran era. But in regard to many of the earlier Ediacaran organisms, one might with some justification quote Dr McCoy (addressing Captain Kirk) from the original Star Trek TV series—“It’s life, Jim, but not as we know it….”

3.2 The Cambrian explosion About 541 Ma there was a sudden diversification of life that is often referred to as the “Cambrian explosion”. Around this time, the “typical” Ediacaran biota became essentially extinct and new groupings of animals proliferated within a relatively brief geological interval. Atmospheric CO2 levels remained high during this transition, but the availability of dissolved carbon may have decreased drastically, and oxygen levels probably increased both in the atmosphere and, rather more patchily, in the ocean— depending on local biotic as well as abiotic factors. Animal characteristics such as motility and active feeding require efficient energy production, which in turn depends on oxygen availability. Thus even a small increase in oxygen levels might have sufficed to promote the evolution of these attributes, which are far more obvious in the early Cambrian than in the Ediacaran (Fox, 2016). Consequences of these developments include telltale signs of disturbance to underwater sediments through the activities of burrowing animals (also apparent during the late Ediacaran). Other factors contributing to the Cambrian explosion included the development of eyes,

Phylogeny and Convergence

67

of specialised mouthparts, and of protective armour, which all bear mute testimony to the evolution of predation—setting in motion countless “ams races” between predators and prey, so leading to more complex food webs (Conway Morris, 1998). Needless to say, the animals that proliferated and diversified during the Cambrian explosion must have sprung from earlier Ediacaran ancestors, and probably many of these were small, soft-bodied, and not readily fossilisable. But as mentioned earlier (§ 3.1), some modern animal phyla do have plausible antecedents among the late Ediacaran biota. The Cambrian explosion is preserved in exquisite detail in several fossil assemblages (technically termed lagerstätten), resulting from burial by fine sediments under anoxic conditions, which delayed decomposition such that even soft-bodied organisms and internal tissues left recognisable traces. Such fossiliferous deposits occur in western Canada (most famously the Burgess shales), but also in Greenland, Utah and China (e.g. Qingjiang; Fu et al., 2019). Thanks to their exceptional preservation, it is possible to reconstruct what these fossils probably looked like in life—and some of them were very strange indeed. Hallucigenia resembled a long-legged caterpillar armed with two dorsal rows of spines; the related Diania cactiformis boasted spiny legs that resembled miniature cacti. Wiwaxia looked rather like a cross between a slug and a small hedgehog, while the related Halkeria featured scales like chain-mail, but with a rounded shell like an inverted saucer at either end. Strangest of all was the giant predator Anomalocaris: a metre-long segmented animal with flexible lateral lobes (probably housing gills) and a fan-shaped tail for swimming, plus large compound eyes with many thousands of ommatidial lenses (Paterson et al., 2011), a pair of grasping anterior appendages resembling ram’s horns, and a circular plate-ringed mouth that was able to constrict and crush prey. The recently described Cambroraster was another sizeable arthropod predator featuring a shield-like carapace (Sokol, 2019). Stephen Jay Gould (1989) has argued that many of these extraordinary animals represent novel body plans (i.e. distinctive phyla) that have since become extinct. On this basis he claimed that if we could “re-run the tape” of evolution from the Cambrian, we might find today’s ecosystems populated by unfamiliar organisms that had descended from a very different selection of those early body-plans, emphasising the role of contingency in evolution. More recent studies of Cambrian fossils (reviewed in Erwin & Valentine, 2013) suggest a rather less extreme interpretation, and it is arguable that most of these Cambrian oddities had affinities with present-day animal phyla. Diania and Hallucigenia were lobopods, probably related to modern onychyphorans (velvet worms); Anomalocaris and Cambroraster were radiodontan arthropods (now extinct), while Wiwaxia and Halkeria were

68

Chapter 3

most likely related to molluscs (cf. Kimberella earlier), but also shared some features with polychaete worms (Annelida) and with brachiopods, according to Conway Morris (1998). These affinities are less surprising now than they would have seemed 30 years ago, when segmentation in annelids was thought to imply kinship with arthropods. DNA sequencing has now placed molluscs, annelids and brachiopods much closer together within a large protostome group called the Lophotrochozoa or Spiralia. The other main protostome group is now termed the Ecdysozoa, because its component phyla (including arthropods, onychyphorans, priapulids and nematodes) mostly undergo some form of moulting or ecdysis during development (Aguinaldo et al., 1997). All of these protostomes differ markedly from the deuterostomes (which include echinoderms and chordates), as defined historically by different embryonic origins for the gut. During gastrulation (§ 4.5), a blastopore is formed by cells migrating into the interior of the blastula; in protostomes this usually gives rise to the mouth, but in deuterostomes it forms the anus. Moreover, the dorso-ventral axis—though established by related genetic mechanisms —is inverted in deuterostome chordates as compared with protostomes. Some modern representatives of these groupings were illustrated in Fig. 27C-H. DNA sequence evidence suggests that the last common ancestor (LCA) of both deuterostomes and protostomes must predate the Ediacaran era (>670 Ma; Erwin & Valentine, 2013). An even more ancient split (>700 Ma) separated these Bilaterian groups from the Radiata (cnidarians; Fig. 2-7B), and one more ancient still (>780 Ma) separated all of these Eumetazoans from sponges (Porifera)—representing the earliest major group of animals—though it is possible that ctenophores split off even earlier (§ 4.12). Since the inferred timing of these splits (Fig. 3-2) predates the appearance of each group in the fossil record, by tens of millions of years, it is likely that their early members were small and soft-bodied, leaving no discernible traces (Cunningham et al., 2016). Such ancestors and transitional forms are likely to have been rare anyway, so the chances of finding their fossil remains are remote. A primitive early Cambrian deuterostome has been described from a 541 Ma lagerstätte in China (Han et al., 2017), though its relationship to later chordates (Fig. 3-3) remains to be clarified. A rough timeline for the emergence of these animal groups is shown in Fig. 3-2, based on molecular-clock estimates of likely divergence times using DNA sequences (§ 1.5), as well as the known fossil record.

Figure 3-2. Early (pre-Ediacaran) emergence of major animal groups. Traditionally, Radiata included ctenophore and cnidarian phyla, but recent genome sequencing suggests that they differ fundamentally from each other and from bilaterian phyla, so ctenophores may represent the most basal branching of the animal tree (dashed line and italici text). Also shown are approximate dates of major geological periods and extinction events up to the end of the Cretaceous (66 Ma). Horizontal placement of major groups is for convenience only, and does not signify relatedness.

Phylogeny and Convergence 69

70

Chapter 3

Although biomarkers characteristic of sponges occur in rocks predating the Marinoan glaciation, putative ancestors of Cnidaria, molluscs and other bilaterians (Dunn & Liu, 2017; Chen et al., 2019) first appear during the late Ediacaran. The subsequent Cambrian era is marked by a proliferation of arthropods, often belonging to groups that have subsequently become extinct. Many Cambrian fossils can reliably be assigned to modern phyla— including priapulids (penis worms; e.g. Louisella), sponges (e.g. Vauxia), polychaete annelids (e.g. Canadia), cnidarians such as sea-pens (e.g. Thaumaptilon), nematomorphs (e.g. Maotianshania), diverse trilobites (e.g. Olenoides), and other arthropods with articulated appendages (e.g. Marrella), as well as chordates with serially repeated muscle blocks and an axial stiffening rod termed the notochord (Conway Morris, 1998). Best-known among these chordates is Pikaia (Fig. 3-3A, B), which is classed as a cephalochordate, related to the modern lancelet or amphioxus (e.g. Branchiostoma); but there are also several primitive Cambrian fish (genuine vertebrates), such as Myllokunmingia or Metaspriggina (Conway Morris & Caron, 2014; Fig. 3-3C, D), as well as urochordate sea squirts (Shankouclava; Chen et al., 2003). In experiments using modern exemplars of both cephalochordates (Branchiostoma) and jawless fish (Lampetra), natural decay processes resulted in a preferential rapid loss of crown-group features characteristic of modern representatives and their direct ancestors. This would systematically bias interpretation of Cambrian fossils towards a stem-group position—typical of extinct ancestral forms possessing only a subset of these diagnostic features (Sansom et al., 2010). Overall, it is evident that chordates diversified considerably during the later Cambrian. Taken together, the Ediacaran (635-541 Ma) and Cambrian (541-488 Ma) periods seem to represent a “test bed” for diverse animal body-plans. Whereas at least one entire clade (the rangeomorphs) disappeared after the Ediacaran, the losses of major arthropod groups during and subsequent to the Cambrian era were most likely at class level. Examples include the radiodonts, which persisted into the early Devonian (~400 Ma), and the trilobites—surviving for 250 million years until the late Permian (Fortey, 2001). Indeed, some surviving animal phyla are represented today by relatively few genera—such as priapulids (which were far more diverse during the Cambrian) and brachiopods (which reached maximum diversity between the Ordovician and Permian eras).

Phylogeny and Convergence

71

Figure 3-3. Cambrian chordates. Parts A and B, the cephalochordate Pikaia gracilens; (B) shows a close-up of the head region. Parts C and D, the primitive fish Metaspriggina walcottii; (D) shows the eyes. All fossils photographed by Prof. J.-B. Caron, and used with permission from the Royal Ontario Museum, © ROM.

3.3 Later evolution of plants and animals Although most modern groups of marine animals are derived from Cambrian ancestors (Bryozoans first appearing in the Ordovician, 488-444 Ma), the invasion of continental land masses by plants (embryophytes) and animals occurred rather later. The earliest plant macrofossil (Cooksonia) dates back to the late Silurian (444-416 Ma), but fossilised cryptospores resembling those of bryophytes (mosses and liverworts) have been found in mid-Ordovician rocks (~470 Ma). Land animals evolved later—with arachnids (scorpions) appearing during the Silurian period, though marine chelicerate ancestors evolved during the Cambrian (Aria & Caron, 2019). Collembolan insects and amphibians (e.g. Elginerpeton) arose during the Devonian (416-359 Ma), while reptiles made their first appearance in the Carboniferous (359-299 Ma). During the Carboniferous period, plant life on land was dominated by swampy forests of giant ferns, clubmosses and horsetails—with evergreen trees (gymnosperms) appearing towards the end of this era. Many insects grew to gigantic sizes, including dragonflies with

Figure 3-4. Appearance of major Arthropod and Chordate groups. Same approximate timescale as Fig. 3-2. Dashed lines indicate related groups without specifying how or when these diverged. Among the Vertebrates (Fish rightwards), solid horizontal lines indicate when different classes split off from their nearest relatives (Amphibian abbreviated to Amph.). Land spiders and scorpions evolved from older marine chelicerates. Similarly, land tetrapods evolved originally from lungfish (Dipnoi), which themselves evolved from lobe-finned fish (surviving today as “living fossil” coelacanths, Latimeria).

72 Chapter 3

Phylogeny and Convergence

73

wingspans of up to 1 metre. Since the size of present-day insects is limited by the ability of their haemolymph (blood) to transport oxygen from spiracles in the outer cuticle to the tissues (especially flight muscles) where it is needed, how then could Carboniferous insects grow so large? At least part of the answer lies in a much higher concentration of oxygen in the atmosphere (over 30%, as compared to 21% today). However, this entailed an environmental cost in terms of frequent forest fires, which have left tell-tale traces in the characteristic Carboniferous coal deposits. Following a catastrophic mass extinction at the end of the Permian era (299-251 Ma), mammals diverged by stages from therapsid reptiles during the Triassic (251-200 Ma), and became a distinctive group by the early Jurassic (200145 Ma). The post-Cambrian appearance and extinction of major groups within the arthropod and chordate phyla is shown in Fig. 3-4 (cf. Fig. 3-2). To summarise, basic animal body-plans (different phyla) seem to have emerged early on, but later evolution has mostly tracked the ecological opportunities offered by new habitats or mass extinctions (often involving major climate change).The fossil record for many taxa provides evidence for rapid increases in diversity during periods of adaptive radiation, e.g. of fish during the Devonian, of insects and non-flowering land plants during the Carboniferous, of dinosaurs during the Jurassic, of flowering plants (angiosperms) during the early Cretaceous (145-66 Ma), and of mammals and birds since the last major mass extinction event 66 Ma, at the end of the Cretaceous. This caused the demise of most dinosaur groups, apart from birds, which had already evolved during the late Jurassic period from theropod dinosaur ancestors—exemplified by Archaeopteryx among others (§ 3.6 and Fig. 3-8 below). In reality, birds are the last surviving dinosaurs! Since the previous chapter was lavishly illustrated with photographs of flowers (see centrefold), it seems only fair to offer at least a token tribute to the astonishing diversity and beauty of fossils (Fig. 3-5). Among those illustrated are fossil representatives of ammonites (extinct shelled cephalopods; Fig. 3-5A), fish (Fig. 3-5B) and crustaceans (Fig. 3-5C), leaf impressions from a redwood and a 300 Ma seed fern (Fig. 3-5D, F), plus a brachiopod and a solitary coral from a shale bed in the Carboniferous limestone of the Yorkshire Dales, UK (Fig. 3-5G, H). Also included is a far more recent fossil clam (mollusc; Fig. 3-5I), along with a Cambrian trilobite (Elatria kingi; Fig. 3-5J), and Ordovician graptolites representing an extinct group of colonial hemichordates (c. 444 Ma; Fig. 3-5K). Finally, Fig. 3-5E shows a spider preserved in amber—which is essentially fossilised resin from an evergreen tree, possibly related to modern pines (gymnosperms). Presumably, this spider became trapped in the sticky

74

Chapter 3

exudate and was engulfed by further accretions of resin, allowing superb preservation. Many other arthropods (especially insects) and even small vertebrates (such as frogs) have been found similarly entombed in amber, although their DNA is seemingly beyond rescue (Penney et al., 2013).

Figure 3-5. The beauty of fossils. Parts A to L, fossil specimen as identified under each panel. Photographs by the author. Scale bars in each panel show 1 cm.

3.4 Contingency and mass extinction in the fossil record The previous chapter referred in passing to the controversial paper of Eldredge and Gould (1972) that postulated punctuated equilibria, as an alternative to gradual Darwinian change resulting from the cumulative effects of natural selection on small-scale isotropic “random” variations. Essentially, the fossil record attests to rather brief bursts (but still on the order of 104-105 years) of rapid evolutionary change and/or diversification, which are followed by long periods of apparent stasis (of the order of 106108 years), during which there is little or no morphological variation in many species. However, there are also instances where a clear sequence of changes can be discerned among fossils of related species in successively younger rock strata, confirming the reality of gradual Darwinian evolution. The relative proportions of these two patterns in the fossil record is a matter of debate—but undoubtedly both occur. Initially, Gould seemed to be arguing for different modes of evolution during the punctuation phases

Phylogeny and Convergence

75

(perhaps involving rapid macromutational or saltational mechanisms?), as compared to the long periods of apparent stasis for many species, which he argued must be maintained in some way against change. These proposals seem at first sight to fly in the face of conventional Darwinian evolution, though in his final magnum opus, Gould (2002) appears to backtrack away from both. The punctuation phases, though real, are sufficiently long as to require no special mode of ultra-rapid evolution. Moreover, they often involve adaptive radiations in the wake of mass extinctions or, more locally, the appearance of new islands or other novel habitats, all of which tend to promote rapid diversification and speciation (chapter 2). As for the maintenance of apparent stasis over long geological periods, this too may be something of an optical illusion. Futuyama (2015) has pointed out that very few changes in phenotypic traits are likely to prove advantageous across a broad range of environmental conditions, whereas a much wider variety of such changes could enhance local adaptation to one or other of several available specialist niches. However, these specialised adaptations may not persist for long enough to engender the reproductive barriers required for eventual speciation—as a result of their interbreeding freely with the parental type or with variants occupying different niches. Unless such novel adaptations become widespread, they are very unlikely to appear in the fossil record as “new” species. As described in chapter 2, so-called “ecological speciation” requires a degree of both spatial and reproductive isolation. Without this, stasis or near-stasis can be maintained, sometimes for astonishingly long periods of time. The two surviving species of coelacanth (Latimeria: Actinistian lobe-finned fish) differ little from their Devonian ancestors 400 Ma. While this is perhaps an extreme example, it underlines the point that species diversification is by no means inevitable. In later life, Gould (2002, pp. 798-802) broadly accepted that an earlier version of Futuyama’s critique could provide a cogent explanation of stasis, and that no further novel mechanisms need be invoked. In retrospect, the hypothesis of punctuated equilibria has perhaps generated more heat than light. Although it describes a pattern in the fossil record that is both real and common, this can be accommodated adequately within the explanatory framework of Darwinian natural selection without major adjustments or special pleading (Futuyama, 2015). A joky summary of the controversy contrasts evolution by jerks against evolution by creeps! Passing reference has also been made to Gould’s earlier book, “Wonderful Life” (1989), in which he argued strongly for the key role of contingency in evolution, based on the (purportedly) haphazard assortment of major animal phyla that have survived from Cambrian times into the present day.

76

Chapter 3

As argued above (and more forcefully by Conway Morris, 1998), this too may be more apparent than real, given that most animal groups in the Cambrian were at least allied to modern phyla—though this may not hold true for the older and more ambiguous Ediacaran biota, whose phyletic affinities remain controversial. Gould, however, held one final trump card to justify his championship of evolutionary contingency—and that is the history of mass extinction events which interrupt the fossil record (Raup & Sepkowski, 1982). In the penultimate chapter of his 2002 book, Gould asks rhetorically how it is possible to defend any notion of evolutionary progression in the face of these rare catastrophes that have wiped out up to 95% of all species. However, this question deserves closer scrutiny—in terms of the extent, causation and time-course of each such event. Broadly speaking, the fossil record attests to five major mass extinctions since the Cambrian (see Figs. 3-2 and 3-4), though up to 15 further but less severe extinctions have been described. At first sight, this entails a retreat from the gradualist views of Lyell (espoused by Darwin) towards a catastrophist view more congenial to creationists. There were probably earlier mass extinctions during the 3 billion-year gap between the first appearances of prokaryotes >3500 Ma and of large multicellular biota (Ediacaran macrofossils dating from ~630 Ma), particularly during the Great Oxygenation Event (2300 Ma) when photosynthetic Cyanobacteria began to produce free oxygen (O2). This element doubtless proved toxic to many anaerobes, but also promoted adaptive radiation of aerobic species. Diversification and increasing complexity among eukaryotes during the Neoproterozoic era (1000-541 Ma) probably co-evolved with rising levels of dissolved oxygen in the deep oceans (Lenton et al., 2014). As to whether a mass extinction demarcated the Ediacaran era from the ensuing Cambrian explosion (§ 3.1, 3.2), the jury remains out. In a recent review, Darroch et al. (2018) suggest a two-pulse extinction: the first at ~550 Ma separated the later Ediacaran Nama fossils (Cambrian-like and metazoandominated) from earlier fossil assemblages (uncertain phyletic affinities), while the second at ~540 Ma marked the start of the Cambrian explosion proper. But arguably it is the first phase that represents the crucial biotic transition. The 5 great mass extinctions since the Cambrian are as follows: i. A double Ordovician-Silurian extinction event 450-440 Ma, when 6070% of all species, 57% of all genera, and 27% of all families disappeared. ii. The Late Devonian series of extinctions from 375-360 Ma, during which >70% of all species, 50% of genera and 19% of families were lost. iii. The massive Permian-Triassic extinction 252 Ma, which eliminated 9095% of all species, 83% of all genera, and 57% of all families. This event saw the final demise of trilobites, but was less severe on land (e.g. among

Phylogeny and Convergence

77

plants; Gastaldo, 2019) than in the oceans. The late Permian era witnessed a major diversification of seed-bearing land plants (Blomenkemper et al., 2018), many of which somehow survived this mass extinction. iv. The Triassic-Jurassic extinction event 201 Ma, which resulted in the disappearance of 70-80% of species, 48% of genera, and 23% of families. v. The Cretaceous-Paleogene (Cretaceous-Tertiary) extinction event 66 Ma —which is undoubtedly the best-known. It was apparently triggered by an asteroid impact (~10 km diameter) at Chicxulub in the Mexican Yucatan peninsula (see e.g. DePalma et al., 2019)—though other near-simultaneous events probably also contributed. Following this, dinosaurs became extinct (except birds), as did the long-established marine ammonites (shelled cephalopod molluscs; Fig. 3-5A), along with 75% of all species, 50% of all genera and 17% of all families. However, the diversity of both dinosaurs and ammonites had already declined during the late Cretaceous period. The first thing to note is that, during each extinction, losses at the level of families are much lower than those for genera, which in turn are lower than those for species. Thus while only 5-40% of species survive a mass extinction, the broader phyletic groups to which they belong show much better survival rates—17 to 50% for genera, and 43 to 83% for families. Total extinctions for even larger taxa (at order, class or phylum level) are rarer still, though important examples are included above in the list of mass extinctions. For comparison, the background rate of extinction between such events is up to 5 families lost per million years for marine taxa. What this all means is that at least some representatives of the majority of phyletic groups manage to survive these mass extinctions. It seems plausible to suggest that flexible generalists are the most likely to survive, while specialist species occupying narrowly defined ecological niches are more likely to succumb. However, the emptying of such niches then becomes a spur for adaptive radiation, such that they are filled fairly rapidly by new species descended from the survivors. During the Triassic, Jurassic and Cretaceous periods when dinosaurs dominated the land fauna, mammals diversified greatly but remained for the most part small in size, supposedly because they could rarely compete directly against their larger reptilian cousins. But there are exceptions—such as the giant late Triassic Lisowicia, an herbivorous “stem mammal” (Sulej & 1LHGĨZLHG]NL 2019). After non-bird dinosaurs died out 66 Ma during the Cretaceous-Paleogene extinction, mammals diversified further and many groups became larger, filling vacant niches or finding new ones. Whales evolved from quadruped amphibious ancestors, one of which crossed South America by land to spread from the Atlantic into the Pacific ocean (Lambert et al., 2019)!

78

Chapter 3

As to the causes of mass extinctions, multiple mechanisms have been inferred. The case for a massive asteroid (bolide) impact 66 Ma is well supported, notably by a thin layer of iridium-rich deposits precisely marking the Cretaceous-Paleogene boundary in many parts of the world. Iridium is far more abundant in some meteorites and asteroids than in the earth’s crust, suggesting that this layer originated from dust blown into the atmosphere immediately after the impact. Whether this event sufficed on its own to exterminate non-avian dinosaurs, along with numerous other species (many marine), is more questionable. Other suggestions include: i. Massive and prolonged volcanic eruptions, creating huge basalt-flood plateaux such as the Deccan Traps in India, which were formed 67-66 Ma. Recent redating of the Deccan Trap eruptions implies that these occurred over a lengthy period preceding the asteroid impact—this last providing the kill factor (Hull et al., 2020). Such eruptions would also have produced vast clouds of dust, cutting off sunlight and cooling the climate, as well as enormous amounts of toxic sulphurous gases and of carbon dioxide. This last would in time have led to climate warming through the greenhouse effect. An even larger basalt flood formed the Siberian Traps 250-251 Ma, coinciding with the Permian-Triassic extinction. One proposal suggests that rare combinations of bolide impact and basalt-flood vulcanism may explain most of the great mass extinctions (White & Saunders, 2005). ii. Rapid falls in sea level and the loss of continental shelves, which could result from global cooling, locking up water in thick ice-caps that reflect back heat from the sun (cf. “Snowball Earth”). Such sea level falls seem to be associated with all five major mass extinction events (Peters, 2008). iii. Sustained and dramatic global warming, which would result in species migrating to more favourable environments (habitat tracking), at least until impassable land or sea barriers were encountered. In warming scenarios, vast releases of methane (CH4)—a potent greenhouse gas—might have further compounded the hothouse effect. This gas is stored in polar regions in shallow marine sediments as methane-water clathrates (4CH4·23H2O), containing methane trapped within ice-like crystalline structures. However, the deglaciation at the end of the last Ice Age did not trigger major releases of stored methane (Dyonisius et al., 2020), so these may not be inevitable. It is likely that at two or more of these factors were involved in each extinction event. Moreover, such factors only triggered a mass extinction following extended periods of environmental stress. Prolonged volcanic eruptions forming basalt floods resulted in pulsed releases of high levels of the toxic metal mercury (Hg) into marine and terrestrial environments (Percival et al., 2017; Meyer et al., 2019; Grasby et al., 2020)—a pattern

Phylogeny and Convergence

79

which seems to precede all five of the major mass extinctions. But other factors may affect only some or even one such event. Deformed fossil spores from the end-Devonian extinction suggest that exposure to intense ultra-violet radiation from a massive hole in the ozone layer (Marshall et al., 2020) was the major kill factor during this terrestrial mass extinction. All of this reinforces the warning from many scientists that the biosphere is now entering a 6th mass extinction triggered by anthropogenic causes— mainly greenhouse gas emissions, plus habitat loss, pollution, intensive agriculture and human overpopulation |(chapter 10). Current extinctions are already well above background rates, perhaps by as much as 1000-fold. Taking a broad view of phyletic diversity since the Cambrian, it is apparent that each mass extinction event represents a major setback for the diversification of species, but even so does not reset the evolutionary clock back to zero. The modern taxa that dominate adaptive radiations in the oceans have themselves been selected through their ability to resist mass extinctions in the past (Knope et al., 2020). As illustrated in Fig. 3-6, the overall direction of evolution (not the same thing as “progress”!) is neither a smooth upward slope (culminating in humankind), nor yet a series of isolated hills cut off from each other by precipitous scarp slopes (mass extinctions), but rather an ascending ridge of ever-higher pinnacles

Figure 3-6. Models of evolutionary directionality. Part A, smooth upward slope; Part B, evolution reset close to its starting point after each mass extinction; Part C, “saw-tooth” model with partial setbacks at each such event. Notches in parts B and C represent losses (at family or genus level) during the major mass extinctions since the Cambrian. Natural landform illustrations are of Salisbury Crags in Edinburgh (UK; part D), two merged profiles from the north side of Arthur’s Seat (Edinburgh; part E), and the Pinnacle Ridge of Sgurr nan Gillean in the Cuillin Hills of Skye, UK (part F). Photographs by the author.

80

Chapter 3

separated by dramatic notches—similar to the “saw-tooth” metaphor used by Richard Dawkins (2004, p. 498). Fig. 3-6A gives a simplistic cartoon of the traditional gradualist view of evolution, and likewise Fig. 3-6B of the catastrophist position, but probably Fig. 3-6C comes closer to reality; local landforms provide vivid illustrations of such profiles (Fig. 3-6D-F). The implication of overall directionality from left to right is misleading; one can legitimately doubt whether mammals today are any better adapted to their environments than were dinosaurs to theirs during the Jurassic and early Cretaceous. Fig. 3-6C as drawn is intended merely to emphasise that a significant fraction of the genetic diversity evolved during each geological epoch (at least at family level) is preserved through each episode of mass extinction. Nor can these extinctions give any crumb of comfort to youngearth creationists, since the time-scales involved—based on stratigraphy and constant decay rates for radioactive isotopes—differ by many orders of magnitude from those implied by or inferred from the Biblical account (as famously calculated by Archbishop James Ussher, 1650/2003).

3.5 Convergent evolution Many adaptations have evolved repeatedly at different times and/or in different groups of animals, plants, or indeed microbes. In the previous chapter, there was passing mention of very similar adaptations for drought resistance among American cacti and in certain Macaronesian and African Euphorbia species. However, Gould (2002, pp. 1068-1089) draws a key distinction between truly convergent evolution (similar endpoints reached from very different starting points and/or by different genetic routes) as opposed to parallel evolution (similar endpoints achieved by re-using essentially the same genetic toolkit). The familiar example of the eye will help to clarify the principles, and highlight some remaining ambiguities. As pointed out by Richard Dawkins (1996, pp. 123-179), eyes have evolved independently ~40 times in virtually every major animal group. Indeed, some unicellular algal protists (dinoflagellates) have light-sensitive ocelloid structures that are clearly convergent with multicellular animal eyes, even though the ocelloid is built from various subcellular organelles that in turn derive from several different prokaryotic endosymbionts (Gavelis et al., 2015). In some cases, animal eyes amount to little more than light-sensitive eye-spots, unable to focus any kind of image. Even so, these would allow the possessor to move towards and/or away from light. Almost every conceivable optical intermediate can be documented in one animal group or another, right up to the sophisticated camera eyes of vertebrates or advanced cephalopod molluscs (squid, octopus, cuttlefish),

Phylogeny and Convergence

81

or indeed the compound ommatidial eyes of arthropods. In all bilaterian animals, the development of eye structures is triggered by activation of the same gene, dubbed Pax-6, which encodes a paired-/homeo-domain transcription factor (1.4; chapter 4) acting as a genetic switch. Loss of function Pax-6 mutants are unable to initiate normal eye development, hence names such as eyeless in Drosophila, Aniridia in humans or Smalleye in mouse (Quiring et al., 1994). Conversely, ectopic activation of wild-type Pax-6 at unusual locations in Drosophila embryos results in the development of supernumerary, yet anatomically normal, eyes at those sites. Remarkably, ectopic eyes are also triggered by Pax-6 genes from an entirely different animal; thus either mouse (Halder et al., 1995) or squid (Tomarev et al., 1997) Pax-6 can initiate eye development in Drosophila. Needless to say, the resultant structures are typical insect eyes rather than vertebrate or cephalopod eyes, because all of the downstream genes activated by the “foreign” Pax-6 protein are those of the host animal, Drosophila. Cases where eye development is initiated by Pax-6 activity should properly be classified as parallel evolution. Pax-6-related genes are expressed during—but do not direct—eye development in more primitive animals such as planarian flatworms, whose eye-spots consist of a cup of sheathing pigment cells and photoreceptive nerve cells (Pineda et al, 2000). However, the similarities between vertebrate and cephalopod eyes (Fig. 3-7) go far beyond the initiating role of Pax-6. In terms of structure, both are remarkably similar, with a transparent lens focussing light onto a layer of specialised photoreceptor cells in the retina, which in turn is enclosed by a layer of pigmented cells that cuts down light reflection within the eye. These genuine anatomical convergences arise from quite different developmental origins. The vast bulk of the vertebrate lens is composed of elongated crystallin-containing fibre cells, which are formed from a skinderived lens placode induced by signals from the underlying optic cup, itself an outgrowth of the embryonic brain. By contrast, the cephalopod lens is acellular, and is formed by closely appressed, elongated outgrowths from the marginal cells surrounding the eye aperture; moreover, the optic placode, which gives rise to the retina as well as the lens, is derived from the epithelium (outer skin) rather than the underlying brain (Koenig et al., 2016). In vertebrate eyes, the outer wall of the neural optic cup becomes pigmented (tapetum) while the inner wall forms a complex multilayered retina—with light-sensitive photoreceptor cells connecting through a layer of amacrine, bipolar and horizontal cells to a third layer of ganglion cells, whose neuronal processes link to the brain. Paradoxically, the vertebrate retina is organised inside out: closest to the lens lie the ganglion cells— connecting mostly to the opposite (contralateral) side of the brain via the

82

Chapter 3

optic nerve—while the photoreceptors (rods and cones) are furthest away and lie adjacent to the pigmented tapetum. Light therefore has to traverse the full thickness of the retina before reaching the photoreceptors, and moreover there is a “blind spot” where the optic nerve exits through the retina. Cephalopods have a more logical optical arrangement, with the photoreceptors positioned closest to the lens; their processes exit through the back of the retina and connect to the optic lobe of the brain. However, the organisation of cells in the cephalopod optic lobe performs a similar processing function to the multiple layers of neural cells in the vertebrate retina. Vertebrate and cephalopod eye structures are outlined in Fig. 3-7. Despite their very different anatomy, the compound eyes of arthropods utilise a similar optical principle; each facet or ommatidium of these eyes consists of an outer light-focussing lens (with 4 cone cells in insects), a sheath of pigment cells and an inner group of photoreceptor cells (8 in Drosophila) wired to the brain. Some extinct trilobites such as Phacops had ommatidial lenses apparently composed of the crystalline mineral calcite, providing excellent visual acuity (Fortey, 2000, pp. 97-102)— though doubt has been cast on this interpretation (Lindgren et al., 2019), based on fossilised insect eyes whose calcification is clearly secondary.

Figure 3-7. Outline of vertebrate and octopus eye structures. Part A, vertebrate eye; Part B, octopus eye. Drawings by the author.

Although vertebrate, cephalopod and arthropod eyes use contrasting developmental mechanisms and tissues to realise convergent design features such as lens, pigmented and photoreceptor elements, these are all

Phylogeny and Convergence

83

initiated through the Pax-6 regulatory pathway, together with a key role for Notch signalling (§ 4.8). This genetic toolkit for making eyes is shared by all bilaterians, suggesting that many apparent convergences among animal eyes should perhaps be re-interpreted as cases of parallel evolution, reflecting so-called “deep homology” in the underlying genetic circuitry for eye development. This view finds support in molecular studies of cephalopod eye development, which confirm the localised expression of several key eye-related genes (previously identified in Drosophila and in vertebrates; Koenig et al., 2016) that act in the Pax-6 and Notch pathways. The composer Anton Bruckner is sometimes said to have composed the same symphony nine times (arguably eleven, if symphonies 0 and 00 are included)—perhaps an unfair aspersion, but not entirely unjustified. Similarly, the claim that eyes have evolved independently as many as 40 times in different animal groups (Dawkins, 1996) may be overstated, if it is indeed the case that many or most of these animal groups utilise a common genetic toolkit driven by Pax-6, which would have been inherited by all of them from their last bilaterian common ancestor back in the Precambrian era. Indeed, Dawkins himself concedes as much in a more recent book (2004, pp. 323-324). Interestingly, nematode worms (very few of which have eyes; but see Burr et al., 2000) nevertheless make use of Pax-6 in the development of non-visual sensory structures, although the functions of this gene in nematodes are complex (Zhang & Emmons, 1995). However, before dismissing convergence in eye evolution as little more than an optical illusion, it is worth noting that some cnidarian groups (particularly box jellyfish belonging to the Cubozoa) possess sophisticated camera-type eyes complete with a retina and lens—though these are connected to a dispersed nerve net rather than a central “brain”, raising questions as to how visual images might be integrated. Underpinning eye development in Cubozoans there is indeed a paired-/homeo-domain transcription factor encoded by a member of the Pax gene family—but this is Pax-B rather than Pax-C, which latter is the closest relative (orthologue) of Pax-6. To make matters even more complex, in another group of eyed jellyfish (belonging to the Hydrozoa), yet a third member of this family (Pax-A) is deployed for the same purpose (Conway Morris, 2015, pp. 97100). Although Pax genes initiate eye development in most animal groups (but not in the eyeless ctenophores and sponges), different members of this family are able to assume this role in some cnidarians, whereas Pax-6 is apparently used for this purpose throughout the Bilateria. Mammalian diversification affords classic case-studies of convergence. Placental eutherian mammals never reached Australia, except for bats and

84

Chapter 3

marine species, or rodents and dingos introduced by humans. This allowed pouched marsupials and a few egg-laying monotremes to diversify and fill ecological niches that are occupied by eutherian species elsewhere in the world—often evolving remarkably convergent traits in the process (§ 3.5). A prime example of this process is the now-extinct thylacine of Tasmania, a marsupial predator that showed striking similarities to wolves. That said, the niche occupied by eutherian antelopes in most parts of the world is filled instead by marsupial kangaroos in Australia—two groups that show contrasting but nonetheless effective “design solutions” for moving fast across plains. Marsupials also diversified greatly in South America, from where they probably colonised Australia via Antarctica (before it became covered by ice). Among South America’s bizarre extinct marsupials was a sabre-toothed-cat-like species (Thylacosmilus atrox), whose dentition and other traits were convergent with those of the more familiar eutherian sabre-toothed tiger (Smilodon fatalis—also extinct), although there were clear differences in the bite and mode of killing prey (Wroe et al., 2013).

3.6 The wider significance of convergence in evolution Simon Conway Morris (2003, 2015) argues strongly that convergence is a very common, if not universal, pattern in evolution, precisely because the “design space” available for providing an effective adaptive solution to any particular environmental or physiological problem is strictly limited. Birds flying at high altitude over major mountain ranges (where the partial pressure of oxygen is low) face a severe challenge in transferring oxygen efficiently to the flight muscles. Certain modifications of the oxygencarrying protein haemoglobin (Į2E2) facilitate this process by increasing its oxygen-binding affinity. The Himalayan bar-headed goose (Anser indicus) has a point mutation in the Į-subunit that removes 2 carbon atoms from an amino-acid side-chain close to the contact-point between Į and E subunits, whereas in the Andean goose (Chloephaga melanoptera) there is a similar but complementary mutation in the E subunit—again removing 2 carbon atoms from a side-chain close to the contact point. By engineering these changes in human haemoglobin expressed in bacteria, the oxygen-binding affinity of this protein can also be vastly increased (Jessen et al., 1991). Likewise, there are relatively few ways in which organisms can sense light or focus an image so that a brain can interpret it. It is therefore hardly surprising that vertebrates and advanced cephalopods have come up with similar design solutions for building efficient eyes. But the convergent traits apparent in these two groups extend far beyond the eye; their heart and circulatory systems show remarkable similarities not found in any other molluscs, and even the functioning of octopus tentacles and suckers

Phylogeny and Convergence

85

bears comparison with that of human arms and hands (Conway Morris, 2015, pp. 11-20). In his 2015 book, and in its 2003 predecessor, Conway Morris documents innumerable case-studies of convergence—only some of which can be explained away as parallel evolution. Some are far from obvious, such as the convergences between human agriculture and leafcutter ants cultivating fungi for food within their nests, a propensity shared with some higher termites (Conway Morris, 2015, pp. 181-188). It is even arguable that the fungal partners of many lichens do something similar, since they are effectively “cultivating” the algal or cyanobacterial component of the symbiotic partnership. Indeed, lichens provide a very clear example of a natural polyphyletic group, since similar symbiotic partnerships have evolved multiple times between many different types of fungi and a smaller range of green algae, a few cyanobacteria and even one marine brown alga; tripartite associations of all three kingdoms are also known (Conway Morris, 2015, pp. 152-153). Modern lichen groups are therefore convergent, rather than sharing a single common ancestor. Descendants of fish evolved limbs and lungs that enabled vertebrates to colonise land—but once there, certain groups of both reptiles (snakes and slow-worms) and amphibians have independently lost their limbs (Conway Morris, 2015, p. 76). Several groups of land crabs have evolved lungs, in addition to structural modifications of the gills used for respiration by their ancestral and modern marine relatives (Conway Morris, 2015, pp. 166-167). Viviparity (where mothers bear live young) and matrotrophy (mother supplying nutrition to the unborn young) are both characteristic of mammals—apart from egg-laying monotremes—but similar adaptations have also evolved in many skinks, snakes, lizards and even sharks, in some cases extending to a functional placenta (Conway Morris, 2015, pp. 215-220). Classic examples of convergence include the curious adaptations needed to exploit a diet of ants—which have evolved independently in spiny anteaters (monotremes) and in numbats and banded anteaters (marsupials), as well as in eutherian pangolins, aardvarks and South American anteaters (Conway Morris, 2015, pp. 51-52, 230-231). Likewise, comparable patterns of streamlining have evolved repeatedly in different animal groups to facilitate rapid movement through water (in certain fish, many marine mammals, extinct ichthyosaurs and plesiosaurs), or indeed through air (e.g. in insects, birds, bats and extinct pterosaurs). In certain avian groups, such as ratites (ostrich, emu, kiwi etc.), multiple lineages became flightless independently via convergent evolution of gene regulatory regions (Sackton et al., 2019), as has also been documented among steamer ducks (Clarke, 2019). The examples cited earlier represent

86

Chapter 3

only a small selection drawn from the encyclopaedic compendium of casestudies presented in Conway Morris’ 2015 book—many unfamiliar even to zoologists. Whether or not one agrees with his underlying thesis, Conway Morris provides an eye-opening overview attesting to the frequency of convergence. However, this is by no means universal. Losos (2017, pp. 101-107) points to several dissimilar adaptations for extracting grubs from wood—utilising divergent bill designs in woodpeckers, in the extinct New Zealand huia and Hawaiian ‘Akapola‘ao (both birds), in the Galapagos woodpecker finch (which uses a carefully chosen stick held in an otherwise unremarkable beak to extract grubs) and—oddest of all—the extraordinary elongated middle finger of the Madagascan aye-aye (a primate lemur). The evolution of flight shows both convergence—since the laws of aerodynamics must always be taken into account—but also astonishing divergence, since several exotic pathways have been explored, though not necessarily pursued. Archaeopteryx from 150 Ma is “the” transition fossil par excellence—with its reptilian teeth, clawed wing digits and a long bony tail, combined with pennaceous feathers and wings suggesting that it could fly, at least for limited distances. But it was by no means alone, as demonstrated by a treasure-trove of Chinese fossils documenting the transition from theropod dinosaurs to modern birds (Brusatte, 2017). Fig. 3-8 illustrates 2 other fossils that had also evolved both flight and feathers. Microraptor (~120 Ma; Fig. 3-8A) shows that some birds experimented with 4 wings rather than 2, as it featured flight feathers on both fore- and hind-limbs as well as long tail feathers. Other theropods, such as 160 Ma Ambopteryx (Wang et al., 2019) and Yi qi (Fig. 3-8B) experimented with membranous wings that were similar in design and convergent with those of mammalian bats or extinct pterosaurs—but they also featured a unique elongated styliform element (modified wrist bone), as well as non-flight feathers covering the body. The skeletal elements that support the wing membrane also differ in several respects between bats and pterosaurs, pointing to a functional rather than structural convergence of wing design. Despite mass extinctions, the evolution of many adaptations is largely predictable in general terms, because these represent the most efficient design solutions available. In Conway Morris’ (2003) view, the evolution of conscious, bipedal beings with large brains and clever hands might be almost inevitable on a benign planet such as our own—so we could expect to encounter similar characteristics among intelligent aliens elsewhere in the universe. If true, this inevitable emergence of humanoid intelligent life could be reconciled with a non-interventionist creator God—whose purposes in creation would thereby be fulfilled, even through the painful saw-tooth

Phylogeny and Convergence

87

Figure 3-8. Two roads not pursued—from dinosaurs to birds. Key features of each fossil noted below the panels. Both images photographed by the author from the first public exhibition of these fossils in the West at Wollaton Hall, Nottingham (1st July-29th October 2017). Bars show 10 cm.

process of evolution. For my part, I am less sanguine that evolution can so easily escape the snares of Gouldian contingency; major groups of animals have indeed perished during the five mass extinctions (e.g. dinosaurs,

88

Chapter 3

ammonites and trilobites), and nothing guaranteed that the mammalian great ape lineage (from which we originate) would be immune to accidental extinction before our culture had a chance to develop. That said, the marine taxa that diversified to dominate modern ocean environments, have been able to so in part through their ability to resist past extinctions (Knope et al., 2020). Equally, I am unconvinced that humans were truly inevitable, since we remain an unparalleled species on this planet. Humans evolved among eutherians, but not among marsupials—despite numerous other convergences between these mammalian groups. There is scant evidence that dinosaurs ever evolved high intelligence, let alone a transmissible culture, yet they dominated the Jurassic and Cretaceous eras for far longer than modern mammals since. The same goes for Conway Morris’ prime invertebrate example, the octopus (2015, pp. 11-20). Although these cephalopod molluscs are undoubtedly intelligent—showing evidence of personality, playfulness, problem-solving and even a form of tool-use, not to mention their astonishing visual communication and camouflage abilities—there is still no evidence for advanced culture; perhaps this is a limitation imposed by their short lifespans. Much the same can be said of whales, dolphins or porpoises among marine mammals, whose webbed flippers could hardly be used to manufacture or use tools, severely restricting any potential for technological development. As for intelligent aliens, who knows what forms might prove adaptive in response to very different planetary environments? My first foray into science fiction was reading Hal Clements’ classic hard-SF novel “Mission of Gravity” (1955/1976), featuring small but intelligent caterpillar-like organisms with clasping pincers, adapted to the extreme gravity at one pole of the gigantic discus-shaped planet Mesklin. Despite an impressive multiplicity of evolutionary convergences documented with great clarity by Conway Morris, I am unpersuaded that the course of evolution is largely, let alone entirely, predictable. Sometimes concatenations of chance events combine to produce something wholly unanticipated, such as Homo sapiens (chapter 5). Nevertheless, it remains true that if a good design solution emerges in one group of organisms, it will very likely re-emerge convergently in another—often multiple times. Richard Dawkins (2004, pp. 489-493) found himself hard-pressed to find examples of unique adaptations that had arisen only once during the course of evolution. Even so, there are species (e.g. the marsupial koala or monotreme platypus) and whole taxa (e.g. eutherian pachyderms: elephants, mammoths, mastodons) that have no convergent parallels elsewhere in the animal kingdom (Losos, 2017, pp. 18-20). However, many of the platypus’ characteristic traits—

Phylogeny and Convergence

89

such as its bill, webbed feet, tail and watertight pelt—have also evolved in other animals; it is their combination that is wholly unique (ibid., p. 328). Gould’s (1989) thought experiment of “replaying the tape of life” can now be realised, using computer modelling based on known evolutionary data (Blount et al., 2018). The outcomes suggest a combination of both contingency and convergence, but neither on its own explains everything. Losos (2017, pp. 57-79) notes that groups of islands which offer broadly similar habitat choices provide a laboratory in which the “tape of evolution” is replayed naturally. On the Caribbean Greater Antilles islands, endemic anole lizards exhibit four characteristic species-types on each island, but these did not arise from four separate invasions by the ancestors of each type. DNA sequence data instead imply a single anole ancestor arriving on each island, then diversifying in remarkably similar ways, such that the four species types on Jamaica (for example) are more closely related to each other genetically than they are to morphologically similar species on the other islands. In this case (and others, such as snails on the Japanese Ogasawara islands), an entire adaptive radiation has effectively been replicated several times over. Adaptive evolution has been demonstrated under laboratory conditions in E. coli bacteria (Tenaillon et al., 2016) over a 35-year period encompassing some 66,000 generations. For the most part, the 12 replicated cultures—growing in a medium where glucose is limiting—have adapted in parallel, convergent ways. However, in a single culture, an unusual combination of mutations arose that allowed mutant cells to metabolise citrate (itself non-limiting in the medium used) as a carbon source and thus overgrow the other cells (Blount et al., 2008). This is a clear example of contingency among the prevalent convergence.

3.7 Co-option for novel functions Before leaving the topic of eyes, lens crystallin proteins provide an excellent illustration of another instructive aspect of evolution, namely the co-option (exaptation in Gould’s terminology) of pre-existing elements for new purposes. Eye lenses are able to focus light thanks to a high refractive index, which in turn necessitates elevated intracellular concentrations of soluble proteins within the fibre cells. These lens proteins need to remain transparent even when packed very closely together in a near-crystalline array (hence the name), but without aggregating and precipitating out of solution—which would cause the opacities known as cataracts. The Įcrystallins, one of the major groups of lens proteins in all vertebrates, are related in sequence to small heat-shock proteins, whose function is precisely to inhibit protein aggregation following physical or chemical

90

Chapter 3

stress. Rather less obvious is the role of the large į-crystallin, which is the predominant lens protein in birds and reptiles. This is similar or identical in sequence to a urea-cycle enzyme, argininosuccinate lyase (ASL)—a protein normally expressed in a wide range of tissues, though it is less used in uricotelic birds that excrete nitrogen mainly as uric acid. In chickens and ducks this gene has been duplicated, with the į gene encoding ASL while į encodes a lens-specific crystallin that has lost its ancestral ASL activity. In ducks, both į genes are expressed at elevated levels in the lens (which shows high ASL enzyme activity), whereas in chickens the į gene is shut down in the lens and only į is active. Interestingly, it seems that this dual function probably emerged before gene duplication (Piatigorsky & Wistow, 1991; Piatigorsky, 1993). Embryonic chick retina cells express low levels of $6/į but when they are grown in cell culture they can convert into lens cells, a process of transdifferentiation that activates the neighbouring į gene to much higher levels of expression (de Pomerai et al., 1991). This įį example also illustrates how duplicated genes can diverge functionally, one copy į retaining its ancestral function (here ASL) while the other is able to accumulate genetic changes resulting in altered functionality (in the case of į losing its ASL activity). A different enzyme, lactate dehydrogenase B, is utilised as the İ-crystallin in many avian lenses, where its level of protein expression correlates closely with exposure to light—suggesting that in this case the enzyme activity may serve to protect against oxidation (a frequent cause of cataract formation). Finally, the main squid lens S-crystallin is related in sequence to another stress-response enzyme, glutathione-S-transferase (GST). Presumably such proteins were recruited for high-level expression in lens fibres in part because of their ability to maintain solubility and transparency at vastly higher protein concentrations than those encountered in other cell-types. Though lens crystallins are anything but convergent, the photoreceptor visual proteins (opsins) responsible for light sensitivity are very similar in all animals. The opsins are G protein-coupled 7-transmembrane receptors (GPCRs) linked through a lysine side-chain to retinal—a vitamin A derivative that is photo-bleached on exposure to light. Different opsins are sensitive to different wavelengths of light, and these retinal-linked opsins are highly concentrated in the stacked membrane systems of photoreceptor cells (e.g. rods and cones). Though most cave-dwelling fish have vestigial eyes, deep-ocean fish living far below the zone where sunlight penetrates retain large eyes and an acute sense of vision. Several such fish possess multiple opsin genes (one as many as 38), and these opsins have evolved to detect extremely faint blue or green wavelengths from bioluminescent prey (Musilova et al., 2019). Genomic analysis of a Cubozoan jellyfish

Phylogeny and Convergence

91

reveals at least 18 opsin genes, a minority of which encode typical GPCRs (Liegertová et al., 2015). Many bacteria (including some Archaea) are also sensitive to light, but this is mediated through bacteriorhodopsin—a rather different type of 7-transmembrane receptor that is also linked to retinal but is not G protein-coupled, and that functions as a light-driven proton pump. Moreover, the dinoflagellate light-sensitive ocelloid mentioned earlier also expresses a type of rhodopsin related to bacteriorhodopsin (Hayakawa et al., 2015). Thus opsin-type light-sensitive proteins are partly convergent in function, whilst also showing evidence of deep homology. Although evolutionary convergence seems to imply a repeated reinvention of the wheel, deep homology suggests that the “recipe” for wheel-making may be part of the genetic repertoire of many, most or even all living organisms. However, this same recipe can also be co-opted for different purposes in some groups, or re-utilised in others for making different wheel designs out of similar, overlapping or even dissimilar materials. Strikingly similar adaptations among the forelimbs of different flying vertebrates (e.g. wings in birds, bats or pterosaurs) must have arisen through changes in the regulation and deployment of essentially the same set of pattern-forming and executive genes—which on Gould’s definition would count as parallel evolution. Even so, the flight feathers of birds represent a unique adaptation of pre-existing keratinous outgrowths from the skin (they are homologous to reptilian scales and mammalian hair)— characterised by extreme lightness and astonishing biomechanical subtlety (Matloff et al., 2020), This design solution differs fundamentally from that provided by the wing membranes in bats, Ambopteryx/Yi qi and pterosaurs —using slightly different skeletal arrangements in each. These adaptations all result from tinkering in various ways with the same basic genetic toolkit. Natural selection ensures that even small “design improvements” from beneficial mutations will be favoured, whereas disadvantageous changes are unlikely to persist, and neutral mutations will fail to spread unless favoured by chance in small isolated populations Shared genetic pathways (e.g the role of Pax-6 in eye development) underlying parallel evolution are best explained in terms of deep homology, which can be traced back—in this case at least—to the last common ancestor of all bilaterian animals. The case-studies cited in these last two sections open up the theme of developmental biology in the context of evolution— commonly abbreviated as evo-devo—which is the topic of the next chapter.

CHAPTER 4 EVOLUTION AND DEVELOPMENT

Summary § 4.1 tells of my own fascination with the question of how genes direct embryonic development, together with its implications for our understanding of evolution—evo-devo for short. § 4.2 recalls salient features of eukaryotic gene control (§ 1.4), plus an outline of cellular signalling. § 4.3 sketches how genes can affect developmental processes in evolution. The first stage of embryogenesis (called cleavage) forms a blastula, as described in § 4.4. Variants of this depend on the amount and distribution of yolk in the egg; mosaic development entails a direct mappng of cell groups in the blastula onto tissues in the future embryo. § 4.5 describes regulative development, allowing compensation for missing pattern elements in early embryos; this section also outlines gastrulation, when embryos become 2- or 3-layered. In § 4.6, the significance of serial repetition is discussed, as a way of building organisms out of repeated (metameric) units. This leads into § 4.7, which describes how homeotic Hox genes help to establish differences between successive metameres (initially as parasegments) in fruit-fly embryos. § 4.8 outlines how this metameric pattern is set up in the first place, while § 4.9 looks in greater detail at Hox gene functions in arthropods. § 4.10 draws comparisons with two other segmented phyla— chordates and annelids—in terms of the roles of related (orthologous) Hox and patterning genes. In § 4.11, the formation of primary body axes is compared across animal groups. § 4.12 discusses the importance of deep homology in evo-devo, outlining where phylogenetic relationships are being reassessed in the light of genomic data.

4.1 A personal story of evo-devo It is over 50 years since I resolved to study molecular biology. This decision greatly simplified my choice of university, because at that time the only UK Honours course in the subject was at the University of Edinburgh—a city to which I returned as a postdoc and very much later in

Evolution and Development

93

retirement. With good school grades at A-level, I was able to skip the first year of a 4-year course, but my initial exposure to molecular biology still had to wait a full year. It was brilliantly taught—by, amongst others, Ken Murray, Bill Hayes and Martin Pollock—but confined itself almost entirely to bacteria. The structure of DNA, replication, transcription and translation, plus the Jacob-Monod model of gene regulation (chapter 1)— everything was beautifully clear and detailed. But somehow it seemed to lack a sense of challenge, as though all of the questions worth asking had already been investigated and answered, leaving only a few i’s to dot and t’s to cross. In retrospect, I realise how wrong I was, and perhaps if I had stayed with my original Honours specialisation through to my final year, I might have discovered some unanticipated question-marks. However, during my second year at Edinburgh I had also taken an extra elective subsidiary in Epigenetics, taught by a sub-department within the Institute of Animal Genetics. Their core interest was in how genes direct animal development—a subject about which little was known back in 1970, though speculative ideas abounded, and tools were just beginning to be developed to address some of the unsolved questions. Fatefully I decided to change my Honours specialisation, and hence my final year was devoted solely to Epigenetics. That sub-department was headed by Professor Conrad Waddington— an eminent embryologist and geneticist—whose somewhat quirky ideas on canalisation of development proved uncannily prescient. In fact, “Wad” had pretty much retired by the time I joined, and most of the teaching was conducted by Des (strictly D.E.S.) Truman and Ian Campbell. However, “Wad” had gathered a remarkable constellation of rising stars under his wing, all of whom contributed lectures and seminars on cutting-edge topics within their own specialisms. There was Max Birnstiel, who had already isolated Xenopus ribosomal genes (rDNA) on the basis of their higher GC content—allowing them to be separated from the rest of the DNA by ultracentrifugation—and was gunning for sea-urchin histone genes. There was John O. Bishop, one of the pioneers of RNA-DNA hybridisation, who calculated that even specialised cells express of the order of 8-10,000 genes—an estimate which seemed improbably high at the time, but proved remarkably accurate. There was also Ken Jones, who helped develop in situ hybridisation, allowing researchers armed with a radioactively-labelled mRNA to visualise where the corresponding gene was being expressed. Last but not least, Ruth Clayton’s studies on all aspects of chick eye development later lured me back to Edinburgh to pursue a postdoc. Truth to tell, the lustre of Epigenetics was somewhat tarnished by the midseventies, compared to its heyday just a few years earlier; Max had moved

94

Chapter 4

back to Switzerland, and by then the truly cutting-edge research was being pursued over in Zoology by figures such as Ed Southern (of blot fame) and future Nobel laureate Paul Nurse (working on cell-cycle genes in yeast). In any case, biology was revolutionised during the late seventies by the advent of genetic engineering, allowing DNA from higher organisms to be “cloned” in bacterial plasmids, such that bulk quantities of specific genes at last became available for analysis. Among the earliest discoveries of this new molecular biology was the fact that the majority of eukaryotic genes are split by introns, which in turn led to the elucidation of RNA splicing (§ 1.4). Meanwhile, elegant studies by Roger Kornberg and others had established nucleosomes as fundamental repeating units in chromatin. Techniques for rapid sequencing of DNA molecules were also devised in the 1970s by Fred Sanger and colleagues. For this achievement Sanger was awarded the 1980 Nobel Prize in Chemistry—along with Paul Berg and Walter Gilbert—having previously won the same prize (solo) in 1958 for his earlier work on protein sequencing. By the time I came to write the first edition of my textbook “From Gene to Animal” (1985), the outlines of eukaryotic molecular biology were far clearer than a decade earlier, and attention had shifted to the problem that so fascinated me as a student: how do genes direct the process of animal development? But in some respects my book was premature, since antibody staining and in situ hybridisation techniques were only just beginning to reveal intriguing expression patterns for important regulatory genes during embryonic development. More timely was the second edition five years later (1990), by which time the ubiquity and significance of these patterns was wellestablished, and an appreciation of their evolutionary significance was developing into the new sub-discipline of evolution and development— evo-devo for short. This is the core topic to be addressed in this chapter.

4.2 Molecular strategies used in animal development It is worth recalling here some of the key features of gene regulation that characterise higher eukaryotes, particularly animals (§ 1.4). (i) Modular control of gene expression through multiple enhancer or silencer sites in the DNA, which are recognised by specific transcription factors (TFs). These regulatory sequences occur scattered across extensive flanking regions of DNA, lying mainly upstream but also within or downstream of the protein-coding gene whose expression they regulate. This constellation of sites allows precise control of gene expression levels.

Evolution and Development

95

(ii) TFs usually bind to relatively short (6 to 20-base pair) core recognition sequences within an enhancer or silencer, through the TF’s DNA-binding domain(s). Slight changes in this core sequence, or in additional sequences flanking it, greatly influence the TF’s binding affinity (strong or weak) for that particular site. Each TF in turn binds through its so-called activation domain to TBP and other proteins bound to the promoter near the start site of a structural gene, thereby influencing the initiation rate for pre-mRNA transcription. Dynamic interactions, involving numerous TFs bound to multiple modular enhancers or silencers, act together to provide greater or lesser regulatory inputs into the final integrated pattern of gene expression. (iii) Because the core recognition sequences are short, but occur scattered across a wide region of regulatory DNA, they can readily be inactivated, changed (perhaps thereby binding a different TF) or even created de novo through mutation. Altered gene-expression patterns, that affect neither the protein’s sequence nor function, can allow diversification of ecotypes (as seen for Pitx1 in Three-Spine Sticklebacks; § 2.5), and probably of species. (iv) Further subtleties in the regulation of eukaryotic gene expression arise from alterations in chromatin architecture, alternative mRNA splicing, mRNA export and translation—as well as post-translational modifications (phosphorylation, dephosphorylation, acetylation, methylation etc.) that result in the activation or inactivation of the final protein product. (v) Duplication of genes (or whole genomes) can lead to diversification of function, as outlined in more detail later in this chapter. Often one copy retains its original function, while the other is co-opted for novel functions through alterations in sequence, or else in the timing, location or level of expression, as seen earlier for chick $6/į and į crystallin genes (§ 3.7). Beyond this, there are additional complexities specific to multicellular animals (and plants), whose development is the main focus of this chapter. (vi) Cells need to “know” their position in relation to the whole developing organism, but additionally they can influence what neighbouring cells are doing or adjust their own activities in response to their immediate or longrange environment. This introduces the topic of intercellular signalling between cells, and the concomitant process of intracellular signalling within an individual cell; both aspects are outlined very briefly below. (vii) Several components are typically involved in intercellular signalling. The signal itself is normally a secreted or cell-surface ligand molecule

96

Chapter 4

(often a protein) emitted by the signalling cell or tissue. Such signals are received by a transmembrane receptor protein on the surface of recipient cells. Receptors bind or respond to ligands through an extracellular ligandbinding domain. This in turn usually activates a kinase phosphorylation domain, located at the intracellular end of the same receptor protein, or sometimes on a different protein within the cell-surface receptor complex. (viii) This receptor kinase domain then initiates an intracellular signal transduction pathway, often involving a series of further kinase enzymes, each of which activates the next in the chain by attaching phosphate groups (phosphorylation), culminating in the activation or inactivation of nuclear TFs through phosphorylation. In this way, the activity of genes in the nucleus becomes responsive to external signals, including cell position in an embryo. Specific phosphatases later remove these phosphate groups. (ix) Sometimes this signalling pathway is radically compressed. Steroid hormones, for instance, are fat-soluble ligand molecules that can readily diffuse through lipid bilayer membranes and so gain entry into cells. Once inside, they bind to cytoplasmic (or sometimes nuclear) steroid receptor proteins, which are thereby activated to become DNA-binding TFs in their own right, directly inducing (up-regulating) and/or repressing (downregulating) sets of target genes through specific DNA recognition elements within the enhancer or silencer regions of those steroid-responsive genes. Ligand binding may also release part of the receptor itself to act as a TF. In these and similar ways, whole sets of target genes respond co-ordinately to ligand signals acting at different times and places during development. Finally, (x) although different organisms develop a bewildering variety of forms and structures, they achieve this in remarkably parsimonious ways. One strategy is through the use of serially reiterated structures—such as arthropod segments, or the vertebrae that give vertebrates their name—as outlined in § 4.6 below. But at a molecular level, animal development uses quite a limited repertoire of important regulatory genes and signalling pathways, which are reutilised repeatedly in different contexts to build diverse structures. Later in this chapter, the spotlight will turn to one group of such genes, encoding homeodomain TFs (Hox genes) involved in anterior/posterior regionalisation. Sequence conservation among the genes that direct key developmental processes in distantly related animals, which often diverged hundreds of millions of years ago, gives insight into genetic circuits likely to have been present in their last common ancestor (LCA).

Evolution and Development

97

4.3 How genes can participate in evolutionary change One simplistic view of gene mutation is that it leads to an altered protein product, known as heterotypy. But this is by no means the only possibility: others include (i) changes in the timing of gene expression (heterochrony), as seen for instance in cases of neoteny (§ 2.7); (ii) altered spatial patterns of gene and/or protein expression (heterotopy), as for example in the case of Pitx1 cited earlier (§ 2.5); or (iii) altered amounts of gene expression (heterometry). Changes in gene expression at one, some or all of these levels can have significant effects on an organism’s phenotype, and if these then impact on its survival or reproductive success, they can provide raw material for natural selection to act on. One example is provided by Darwin’s “finches” of the Galapagos Islands (§ 2.2), whose beak morphologies are affected by changes in both the amount and timing of expression of a key extracellular protein ligand known as BMP4 (Bone Morphogenetic Protein 4), and by changes in the amount of the calciumbinding protein calmodulin. The more strongly BMP4 is expressed, the larger and stronger the beak—while the more strongly calmodulin is expressed, the longer the beak (see Wagner et al., 2007, pp. 923-924). As a consequence of partial or complete duplication of chromosomes or even whole genomes, individual genes or gene regions may be present in two or more copies in an organism’s genome. There is evidence (to be reviewed later in the context of Hox genes) that vertebrate genomes have undergone two rounds of genome duplication relative to more primitive chordates, and bony fish (teleosts) perhaps as many as three rounds. Once two copies of a gene are available, they can pursue separate evolutionary paths. Commonly, one copy retains the original role of that gene while the other acquires new functions (neofunctionalisation). Some genes may have multiple functions—often carried out by different domains of the protein product—say for example A, B and C. After duplication, these can become separated such that each gene copy retains only a subset of the initial functions: say B alone from one copy, while the other retains A and C but loses B (subfunctionalisation). The converse process also occurs, whereby genes acquire additional exons encoding extra protein domains that may confer new functions. Alternatively, one gene copy may remain functional while the other is inactivated as a non-expressed pseudogene, or even lost.

4.4 Oogenesis, cleavage and mosaic development Development in sexually reproducing multicellular organisms begins with a single fertilised egg or zygote following fertilisation. But an important

98

Chapter 4

prelude to this is the development of parental eggs and sperm (gametogenesis), as described briefly below. Each unique new genetic identity is created by the fusion of two haploid nuclei, one from a male gamete (sperm cell or pollen grain) while the other remains within the female gamete or egg (ovum or ovule). This has an important consequence for early development, because essentially all of the cytoplasm of the large zygote cell comes from the egg, while the male gamete contributes virtually nothing apart from a haploid nucleus. In most animals (aside from mammals, or viviparous forms in other groups), nutrition of the developing embryo depends entirely on nutrients synthesised by the mother and stored in each of her eggs—mainly in the form of yolk (also egg white in birds). This would impose a heavy demand on the female egg-producing organs (ovaries), so often this task is delegated to other organ systems—such as the liver in vertebrates (where expression of yolk-protein genes is controlled by oestrogens), intestine in nematodes, or fat-body in insects. Similarly, egg-white proteins in birds are secreted by the oviduct (again under oestrogen control) and laid down around the yolk before the calcareous shell is added prior to laying. Over and above these nutritional reserves, animal eggs also provide all of the mitochondria to the developing embryo, hence the inheritance of mitochondrial DNA is strictly maternal, and the mother’s genotype dictates the mitochondrial traits expressed in all her offspring. Nor is this limited to mitochondria, since large amounts of mRNAs and proteins are synthesised from the mother’s genes during egg development (oogenesis), and these direct many early events occuring during embryogenesis, sometimes determining important features of the developing organism. These maternal mRNAs often remain untranslated during oogenesis and in quiescent unfertilised eggs, but their translation is activated following fertilisation. One major class of maternal mRNAs encodes the histones—needed in vast quantities for chromatin assembly during the rapid cell divisions of early development. Large amounts of ribosomes and other materials for protein synthesis are stockpiled in the egg, ready for deployment after fertilisation. One classic example of maternal inheritance involves the direction of shell coiling (chirality) in gastropod molluscs, as studied originally in the pond snail Lymnaea. Right-handed (dextral) coiling is specified by the dominant D gene, while left-handed (sinistral) coiling is determined by a recessive allele, d. However, in crosses between pure-breeding male dextral (D/D) and female sinistral (d/d) lines, the F1 offspring (genotype Dd) all coil to the left in accordance with their mother’s d/d genotype. Only in the second generation (F2, after selfing) do all offspring show the expected right-handed dominant coiling trait, again reflecting the mothers’

Evolution and Development

99

heterozygous Dd genotype. After selfing again, it is only in the third (F3) generation that the expected Mendelian F2 ratios (§ 1.6) are revealed— with one-quarter pure-breeding dextral (DD), one-half heterozygous dextral (Dd), and one-quarter pure-breeding sinistral (dd). The inheritance pattern for shell-coiling therefore lags one generation behind the genotype, because it is the mother’s genes that direct shell coiling in all her offspring (Boycott et al., 1931). At first sight this is rather surprising, since the shell appears quite late in snail development—but in fact its direction of coiling reflects a much earlier pattern of spiral displacement between tiers of cells in the early embryo. The “D” gene responsible for chirality in Lymnaea has finally been identified as Ls-dia1 (Abe & Kuroda, 2019), encoding a formin that acts at the 1-cell stage to generate asymmetry, a trait which influences later expression of Nodal (§ 4.11). The phenotypes of patterning genes that act early in development often show such maternal inheritance, while influences from the paternal genes only become apparent during later development (earlier in mammalian embryos with few maternal reserves). The first stage of embryonic development in animals is called cleavage, during which the huge zygote cell (fertilised egg) becomes subdivided into much smaller average-sized cells (Fig. 4-1A left and Bi). Cleavage may be slowed down by large amounts of yolk (e.g. in frogs; Fig. 4-1Bii), and in extreme cases the yolk mass may not become cleaved at all. In most animals, the cleavage stage is characterised by rapid DNA synthesis and cell division, and it is not until mid- to late cleavage that the embryo’s own zygotic genome starts to be expressed, and paternal genes begin to influence development. This is the maternal to zygotic transition (MZT), and in some cases it involves wholesale inactivation or destruction of maternal mRNAs. The end-product of cleavage is usually a hollow ball of cells (blastomeres; Fig. 4-1Bi, ii) termed a blastula. Variants include a layer of cells (blastoderm; Fig. 4-1Biii) surrounding a central yolk mass in many insects; a discoid cap of cells (blastodisc; Fig. 4-1Biv) floating atop the uncleaved yolk mass in birds and reptiles—though this is later engulfed by the growing embryo; or a fluid-filled sac (blastocyst; Fig. 4-1Bv) with an inner cluster of embryo-forming cells (inner cell mass) in mammals. Up to this point, any localised cytoplasmic constituents (e.g. mRNAs or proteins) that were differentially distributed in the egg simply become partitioned among the blastomeres. Classical embryology described several examples where such localised ooplasms are apportioned preferentially into one or a few cells by the end of cleavage, and from elegant grafting and deletion experiments it was shown that their ooplasmic components in some way direct the appearance of particular cell fates during later development. Examples include the polar plasm in Dentalium embryos (a

100

Chapter 4

Figure 4-1. Cleavage. Fertilisation (top centre) generates a zygote which initiates cleavage. Part A, in embryos with little yolk, early blastomere cells are equivalent in size and cytoplasmic composition (left). However, in some mosaic embryos, various cytoplasmic constituents from the zygote are apportioned differentially among the blastomeres (right); in the example illustrated (the scaphopod mollusc Dentalium), a distinctive polar lobe is extruded prior to each of the first two cleavage divisions, and is resorbed into only one of the daughter cells (first CD and then D). Only descendants of the polar-lobe-containing D blastomere can generate mesodermal tissues. Part B shows five variants of the blastula formed at the end of cleavage: i, eggs with sparse reserves of yolk generate a hollow blastula with roughly equal-sized cells; ii, eggs with more yolk, concentrated towards the vegetal pole (e.g. frogs or toads), generate a blastula with larger yolky vegetal cells; iii, in many insects, superficial cleavage generates a blastoderm layer of cells surrounding an uncleaved central yolk mass; iv, in birds and reptiles, the large yolk again remains mostly uncleaved, and cell division is confined to a saucer-shaped blastodisc floating on top of the yolk; v, in mammals with yolk-poor eggs, cleavage generates a fluid-filled blastocyst containing a cluster of cells (inner cell mass) that will give rise to the embryo proper, while trophoblast cells of the blastocyst wall give rise to the placenta etc.

tusk-shell mollusc), which forms a lobe that passes at the 4-cell stage into one specific blastomere designated D (Fig. 4-1A right), whose descendants generate all the mesodermal tissues (muscle bands, foot, shell) during later development (Wilson, 1904a, b); polar plasm also influences dorso-ventral (D/V) polarity. In the sea squirt Styela (ascidean urochordate), fertilisation triggers a process of cytoplasmic streaming within the zygote, from which emerge five distinct sectors, each with a different tissue fate during later development. Cells which inherit dark grey yolky cytoplasm develop into gut (endoderm), whereas cells derived from a dark yellow crescent-shaped

Evolution and Development

101

sector of the egg develop into tail muscles in the tadpole-like larva; cells inheriting clear cytoplasm become ectoderm, those with pale grey material form the notochord, and those with pale yellow ooplasm produce coelomic mesoderm (all beautifully illustrated with hand-coloured plates in Conklin, 1895). These and similar case-studies exemplify mosaic development, where distinctive cytoplasmic regions in the egg or zygote map out future tissue territories. Removing all blastomeres containing one type of ooplasm from a cleaving mosaic embryo leads to specific tissue deficits later on in development. The localised factors directing the development of one tissue type rather than another are generically termed determinants (originally morphogenetic determinants); these can include signalling proteins ot TFs, all of which are now amenable to molecular analysis. A mosaic embryo develops like a confederation of autonomous territories, analogous to the independent countries that make up the EU (European Union). Recent genome sequencing, cell-lineage studies and single-cell gene-expression analyses, using a different ascidean species (Ciona intestinalis), have emphasised the close relationship between this group and the vertebrates (Satoh, 2019; Cao et al., 2019). Curiously, however, vertebrate early development is not mosaic, but rather regulative (§ 4.5)

4.5 Gastrulation and regulative development During the next phase of development (gastrulation), cell movements become crucially important. Through this process, groups of cells derived from different regions of the original zygote come into contact, and 1- or 2-way inductive signals are exchanged between them, altering their course of development. The importance of cell signalling (§ 4.2) is evident even during cleavage in embryos whose early development is best described as regulative (e.g. sea urchins) rather than mosaic. Sea urchin zygotes contain a modest amount of yolk, concentrated more towards one end of the cell (the vegetal pole), while the nucleus is at the opposite (animal) pole. The first two cleavages are vertical with respect to the animal-vegetal axis, but the third is horizontal, generating a vegetal tier of 4 large yolky blastomeres and an animal tier of 4 smaller non-yolky blastomeres. The fourth cleavage is vertical in the animal tier but horizontal in the vegetal tier, producing a ring of 8 mesomeres nearest the animal pole, then 4 large yolky macromeres, and a tier of 4 small micromeres at the vegetal pole (Fig. 42A). Mesomeres, if separated and grown on their own, develop mainly into ectoderm tissues (skin etc), whereas isolated macromeres develop into endoderm (gut tissues) and micromeres into primary mesenchyme (mesoderm, including skeletal elements), as shown in Fig. 4-2B. So far, so seemingly mosaic. But if the mesomeres are recombined with either

102

Chapter 4

macromeres or micromeres alone, the embryo which develops is fully normal in terms of its complement of ectoderm, gut and primary mesenchyme (Fig. 4-2C). It is, admittedly, rather on the small side in the case of mesomere plus micromere combinations—omitting the entire macromere tier. Note also that micromeres plus macromeres fail to develop sufficient ectoderm. It is thus over-simplistic to infer that putative mesenchyme determinants are localised in the micromeres and gut determinants in the macromeres, as in a typical mosaic system. Rather, the sea urchin embryo is able to regulate its early development so as to compensate for the loss of significant amounts of material. Based on these and other elegant experiments, two embryologists independently proposed the double-gradient hypothesis, with an ectoderm-promoting influence centred on the animal pole and declining towards the vegetal pole, plus an endoderm- and mesoderm-promoting influence with the opposite orientation (Runnstrom, 1928; Hörstadius, 1928; Fig. 4.2-A right). Clearly this requires interactions between the tiers of cells, so that the absence of the micromeres or macromeres is recognised by the rest of the embryo and appropriate compensatory processes are initiated. In a nutshell, cells “know their position” within the embryo as a whole, and in regulative systems they can adjust their developmental fate accordingly. This is the essence of the French flag problem posed by Lewis Wolpert (1969), whereby cells need to “know” whether they are supposed to be red, white or blue within the “field” of the overall flag. Several examples of such signalling gradients will be described later in this chapter. It is worth noting that vertebrate embryos are highly regulative in terms of their early development—unlike their mosaic relatives, the ascideans. In a memorable aphorism, Lewis Wolpert quipped that “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” (Wolpert & Slack, 1986, p. 1). In a typical blastula embryo, there is essentially a single layer of cells enclosing a fluid-filled cavity, and this layout is not greatly affected by alternative arrangements such as the blastoderm, blastodisc (both yolk-filled) or blastocyst (Fig. 4-1B, iiiv). In animals other than sponges (which do not really gastrulate), migration of cells into the interior of the embryo during gastrulation converts a blastula into either a two-layered (diploblastic) or three-layered (triploblastic) gastrula. Diploblastic animals (cnidarians and ctenophorans) have an outer layer of ectoderm (skin, epithelial muscle cells and a nerve net) plus an inner layer of endoderm (forming gut) separated by a gelatinous acellular mesogloea. Triploblastic animals include both the protostomes and deuterostomes; here, gastrulation produces 3 concentric layers—again the outer ectoderm (from which the skin and nervous

Evolution and Development

103

system are derived) and inner endoderm (generating the gut and associated organs), but separated by a middle layer of mesoderm that gives rise to muscles, connective tissue and skeletal elements (if any). These three germ layers, alone or in combination, produce all of the organs and structures to be found in the adult organism. In mammals, the germ-line cells that generate future eggs or sperm originate from primitive ectoderm early in development, and are then set aside as primordial germ cells. A major difference between protostomes and deuterostomes involves the blastopore marking the site where cells begin to migrate inside the blastula during gastrulation; this will become the anus in deuterostomes but the mouth in protostomes. While the first of these statements holds true for all deuterostomes, the second does not apply to all protostomes—in some of

Figure 4-2. Regulative development in early sea urchin embryo. Part A, the first four cleavages of the zygote, generating at the 16-cell stage a tier of 8 non-yolky cells (mesomeres) at the animal pole (AP), plus a central tier of 4 yolky macromeres and 4 small micromeres at the vegetal pole (VP). The double-gradient hypothesis of Runnstrom and of Hörstadius is shown (right), with an AP-centred ectoderm-promoting influence (Ect) declining towards the VP, plus a VP-centred endo- and mesoderm-promoting influence (EnM) declining towards the AP. Part B, if the cells from each tier are cultured separately, mesomeres develop into ectoderm (skin etc), macromeres into endoderm (gut) and micromeres into primary mesenchyme (mesoderm, including skeletal elements). However, as shown in Part C, recombining mesomeres plus macromeres, or mesomeres plus micromeres, allows regulative development, yielding a normal complement of tissues. The double-gradient hypothesis implies that both combinations shown will retain a balance of ectodermal and endo/mesodermal influences sufficient to permit regulation of the missing pattern elements.

104

Chapter 4

which the mouth develops at a site distant from the blastopore (MartínDurán et al., 2017). The occurrence of both patterns within monophyletic groups such as brachiopods and annelids implies that deuterostomy and protostomy may have evolved, not once, but several times independently. Two-dimensional diagrams of gastrulation fail to capture its dynamic character, with cells moving in wonderfully choreographed streams and tides towards their predetermined destinations—at which point they halt and begin to organise themselves into ever-more-elaborate tissues and organs. With modern imaging techniques, this whole process can be captured in exquisite detail; many such videos are freely available online. In vertebrates, gastrulation is followed by neurulation, during which a rod of mesodermal cells (the notochord) forms beneath the dorsal midline, inducing a strip of the overlying ectodermal cells to become neural. The lateral edges of this neural plate ruck up into neural folds, which meet and fuse together (proceeding from head to tail) to form a neural tube— generating the rudiments of the brain at the anterior (head) end and spinal cord further back. This lays out the overall body plan of the future animal.

4.6 Serial repetition, symmetry and polarity Both plants and animals utilise repeated building blocks to construct the final organism. Such blocks can vary greatly in form—for instance the hindlimbs for walking and forelimbs for flying in birds or bats. The forelimbs in both these groups are obviously homologous structures, as are human arms and the forelimbs (unless absent) of all other land vertebrates. But clearly forelimbs and hindlimbs are also related to each other as paired outgrowths from the trunk; they are properly described as serially homologous structures, since they arise through similar developmental processes but at different positions within the embryo (Carroll, 2006/2011, pp. 19-34). Other obvious serially repeated structures in the human body include the digits of both hands and feet, or the vertebrae of the spinal column together with their associated ribs, nerves and musculature. In plants, serially repeated structures include leaves and the various whorls of the flower (sepals, petals, stamens and carpels). Many flowers are radially symmetrical (e.g. the gentian family in the middle row of Fig. 2-5), while others show petal fusions and other modifications that often result in bilateral symmetry (e.g. orchids in Fig. 2-1). Among mammals, there are clear regional differences between cervical (neck), thoracic (rib-bearing), lumbar and caudal (tail) vertebrae, whereas in snakes there can be several hundred near-identical rib-bearing thoracic vertebrae. Much the same is

Evolution and Development

105

true in arthropods: insects possess three leg-bearing thoracic segments, whereas chelicerates have four, and myriapods may have several tens. Different species of animals or plants, as well as their higher taxonomic groupings, vary greatly in the number of serially repeated units and in the structure and/or function of the individual units. Thus it is possible for vertebrates to evolve long necks through either or both of two distinct routes. The first involves increasing the number of cervical vertebrae, as in the extinct plesiosaur Elasmosaurus with 72 neck vertebrae. However, the same end can also be accomplished by a second route—namely by increasing the length of the individual cervical vertebrae present in ancestral forms, as shown by the seven vastly elongated neck vertebrae of modern and ancestral giraffes (Danowitz et al., 2015), and likewise in Diplodocus—the longest of extinct land dinosaurs—with just 15 neck vertebrae. Although most animals show bilateral symmetry, both the Cnidaria and Ctenophora display radial symmetry, as do most adult echinoderms (which are deuterostomes with bilaterally symmetrical larvae). The arms of a starfish echinoderm provide an excellent example of serially repeated structures arranged in a radial pattern. Although repeating structural units are frequently used in a modular fashion to build both animals and plants, there are many groups (e.g. the abundant nematodes) where such features seem far less apparent. However, detailed elucidation of the embryonic and larval cell lineages in the model nematode Caenorhabditis elegans (Sulston et al., 1983) reveals numerous instances where cell division patterns are serially repeated (with variations) in different parts of the body. Thus modular construction is an abundant, if not quite ubiquitous, means for building complex multicellular organisms. In order for each such module to acquire the specific features appropriate to its location—e.g. differences between thumb and little finger in a human hand—the cells contributing to each module need to know where they are in relation to the whole structure—in this specific instance, in the autopod or distal margin of the embryonic forelimb bud. Early in limb-bud autopod development, a gradient of the secreted signal protein Sonic hedgehog (Shh) is established, which is highest at the posterior edge of the limb bud (termed the zone of polarising activity, or ZPA) and declines towards the anterior (Fig. 4-3A). Cells in different parts of the limb bud margin respond to varying levels of Shh signal by activating appropriate genes (members of the HoxD complex), which in turn determine the type of digit that will develop and—importantly—in what temporal sequence. In early chick embryos, transplanting a ZPA or a bead soaked in Shh protein to the anterior forelimb-bud margin establishes

106

Chapter 4

a second Shh signal gradient with opposite orientation, which causes reduplication of the digits in a mirror-image pattern. Since chick forelimbs normally develop only three digits (nos. 2, 3 and 4, relative to the basic 5digit pentadactyl pattern of land vertebrates), the end result is a 4-3-(2)-3-4 pattern (Fig. 4-3B). In the limb bud, the Shh protein acts as a diffusible morphogen or form-determining signal acting over significant distances, spanning many cell diameters. The entire region of the limb bud autopod that is capable of responding to Shh is technically termed a field, such that alterations or disruptions of the Shh signal gradient will generate corresponding distortions or reorganisations of pattern elements within the final autopod structure. A similar posterior-to-anterior gradient of Shh protein is established in the distal hindlimb bud, resulting for instance in the differences between big and little toes in human feet. Various developmental abnormalities in humans (some of them genetic) cause the appearance of extra digits on the hands and/or feet, commonly in mirrorimage patterns. Needless to say, the roles of Shh and of Hox genes in digit patterning are more complex than this brief outline suggests (Pérez-Gómez et al., 2018). In addition to the anterior-posterior (head to tail) A/P axis in bilaterian animals, there is also the dorso-ventral D/V axis from back to front,

Figure 4-3. Chick forelimb development (schematic). Part A, normal forelimb bud generating a proximal humerus, middle radius plus ulna, and 3 distal digits (nos. 2, 3 and 4 of pentadactyl pattern). Absent digits 1 and 5 are shown dashed in grey. In the distal autopod, a Shh gradient diffusing from the ZPA determines digit type. Part B, limb bud with a transplanted ZPA or Shh-soaked bead placed at the bud’s anterior margin, creating a second Shh gradient with opposite orientation to that already centred on the ZPA: this results in a mirror-image reduplication of distal digit elements (4-3-[2]-3-4). Right: in both parts, nested expression patterns of 5’ HoxD genes (hoxd9-d13) are shown for each digit; for details, see § 4.10 below.

Evolution and Development

107

the proximo-distal P/D axis from centre to periphery, and also left-right L/R asymmetries. Conserved genetic circuits establish all of these in animal embryos (§ 4.11), but my primary focus here will be the A/P axis.

4.7 Introducing segmentation in Drosophila Nobel laureate Ed Lewis published a ground-breaking paper in 1978 that completely revolutionised our understanding of how genes direct development. For many years he had studied the genetics of an obscure class of developmental mutants in the fruit-fly Drosophila. These homoeotic (now homeotic) mutations had the bizarre effect of causing apparently normal structures to appear in the wrong place during development. From a painstaking analysis of such mutations, their map positions and precise developmental effects, Lewis was able to discern underlying patterns in these odd-looking flies. They included the famous four-winged fly caused by the bithorax (bx) mutation, mapping to the Bithorax gene complex (BX-C) located on chromosome 3. Drosophila is a dipteran or two-winged fly, normally carrying a single pair of wings on its second thoracic segment (T2), plus a small pair of halteres or balancing organs on the third thoracic segment (T3). However, in other orders of flying insect, T3 carries a second pair of wings. In Drosophila bithorax mutants, the 3rd thoracic segment (T3) is essentially transformed into a replica of T2—complete with wings. Lewis suggested that T2 represents a ground-state thoracic identity that is modified in T3 by the actions of bx and other genetic elements. Mutations of other elements within the BX-C produce further modifications affecting abdominal (A) segments, which normally develop without legs, wings or halteres. Subsequent molecular analyses identified bx as a regulatory mutation altering the expression of the Ultrabithorax (Ubx) gene, which itself encodes a homeodomain TF (transcription factor). The homeobox specifying this 60 amino-acid DNAbinding homeodomain was first identified as a conserved 180 bp DNA sequence in several Drosophila homeotic Hox genes (McGinnis et al., 1984). This implied that Ubx is a protein-coding Hox gene affecting at least the T3 segment. Two further BX-C genes, abdominal-A (abdA) and Abdominal-B (AbdB), respectively affect anterior and posterior abdominal (A) segments; both are also Hox genes that encode homeodomain TFs. Alfonso Martinez-Arias and Peter Lawrence (1985) later showed that the initial repeating units (or metameres) established during Drosophila development lie out-of-register with the final adult segment pattern; these early ectodermal metameres are properly termed parasegments. In fact, each segment or parasegment comprises two distinct compartments, where

108

Chapter 4

cells cannot normally cross over compartmental boundaries. The chain of alternating anterior and posterior compartments can be grouped pairwise into either a parasegmental (embryonic) or segmental (larval and adult) arrangement (Fig. 4-4). The region affected by Ubx spans parasegments (ps) 5 and 6, while abd-A influences ps 7 to 9 and AbdB likewise affects ps 10 to 14. Initially, it was thought that these homeotic genes act as selectors or binary switches (on/off), imposing global fates on successive metameres —but this is undoubtedly an oversimplification, as hinted earlier when discussing “hopeful monsters” in § 2.9. Much of the pioneering work used Drosophila, whose development is unfortunately atypical among insects. What no-one had anticipated was that related (orthologous) genes with strikingly similar developmental patterns of expression would soon be identified in quite different animal groups, including vertebrates. This remarkable story is outlined below (§ 4.8 to 4.10). But we will first look at the genes which progressively subdivide the insect anterior/posterior (A/P) axis into metameres (§ 4.8), before returning to Hox genes in more detail (§ 4.9), and to the intriguing parallels between the segmentation processes in arthropods, annelids, and vertebrates in § 4.10 below.

Figure 4.4. Metameres in Drosophila embryogenesis. After germ band shortening in post-gastrula embryos, several parallel grooves appear on the ectoderm surface, demarcating segment-sized units. These are probably parasegments rather than adult segments. Each such unit comprises a narrow posterior and a much broader anterior compartment (mid-grey boxes in table). The parasegmental pairings (p, a; p, a; etc) are shown as dark grey boxes; the adult segments (a, p; a, p; etc) are shown as pale grey boxes. Md (mandibular), Mx (maxillary) and Lb (labial) are all posterior head segments; T1-T3 are thoracic segments; A1-A9/10 are abdominal segments. Figure based on D. de Pomerai, 1990, From Gene to Animal, CUP (2nd ed., p. 247), and simplified from Martinez-Arias & Lawrence, 1985.

Evolution and Development

109

4.8 Subdividing the anterior/posterior axis in Drosophila But how are parasegments and compartments set up in the first place in a Drosophila embryo? It is worth noting that fruit flies belong to an insect group characterised by long germ-band development, a derived process in which all 14 parasegments are established almost simultaneously. In other insects with short germ-band development, most segments are established sequentially as successive metameres are budded off posteriorly. Yet these apparently divergent modes of segmentation both utilise a similar genetic toolkit, elucidated in Drosophila by the three 1995 Nobel laureates for Medicine or Physiology—Ed Lewis (1978), Christiane Nusslein-Volhard and Eric Wieschaus (1980)—showing how segments become established and then acquire distinctive identities. This remains one of the foremost achievements in developmental genetics. In vertebrate embryos, paired mesodermal somites are formed on either side of the neural tube in an anterior-to-posterior sequence, a process broadly similar to the posterior budding-off of segments in short germ-band insects and in many annelids. In Drosophila and other holometabolous insects, each oogonial stem cell in the female ovary undergoes three or four incomplete cell divisions, resulting in a cluster of 7 or 15 nurse cells—all connected through open cytoplasmic channels (ring canals) to the anterior pole of the single egg cell (oocyte)—a process termed meroistic oogenesis. During this process, the maternal mRNA and protein products of all 7 or 15 nurse cells are transported via the ring canals into the growing oocyte, which thereby rapidly accumulates all the reserves required to sustain embryonic development until hatching. Because of the central yolk mass in insect eggs (Fig. 4-1Biii), all of the events described below take place within the superficial layer of cytoplasm that surrounds it. Initial cleavage divisions of the zygote nucleus occur without formation of cell walls, generating a syncytial blastoderm—with numerous nuclei scattered through the surface layer of undivided cytoplasm (a syncytium). Later on, cell membranes separate these nuclei into individual cells, forming the cellular blastoderm. Four maternal mRNAs are crucial for setting up the anterior-toposterior (A/P = head-to-tail) polarity of the embryo. Firstly, bicoid (bcd) mRNA encodes a homeodomain TF, termed Bcd, that is also (unusually) an RNA-binding protein. This mRNA is bound close to its anterior site of entry into the oocyte, and so forms a gradient diminishing steeply away from the anterior pole—although its protein product is translated only after fertilisation, forming a shallower gradient that declines from high to low along the entire A/P axis. An opposite posterior-to-anterior gradient (steep

110

Chapter 4

for the mRNA, shallower for the protein) is formed by the second such mRNA, nanos (nos), which encodes the RNA-binding protein Nos. A set of eleven interacting maternal gene products is responsible for transporting nurse-cell-derived nos maternal mRNA away from its anterior site of entry, along the A/P axis of the egg, and binding it at the posterior pole. The other two A/P mRNAs (hb and cad) are both evenly distributed throughout the egg—but the hunchback TF protein (Hb) encoded by hb mRNA forms an A/P gradient (high throughout the anterior part of the embryo, then declining posteriorly), because Nos protein inhibits the translation of hb mRNA. An opposite posterior-to-anterior gradient is established for the caudal homeobox TF protein (Cad) encoded by cad mRNA, whose translation is similarly inhibited by Bcd. For both Nos and Bcd, this inhibition depends on the RNA-binding domain of the protein, which recognises specific response elements within the target hb or cad mRNAs, inhibiting their translation in a concentration-dependent manner. Bcd, and perhaps Nos (Wharton & Struhl, 1991), act as morphogens— forming protein gradients along the A/P axis of the Drosophila zygote and syncytial blastoderm that will determine the later development of anterior and posterior structures, respectively (Fig. 4-5A). In the next stage of the segmentation process, several zygotic gap genes (Nusslein-Volhard & Wieschaus, 1980) are activated in one (Krüppel) or more (tailless, giant, knirps) bands of expression along the A/P axis of the syncytial blastoderm (Fig. 4-5B). Gap genes are so named because their inactivation by mutation causes groups of segments to be lost from the final pattern. The hunchback gap gene is also activated zygotically in the same anterior zone where its maternal protein gradient was highest, tailing off posteriorly. Zygotic caudal expression is likewise activated at the posterior end. Gap-gene expression often tails away on both sides of a peak. The genetic circuitry underlying the delineation of these gap-gene expression zones is extremely complex, involving activation or repression by different combinations and thresholds of maternal TF gradients (Bcd, Hb, Cad), plus cross-regulation by the other gap-gene proteins, all of which are also TFs. As usual, this is underpinned by multiple enhancer elements regulating each gap gene. As cell walls separate off nuclei during the transition from syncytial to cellular blastoderm, so a second group of segmentation genes is switched on. These are termed pair-rule genes—because their inactivation causes the loss of alternating segment-sized regions in the trunk region, while separate systems govern the head and tail terminal regions. The 8 classical pair-rule genes are runt (run), hairy (h), even-skipped (eve), fushi tarazu (ftz), odd-skipped (odd), paired (prd), odd-paired (opa) and sloppy-paired (slp), all of which also encode TFs. Among these, both ftz and odd are

Evolution and Development

111

expressed in 7 broad stripes in the trunk, marking out the even-numbered parasegments (2, 4, 6 etc; Fig. 4-5C). An exactly complementary pattern of expression is shown by eve, which is expressed in the odd-numbered parasegments (1, 3, 5 etc). In all 3 cases, loss of gene function results in the absence of those parasegments in which it is normally expressed. The complex bands of gap-gene proteins therefore need to be translated into a repeating 7-stripe pattern for most of the pair-rule genes (opa shows more complex expression). Responsibility for this is shouldered mainly by the primary pair-rule genes—h, run, eve, odd and probably ftz (Schroeder et al., 2011). Just as eve and odd show mutually exclusive expression domains, so too do h and run, which are expressed in stripes that are offset from the parasegmental boundaries. The primary pair-rule genes all possess extensive regulatory regions with multiple stripe-specific enhancers responding to different combinations of gap-gene TFs (e.g. Klingler & Gergen, 1993), though ftz lacks one and odd is missing 3 such elements. In addition, all except h and eve also possess a 7-stripe “zebra” enhancer that allows cross-regulation by other pair-rule TFs (Schroeder et al., 2011). The primary pair-rule TFs then cue in expression of secondary pair-rule genes (prd and slp), each of which is regulated primarily through a zebra element. These 7-stripe patterns of pair-rule gene expression are dynamic and transient. For example, intercalated stripes of eve expression generate a 14-stripe pattern (one per parasegment) just before germ-band elongation begins, precisely prefiguring the later expression pattern of the segment polarity gene known as engrailed (en). This transition from double- (7stripe) to single- (14-stripe) segment periodicity involves the Opa TF encoded by the broadly-expressed pair-rule gene opa (Clark & Akam, 2016). Like other genes in the segment polarity class, engrailed is expressed in 14 narrow stripes (Fig. 4-5D), specifically in cells marking the posterior compartment of each trunk segment (= anterior compartment of every parasegment). The En protein is another homeodomain TF, and one of the genes that it regulates is hedgehog (hh), encoding a signalling protein (Hh) that is related in sequence to the vertebrate Sonic hedgehog mentioned earlier. The Hh signal then interacts with a receptor (Ptc), encoded by the patched (ptc) gene, which is expressed on the surfaces of adjacent cells in a narrow stripe. Cells responding to Hh via Ptc in turn express another signalling protein (Wg), encoded by the wingless (wg) gene. Wg then interacts with the Fz receptor encoded by the frizzled (fz) gene, which is expressed on the surfaces of a third adjacent stripe of cells. In this way, each stripe of cells acquires a distinctive positional identity within every parasegment. The fine details of this segment-polarity system might seem unnecessary for this brief outline account, except for the fact

112

Chapter 4

that both the hedgehog/patched and wingless/frizzled signal/receptor pairings—not to mention their downstream intracellular kinases and target TFs, as well as engrailed itself—are utilised in a wide variety of different developmental contexts across most groups of animals. Both the hedgehog and wingless (Wnt) signalling systems are fundamental genetic modules that underlie the construction of many different structures, and are re-used again and again for a wide variety of purposes. The presence of these modules in widely separated phyletic groups allows rational inferences to be drawn about the genetic toolkit present in the last common ancestor (LCA) of all animals, of all bilaterians, and also of each component phylum (chapter 3). This is one of the great insights of evo-devo. In short germ-band insects, such as the flour beetle Tribolium castaneum, a similar set of gap, pair-rule and segment polarity genes is utilised for segmentation—though here the pair-rule expression stripes corresponding to the abdominal segments arise sequentially during postblastoderm growth of the embryo, as successive new segments are budded off posteriorly. However, there are also clear differences in the expression patterns and roles of these genes, showing that their precise functions are not all that tightly conserved (Bucher & Klingler, 2004; Cerny et al., 2005, 2008). In Tribolium castaneum, gap genes serve rather different functions, and the primary pair-rule expression pattern is established by Tc-run with Tc-eve and Tc-odd, whereas Tc-hairy appears to perform a subsidiary role (Choe et al., 2006). The take-home message from these and many similar examples is that evolution can tinker with the details of this genetic circuitry—often through mutation of regulatory modules rather than by altering the sequences of key TF proteins—but the broad outlines of the individual circuits remain recognisable, with orthologous genes performing similar functions, even in insects with contrasting patterns of development. Figure 4-5 (next page). Genetic control of segmentation in Drosophila. Part A shows opposed gradients of maternal Bcd (A o P) and Nos (P o A) proteins in 2 offset embryos at the syncytial blastoderm stage. Part B shows approximate zones of zygotic gap-gene expression in late syncytial blastoderm (gradients of expression omitted for clarity). Part C shows the 7-stripe expression pattern of two of the zygotic pair-rule genes (ftz and odd) during cellular blastoderm stage, marking out even-numbered parasegments in the central trunk region; even-skipped similarly marks out the oddnumbered parasegments. Part D shows the 14-stripe pattern characteristic of segmentpolarity gene expression, e.g. for engrailed. In fact, these genes are not activated until germ-band extension, by which time the embryo has greatly elongated and doubled back on itself with the tail tucked in behind the head. The pattern shown in the late cellular blastoderm stage is in fact that of late even-skipped expression, which forms 14 equally spaced stripes (one per parasegment) exactly delineating the cells in which engrailed will be expressed later in development. D, dorsal; V, ventral; A, anterior; P, posterior.

Evolution and Development

113

114

Chapter 4

Recently, a deeper understanding of events within the posterior Segment Addition Zone (SAZ) of short germ-band insects has allowed insights into the later evolution of long germ-band insects such as Drosophila, where most segments are established simultaneously (Clark et al., 2019). The “clock and wavefront” model postulates an intracellular clock, based on oscillating patterns of gene expression and synchronised across cells in the posterior SAZ, plus a wavefront generating striped expression patterns in cells emerging from the receding SAZ. The intracellular clock or oscillator involves a cycle of 3 primary pair-rule genes—eve, run and odd—where each of these three TFs most likely inhibits expression of the preceding gene in the cycle, with intrinsic time-delays for each step (Clark & Akam, 2019). This repressilator system results in staggered bursts of activity for each of the 3 genes in succession, so generating the oscillator function. But how is clock timing synchronised between cells? The Drosophila Notch gene encodes a cell-surface receptor that binds a ligand specified by the Delta gene. The intracellular domain of the Notch protein then becomes cleaved and internalised, directly regulating its target genes in the nucleus (Bray, 2016). Many animals possess multiple Notch genes (e.g. lin-12 and glp-1 in Caenorhabditis) that can bind alternative Delta-related ligands in different developmental contexts. An important detail here is that Notch activates the expression of HES (hairy/Enhancer of Split) transcriptional repressors, which in turn down-regulate expression of the Notch gene itself. This creates a negative feedback loop that readily generates cyclical patterns of expression over time. Such a module is eminently suitable for regulating periodic bursts of gene activity, such as those of the clock involved in budding off posterior segmental units. This suggests that Notch and the Hairy/HES repressor mediate between the intercellular ligand and the intracellular clock, cyclically cueing in the latter via hairy protein repressing run and odd (Clark et al., 2019). In many short germ-band insects, as cells emerge out of the posterior SAZ, the double-segment pair-rule periodicity becomes “rewired” by Opa activity (above) so as to generate the single-segment periodicity typical of segment polarity genes. Likewise in long germ-band insects, Opa converts the early 7-stripe pair-rule pattern into a 14-stripe pattern, implying that the same regulatory logic applies in both cases. But in other insects and arthropods, the pair-rule genes are expressed in single-segment stripes from the outset, implying that double-segment periodicity may be a later evolutionary refinement, perhaps helping to speed up development. The long germ-band pattern found in Drosophila may have evolved progressively from an older short germ-band pattern by adding new stripespecific enhancers to the primary pair-rule genes, making them responsive

Evolution and Development

115

to the gap-gene TFs. Gap genes function rather differently in short germband insects; for instance, in Tribolium the gap-gene network is “speedregulated” by a posterior signal and cued in by Tc-hunchback expression (Boos et al., 2018), instead of responding to threshold levels of morphogen gradients—such as that of Bcd in Drosophila. Gap genes have been coopted via novel regulatory modules for modified roles in segmentation in Drosophila and other long germ-band insects (Clark et al., 2019).

4.9 Hox genes and metamere identity It remains to revisit the homeotic Hox genes, asking how they act to establish differences between parasegments and subsequently segments. So far we have met the 3 homeobox genes of the Bithorax complex (BXC), affecting metamere identities posterior to T2. In fact, this is less than half the story, since chromosome 3 also contains a second cluster of Hox genes—known as the Antennapedia complex, ANT-C—which influence segments in the posterior head and anterior thorax. These ANT-C genes again give rise to some spectacular homeotic mutants. A dominant mutation of the Antennapedia (Antp) gene causes T2-type legs to sprout from the head in place of antennae. Wild-type Antp normally directs T2 leg development, but the dominant mutant described results from an inversion causing inappropriate Antp activation in the antennal imaginal discs. Loss-of-function regulatory mutations affecting Antp cause reverse transformations of T2 legs into antennae. In total, the ANT-C comprises 5 homeotic Hox genes: labial (lab), proboscipedia (pb), Deformed (Dfd), Sex-combs reduced (Scr) and Antennapedia (Antp), though these are interspersed with other homeobox-containing but non-Hox genes such as bcd and ftz (see above). This split two-cluster arrangement is atypical among arthropods (Pace et al., 2016). In Tribolium, both ANT-C and BXC Hox genes are included within a single giant cluster termed the HOM-C, while in the silk moth Bombyx, a different split separates the labial orthologue from all of the other clustered Hox genes. In most cases, the gene order (synteny) within the cluster (or clusters) is tightly conserved, with genes expressed towards the anterior of the embryo (lab) at one end of the cluster and posterior genes (AbdB) at the other end (spatial collinearity). Furthermore, most Hox clusters also show transcriptional collinearity, with genes being oriented in the same 5’-3’ direction within the cluster (Gaunt, 2015), although the Drosophila Dfd gene is reversed relative to the other ANT-C/BX-C genes (as is ftz). It is worth noting that, for short germ-band insects and for many other arthropods where successive metameres are formed at the posterior end of the embryo, spatial collinearity also correlates with the timing of expression for these

116

Chapter 4

Hox genes. The ancestral arthropod gene cluster probably contained 10 Hox genes, one of which was ftz—which seems to have lost its original Hox6 function, and has in most cases become co-opted as a pair-rule segmentation gene. In Drosophila, one other member of the cluster (Hox3) has also been lost. But there are also exceptions to this collinearity rule, where some or all of these Hox genes occur scattered through the genome. Lewis’ original 1978 model proposed that the superimposed activities of successive Hox genes within the BX-C cluster specified segmental identities that differed increasingly from the T2 ground state. Although a deletion of the entire BX-C is lethal, mutant embryos develop far enough to show that the denticle belts of T3 and of all abdominal segments are transformed into replicas of the T2 pattern. However, although Hox genes are expressed in partially overlapping domains along the anterior-posterior axis in Drosophila (with sharp anterior boundaries, tailing off posteriorly), the reality is more complex than Lewis’ model suggested. The combined activities of different Hox genes do not impose a blanket identity on any given metamere. Instead, and consistent with the TF functions of all homeodomain Hox proteins, these genes are active locally in those parts of a segment (or rather, in its larval imaginal discs) that give rise to the characteristic structures which differentiate it from neighbouring segments. Thus Ubx gene-activity in the larval T3 haltere discs is localised so as to ensure that these discs do not develop an extra pair of wings (duplicating those on T2), but instead form the small T3 halteres. TFs encoded by Hox genes seem to be micromanagers rather than dictators of metamere identity (reviewed by Akam, 1998b). An example of this is provided by late-acting changes in the pattern of AbdB expression in the bumble bee Bombus melanopygus, which underlie mimetic colour variations affecting its abdominal pigmentation patterns (Tian et al., 2019). Hox gene functions in Drosophila may not be truly typical, since the long germ-band mode of development requires almost simultaneous acquisition of segmental identities. In short germ-band insects, posterior segments are formed successively, so that many of the Hox cluster genes are activated in a corresponding temporal sequence. Even arthropods with numerous near-identical segments along much of the body length, such as the centipede Strigamia maritima, retain a full Hox gene cluster with all 10 genes present (Chipman et al., 2014). In Strigamia, nearly all of the embryonic leg-bearing segments (apart from the anterior-most) express the same combination of Hox genes (Sm-Antp + Sm-Ubx + Sm-abdA), emphasising their apparent uniformity. Despite huge variety in segment patterns and specialisations among arthropods, the Hox gene cluster

Evolution and Development

117

remains remarkably constant, despite frequent losses of Hox3 and abd-A. One exception to this rule may be the isolation of Abd-B (whose expression normally terminates the segment pattern) as a result of abd-A loss in groups that are characterised by much reduced trunk segmentation, such as chelicerate spiders and crustacean barnacles (Pace et al., 2016).

4.10 Segmentation in annelids and vertebrates Out of all the animal phyla, only 3 are predominantly segmented—the arthropods, chordates and annelids. To make matters worse, each of these phyla belongs on a different branch of the bilaterian tree, since arthropods are Ecdysozoan protostomes (along with non-segmented groups such as nematodes), annelids are Lophotrochozoan protostomes (along with nonsegmented molluscs), and chordates are deuterostomes (along with nonsegmented echinoderms). As one might expect, there are exceptions to each of these generalisations. Some groups of annelids have become secondarily non-segmented, while on the other hand metameric features are found in Monoplacophoran and Polyplacophoran (chiton) molluscs. Moreover, at least one group of fossil echinoderms (the Stylophorans) possessed reiterated structures that may be gill slits, which are segmental in chordates. Lastly, there is a primitive group of nematodes (the Enoplea) in which one species produces much of its body by duplicating segment-like building blocks comprising rings of cells (Schulze & Schierenberg, 2009). So—was the LCA of all bilaterian animals segmented or not? Available data remain inconclusive, and the issue can be argued with conviction in either direction. Advocates of deep homology favour a segmented LCA, whose segmentation has since been lost secondarily in the non-metameric phyletic groups (Couso, 2009). This would predict a common suite of genetic modules and developmental processes underlying segment formation in all three of the segmented phyla. The alternative scenario of a non-segmented bilaterian LCA might seem at first sight less plausible, since this would require segmentation to evolve independently at least three times. Although not decisive in resolving this dilemma, evidence on the genetic mechanisms that regulate segmentation in chordates, annelids and arthropods may prove informative in this regard, as outlined below. Hox genes occur in multiple copies in most animals (even cnidarians), but they are not always clustered in their organisation—a diversity already encountered in the arthropods. Moreover, the homeobox sequence of each Hox gene is related to that of the corresponding member (or orthologue) of the Drosophila ANT-C or BX-C clusters. Most genomes usually include

118

Chapter 4

anterior (hox-1/-2 etc), central (hox-5/-6 etc) and posterior (hox-9/-10 etc) representatives—where hox1 corresponds to a lab-type and hox10 to an AbdB-type homeobox. In the late 1980s and 1990s, four separate clusters of collinear Hox genes (termed HoxA, B, C and D, respectively) were described—first in mouse and then in all other vertebrates, apart from teleost (bony) fish—which possess 7 or 8 reduced clusters. “Reduced” in this context means that several of the usual Hox genes are missing, but commonly there are up to 4 extra Abd-B-related homeobox genes dubbed hox-11, -12, -13 and -14. Fig. 4-6 shows the typical cluster alignments, along with the single 14-member Hox cluster of Branchiostoma, a cephalochordate reminiscent of the ancient Cambrian Pikaia (Fig. 3-3A).

Figure 4-6. Hox clusters in Drosophila, Branchiostoma, Mus. This diagram, based on Figure 1 of Duboule (2007), shows a hypothetical alignment of the Drosophila BX-C plus ANTP-C complexes (separated by 6.7 Mbp of DNA on chromosome 3) with the single Hox complex in Branchiostoma (400,000 base pairs) and the 4 compact Hox complexes in mouse (100,000 base pairs each). The genomic interval in Drosophila is 20-fold longer than in Branchiostoma and 80-fold longer than in Mus. Note transcriptional collinearity for Branchiostoma and Mus clusters, but not for Drosophila. N.B. hox-3 is missing and hox-6 co-opted for other uses (ftz) in Drosophila; hox genes are also missing (M) from each of the 4 mouse Hox complexes. Open arrows show 5’ to 3’ direction of transcription for each gene.

Evolution and Development

119

It is likely that wholesale duplication of much or all of the genome has occurred twice over in the chordate lineage leading to vertebrates, since 4 tight (but usually incomplete) Hox clusters are found in all extant vertebrates—apart from teleosts, which seem to have undergone an extra round of duplication to generate 8 (or 7) such Hox clusters. The cephalochordate Branchiostoma (Fig. 4-6 centre) has only one Hox cluster, while ascideans (urochordates) have several non-clustered Hox genes dispersed throughout the genome (atomised arrangement). Each of the 4 Hox gene clusters in mouse contains a subset of 13 Hox genes, as shown in Fig. 4-6; the corresponding members of each cluster are termed paralogues, e.g. hoxa13, hoxb13, hoxc13 and hoxd13. Denis Duboule (2007) has pointed out that Hox clusters can vary greatly in size within and between animal phyla. This is true, for instance, in non-segmented nematodes—where the model organism Caenorhabditis elegans has only six Hox genes (one anterior, two central and three posterior), while other nematodes possess additional members of the ancestral cluster (e.g. hox3 and hox7; Aboobaker & Blaxter, 2003). It seems likely that an original collinear gene cluster has become split or even dispersed in some groups, while in vertebrates all 4 clusters (7 or 8 in teleosts) have become more compact and tightly organised, perhaps through acquiring global regulatory elements that control the sequential expression of the genes in each cluster (temporal collinearity; Duboule, 2007). Generally, it is the posterior-most gene expressed in any metamere that takes precedence in terms of its patterning. Two well-studied example of hox gene expression patterns in vertebrate embryos will be described below, in limb bud (HoxD genes) and in hindbrain (all four Hox clusters), respectively. The digit pattern in the distal limb autopod is set up by a posterior-toanterior gradient of Sonic Hedgehog protein (Shh), shown schematically in Fig. 4.3 earlier. Genes in the HoxD cluster are activated in two waves during limb bud development in higher vertebrates (Tarchini & Duboule, 2006; Zakany & Duboule, 2007). In the first phase, 3’ genes are activated in a temporal sequence, starting with hoxd1 and progressing as far as hoxd9 (note that hoxd2 and hoxd5-7 are missing from this cluster), but they are expressed quite homogeneously throughout the developing limb bud. There are, however, A/P asymmetries in HoxD gene expression that selectively activate the Shh gene at the posterior distal margin of the limb bud (Fig. 4-3). In the second phase, the most 5’ genes in the HoxD cluster (hoxd10-13) are activated sequentially in nested expression domains by the gradient of Shh—such that each digit acquires a different “Hox code”. Digit 1 expresses only hoxd9, while hoxd10 + hoxd9 are expressed in digit 2, hoxd11 (+ hoxd9 and 10) in digit 3, hoxd12 (+ hoxd9-11) in digit 4, and

120

Chapter 4

hoxd13 (+ hoxd9-12) in digit 5 only—as shown on the right in Fig. 4-3A. There are also quantitative as well as temporal gradations in these hoxd expression domains, with hoxd13 the most strongly as well as the last to be expressed (Kmita et al, 2002)—reflecting the influence of a powerful global enhancer that lies beyond the 5’ end of the HoxD cluster. From the fossil record, it is clear that the fore- and hind-limbs of higher vertebrates evolved originally from fish fins, via lobe fins in coelacanths and lungfish. This relationship is also apparent from the role of hox13 paralogues in forming the fin rays of zebrafish (Nakamura et al., 2016). Turning now to the hindbrain and spinal cord, the former is transiently segmented during embryonic development in vertebrates, forming roughly seven swellings between the midbrain and the anterior end of the spinal cord (SC). The SC is of course surrounded by mesodermal somite-derived vertebrae (plus ribs in the thoracic region), and is itself organised into 31 segmental units in humans, defined by 31 pairs of nerves exiting the cord; theses comprise 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal pairs. The transient swellings in the vertebrate embryonic hindbrain are termed rhombomeres (r1 to r7), though the medulla oblongata at the posterior end of the hindbrain may contain up to four additional cryptorhombomeres (r8 to r11; Tomas-Roca et al., 2014). Rhombomeres share some features with Drosophila compartments, in that cells do not mix or migrate across rhombomere borders. Boundaries between adjacent rhombomeres are established by expression of the ephrin membranebound ligand in r2, r4 and r6, while the transmembrane Eph receptors that bind this ligand are expressed both in r3 and r5—though r1 and r7 express neither (Lumsden, 1999). There is an element of pair-rule organisation here, with several molecular characteristics shared between the oddnumbered rhombomeres, and likewise between even-numbered hindbrain segments. The zinc-finger TF encoded by the Krox20 gene is expressed specifically in r3 and r5, where it directly upregulates expression of the Eph4A ephrin-receptor gene. Fig. 4-7 shows a simplified diagram of Hox cluster gene expression within the hindbrain region, including both the rhombomeres and crypto-rhombomeres of the medulla oblongata (diagram based on Alexander et al., 2009, and Tomas-Roca et al., 2014). It is clear that anterior boundaries of Hox gene expression coincide with rhombomere boundaries from r2 back to the anterior end of the spinal cord, though in some cases expression levels are much stronger within one or more specific rhombomeres (Fig. 4-7). Similar hindbrain patterns of Hox gene expression are found for all paralogue groups in the most primitive extant vertebrates, the jawless lampreys (Parker et al., 2019). Nested zones of Hox gene expression also help to define metameric units in the spinal cord itself, as

Evolution and Development

121

well as in its encasing vertebral column (derived from somites)—where genetic inactivation (loss-of-function) or ectopic activation (gain-offunction) for specific Hox genes can cause homeotic transformations of vertebral morphology. These are similar to, though less dramatic than, the bizarre Drosophila mutants that first attracted Ed Lewis to homeotic genes. However, patterns of Hox gene expression in mesodermal somites are complex and dynamic (Alexander et al., 2009). In tetrapod vertebrates, thoracic rib-bearing vertebrae always correspond to the expression domains of hoxb5, hoxc6 and hoxc8, whereas in snakes the expression domains of the orthologues these 3 genes are vastly expanded to span the entire rib-bearing trunk (Chipman, 2009).

Figure 4-7. Hox and Krox20 expression in vertebrate hindbrain. This figure summarises the pattern of hox gene expression in the embryonic hindbrain (rhombomeres r1 to r7) and medulla oblongata (MO; crypto-rhombomeres r8 to r11), shown diagrammatically at the top. The hindbrain is flanked anteriorly by the midbrain (MB) and posteriorly by the spinal cord (SC). Below are shown approximate expression patterns for Krox20 (top) and for multiple hox genes belonging to all 4 clusters, with an indication of regions within which expression is more intense (extra shading). Data collated from Alexander et al., 2009 (rhombomeres) and Tomas-Roca et al., 2014. Boundaries between putative cryptorhombomeres are indicated roughly by dashed lines in the medulla oblongata. These patterns are consistent between mouse and chick.

Turning briefly to annelids, Hox genes are deployed in a similar overall manner during larval development of the polychaetes Nereis and Platynereis, with 3’ (Hox1/2/3) genes activated earliest in development. All genes in the 11(+)-member Hox gene cluster are expressed in staggered

122

Chapter 4

A/P domains, suggesting a role in regionalising this axis (Kulakova et al., 2007). However, not all polychaetes develop directly into the adult form. In Chaetopterus, a free-living trochophore larva develops after embryogenesis, and only during post-embryonic larval development is the adult body-plan laid down—using “set-aside” endomesodermal cells (teloblasts at the posterior end). A similar mode of development is seen in echinoderms (deuterostomes), where a bilaterally symmetrical free-living larva is transformed into a pentameral (radially symmetrical) adult, again built out of set-aside endomesodermal cells. Notably, both in Chaeopterus (Peterson et al., 2000) and in echinoderms (Arenas-Mena et al., 2000), Hox gene expression is essentially undetectable in embryos and early larvae, but becomes activated in the set-aside cells as the adult body plan begins to be laid down in later larvae—again with the 3’ genes being activated first, followed by more 5’ genes in temporal and spatial order along the A/P axis (most probably the oral/aboral axis in sea urchin). This may suggest how hox-dependent “segment identities” could have become superimposed secondarily on unsegmented bilaterian ancestors. Moreover, there is recent evidence that nested Hox gene-expression patterns (3 canonical Hox genes plus the related Gbx gene) distinguish the radially reiterated endodermal gut-pouches in larvae of the sea anemone Nematostella (He et al, 2018). This animal belongs to the Cnidaria, a sister-group to the Bilateria—suggesting that axial Hox codes may be truly ancient, predating the split between these phyletic groups (Arendt, 2018). As a coda to this section, many of the segment polarity and pair-rule genes that regulate segmentation in Drosophila have orthologues in both vertebrates and annelids. But do these genes perform similar patterning functions in the posterior budding-off of new segments in these phyletically distant groups, as they do in short germ-band insects and other arthropods? Currently, the evidence remains ambiguous, since annelid orthologues of engrailed and wingless exhibit a variety of expression patterns. In Platynereis, both genes are expressed in reiterated segmental stripes in the ectoderm (Prud’homme et al., 2003), as are the orthologues of hedgehog and patched (Dray et al., 2010), in patterns broadly similar to those in Drosophila. However, in Chaeopterus, an engrailed orthologue is expressed in segmental stripes only in the nerve cord rather than the ectoderm, suggesting a different role (Seaver et al., 2001). In brachiopods (an unsegmented lophotrochozoan group related to annelids), an engrailed orthologue is expressed in a single ectodermal stripe that demarcates the anterior region of the embryo, and in at least one species this is abutted by a stripe of wingless expression (Vellutini & Hejnol, 2016). A segmental expression pattern for engrailed is apparent in the cephalochordate

Evolution and Development

123

Branchiostoma (Holland et al., 1997), but vertebrate engrailed orthologues are expressed in a single stripe spanning the midbrain/hindbrain boundary, as well as elsewhere later in development. This again suggests a different role from the segment-polarity function characteristic of en in Drosophila. Interestingly, a striped ectodermal pattern of engrailed expression is apparent in chitons (Polyplacophoran molluscs), corresponding to the articulations between “metameric” shell plates (Jacobs et al., 2000). This suggests a possible role for en in demarcating exoskeletal elements in a broad range of animal phyla. Notably, en stripes are absent in the ectoderm of modern onychyphorans (velvet worms), which like their Cambrian lobopod ancestors lack an exoskeleton. Instances of similar segmental expression patterns across different phyletic groups may thus reflect parallel evolution. Plausibly, the segment polarity genes originally constituted a genetic module for establishing boundaries between cell groups—but this module may have been co-opted to serve a range of functions in different animal groups (Vellutini & Hejnol, 2016). Arguments favouring a common segmentation process in all three segmented phyla—namely annelids, arthropods and chordates (see Couso, 2009)—are far from straightforward. The posterior growth zone where new segments are budded off (SAZ; except in long germ-band insects such as Drosophila) typically expresses one or more caudal orthologues (de Rosa et al., 2005), suggesting the primacy of this posterior signal for segment formation. In Drosophila, caudal is expressed zygotically in the hindgut as well as at the posterior end of the segmented region. In the nonsegmented nematode Caenorhabditis, the caudal orthologue pal-1 is also essential for posterior patterning. Ariel Chipman (2010) has argued for the independent but parallel evolution of segmentation in all three phyla, through co-option of similar pre-existing genetic modules for essentially similar purposes in each. Crucial component modules, apart from caudal, include the signalling pathways involving Notch and wingless/Wnt. As we saw earlier, Notch lends itself to generating cyclical patterns of geneexpression suitable for budding off new segments posteriorly. This occurs in vertebrate embryos during formation of paired mesodermal somites— governed by a clock and wavefront mechanism that can now be studied genetically in human pluripotent cell cultures (Matsuda et al., 2020). The somite clock utilises orthologues of Notch and a hairy/HES transcriptional repressor, while in mouse the wavefront involves Wnt and members of the FGF (fibroblast growth factor; Naiche et al., 2011) family. This genetic module could constitute a segmentation pathway present in the bilaterian LCA or could have been co-opted independently in all 3 segmented groups.

124

Chapter 4

4.11 Conserved genetic modules specifying body axes There seems to be no single common factor specifying position along the antero-posterior (A/P) axis in all animals. In Drosophila, the primary triggers are the AoP gradient of maternal bcd mRNA (and later Bcd protein) plus the PoA gradient of nos mRNA (and Nos protein). In the vertebrate CNS, a gradient of the morphogen retinoic acid (RA) strongly influences the position of expression boundaries for most hox genes, though this may not be the primary factor in setting up the A/P axis initially (see Held, 2017, pp. 7-20). Evidence suggests that bcd at least is a relatively recent innovation (Held describes it as a usurper!), and that the ancestral A/P pattern-forming gradients were established by caudal (Cdx in vertebrates) expression centred at the posterior end, and perhaps by orthodenticle (Otx in vertebrates) centred at the anterior end. This appears to hold true in at least some arthropods, as well as in a range of other bilaterian groups. Notwithstanding how it is initially established, the A/P axis is later regionalised by nested Hox gene expression patterns in most bilaterian animal groups (Fig. 4-8), and this may also hold true for the formation of radial metameric structures in some Cnidaria (Arendt, 2018). Things are little simpler for the other major body axes, which will be dealt with only in outline here. In Drosophila, the dorso-ventral (D/V) axis is also established by two morphogens. The decapentaplegic protein (Dpp) forms a DoV gradient, and dorsal protein (Dl) a VoD gradient, although the genetic circuitry involved in setting up these twin gradients is extremely complex. In mutants lacking wild-type Dl protein activity, ventral features are abolished so that only dorsal structures develop. The action of Dpp is antagonised by another protein (Sog) encoded by the short gastrulation gene. The vertebrate orthologue of Dpp is known as BMP4 (Bone Morphogenetic Protein 4), while the orthologue of Sog is chordin, and both are crucial for establishing the D/V axis in vertebrates (Fig. 4-8, right). However, what is dorsal in flies is ventral in vertebrates and vice versa. This reflects their anatomy, as pointed out by Geoffroy SaintHilaire (1822) two centuries ago, since the D/V axis of vertebrates appears to be inverted with respect to that of insects, and indeed most other animal groups. Arthropods have a ventral nerve cord and dorsal heart, in contrast to the dorsal spinal cord and ventral heart found in vertebrates and also in the cephalochordate Branchiostoma. It follows that vertebrates and certain other chordates resemble upside-down arthropods, though this inversion has necessitated a repositioning of limbs and mouth. Establishing the D/V axis in Branchiostoma (Onai et al., 2010) or vertebrate (Xenopus; De Robertis & Kuroda, 2004) embryos is a multi-step process, requiring many

Evolution and Development

125

molecular players apart from BMP4 and chordin. Recent sequencing of the Branchiostoma genome (Marlétaz et al., 2019) has also afforded valuable insights into the evolution of vertebrate gene regulation. Left/Right (L/R) asymmetries occur even in bilaterally symmetrical animals, as exemplified by the twists of the human gut and the asymmetric placing of major gut organs, or indeed the left-side placement of the heart. Key to this is the asymmetric expression of another conserved signalling protein, Nodal, only on the left side but not on the right. The underlying regulation of Nodal is complex, as illustrated by several situs inversus mutations that cause reversals of this L/R axis (Held, 2017, pp. 26-35). However Nodal is expressed instead on the right-hand side in echinoderms, hemichordates and also in lophotrochozoans (this gene is apparently absent in ecdysozoans). The D/V axis inversion in vertebrates may underlie this reversal of Nodal expression from the right- (Fig. 4-8) to left-hand side. Finally, a proximo-distal (P/D) axis needs to be established for any outgrowth from the main body of an animal. Even in some worm-like groups, there may be appendages such as the segmental parapodia used for motility in polychaete annelids. Other examples of such outgrowths include tetrapod or arthropod limbs (not to mention sensory and feeding structures such as antennae, palps and mouthparts), or fins in fish. In Drosophila, mutation of a homeobox gene called Distal-less (Dll) results in the loss of distal portions of all appendages, implying that the wild-type Dll gene functions to specify these distal structures (Fig. 4-8; Carroll, 2006/2011, pp. 69-71). Dll expression is initiated where segmental bands of wingless expression intersect with the dorsal stripe of dpp expression extending along the A/P axis. Vertebrates possess multiple Distal-lessrelated homeobox (Dlx) genes, commonly arranged in pairs close to the HoxA/B/D (but not HoxC) clusters. The Dlx genes have multiple functions, not only in limb outgrowth, but also in craniofacial development and in the growth of nerve cells in the brain. In annelids, the role of Dll orthologues remains unclear; they are expressed in parapodial rudiments in certain species but apparently not in others, while expression in the brain and nervous system is also prominent. It is still a moot point as to whether the LCA of all bilaterians possessed appendages whose distal parts were specified by an ancestral Dll gene (cf. Fig. 4-8), or whether this gene had a primary function in neural tissue, but has subsequently been co-opted for a major role in distal limb development in both arthropods and chordates, and maybe also in some annelids. The latter view is supported by a variety of animals with no limbs or other outgrowths from the body (e.g. nematodes, or cephalochordates such as Branchiostoma), yet which still express Dll orthologues—primarily in the nervous system.

126

Chapter 4

Figure 4-8. Shared features of most Bilateria. Diagrammatic representation of a bilaterian animal with staggered expression of Hox genes (only alternate members of cluster shown for clarity) along its anterior-posterior axis, plus Pax6 expression initiating the formation of anterior eyes, Distal-less expression specifying distal regions of limbs or other outgrowths, and Nodal expression on the right-hand side of the ancestral body (left in vertebrates) determining left/right asymmetries (dark grey spots to right of black midline). Insert to right of main figure shows opposing protein gradients of Decapentaplegic/BMP4 and Sog/chordin specifying the dorsal/ ventral axis (ch = inverted chordate pattern). Intensity of expression is indicated by gradients of shading, but anatomical detail is omitted. The structures shown (unlike the requisite genes) need not have featured in the LCA of all bilaterians.

4.12 Some lessons from evo-devo Of necessity, this has been a rather brief excursion through early development in a range of animals, focussing largely on the A/P axis and its regionalisation via Hox genes. What should be apparent from the foregoing is that the functions of key pattern-forming genes are conserved but by no means identical across the animal kingdom. Many mid-20th century CE evolutionary geneticists were gloomy about the promise of evo-devo, and speculated that conserved genes governing development would most likely be found only in closely related animals. However, the discovery of Hox genes in the 1980s seemed to suggest the opposite: namely, a set of universal genetic instructions for establishing diverse animal body plans. Even so, this notion of “deep homology” may also be over-simplistic, since virtually none of the “rules” are truly universal, and there are well-documented exceptions to most of them. A halfway house

Evolution and Development

127

seems a safer bet—where conserved genetic modules undergo regulatory changes that modify but do not abolish their functions. As pointed out by Gould (2002) and many others, evolution engages in tinkering with the ancestral genetic toolkit—adjusting regulatory inputs here, suppressing old outputs there, and establishing new pathways with a motley assortment of ancient genes cobbled together from diverse origins. This makes eminent sense from an evolutionary perspective: even the most striking novelties cannot appear out of nowhere overnight, but rather require a gradual, progressive modification of pre-existing genes, pathways and structures. The stepwise evolution of avian flight feathers from keratin filaments in ancestral dinosaurs was mentioned in the Preface (also § 3.6 and Fig. 3-8). Nor is this strategy unique to animals: the great German writer Johann Wolfgang von Goethe was also a gifted naturalist, and in one paper suggested that the various parts of flowers were in fact modified leaves (Goethe, 1790). His conjecture was proved correct two centuries later with the elucidation of plant homeotic mutants involving genes such as APETALA and AGAMOUS. These in turn are influenced by the upstream regulator LEAFY—whose inactivation converts all of the floral whorls into leaves. The ABC model of floral development (Haughn & Someville, 1988) requires three genes designated A, B and C: expression of A alone leads to sepals, whereas A+B combined leads to petals, B+C to stamens, and C alone to carpels. Variants of this model can account for many diverse floral patterns. In the model plant Arabidopsis thaliana, type A activity is shown by APETALA1/2, type B activity by APETALA3 and PISTILLATA, and type C activity by AGAMOUS (Fig. 8-9). Like Hox genes in animals, these plant genes encode transcription factors that help to specify the identity of outgrowths from the floral growth zone (meristem), with “leaf” as a kind of ground state. However, there are also important differences—most notably the fact that these plant homeotic genes are not members of the Hox clan, but usually encode MADS box DNA-binding transcription factors (reviewed by Ng & Yanovsky, 2001). By examining the repertoire of key developmental genes available in the genomes of different animal (or indeed plant) groups, it is possible to make reasonable inferences about the likely genetic repertoire of their LCA. For example, homeodomain TFs are present in fungi, plants and sponges, but Hox genes as such are not represented in these groups. In Cnidaria such as Hydra and Clytia, Hox cluster genes (paralogues 1, 2 and 9-14 only, 3 to 8 being absent) are expressed sequentially during head regeneration, but with no clear regional expression pattern along the major body axes (Chiori et al., 2009). Thus, in contrast to most bilaterian

128

Chapter 4

animals, there is little evidence in Cnidaria for the delineation of axial regions through a “Hox code”. One exception here is Nematostella, a sea anemone displaying signs of bilateral symmetry, which shows nested radial expression patterns for several Hox genes (He et al., 2018), plus localised expression of a dpp orthologue in a second body axis (Finnerty et al., 2004); these features may predate the split between Cnidaria and Bilateria.

Figure 4-9. ABC model of floral development. In the centre is a diagrammatic outline of flower structure, with whorls of sepals, petals, stamens and carpels—all distinct from leaves. Centre left is a simplified version of the ABC genetic model, where A alone specifies sepals, A+B petals, B+C stamens and C alone carpels. These are all upregulated by the upstream TF LEAFY, in whose absence all floral whorls develop as extra leafy shoots, as shown on far left. On the right are shown the homeotic transformations caused by mutants abolishing type A (bottom), type B (centre) and type C (top) activities. In Arabidopisis thaliana, type A genes are APETALA 1 and 2, type B are APETALA3 and PISTILLATA, and type C is AGAMOUS. Diagram based on Ng & Yanovsky (2001).

The phylum Ctenophora (comb jellies) was formerly classed along with Cnidaria within the Radiata—but like sponges, ctenophores appear to lack true Hox genes. Ctenophoran genome sequences (Moroz et al., 2014 for Pleurobranchia; Ryan et al., 2013 for Mnemiopsis) differ in significant respects from both bilaterian and cnidarian genomes, suggesting that the Ctenophora might represent the most basal branch of the animal tree, a separation perhaps even predating that of the sponges—judging from the genome sequence of the demosponge Amphimedon (Srivastava et al., 2010). If so, then ctenophores could no longer be classed as Radiata along with the (less divergent) Cnidaria. Moreover, sponges lack both nerve and muscle cells yet ctenophores possess both, perhaps implying independent but convergent evolution of both cell types in ctenophores and in the common ancestor of Cnidaria and Bilateria (Moroz et al., 2014). Although

Evolution and Development

129

sponges lack nerve cells, their genomes do possess the requisite genes for a functional nervous system, raising the alternative possibility that this feature might have been lost secondarily (Srivastava et al., 2010). Recent cell lineage studies suggest that ctenophoran nerve cells arise from the same progenitors as secretory colloblast cells (whose “glue” traps plankton as food); the same is also true for neurons and stinging cells in jellyfish (Cnidaria; Pennisi, 2019b). If so, this might favour a single evolutionary origin for animal nerve cells—and perhaps their secondary loss in sponges. A useful overview of the likely genetic repertoires available in the LCAs of major animal groupings is given in chapter 9 of Erwin & Valentine (2013, pp. 294-317), though this is a highly speculative and rapidly changing field (compared by the authors to “seeing ghosts”!), and is rife with competing interpretations and hypotheses. As we have seen, it is possible, but not strictly necessary, to infer that the LCA of all animals had functioning nerve cells (later lost in sponges)—although this ancestor must already have possessed the genes needed to construct a basic nervous system—since otherwise this gene-set would have to evolve at least twice independently. Similarly, the LCA of all bilaterians need not have been segmented, nor possessed eyes or appendages (despite Fig. 4-8), but the requisite genes must already have been present. It remains true that each of these features occurs in some but not all bilaterians, and their secondary loss cannot be excluded. Indeed, comparative genomics can look still further back, for instance to the LCA of all eukaryotes. Again, widespread features such as multicellularity and tissue organisation most likely evolved several times independently, notably in plants/green algae and in animals, as well as in the brown and red algae, and in fungi (many of these groups include unicellular forms). As more present-day genomes are sequenced, these inferences will become better founded, but in the absence of truly ancient DNA definitive proof remains elusive. Even trapped insects preserved in copal (a sub-fossilised precursor of amber) contain no DNA that can be extracted or sequenced (see Penney et al., 2013), so this hypothetical window onto the past remains opaque, at least for now. Ultimately, the breathtaking diversity of eukaryotic life depends on complex patterns of gene expression, resulting from flexible modular control through numerous enhancer and silencer regions that bind multiple TFs and perhaps non-coding RNAs (§ 1.4; Carroll, 2006/2011, pp. 118131). Favourable traits that increase fitness and are thus selected need not always arise through mutations in the coding sequence of a gene, but may instead involve alterations in one or several aspects of a gene’s regulatory switchgear (e.g. Pitx1). There is good reason to suppose that combinations of similar but more extensive changes could underlie speciation and even

130

Chapter 4

the emergence of higher-level taxa (chapter 2). The fossil record attests to a vast diversity of animal life since the Cambrian, and is replete with examples of convergence (chapter 3). But it is vital to distinguish cases where different genetic toolkits are deployed to construct a similar endpoint (truly convergent evolution) from those where similar ends are achieved by reusing the same basic toolkit (parallel evolution). The latter may imply underlying deep homologies across many animal phyla, since striking parallels and conserved expression patterns abound, even between such apparently dissimilar organisms as humans and fruit-flies (Held, 2017). For instance, a gene called tinman in Drosophila and (more prosaically) Nkx2.5 in vertebrates specifies heart development and cardiac muscle differentiation in both, despite the enormous evolutionary distance between Ecdysozoan protostome fruit flies and deuterostome humans. The quirky—indeed humorous—name of this Drosophila gene arises from its mutant phenotype, which develops without a heart. Held (2017, pp. 127134) describes several other parallel features of heart development that also link flies and vertebrates. The Drosophila pair-rule gene odd-skipped (encoding a zinc-finger TF) plays a second important role in the later formation of joints along the limbs, not only in insects, but also in vertebrates. Overall, the evidence presented in this chapter suggests that evolution has tinkered extensively with the functions and expression patterns of conserved developmental genes, both within and especially between taxa. In the next chapter, we will look in outline at the picture that science paints of human beings, including their evolution from primate ancestors, their apparently unique traits—many of which are in fact shared with at least a few other animals—and the possible origins of transmissible culture through language and later writing.

CHAPTER 5 HUMANITY

Summary § 5.1 outlines the close genomic relationships between humans and great apes (collectively hominids), and traces our hominin ancestry along with other species of Homo, e.g. Neanderthals. § 5.2 asks what can be learned from the human genome about ourselves—including cultural adaptations, disease susceptibility and personality traits. These last are also strongly influenced by our environment—raising the question of nature versus nurture (commonly studied in identical twins), as discussed in § 5.3. This section also addresses genetic determinism and whether humans can have free will. § 5.4 describes how humans inherit mitochondrial DNA from their mothers, and men their Y chromosome from their fathers, together with questions of ethnicity that have very little to do with genetics. § 5.5 looks briefly at the human brain, neural circuits and functional brain imaging, while § 5.6 asks how a unified sense of “self” can arise from neural processes distributed across several different regions of the brain. § 5.7 looks at the role of the FOXP2 gene in human language production. This gene reappears in the context of animal vocal communication in § 5.8, which asks how far humans are truly unique among animals. § 5.9 briefly sketches of the development of human culture. In § 5.10 the co-evolution of genes and culture is outlined, but this seems too slow to account for rapid cultural changes in recent ages. Dawkins’ concept of memes—units of cultural inheritance analogous to genes—is discussed in § 5.11. This is followed by a brief account of some plausible evolutionary interpretations of religion in § 5.12. Finally, § 5.13 reconsiders consciousness and memes, ending with a musical illustration that links directly ino part 2.

5.1 What does our genome tell us about our ancestry? I am conscious of venturing where angels fear to tread in writing this chapter. Nonetheless, it represents an important pivotal point in this book, since Homo sapiens can be described scientifically in terms of our evolution,

132

Chapter 5

development, genetics and psychology, while also taking centre stage in the humanities—perhaps particularly in the arts and religion. Darwin’s theory of evolution clearly implied that humans are descended from great apes, a point elaborated in his later book “The Descent of Man” (Darwin, 1871). This ancestry has been confirmed by many subsequent studies—but perhaps most definitively by recent genome sequencing. The draft human genome sequence was reported simultaneously in 2001 from two projects, one publicly and one privately funded (International Human Genome Sequencing Consortium, 2001; Venter et al., 2001). Since then, full genome sequences have become available for all of the great apes— namely chimpanzees, orang-utans, bonobos and gorillas (Chimpanzee Sequencing and Analysis Consortium, 2005; Locke et al., 2011; Prüfer et al., 2012; Scally et al., 2012), and for Neanderthal remains (Prüfer et al., 2014). These sequences confirm that humans are indeed related most closely to chimpanzees among the great apes; the number of single basepair alterations is 1.2%, though the overall sequence difference is greater than this due to insertion and deletion events (Varki & Altheide, 2005). Certain genes have undergone positive selection during the evolution of modern humans from an ancestor shared with chimpanzees 5 to 13 Ma (Khaitovich et al., 2005). The split between these two lineages seems to have been long and complex, with periods of divergence followed by hybridisation. A major hair keratin gene has been lost from the human line, perhaps in part accounting for humans’ lack of body hair, and several genes that regulate brain size have evolved adaptively in humans, including microcephalin/MCPH (Evans et al., 2005) and ASPM (Mekel-Bobrov et al., 2005). Three Notch-related genes unique to humans and Neanderthals (termed NOTCH2NL A, B and C; Fiddes et al., 2018) are expressed at high levels in proliferating glial stem cells within the embryonic brain cortex, delaying their differentiation into nondividing cortical neurons and thereby promoting brain growth. Deletions of the A and/or B genes result in microcephaly (reduced brain size), while duplications cause macrocephaly (increased brain size). These genes seem to play a key role underlying the large size of human brains. Notably, this genomic region is represented by non-expressed pseudogenes in gorilla and chimpanzee. Increased cranial capacity (BV = brain volume), along with hairlessness, a unique upright bipedal gait, and hands with opposable thumbs enabling fine manipulation —all were crucial for the evolution of modern Homo sapiens. But these anatomical traits provide no more than a necessary substrate for humanity, and cannot fully account for what it is that makes our species distinctive. The precise ancestry of modern H. sapiens is still hotly debated, but since our lineage split from that of chimpanzees and bonobos (BV 400 cubic

Humanity

133

centimetres = cc), human ancestors have likely included Australopithecus afarensis (c. 4 Ma, bipedal, BV 450 cc), Homo habilis (c. 2.5 Ma; prolific tool-maker, BV 650 cc), and H. erectus (c. 1.8 Ma, advanced tool-maker, BV 1200 cc). For comparison, the BV of modern humans is 1300-1400 cc, thrice that of Australopithecus. Confusingly, the term hominid now denotes the primate group comprising humans and great apes (current or extinct), whereas hominin denotes only the sub-group distinct from great apes— comprising modern humans, their ancestors, and extinct related species. Neanderthals probably represent a separate species in the genus Homo (H. neanderthalensis), though they have also been seen as a subspecies of human (H. sapiens neanderthalensis). Their brain volume was comparable to ours, but due to their larger build, this represented a smaller proportion of total body mass. The genome sequences of these two hominins are over 99% identical, and there is strong evidence for interbreeding between them. Neanderthal DNA sequences were first detected in non-African human populations (Sankararaman et al., 2014), but have recently been found in African populations as well (Chen, L., et al. 2020); moreover, human sequences are also detectable in Neanderthal DNA. Why the Neanderthals became extinct some 30,000 years ago is still a matter of debate. Possibly they were absorbed through interbreeding into populations of Homo sapiens migrating out of Africa, but they could conceivably have been the victims of genocide (by humans), or of unfamiliar disease pathogens (spread by migrant humans?), or of climate change. Neither mitochondrial DNA (maternally inherited) nor Y chromosomal DNA (paternally inherited) of Neanderthal origin has been detected in modern humans, but this could simply be a consequence of the accidental loss of any human lineages that once carried these sequences. It is likely that other hominins also co-existed alongside modern humans until ~50,000 years ago—such as the diminutive (1.1 m) “hobbit”-like species from the island of Flores, Homo floresiensis (Morwood et al., 2004; van den Bergh et al., 2016). Though H. floresiensis had a small brain (BV only c. 425 cc), there is good evidence for both tool use and hunting ability. Some data suggest that this species may be a primitive offshoot of the human evolutionary tree, descended from H. habilis rather than the more recent H. erectus. This could be a case of island dwarfism, where evolution of small stature is favoured on islands with limited resources. Other hominins include the mysterious Denisovans (see Callaway, 2019) and the recently reported Homo luzonensis from the Philipppines (Détroit et al., 2019). Perhaps our legends and myths of other humanoid creatures carry distant echoes of past encounters with peoples who were indeed both like and unlike us?

134

Chapter 5

Recent evidence seems to imply that Neanderthals might have engaged in art, or even in abstract symbolic thought. A criss-cross pattern of deeply incised lines on a rock slab in a Gibraltar cave has been dated to 39,000 years ago, well before modern humans reached the southern Iberian peninsula (Rodríguez-Vidal et al., 2014). But since Homo sapiens lived in North Africa across a narrow strait at that time, it is conceivable that some of them found a way of crossing over. There are also controversial claims that Homo sapiens reached southern Greece 200,000 years ago, but later died out (Harvati et al., 2019). Putative Neanderthal cave paintings (including hand-stencils and abstract patterns of lines and dots) have been identified at three widely separated sites in Spain; these were dated, using Uranium 234-Thorium230 ratios, to ~64,000 years ago—some 20,000 years before modern humans migrated into western Europe ~45,000 years ago. If true, a Neanderthal origin for these paintings would seem the simplest explanation, as this was the only hominin species living in the area at that time (Hoffmann et al., 2018). However, considerable caution has been raised about this dating (Slimak et al., 2018); until it can be confirmed by independent methods, the case for crediting human-like artistic abilities to Neanderthals is best regarded as unproven. Certainly the great flowering of cave art by modern humans, dating back as far as 40,000 years ago in Europe, is seen by many as the first clear evidence of “religious” symbolism in human history (Aslan, 2017, pp. 3-18). Many such painted images were executed in parts of the cave system that were difficult to access, and usually remote from regions that were lived in. The images in Fig. 5-1 come from the Grotte du Pech-Merle near Cabrerets in the Lot region of France, which is one of the few painted caves still open to the public (albeit in strictly limited numbers). These hand-stencils (both parts) and vivid animal images (Fig. 5-1B), as well as more abstract designs (e.g. the dots in Fig. 5-1A), were definitely painted by modern humans ~25,000 years ago—some time after the final disappearance of Neanderthals.

Humanity

135

Figure 5-1. Cave paintings from the Grotte du Pech-Merle. Public domain images showing two of the many hand-stencils (parts A and B), an abstract pattern of red dots (part A), and vivid images of spotted horses (part B); source "Grotte de Pech Merle" by CyclicalCore is licensed under CC BY-SA 3.0.

5.2 What does our genome tell us about ourselves? Now that numerous individual genomes from many diverse human populations have been sequenced, one can ask whether specific variant alleles have been selected differentially, and how far this has been influenced by particular cultural practices (Laland et al., 2010)—in other words, have human genes and cultures co-evolved? Genetic criteria have been established for detecting strong positive selection, and among the genes fulfilling those criteria are many involved in pathogen resistance and metabolism of local dietary items. One classic and well-established case-study in this field involves the co-evolution of lactose tolerance and pastoralist practices such as livestock rearing. In most human populations, the ability to digest milk (using the enzyme lactase) is lost during childhood when the lactase gene is switched off; individuals are thereafter lactose-intolerant and cannot digest milk products. Presumed regulatory mutations (mapping well upstream of the gene start site) allow lactase expression to persist into adulthood, conferring lactose tolerance and hence the ability to digest milk products throughout life. One such lactosetolerant variant is very widespread in northern Europeans, others in African and in Middle Eastern pastoralist populations; in all of these, dairy products have been an important foodstuff for thousands of years. Even so, these variants have not been detected in human DNA dating from 7080,000 years ago, suggesting strong selection among Neolithic pastoralist groups who engaged in livestock rearing and the consumption of dairy

136

Chapter 5

products. Lactose tolerance would offer a major survival advantage when other food sources were scanty (Curry, 2013). Populations that consume fermented milk products (cheese or yoghurt, containing lower levels of lactose)—rather than fresh milk—display intermediate levels of lactose tolerance. Fermentation microbes break down much of the lactose, without destroying the rich fat and protein nutrients in milk. This may explain why certain pastoralist groups (e.g. Mongolian herders; Curry, 2018) remain lactose-intolerant even today, and why there was a long time-gap between the first adoption of dairy practices and the appearance of lactose-tolerant mutations. Similarly, the number of copies of the gene encoding salivary amylase for digesting starch correlates closely with dietary starch intake. Over the past few decades, enormous research efforts have been devoted to investigating the genetic basis of many different human diseases, focussing especially on chronic conditions that cause major health problems or mortality in the West. For infectious or parasitic diseases— which are far more prevalent in developing countries—effective drug treatments are becoming vitiated by the spread of drug resistance among pathogens, so it is here that belated research efforts are being focussed. The majority of simple Mendelian genetic diseases (recessive, or more rarely dominant) are relatively infrequent in human populations, although a minority are far commoner than would be expected. One such disease is sickle-cell anaemia, caused by a point mutation in the E-globin gene that encodes one of the two globin proteins whose Į2E2 tetramers make up the oxygen-binding haemoglobin of red blood cells. Two copies of this recessive ES mutation cause full-blown sickle-cell anaemia, where red blood cells adopt an inflexible sickled shape that restricts oxygen delivery to the tissues. Given this severe (usually fatal, if untreated) disease phenotype in double-recessive offspring, why is this ES mutation maintained at high frequencies in certain human populations (up to 20% in parts of Africa)? The explanation here involves heterozygote advantage, where heterozygotes carrying one wild-type E and one mutant ES gene are not only healthy, thanks to the wild-type allele, but also show significantly higher resistance to the Plasmodium malarial parasite. This means that such heterozygotes (50% of offspring, versus 25% double recessive) have a selective advantage in areas where malaria is endemic (Allison, 1954). In fact, as Laland (2017, pp. 218-222) points out, there are also strong cultural influences in this story; the Kwa-speaking people of West Africa used to clear patches of forest by slash-and-burn methods in order to cultivate crops, but inadvertently caused soil erosion and the formation of pools of standing water—which became breeding grounds for malarial mosquitoes, thereby increasing selection for the ES allele. But the principal

Humanity

137

crop grown in recent times has been yams, which turn out to contain compounds that are beneficial to sufferers from sickle-cell disease: this is hardly coincidental! Similar disease-resistant heterozygotes may explain an unexpected prevalence of other single-gene conditions, e.g. cystic fibrosis. However, the majority of non-transmissible human diseases—such as cancers, diabetes, many dementias and cardiovascular diseases—are caused by a multiplicity of interacting factors. Some of these are genetic in origin (involving risk-factor alleles that confer a propensity to develop that disease), some result from lifestyle choices (e.g. diet, smoking or lack of exercise), and some involve acute or chronic exposure to environmental influences (such as natural or occupational toxins). For many common diseases, the genetic risk factors involved are themselves highly complex, with different alleles of multiple genes conferring varying degrees of risk. Human genetics, in the form of pharmacogenomics, can help more directly in treating patients with such diseases, since variant alleles that alter the metabolism of specific drugs and render them ineffective can be identified by genetic testing, allowing clinicians to home in directly on those drugs that are more likely to work well for any individual patient. Overall, these studies of multi-factorial diseases carry the clear implication that human disease susceptibility is not purely genetic, but also reflects prenatal uterine exposure to maternal antibodies, as well as the upbringing, surroundings, lifestyle choices and personal history of each individual— collectively termed “environmental factors”. It is to these that we turn next, as we examine the long-running but inconclusive “Nature/Nurture” debate—roughly translated for biologists as “genes versus environment”.

5.3 Nature versus Nurture? Of course, when posed like this as a stark opposition, the false dichotomy here becomes immediately apparent. Common sense tells us that genes and environment (which includes upbringing) must both play important roles in the persons we become. We are neither blank slates upon which culture and environment can write unhindered, nor are we automata whose every move and response is dictated by our genes (dubbed “genetic determinism”). A halfway house of “both/and” seems far more appropriate than “either/or” in this context (Robinson, 2004). The study of identical or monozygotic twins affords one useful tool for disentangling the roles of genes and environment— e.g. in the development of human diseases, in behavioural patterns (such as risk-taking or alcoholism), or in personality traits Non-identical or dizygotic twins develop (Fig. 5-2A) when a woman releases 2 eggs simultaneously and both are fertilised by different sperm; these twins therefore show the

138

Chapter 5

same genetic relatedness (50%) as ordinary siblings from the same parents, though they also shared the same uterine environment (an important aspect of nurture), which normal siblings do not. By contrast, monozygotic twins arise when one embryo—derived from a single fertilised egg—splits into two during early development (Fig. 5-2B), with each fragment regulating (§ 4.5) to form a complete but separate individual. In consequence, such twins are genetically identical (100%). Splitting can occur at any time during the first 14 days of development (Fig. 5-2B), though identical twinning at later stages (e.g. during embryonic axis formation) usually results in conjoined twins sharing organs or skeletal elements—situations which may or may not allow postnatal separation by surgery. Yet even identical twins can develop very different personal identities—as in the cases of the Belgian twin boys Arno and Aaron Monsecour. The former became a professional footballer, while the latter experienced gender dysphoria and later transitioned to a female identity as Nora—now a top-flight dancer (Smith, 2019). Clearly there must be facets of personality that are not solely dictated by genetic factors. Even in singletons, the left and right halves of the brain have rather different functions and outlooks on the world, a question explored in fascinating depth by Iain McGilchrist (2009).

Figure 5-2. Twinning. Diagrammatic representations of the early developmental events leading to non-identical dizygotic twins (Part A; left) versus genetically identical monozygotic twins (Part B; centre and right). Mammalian embryos regulate to achieve normal size after embryo splitting, which can occur at any stage up to and including the formation of the embryonic axis at around 14 days in humans. In Part B, both an early split at the 2-cell stage (centre) and a later split within the inner cell mass (right) are shown.

Humanity

139

A large meta-analysis surveying the results of 50 years of published twin studies (Polderman et al., 2015) concluded that the overall heritability of the traits studied—i.e. the extent to which they are determined by genetic rather than environmental factors—was 49%, suggesting a virtual draw in terms of the nature/nurture controversy. Almost all of the similarity between identical twins is genetic in origin, down-playing the role of shared environmental factors (both intrauterine and during postnatal upbringing). Of course, it all depends on which traits are under study; some are almost wholly genetic (nature), while others are largely environmental (nurture). But even monozygotic twins may in later life become increasingly discordant in terms of gene expression profiles (Fraga et al., 2005), arising from differences in DNA methylation (§ 1.4) that presumably reflect different environmental influences on each twin. Curiously, homosexuality shows unexpectedly low genetic influence in such twin studies, except for a minority subgroup where male relatives on the mother’s side are also homosexual (Sanders et al., 2015); here, the apparent genetic influence observed may involve one or more sites on the maternal X chromosome, particularly Xq28. However, a recent large-scale genome-wide association study discounts this specific site, but identifies 5 others that show significant associations with non-heterosexual behaviour —yet cannot predict sexual orientation (Mills, 2019; Ganna et al., 2019). Homosexuality is a good example of a superficially uniform trait that probably has multiple manifestations and underlying causations, arising from the interaction of numerous environmental as well as genetic factors (de Pomerai, 2008). Same-sex sexual behaviour (SSSB) has been observed in many different animals as well as humans, making it difficult to suggest plausible evolutionary explanations for traits that cannot serve any obvious reproductive function. Perhaps the simplest interpretation is that SSSB may occur by default, alongside heterosexual behaviour (Monk et al., 2019). With sufficiently large samples of twins, it is possible to disentangle different components of the environmental influences affecting such traits. Monozygotic twins reared together (MZT) shared a family upbringing, whereas those reared apart (MZA) did not. Similarly, dizygotic twins (DZ) shared the same uterine environment, whereas normal siblings did not, though both have the same degree of genetic relatedness (50%). Strong influences from upbringing affect adoptive children (genetically unrelated) as well as natural children, but environmental effects of upbringing may fade later in life, so that genetic effects become proportionately stronger.

140

Chapter 5

For my own part, I am wary of genetic determinism, since if we believe that our choices and behaviours are wholly dictated by our genes, then we seem to be absolved of any direct responsibility for our actions—however callous or downright evil. “It was my genes that made me do it, m’lud” strikes me as a weak defence in law, although in fairness much the same could be said about extreme versions of environmental determinism (“it was my upbringing that made me do it”), as noted by Daniel Dennett (2003/2004, pp. 157-158). Even so, there are numerous legal precedents for taking account of psychological factors as mitigating circumstances. None of these provides us with complete exculpation from responsibility for our deeds. An engaging account of the uneasy relationship between genetics and the law is given in chapter V of Steve Jones’ “In the Blood” (1996), though this was written in the pre-human-genome era. Findings from experimental psychology seem to suggest that our neural circuits react automatically before we have had time to think consciously about what our responses should be—in other words, these reactions seem to be hard-wired into our nervous systems—implying they are under the control of unconscious neural circuits rather than our conscious choice (free will). The best-known experiments of this type were conducted by Benjamin Libet’s group (Libet et al., 1999), setting out to measure brain activities correlated with simple voluntary actions such as flicking one wrist. Subjects were asked to register the time of their conscious decision to carry out this action, but in fact such decisions were always preceded up to a second beforehand by a Readiness Potential (RP)—a wave of neural activity in the brain that is a highly reliable predictor of the action. At first sight, it looks as though our “conscious intention” merely confirms a decision that has already been made unconsciously in the brain. Daniel Dennett (2003/2004, pp. 227-242) discusses this experiment in some detail, pointing out that the subject’s decision will most likely involve a different region(s) of the brain from the visual centre that notes the clockface position of a rapidly rotating dot acting as a time-marker for the conscious decision to flick a wrist. Either or both of these brain areas may communicate relatively sluggishly, in which case the conscious decision might still precede the RP. A related resolution of this apparent paradox is given by Susan Greenfield (2016, pp. 84-86), in terms of the half-second “processing delay” that characterises our conscious awareness of the present moment. It follows that truly fast reactions (e.g. returning an ultrarapid serve in tennis) must be learned through assiduous practice so that the need for conscious decision-making is effectively by-passed. Dennett (2003/2004) concludes that, in reality, Libet’s experiments do not deal the fatal blow to human free will that many fear, and this cherished freedom is

Humanity

141

defensible (albeit not in the full libertarian sense) within a deterministic universe. However, free will is writ large only within the social, linguistic and intellectual complexities of human interactions (envisaged as “degrees of freedom”, to borrow a phrase from statistics). It is a capacity that has evolved far more strongly in humans than in other animals, since these interactions afford us far more options, despite the interventions of simple luck or happenstance. Even those of us who baulk at Dennett’s materialism should nevertheless celebrate his defence of human free will. My own academic career hung on a finely poised choice back in the spring of 1978, when I received two invitations to interviews for tenured university lectureships scheduled on the selfsame day (14th March), one in the Department of Zoology at Nottingham, the other in the Department of Developmental Biology at Aberdeen. That much is pure coincidence. Left to my own devices, I would have chosen the latter, not least because of my love of Scottish mountains. But I was married at that time to Val, whose family lived a long way south in the small North Devon town where I had grown up. Aberdeen was even further away than Edinburgh, where we were then living. So my free-will choice was constrained in this instance by family considerations; I opted for the Nottingham interview and was fortunate enough to be appointed. But hindsight gives us new perspectives on past choices. Had I guessed that Val would die of Hodgkins’ disease within a year of my move to Nottingham, would I have held out for Aberdeen? Conversely, moving forward a few years, I felt justified in my original decision on reading that Aberdeen had decided to close its Department of Developmental Biology! But neither event was readily foreseeable early in 1978. This underlines the importance of happenstance and geography; events in my life cannot be seen as an inevitable readout from my genes, but only as dynamic selections from among innumerable possible readouts, each one conditional upon local circumstances.

5.4 Ethnicity, gender and genetics Most of us claim some sort of ethnic affiliation, to a group or groups with whom we identify. In my own case, I think of myself as slightly more than half French, on the grounds that my mother Odile was born in Normandy during World War 1 (a conflict which claimed the life of her father, Jules Morcamp, before she was even born), while my father’s surname is linked to one Raoul de la Pommeraye, whose name appears among the companions of William the Conqueror on the plaque at Falaise Castle in western Normandy. Needless to say, it isn’t quite that simple.

142

Chapter 5

Raoul’s name appears on no other list of those companions, so he might just have been a local Norman freebooter who headed over to England only after the battle of Hastings had been won. Furthermore, my father changed his original surname by deed-poll from Tolley to de Pomerai, adopting a Frenchified version of his mother’s maiden name, Pomeroy! On my mother’s side, however, the Norman roots go deep…. So I am probably not 50% anything, and both parents have provided a diverse mix of genes from different origins (see below). This is, indeed, typical of the Normans—who ruthlessly expanded their mediaeval territories through military conquest—not just across Britain, but also in southern Italy and Sicily, and even as far as Antioch—but then adapted and assimilated into local populations through interbreeding. This is a pattern of settlement that has been repeated innumerable times throughout human history. Female human cells carry two copies of the large X chromosome, whereas male cells carry one X chromosome and one much smaller Y chromosome—which all men inherit from their fathers. As explained in chapter 4, mitochondrial DNA (mtDNA) is inherited solely through the female line. However, recent evidence (still disputed) has suggested the possibility that mtDNA can rarely be inherited from the father as well (Luo et al., 2019)—presumably from the mitochondrion that powers the sperm cell but which normally remains outside the egg during fertilisation. By examining sequence variations in mtDNA, it is possible to trace all present-day human groups back to a single mtDNA prototype—so-called “mitochondrial Eve”—who probably lived 200,000-250,000 years ago in a former wetland region of southern Africa (Chan et al., 2019). This inferred location reflects the fact that the deepest forks in the evolutionary “tree” of mtDNA sequences separate different populations within that part of the continent. A more accurate descriptive phrase is our mitochondrial most recent common ancestor (mtMRCA). However, the migration pattern of modern humans out of Africa is far from straightforward. Similarly, all Y chromosome variants can be traced back to a prototypic “Y-chromosomal Adam” or Y-MRCA, who probably lived around 200,000-280,000 years ago (though this is more controversial) in western Africa—most probably not at the same time nor in the same place as mitochondrial Eve. Although these Biblical nicknames have helped to popularise this research, they are in fact quite misleading. Mitochondrial Eve and Y-chromosomal Adam were not a couple, nor were they the only humans who existed at that time. Rather, mitochondrial Eve is the only female human whose descendants include an unbroken line of daughters, grand-daughters, great-granddaughters and so on. Among the descendants of other women living at the same time as mitochondrial Eve, at some point there were only male

Humanity

143

descendants (or none), so that the female line needed to transmit that mtDNA was broken. Similar arguments apply to Y-chromosomal Adam; at some stage, the family trees of all other contemporaneous males produced either no offspring at all or else only daughters, so breaking the male line required to pass on that Y chromosome. The numerous sequence variants that have subsequently appeared in both mtDNA and Y chromosome sequences predominantly reflect the later accumulation of neutral mutations among modern human groups, whose unbroken female or male ancestry can be traced back to these two prototypes. But this does not mean that all our genes originated from mitochondrial Eve and Ychromosomal Adam; all we can say is that our mtDNA came from the former, and for men that our Y chromosome came from the latter. Though Neanderthal genes are detectable in all modern humans, there are no signs of either Neanderthal mtDNA or Y chromosome sequences. A variety of genetic approaches have been used to trace patterns of human migration and ethnicity—many of them predating the sequencing of the human genome (Jones, 1996, pp. 124-167). Fascinating as this story is, my focus in this chapter is rather different, and I will confine myself to just a few examples. Ethnic groups that have remained isolated for very long periods tend to show the most uniform and often unusual palette of genetic sequences, whereas populations that have migrated, colonised other lands, or been invaded, show evidence of greater genetic mixing through interbreeding—with a more diverse range of genes from multiple sources. Commercial DNA sequencing companies will now (for a fee) sequence selected regions of your genome and use this information to infer your most likely ethnic affiliations. In my own case, the results were quite unexpected; I had expected Viking and French influences to predominate, but in fact by far my strongest local population match (within north-west Europe generally) was with Strathclyde in Scotland, plus a dash of Portugese/Brazilian spice! Perhaps this explains why I (a typical English Sassenach) feel such strong affinity for Scotland and have chosen to retire here? At all events, for most of us there can be no pretence of ethnic or racial “purity”; we each result from a mixed bag of genes with multifarious origins—what would be termed mongrels in the world of dog-breeding, and none the worse for that. One bitter irony of ethnic cleansing (to say nothing of its immense human cost) is that greater genetic differences exist within both the oppressor and victim populations than between them, so that ethnic identity is largely illusory at the level of the genes. Ethnic affiliations are far more a matter of nurture than of nature.

144

Chapter 5

Nonetheless, tracing direct ancestry to a particular ethnic or racial group is sometimes of paramount importance. Jews reckon their identity through the maternal line, hence Jewish men who marry outside that community are effectively lost to it. But expulsions, pogroms and the Holocaust directed against Jews knew no such distinctions—anyone with Jewish ancestry (even several generations previously) was regarded as a target. Now, perhaps, the tide has turned, with the state of Israel requiring proof of Jewish ancestry as a precondition for immigration (the Law of Return of 1950, amended in 1970). To be precise, anyone with a Jewish parent or grandparent, or who is the spouse of Jew, qualifies as eligible for immigration into Israel—provided that person has not changed religion. There are other ethnic groups facing similar dilemmas over who qualifies for membership. Several Native American groups have struck lucrative local agreements, including a number in the USA that involved casino developments. Steve Jones (1996, pp. 105-111) cites the Mashantucket Pequot Indian tribe, who had a large casino built on their reservation in Connecticut in the 1990s by exercising a titular right to permit gambling on their lands despite state legislative strictures elsewhere. The resultant cash-cow made tribe members very rich, such that spurious claims to be descended from Pequot ancestors (and hence to have a stake in this newfound wealth) became a serious problem; strong documentary evidence is now required to support such claims. Prospects of prosperity for previously persecuted groups makes proven ancestry a key criterion. Historically, the Musqueam Band of First Nations peoples once occupied the territory on which the modern cities of Greater Vancouver are built (worth billions of dollars in real-estate value). However, British settlers in the area never drew up any treaty agreements whereby these indigenous lands were ceded to them; instead, local First Nations peoples were forcibly evicted and relocated into 17 reservations in less desirable marginal areas. In 1977 the Musqueam Nation submitted a comprehensive land claim to the Canadian Government’s Department of Indian Affairs (!), asserting a historic title to those lands and demanding financial compensation. Needless to say, this claim has dragged on in the courts for years without reaching settlement, given the vast sums of money involved. But since then, the Musqueam Band has participated in major property deals affecting its reservation lands—most recently one involving Sea Island on which Vancouver International Airport is built, such that 1% of the annual revenues from the airport accrues to the Band, along with other benefits (Korstrom, 2017).

Humanity

145

5.5 Mind and Brain That our consciousness is in some sense a product of processes occurring inside the brain is an obvious truism, but the physical and biological basis for awareness, emotion, memory, inspiration or problemsolving remains enigmatic and elusive. Each one of the ~86 x 109 nerve cells (neurons) in a human brain forms complex electrical circuits through thousands of synapses that link it with neighbouring or distant cells. They reach the latter through long neurites or neuronal processes, which are frequently subdivided into a spindle-shaped axon and branching terminal dendrites that nearly (but not quite) make contact with other cells. This cellular basis for brain function was first established by Santiago Ramon y Cajal (1850-1934), using Camillo Golgi’s neuron-specific silver staining technique to highlight the intricacy of dendritic connections in sections of brain tissue. Both scientists were jointly awarded the 1906 Nobel Prize for Physiology or Medicine, despite having diametrically opposed views on how the brain and nervous system function. But time has vindicated Cajal; brain development involves the establishment, and subsequent pruning, of new neuronal connections and circuits in the central nervous system (CNS), which can reinforce or inhibit existing pathways, or else set up new ones. Neural circuits develop as we learn novel skills, as children or in adulthood, but such pathways can also be lost through old age or dementia. What distinguishes human from primate brains is not differential growth of specific regions, but rather the total number of neurons (Gabi et al., 2016). Neurons are cells specialised for conducting electrical impulses. But where the dendrites approach other cells (whether neurons or muscles or other types), there is a gap termed the synaptic cleft. The electrical impulse carried by a neuron stimulates each dendrite terminal to release chemicals known as neurotransmitters (such as acetylcholine, dopamine, serotonin, GABA or glutamate) into the synaptic cleft. Specific receptors on the surface of a receiving cell on the far side of the cleft bind this transmitter chemical and initiate a response, for instance a muscle contraction or a further electrical impulse to be transmitted along another neuron. Neurotransmitters released into the synaptic cleft can be either excitatory (stimulating a response) or else inhibitory (moderating or blocking a response), allowing multiple neuronal inputs to fine tune the final signal. These transmitters are then taken back into the neurons by re-uptake via transmembrane transporter proteins. Pre- and post-synaptic compartments of neurons are both sites of active protein synthesis (Hafner et al., 2019).

146

Chapter 5

It turns out that the human brain is remarkably malleable; many behaviours are learned through practice until they eventually become almost instinctive (e.g. musical or sporting skills). One of the clearest confirmations of this flexibility came from a study of London taxi-drivers (Maguire et al., 2000), whose experience-dependent familiarity with London streets—known colloquially as “the Knowledge”—is correlated positively with the size of the posterior hippocampus, a brain region associated with spatial orientation and direction finding, as compared with a control group of non-taxi-drivers. The relative size and development of specific brain areas, and the complexity of their underlying neural circuits, can literally grow out of our individual education and experience. If free will is real (as discussed briefly earlier), then we are able to make conscious moral choices, perhaps even acting against our immediate impulses (Heisenberg, 2009). At a minimum, this might simply involve learning to act morally and with due consideration for others, until these responses become habitual in us (as in the case of good manners). Certainly this is the witness of religion, where individual converts can sometimes transform their ingrained habits, however evil, and lead exemplary lives thereafter. A key reinforcement for most new converts is the community of believers, among whom appropriate ethical and moral codes are hopefully lived out and nurtured by example (Northcott, 2014, pp. 259-265). On joining the University of Nottingham in 1978 as a lecturer in Zoology, I was approached by Peter (later Sir Peter) Mansfield’s team in Physics, who were then developing Magnetic Resonance Imaging (MRI). They were naturally concerned about possible adverse effects of strong magnetic fields on living biological systems. At that time I was working on chick embryos, so we exposed batches of fertile eggs at 37 °C inside the prototype MRI scanner for various lengths of time. I then screened the resultant embryos for anatomical defects or other signs of abnormality, but found nothing untoward. Sir Peter (1933-2017) then courageously—but unbeknownst to me—put himself through the MRI scanner and emerged unscathed; the rest, as they say, is history, and he was jointly awarded the Nobel Prize for Physiology or Medicine in 2003 with Paul Lauterbur. The point of this aside is to introduce functional MRI (fMRI), which can be used to image what is happening inside the brain in real time, as different areas become activated or quiescent in response to particular stimuli. More recent techniques for brain imaging include Positron Emission Tomography (PET), using positron-emitting fluorine 18-fludeoxyglucose as a glucose analogue to highlight metabolically active regions.

Humanity

147

A great deal has been learned from these neuroimaging studies, though sometimes this simply confirms what we already knew or suspected. Sex pheromones are powerful, generally species-specific, attractants released in vapour form by members of one sex (often by females in mating condition) as a way of attracting members of the opposite sex through elaborate detection devices, such as the plumose antennae of many male moths. In some cases, these chemical signals can be detected over distances of a kilometre or more. Their role in attracting mates is well established in many animals, especially insects, but still remains controversial in humans. Nevertheless, candidate human pheromones have been identified, including a male androgen derivative designated AND (androstadienone) and a female oestrogen derivative known as EST (estratetraenol). AND is perceived simply as an odorant by heterosexual men, but additionally causes activation in brain areas associated with sexual arousal in heterosexual women and in homosexual men. Similarly, EST is interpreted as an odorant by heterosexual women, but elicits sexual arousal (as measured using brain PET scans) in both heterosexual men and lesbian women (Savic et al., 2005; Berglund et al., 2006). These conclusions may seem blindingly obvious, even if they do help to validate AND and EST as pheromones. But other questions remain unresolved: are these responses hard-wired from adolescence (or even earlier) onwards, or can they change over time—e.g. in those reporting alterations in sexual orientation? Would bisexual people respond similarly or differently to these two candidate pheromones? Elsewhere, neuroimaging has confirmed older inferences (based on the deficits caused by localised brain lesions) as to the functions of specific brain regions. These various neuroimaging techniques provide a window into the functioning of the brain—but the glass remains frosted and the images blurred, lacking in fine detail. Within the living brain, a dynamic, real-time, 3-dimensional imaging equivalent of Ramon y Cajal’s dendrite staining patterns would provide a real breakthrough!

5.6 Consciousness: the unitary self in a distributed brain When I engage in conversation, the “me” that hears and the “me” that speaks seem to constitute a single undivided whole—my conscious self. But functional imaging has shown that our language abilities are located in several distinct regions of the brain, usually on the dominant left side in most people. Wernicke’s area is located between the auditory and visual cortex and takes charge of most language comprehension, though verbal ambiguities appear to be resolved using the corresponding region of the non-dominant right hemisphere. Broca’s area occupies a more anterior region of the brain close to the motor cortex, and is primarily responsible

148

Chapter 5

for speech production, sending neurons to the larynx, tongue and mouth to exert precise control over the sound combinations constituting speech. Acute damage to Broca’s area usually makes speech impossible—but interestingly, in patients where this area is destroyed gradually (e.g. by slow-growing tumours), speech is sometimes only slightly impaired, because adjacent brain regions seem able to take over these functions. Once again, we see both the delegation of related functions to different brain structures, alongside remarkable plasticity. Communication between Wernicke’s and Broca’s areas is achieved by bundles of neurons in the arcuate fasciculus, but pathways linking the two cerebral hemispheres are also important, since the non-dominant (usually right) hemisphere also participates in language comprehension. In reality, the whole system that enables us to receive, interpret and produce spoken language is far more complex than this brief sketch implies (see e.g. Jarvis, 2019). Language is among the chief features that distinguish Homo sapiens from other animals (Dennett, 2017) and probably emerged in Africa 50-150,000 years ago, paralleling or following the emergence of truly modern humans. Examples such as language ability could be multiplied a hundred-fold. Susan Greenfield (2016) vividly charts the brain areas and neural pathways involved in apparently mundane tasks through a typical day. While performing these tasks we are not consciously aware that each of them is delegated to specific, often multiple, sometimes widely separated regions of the brain. All of these functions are distributed rather than centralised, and there is no evidence for any overall “command centre” that could integrate all sensory inputs and issue executive instructions. Nor is there any single definable location in my brain responsible for my sense of self—my identity or personality; this seems instead to be a composite function of multiple brain areas. We know that brain damage or dementia can destroy these key aspects of selfhood, but localised brain damage often changes these traits in very limited and sometimes surprising ways (McGilchrist, 2009—on left versus right brain lesions). The human brain is capable of many amazing feats, yet in some respects it remains limited. Problems that single brains cannot solve may prove more amenable to several working together, especially in interdisciplinary teams. Recent developments in Artificial Intelligence (AI) have allowed computers to improve their performance rapidly by taking account of past failures and successes. They are especially good at learning how to pick out elusive elements of pattern from amongst a great deal of ambient noise—a feature invaluable for making sense of huge biological data-sets in many different fields, from genomics to ecology. Much time-consuming drudgery has

Humanity

149

thereby been removed from the pursuit of scientific research, as computers don’t get bored with humdrum tasks! (Dennett, 2017, pp. 371-400). This brings us to a contentious issue: the question as to whether there is a non-physical “essence” or soul that is distinct (separable?) from the human body—which includes the brain. Dualists hold that such an essence is real, whereas monists and materialists deny its existence. For evolution, dualism poses a particular problem if the soul is held to be unique to human beings; at what point during our descent from other hominins and hominids did such an entity arise, and what was its source? (God?). Many religious believers cling tenaciously to the concept of a soul or spirit, trusting that this personal essence can somehow survive the death and decay of the body. Modern forms of dualism are often described as Cartesian, after René Descartes—the 17th C CE French philosopher who distinguished between the res extensa (essentially the body or “corporeal substance”) and the res cogitans, the self that thinks (“I think, therefore I am”). But dualism is far older than this, with complex roots in Greek philosophy and early Christianity (reviewed by Murphy, 1998). Suffice it to say that there is a third way—explored throughout the essays in Brown et al. (1998)—which is neither dualist nor materialist, but rather envisages spirit as an emergent property of the brain complexity characteristic of human beings, and hence not readily predictable from the properties of its component parts. This property might therefore be shared in some measure with our ancestors, our great ape cousins, and even with other animal groups where intelligence has evolved. This view is termed non-reductive physicalism: non-reductive because it sees human personhood as emergent and therefore greater than the sum total of neural circuit functions in the brain, but physicalist because it locates our spirit (however understood) as emerging from those brain functions, and thus remains essentially monist. This is not the place to divert at length into theology, but a brief aside is warranted here, since Christianity is often held responsible for an almost pathological body/spirit dualism that denigrates the body and its appetites but glorifies the spirit. At least in popular Christian understanding, it is the soul or spirit that survives death while the physical body decays. But the New Testament texts most often cited in defence of this view can also bear a very different interpretation. When St. Paul speaks of the resurrection, there is no suggestion of a “disembodied soul”—but rather of a transformation, a re-clothing in an immortal and imperishable resurrection body (1 Corinthians 15:50-53)—instantly, “in the twinkling of an eye”. Thus orthodox belief in resurrection does not in itself depend on a nonmaterial soul that is somehow separable from the body (Green, 1998).

150

Chapter 5

5.7 FOXP2—a “language gene”? Whilst skirting around the vast topic of human language and speech, it is instructive to return briefly to genetics, outlining a much-publicised story that illustrates the pitfalls of talking about “genes for” function x— where x in this case denotes language. A mutation in the human gene FOXP2 (encoding a forkhead-domain transcription factor) was initially identified as the cause of a rare autosomal dominant disorder known as Developmental Verbal Dyspraxia, which severely affects both speech and pronunciation, e.g. in three generations of the KE family (Lai et al., 2000, 2001; Fig. 5-3). This mutation, which causes a single amino-acid change within the DNA-binding domain of the FOXP2 TF, is carried by all affected individuals (50% of both sexes) but by none of the unaffected family members. Wild-type FOXP2 protein is expressed in several tissues during mammalian development, including various regions of the brain— among them Broca’s area and other components of the neural circuits controlling the larynx, tongue and mouth—all involved in human speech production (Vargha-Khadem et al., 2005). It follows that FOXP2 does indeed plays an important neurodevelopmental role in our ability to speak.

Figure 5-3. Inheritance of a FOXP2 mutation in family KE. Solid symbols indicate affected individuals, open symbols those unaffected; squares = males, circles = females. * indicates individuals whose DNA was not available for analysis, two of whom (indicated by a slash through the symbol) had died. Three generations are shown: G1, G2, and G3 on two rows. Figure modified and redrawn from Lai et al. (2000). Since closely related FOXP2 genes are found in all vertebrates and are expressed in brain and other tissues, it seems plausible to infer an evolutionarily conserved role, though in mice FOXP2 appears to function

Humanity

151

mainly in learning (Scharff & Petri, 2011). So is there anything unusual about human FOXP2 that could link it to our unique language capabilities? Other primates produce a very limited range of vocal signals that cannot really be described as “language”, though they certainly provide essential communication within conspecific social groups. Comparing the human FOXP2 sequence with the orthologous chimpanzee gene, two amino-acid changes encoded within exon 7 have become fixed in the human lineage— in other words, these specific sequence variants are found in all modern humans. This has happened during recent evolution, maybe 200,000 years ago, through a “selective sweep” that has preserved both this version of the FOXP2 gene and a subset of its target genes (those regulated by the FOXP2 TF) within a highly conserved genomic region, which implies that this region contains important beneficial mutations. Sequence changes have been engineered into the orthologous mouse gene so that it encodes a humanised version of the FOXP2 TF. This modified gene accelerates the transition from place-based to response-based learning in the engineered mice (Schreiweis et al., 2014), also altering their ultrasonic vocalisations and increasing both dendrite length and synaptic plasticity. Overall, the evidence is suggestive, but hardly justifies media stories hailing FOXP2 as the gene underlying human speech. It must play a key role in that story, but cannot act in isolation—only as one player in genetic circuits subject to complex regulation. The modern human variant of the FOXP2 protein was also present in Neanderthals, implying that they might have shared our capacity for speech (Krause et al., 2007), though not necessarily our language abilities. Even so, they lacked a variant sequence in intron 8 that upregulates FOXP2 expression in Homo sapiens (Maricik et al., 2013).

5.8 What makes humans unique? All organisms exhibit some ability to respond appropriately to what is going on around them. Since it would be impossible to register every feature or change in the environment, organisms are selected through evolution to take note of only certain key cues or clues afforded by their surroundings (technically termed affordances) and to display a range of so-called competences to respond (deciduous trees shedding leaves in autumn, for instance). As noted earlier, human language abilities far exceed anything encountered in the animal kingdom in terms of the range, subtlety and content of our spoken (and latterly written) communications. Nevertheless, a wide variety of both mammals and especially birds use elaborate systems of vocal communication—sometimes learned imitatively by juveniles from their parents, e.g. in songbirds, cetaceans and monkeys (see Laland, 2017, pp. 175-207). Studies of FOXP2 in songbirds suggest

152

Chapter 5

that exon 7 of this gene is again very tightly conserved, but this sequence is rather different from that found in humans. FOXP2 expression is again prominent in those regions of the songbird brain associated with the neural control of singing, and has been linked to synaptic plasticity and the modulation of signalling by the neurotransmitter dopamine, particularly during those stages of juvenile development when song patterns are being learned (Wohlgemuth et al., 2014). There are fascinating parallels between song-learning in birds and language acquisition in humans; both involve specialised brain pathways and structures that are far less developed in vocal birds that do not learn songs, or in non-human primates (see Jarvis, 2019). Both seem to have evolved convergently (§ 3.5 and 3.6) from ancestral motor learning pathways. In finches, imitative learning of songpatterns by juveniles is a 2-stage process—firstly producing a sensory “template” that remembers the tutor’s song, and secondly developing the motor abilities needed to produce an imitation of that song (Clayton, 2019). Overall, FOXP2 is important both for vocalisation and learning in many vertebrates, but its function and sequence vary considerably, and its role in humans may be an atypical extreme case rather than a truly unique trait. Bottlenose Dolphins (Tursiops truncatus) learn individual, distinctive “signature whistles” that seem to broadcast the identity of the emitter, particularly in larger groups with calves present (Kriesell et al., 2014). Much more detailed analysis has been conducted on alarm calls in Vervet Monkeys (Chlorocebus pygerythrus); these calls differ in response to leopards, snakes or eagles—allowing listeners to take appropriate evasive or defensive actions (Price et al., 2015). While these vocalisations fall short of true language, they do enhance communication within groups of social animals, though it would be difficult to convey novel information. Indeed, such communications can extend beyond the auditory and into the realms of sight, smell or movement—as in the famous waggle-dance of honeybees that conveys spatial information about the location of nectar resources. However, this is rather inefficient as a means of communication on its own, and is backed up in practice by repeat performances and by additional—e.g. olfactory—cues about the food source (Brockman & Sen Sarma, 2009). A strong case can also be made for visual communication through the subtle and rapid changes in colour and pattern displayed by cephalopods. In large part, this clearly serves to camouflage an otherwise vulnerable animal, but other signals serve distinctive functions in mating or aggression. However, many cephalopods lead largely solitary rather than social lives, and some displays look remarkably like soliloquies in colour (Godfrey-Smith, 2016). Cephalopods certainly display many clear signs of intelligence, though this is based on an advanced molluscan

Humanity

153

nervous system totally different from our own. The brain (which surrounds the gullet) provides central control, with excellent visual input from the eyes (comparable to our own in structure; § 3.5), but an extensive nerve net throughout the body allows considerable independence—particularly in octopus arms. However, the potential of these advanced invertebrates to evolve more elaborate communications or culture may be limited by their relatively short lifespans (often only 2 years; Godfrey-Smith, 2016). Much the same is true for other traits once thought to distinguish humans from animals—a phrase which in itself betrays our ingrained habit of emphasising discontinuity between “them” and us. Tool-use has been observed in several bird species, while both tool-making and tool-use are well attested in wild chimpanzees (Boesch & Boesch, 1990). Sedimentdwelling octopuses have been observed carrying around half coconut shells (jettisoned by humans) and assembling these into a shelter when threatened (Finn et al., 2009). In some cases, tool-use seems to have arisen only in specific local populations, and may involve a degree of planning— meaning that animals faced with problems such as exploiting a known but difficult-to-access food source can envisage ways of using suitable tools to gain that prize. Such practices may also be passed on to juveniles through learning by imitation—a rudimentary form of “cultural” education. Preyhunting skills—including the safe handling of scorpions—are learned by juvenile wild meerkats (Suricata suricata) from more experienced adults, though this does not require very advanced cognition (Thornton & McAuliffe, 2006). Human language and more recently writing both extend the range of what can be taught and the period over which learning occurs (often lifelong), but there are at least sketchy precedents for such abilities among animals. When observing animal behaviour, it is all too easy for us to slip into the anthropomorphic habit of ascribing intelligence, forethought and even conscious intentionality—but appearances can often be deceptive. Rigorous proof is needed in such cases, since instincts honed by evolution can easily masquerade as intentionality. Australian Magpies (Cracticus tibicen dorsalis) display more advanced cognitive abilities in larger as compared to smaller social groups, and this is clearly correlated with improved reproductive success—in other words greater fitness (Ashton et al., 2018). In general, more advanced cognitive abilities are found in those animals that live in complex social groups with a hierarchical organisation, which individuals must negotiate carefully to avoid unnecessary conflicts. Nevertheless, imitative behaviour is widespread and evolutionarily advantageous in many animals that live in groups (reviewed in Laland, 2017). Rats learn from others how to avoid poison and eat only palatable

154

Chapter 5

foods. Nine-Spine Sticklebacks, but not their Three-Spine cousins, learn from other sticklebacks (of both species, since they shoal together) where richer food pickings are to be found. The Nine-Spine species is only weakly defended by its small spines, and prefers to hide in sheltered refuges rather than risk predation by foraging on its own for food. It is thus advantageous to learn, by observing other fish, where good food resources are located. By contrast, the Three-Spine species is much better defended against predators; it can probably afford to forage independently without incurring the evolutionary costs associated with learning and imitation (Laland, 2017, pp. 77-98). In such cases, the observer benefits by learning from others, but the latter play no active role in teaching. The meerkat case mentioned earlier is one of very few documented examples where adult animals actively teach juveniles within a family group of close kin. There is clearly an evolutionary benefit here (essentially kin selection) in terms of juvenile survival rates; in the absence of such teaching, untutored juveniles would succumb far more often to fatal scorpion stings. But mathematical modelling suggests that such teaching behaviour can only evolve when this involves: (i) clear fitness benefits to the pupil, (ii) minimal costs to the teacher, and (iii) high accuracy in the transmission process (Laland, 2017, pp. 150-174). Humans have developed this type of teaching far beyond anything seen elsewhere in the animal kingdom. It is easy to envisage why teaching and learning might have been advantageous in hunter/gatherer groups, so that adults transmit to juveniles (among close kin) their foraging, hunting, cooking and tool-making skills; the gradual development of human language would have strongly reinforced this process (§ 5.9). Once settled communities emerged and more differentiated roles developed within stratified societies, so teaching became delegated to specialist teachers, and groups of pupils opened up to include non-kin. Part of our sense of self emerges from the way in which our memories are organised. To oversimplify a hugely complex topic, we can distinguish between procedural memory—of how to exercise some skill, which has to be learnt initially but later becomes instinctive (e.g. how to ride a bicycle or use simple arithmetic)—and declarative memory, which is experienced consciously. Declarative memory can be further subdivided into semantic and episodic memory, the former recalling general but essentially impersonal information about the world, whereas the latter recounts parts of our own personal stories—our autobiographies—often vividly attached to particular places or times or people (Brown, 1998). Episodic memory might seem the most purely human of these abilities, but among great apes, as well as rodents and corvids, there is some evidence for “episodiclike” memory (e.g. Martin-Ordas et al., 2010)—since they can apparently

Humanity

155

remember events in temporal sequence. Once again, we should be wary of claiming any human uniqueness here. Although most animals tend to ignore dead members of their own species, African elephants (Loxodonta africana) take an unusual interest in the skulls and particularly tusks of dead members of their clan (McComb et al., 2006), perhaps because ivory feels much the same in death as in life. Indeed, these animals can become quite agitated while doing so, which suggests that elephants have some awareness of mortality. By implication, at least, they must remember the dead and may in some sense mourn their passing. These pachyderms are also long-lived, intelligent and have a sophisticated social system centred around a clan matriarch. Elephants are among an élite group of animals (otherwise including, e.g. great apes and dolphins) that can recognise themselves in a mirror (Plotnik et al., 2006), implying both a sense of self and a so-called “Theory of Mind”—meaning the ability to infer, and even empathise with, the thought-processes and feelings of other, non-self individuals. This ability may be correlated with the activity of “mirror neurons”, which fire both when an animal acts and also when it observes another individual undertaking that same action, though this is undoubtedly an over-simplification. Moreover, the mirror recognition test used above does not necessarily suit all animals, which may explain some unexpected absences from the list. So humans are not necessarily unique in these respects either, but whether other animals share our sense of conscious top-down agency—the ability to direct or modify behaviour through rational conscious thought—is more difficult to decide. Another key feature of human societies is our increasingly far-reaching ability to modify the environment to suit our own needs and comforts. Cities, farming and transport links are just a few of the most obvious examples of this elaborate niche construction. But many other organisms also do this, though usually on a more limited scale (coral reefs are an obvious exception here). Classic examples include nest-building by birds (benefitting kin only), or the larger-scale ecological effects of dam construction by beavers. In this way, genes of one species can have narrow or sometimes wide-ranging impacts on other species—aptly summed up by the title of Richard Dawkins’ 1982 book, “The Extended Phenotype”.

5.9 Development of human culture The oldest known stone tools date from c. 3.3 Ma, associated with the ancestral hominin Australopithecus afarensis. Homo erectus developed

156

Chapter 5

more sophisticated Acheulian tools featuring the biface, and further technological advances characterised the later Mousterian (Neanderthal), Aurignacian (early modern human) and Neolithic stone tools—which are often beautifully wrought, though other examples show comparatively crude workmanship (Fig. 5-4A). Some evidence implies that fire was used by Homo erectus as early as 600,000 years ago, but its controlled use by modern humans is attested by charred flints dating back 300,000 years. Early Homo sapiens was a hunter/gatherer, moving around in groups from place to place, hunting fish, birds and animals, and collecting wild grains, roots, fruit and nuts. Most, but perhaps not all, members of such groups probably shared kinship ties, and co-operation between group members would have been essential for their survival. However, hunter/gatherers were and are nomadic, moving from place to place in pursuit of food. This limits the rate of population growth, since babies and small children would need to be carried around by older group members. The oldest pottery remains date from 25,000 years ago, or even earlier, some time after the great flowering of cave art, but before the advent of agriculture. Dogs were first domesticated from wolves >20,000 years ago by our hunter/gatherer ancestors (Wang et al., 2015), perhaps initially as commensals. These cultural developments spread widely long before settled communities existed, let alone writing. Many were enshrined in oral traditions that were passed on (frequently with embellishments) by story-tellers and shamans. Then came the Neolithic Revolution, starting about 12,500 years ago (10,500 BCE), when humans first began to farm the wild grains, pulses and vegetables that have since been bred selectively to generate the many crop varieties grown today (§ 2.9). Around this time, sheep, goats and later pigs and cattle, were first domesticated and bred as agricultural livestock. This revolution began in ancient Mesopotamia and the Levant (spreading rapidly to Egypt), but similar developments arose independently and nearsimultaneously in China (Yangtze and Yellow River basins), in Amazonia (Lombardo et al., 2020), and in Melanesia (Kuk Early Agricultural Site in New Guinea). Chickens were first domesticated in south-east Asia ~7500 years ago (Lawler, 2020). More recently (4000-6000 years ago), separate agricultural practices arose in central America and in West Africa (Pennisi, 2019c). Despite the many changes it brought to human society, agriculture was not an unqualified success. By restricting the range of animal and plant species consumed by humans, farming led to increased dependence on a few basic foods, whose supply varied from year to year, leading to dietary deficiencies in nutrition and occasionally famine. The sheer hard labour required for agriculture (cf. Genesis 3:17-19) was arguably greater than that needed for hunting and gathering, at least in resource-rich areas.

Humanity

157

But farming also encouraged numerous technological innovations, such as the construction of elaborate irrigation systems in Mesopotamia and Egypt. In the wake of agriculture came settled communities—gathered together for co-operation and mutual protection from invaders or hostile neighbours. The earliest stone-built structures were religious or funerary complexes, such as Gobekli Tepe in south-eastern Turkey (10-11,000 years ago; Aslan, 2017, pp. 53-58), or the ancient temples of Malta such as Ggantija on the island of Gozo (~5500 years ago; Fig. 5-4C). From this period also came the burial monuments of northern Europe, such as the Tumulus de Barnenez near Morlaix in Brittany (~6800 years ago; Fig. 54D), as well as passage graves and dolmens (e.g. Poulnabrone in the Burren region of Eire, 5-6000 years ago; Fig. 5-4E), and alignments of standing stones (e.g. Carnac, or Lagatjar near Camaret in Brittany, 45005000 years ago; Fig. 5-4F). The most famous such monument is doubtless Stonehenge, near Avebury in the UK, which was built between 4000 and 5000 years ago. Mud bricks were also used from an early date for the construction of dwellings in Mesopotamia and elsewhere. The earliest settlements of this type—e.g. at Jericho in the Jordan valley—date back to 11,000 years ago, though the upper fortifications were added far later (Fig. 5-4B). In Egypt, the oldest pyramids date from 5000 years ago, and those at Giza from 4500 years ago. Ambitious construction projects evince an unprecedented level of co-operation between mostly unrelated individuals, with large teams of people working in a co-ordinated fashion to realise a structure that had been envisioned and planned intentionally by human architects. This is indeed a form of niche construction, but on a scale never before witnessed on this planet. [Even the immense “constructed” niches of coral reefs developed haphazardly, without intentionality]. One further consequence of agriculture and settlements was an increase in the birth rate, since women (mostly) could more easily look after several young children once freed from the need to move on to new foraging grounds. Developments in building were accompanied by—indeed, depended upon—other technological advances, notably in metallurgy and also transportation. The Chalcolithic or Copper Age, extending roughly from 6000 to 5000 years ago, saw the addition of copper tools and other items to those made from stone (above). The subsequent development of bronze—a much harder alloy of copper with tin—depended in part on the establishment of trade routes, since the principal ore of tin (cassiterite, SnO2) only rarely occurs in conjunction with copper ores. Bronze tools, weapons and decorative items first appeared about 5200 years ago and held sway for nearly 2000 years in Mesopotamia, the Levant and the Indus

158

Chapter 5

valley civilisation (even longer in parts of Europe). This lengthy Bronze Age was eventually overtaken by the advent of iron—a still harder metal, but one requiring much higher temperatures for smelting—with the Iron Age starting ~3300 years ago. The earlier domestication of horses (~7500 years agio), donkeys, camels and oxen allowed humans to travel faster and to carry heavier loads. However, major building projects (e.g. Fig. 5-4B-F) necessitated cutting and moving heavy stone blocks. At Ggantija, small rounded pebbles may have been used as ball-bearings to reduce friction, whereas pyramid construction in Egypt used ramps (traces of which remain), rollers, ropes and levers—as well as a large human workforce. A recent compilation of historical land-use records suggests that humans had greatly transformed large parts of the world by 3000 years ago, though not all sources of data concur (ArchaeoGLOBE Project, 2019; Roberts, 2019). The invention of the wheel is another crucial step forward in technology. Potters’ wheels were certainly used in ancient Mesopotamia as early as 5500 years ago, while a wheel/axle combination from a cart—found near Ljubljana in Slovenia—has been dated to 5200 years ago. But perhaps the greatest innovation during the Bronze Age was the invention of writing. Once again, this did not emerge completely out of the blue, since tally marks—incised on bone, wood or stone—had been used to keep a record of numbers for at least 40,000 years. But it was around 5100 years ago, probably in the Mesopotamian city of Sumer, that the first recognisable writing system (cuneiform) was developed, incised on clay tablets, providing records of actual words rather than just numbers. About the same time, a different form of writing (hieroglyphics) developed in Egypt, perhaps suggesting a common origin. Writing systems developed independently in China some 3200 years ago, and also in central America (Olmec) about 2300 years ago. Many of the earliest written records that have come down to us—both from Mesopotamia and from Egypt—are essentially administrative and trade documents. But literature was not far behind; clay tablets recounting the Sumerian Epic of Gilgamesh date from around 3800 years ago, and some of the poems on which it is based come from sources in Ur two or three centuries earlier. In China, many early inscriptions took the form of oracles inscribed on shoulder bones of oxen. However, any writings on more perishable materials (such as paper or silk) would be less likely to survive, unlike the clay tablets of Sumer. For the sake of brevity, I shall gloss over the distinctions between early systems of ideographic proto-writing, from which many details are omitted, and the later development of true writing where the full content of an utterance is conveyed through written symbols. The most familiar example of the latter

Humanity

159

is the alphabetic system devised in Phoenicia some 3200 years ago, where each letter corresponds to a particular spoken sound (phoneme).

Figure 5-4. Neolithic artefacts. Part A, Mesolithic flint scraper (age uncertain) from North Yorkshire, UK (bar = 1 cm). Part B, section of the extensive excavations at Jericho in the Jordan valley. Parts C to F show some outstanding European Neolithic monuments; see text. All photographs by the author.

The earliest written laws to have come down to us are the Babylonian Code of Hammurabi engraved on a diorite stele (now in the Louvre Museum in Paris), dating from around 3700 years ago, but probably based on earlier legal systems that governed life in Sumer and other cities in the region. Literature also flourished—including poetry and poetic epics such as the above-mentioned Epic of Gilgamesh, or the Greek Iliad and Odyssey attributed to Homer. These last were probably written down about 2600 years ago, but were doubtless preceded by a long oral tradition. The presence of putative musical instruments (animal horns, bird-bone flutes and bull-roarers) in many painted caves implies that music and dance may have played an important part in human rituals from a very early date, but unfortunately the invention of full musical notation is fairly recent. A 4000 year-old Sumerian tablet from Nippur preserves partial instructions for performing a Hymn to Nikkal, while a different musical notation system was used by the Greeks from 2600 to 1600 years ago, exemplified by two fragmentary Delphic Hymns from the 2 nd century BCE. Modern musical notation was devised only in the medieval period (around 1000 years ago),

160

Chapter 5

to standardise the Gregorian chants used in church and monastic circles. From these roots has developed a vast range of Western musical styles, but very different sound worlds and traditions arose in Africa, in the Far East (notably in China and Japan), and in south-east Asia (e.g. classical Indian ragas, or Javanese gamelan music using tuned percussion). One of the main constraints of early writing systems was that all written documents had to be produced and copied by hand, which limited their availability and tended to restrict reading to an elite group of powerful administrators and/or priests. During the so-called Dark Ages of Europe, Celtic and Saxon monks penned richly illuminated gospel manuscripts (e.g. the Books of Kells or Durrow; Lindisfarne or Lichfield gospels), which were truly gifts fit for a king. This bottleneck remained until 1439 CE, in the late Middle Ages, when Johannes Gutenberg (c. 1400-1468) invented a printing press that made possible the production and widespread dissemination of printed books at an affordable price. By the year 1500 CE, publishing houses had sprung up all over Europe, and among other things, their rivalry facilitated the later spread of the Reformation initiated by Martin Luther. But once again, Gutenberg’s invention did not spring out of nowhere—wood block printing had been used in China since the Tang dynasty (7th century CE), and in Europe since the 13th century CE. Gutenberg’s innovations included hand moulds, oil-based inks and moveable metal type, greatly reducing the cost of printing. Later developments that have increased the range and rapidity of human communications over the past 200 years include photography, music and voice recording, film, the telephone, radio, television, video and—most recently but arguably most far-reachingly—digital information exchange via the internet. We now take “instant” communication around the world for granted, an ability that greatly speeds up the spread of ideas and ideals, of fashions and fads, but unfortunately also of lies, smears and disinformation. Steven Pinker (2018) has vividly documented the genuine progress achieved in terms of human well-being (especially in the West) during the post-Enlightenment era of science and rationality, as measured by an avalanche of quantitative data. But the moral basis for this progress is arguably much older, a point I shall return to in the next chapter.

5.10 Gene/culture co-evolution The preceding thumbnail sketch of human culture glosses over many details, and covers all too few of the fascinating parallel developments that occurred elsewhere in the world—either simultaneously or subsequently. But it should be clear that a great many key innovations date from the

Humanity

161

Bronze Age, though some (such as tool-making, art and agriculture) arose much earlier. In § 5.2 I cited one case-study where specific mutant alleles affecting regulation of the lactase gene facilitated dairy consumption by adult pastoralists—a trait that has presumably been selected only since the Neolithic Revolution ~12,500 years ago. If nothing else, this shows that alleles conferring a significant selective advantage can spread rapidly in human populations. Kevin Laland (2017, pp. 208-233) cites numerous examples of genes that have co-evolved with specific cultural practices, and many others can be inferred from prehistoric relics. For instance, with the taming of fire came the ability to cook (and so effectively pre-digest) raw foods, allowing a reduction in the size of our large intestine and jaw muscles relative to great apes. Lengthy sequences of precise actions are necessary for obtaining and processing many foods, and for tool-making, hence the need to transmit these sequences with high fidelity may have contributed to the development of teaching and learning (by imitation) among humans—abilities which in turn depend on increases in brain size during our evolution. Laland (2017) argues that the human brain and culture have co-evolved in a mutually reinforcing cycle that (at least for the most part) ratchets ever upwards. New affordances call forth new skills, and those that increase fitness will in turn promote the spread of alleles favouring those skills, and so on. The greater the fitness benefits, the more rapidly such alleles will spread. Thus increases in brain size facilitated the development of culture, which in turn encouraged the appearance and elaboration of language, and of practices such as teaching and team-work. In such an environment, alleles favouring increased brain size would undergo positive selection. This mutual reinforcement between genes and culture helps to explain much of our human distinctiveness, as inferred from genetics, archaeology and ethology. It is also noteworthy that increased fidelity of transmission promotes the longevity of cultural traits. Co-operation is by no means unique to humans, but is in fact very widespread among social animals. However, Homo sapiens is unusual in the degree to which co-operation has developed among non-kin groups— especially since the Neolithic revolution. There are obvious risks from cheats and parasites, who make a show of co-operation but in fact do very little work or just line their pockets at the expense of others. Mathematical modelling using game theory has proved instructive in terms of identifying scenarios where co-operation becomes evolutionarily advantageous. This is an interdisciplinary field that has promoted fruitful discussions between philosophers, evolutionary biologists and mathematical modellers, as well as theologians—as exemplified in Nowak & Coakley ([eds.], 2013).

162

Chapter 5

5.11 Cultural transmission and the meme controversy In § 5.9, I had no space to chronicle many more recent developments through classical antiquity, the Dark Ages, the Renaissance, the Reformation, the Enlightenment or the Industrial Revolution—all of which continued the accelerating trend in human innovation and culture that has mushroomed so spectacularly during the 20th and into the 21st century CE. It is debatable whether, as proposed by Iain McGilchrist (2009, pp. 240462), the history of Western civilisation can be subdivided neatly into periods when the creative and holistic right brain was in the ascendancy (classical Greece, the Renaissance, and the Romantic period) versus those when the logical but narrower left brain dominated (classical Rome, the Reformation and Enlightenment, and the modern/post-modern period). But even if this is an over-simplification of history, it tells us much about the power of new insights and world-views to sweep like tidal waves across national frontiers. The question that concerns us here is how these major cultural shifts are transmitted—often with astonishing rapidity. The kind of gene/culture co-evolution outlined in § 5.10 is far too slow to explain the rapid spread of recent cultural practices. Written and now electronic communications obviously play an important role, but they simply afford faster vehicles for spreading change—in a process that has repeatedly transformed societies since the appearance of modern humans—using sophisticated language as the “engine” which facilitates such movements. Arguably, our genes have not caught up with our culture in recent times. Richard Dawkins (1976, 1982, 2006) suggests that culture is transmitted from mind to mind as memes—units of “cultural inheritance” that are subject to Darwinian evolution by natural selection in much the same way as genes. This deceptively simple proposal—like the same author’s metaphor of the selfish gene—has attracted both adulation and vilification. At least some of the criticisms are unjustified: for instance, the jibe that meme inheritance is “Lamarckian” (involving acquired traits) rather than Darwinian is misplaced. Firstly, this takes a host-organism rather than a meme’s-eye view of transmission. But secondly, the lateral inheritance of acquired genes (supposedly Lamarckian) is commonplace among bacteria, e.g. through plasmid transfer (§ 1.3) and other routes. More serious, perhaps, is the lack of any clear definition as to what a meme is or how it should be delimited. To take an obvious example, the phrase “to be or not to be, / that is the question” from Hamlet’s speech in Act 3, scene 1 of Shakespeare’s tragedy, is something that lodges in most peoples’ minds after watching or reading the play. A smaller number (perhaps those who studied it at school, or theatre directors) may remember the whole speech,

Humanity

163

or even the entire play. So which is the meme?—or are they all embedded one inside another like Russian Matryoshka dolls? But having pointed out this difficulty, it is worth noting that a similar problem complicates the definition of genes, especially in eukaryotic DNA. If a gene is viewed in terms of its normal functions, which include specific patterns of spatial and/or temporal expression (chapter 4), then the DNA region involved should include the extensive regulatory sequences flanking a coding gene (chapter 1). If we define a gene only in terms of its protein product, then we can ignore this regulation and focus on the coding or structural gene, stretching between the transcriptional start and stop sites. But even this is arguably misleading, since the final protein product represents only the exon regions of a gene—and sometimes only a selection of these, via alternative splicing of transcripts (§ 1.4). Moreover, specific sub-functions of the protein often reflect its underlying domain structure, and commonly each domain is encoded by a single exon—which can be deleted, mutated or acquired by other genes during the course of evolution. In many ways this mirrors the problem of defining a meme. Moreover, genes co-operate together in genetic circuits, and so too do memes (termed meme-plexes by Dawkins). Finally, it is often claimed that memes are too easily changed (mutated) to preserve any recognisable identity over the long term. But as Dawkins himself points out (2006, pp. 222-234), this depends on what counts as a meme. Ask a group of non-artists to make sequential copies of a picture of a Chinese junk, and it will soon become unrecognisable, because of low-fidelity copying. However, ask the same individuals to pass on a set of paper-folding instructions for making an origami model junk, and transmission errors would be absent, or at least far fewer, because each step along the way is discrete, simple and easily memorised. Returning briefly to Shakespeare plays, that familiar meme from the end of Macbeth (“Lead on, Macduff”) misquotes the original, which actually reads “Lay on, Macduff” (Act 5, scene 8)! Ideas and cultural traditions are passed on among humans through family, education and experience—something that occurs to a far more limited extent among animals (§ 5.8). We may argue about the modes of transmission or the units of cultural inheritance involved, but I think the importance of Dawkins’ meme model lies in its invocation of competition and (natural) selection among the bewildering plethora of ideas, traditions and beliefs available to modern humans. Some appear to enjoy runaway (though often brief) success, while others may be restricted to a few cognoscenti—such as experts in a particular field. At least in science, when models or paradigms become discredited, they quickly disappear from view (except among historians of science), and new replacements are

164

Chapter 5

adopted. Useful inventions achieve widespread success (until bettered), while those that prove impractical or inefficient do not. What we hail as “human culture” is just the visible tip of the iceberg, but a great deal of largely forgotten dross lies beneath the waterline. As Dennett points out (2017, p. 310), for every classical symphony that gets played in the concert hall, there are library shelves sagging under the weight of mouldering manuscripts that are probably not worth reviving—even if there are occasional gems among them that might repay investigation. The same is true in science; for every highly cited paper, there are hundreds if not thousands of published articles that rarely if ever get cited—they simply disappear without trace (which was very nearly the fate of Gregor Mendel’s 1866 paper!). However, some cultural traditions—particularly in matters of religion—seem far more resistant to change; believers often adhere doggedly to their traditional world-view, even if this seems to fly in the face of reason or modern science—a topic to be explored in part 2 of this book. So at this point it is worth pausing to consider (briefly) the possible evolutionary significance of human religious beliefs.

5.12 An evolutionary perspective on religion Religious rituals seem to have developed early on in the history of modern humans (and perhaps also in other hominins), but have evolved in many varied directions in different societies. Dating to 40,000 years ago, the famous Lion-Man statue—found in an inner chamber of the Stadel cave in Baden-Wurttemberg (Germany)—was carved from mammoth-tusk ivory. Although its body is clearly human, the head is that of a lion, suggesting some shamanistic transformation of the former into the latter. A similar but more complex hybrid image is that of the 13,000 year-old “Sorcerer”, a cave-painting discovered by the Abbé Breuil in the remote “Sanctuary” of the Trois Frères cave system in the Ariège region of southwestern France. While the legs, feet and beard look human, it has the eyes of an owl, the ears and antlers of a deer, the forelimbs and paws of a bear, the torso of an antelope and the tail of a horse. Neither of these images depicts a real animal, but rather something other-worldly from the realm of “spirits”, or at least of the imagination (Aslan, 2017, pp. 15-18). Many religions ascribe spiritual significance to special places, trees or animals, or to the natural environment more generally (e.g. among North American First Nations peoples). Such beliefs and associated rituals also commonly honour the spirits of the ancestors, but are not seen as incompatible with a supreme creator God. Before dismissing all this as irrational, we might reflect that such cultures respected nature and lived more harmoniously with their local environment than we do. It was the European settlers’ guns

Humanity

165

that drove the vast bison herds of North America to near-extinction within decades, not millennia of moderate hunting by indigenous tribes. BaynesRock (2017) suggests that effective co-operative hunting by our hunter/ gatherer ancestors depended on a sophisticated Theory of Mind that involved not merely an ascription of human motivations and intentionality to the quarry animal, but also required thinking oneself into the mindset of that animal’s spirit, so as to predict its likely behavioural responses based on past observations. We should also remember that religious rituals are primarily about belonging to a human community—far more than seeking answers to abstract questions about our origins or the purpose of existence. There was a lengthy and perhaps convoluted transition from religions that imbued the natural world with spirituality, to those that conflated humanity with divinity—ascribing superhuman powers to recognisably human gods—as in the polytheistic Greek or Norse pantheons of wilful and often duplicitous divinities who displayed all-too-human foibles in their dealings with each other and with humanity (Aslan, 2017, pp. 51-87). This may be another consequence of the Neolithic Revolution and emergence of hierarchically organised settled communities. Myths and stories about the gods often projected human aspirations and emotions onto a higher “divine” plane. Given this background, it is unsurprising that societal structures among the gods mirrored those of earthly cities—with a “high god” taking the king’s place and ruling with greater or lesser effectiveness over quarrelsome lower gods (Aslan, 2017, pp. 89-107). Indeed, it is not too difficult to see how such a high god could be promoted to become the one-and-only true God of monotheistic religions (e.g. Judaism), though Reza Aslan (2017) notes that early moves in this direction, by Zarathustra in Persia and by Pharaoh Akhenaten in Egypt, failed to win acceptance. For religious rituals and beliefs to emerge in every human society, notwithstanding their rejection by non-believers in every age (cf. Psalm 53:1), there must have been some underlying evolutionary advantage for those human groups who engaged in such practices over those who did not. Atheists will doubtless argue that, even if religion conferred fitness benefits in the past, it has become maladaptive in the modern world. My purpose here is not to engage with that debate, nor yet to argue that human intimations of divinity have a basis in reality, but rather to outline briefly some plausible evolutionary scenarios that might perhaps have promoted the spread of religious practices; the validity or otherwise of specific belief systems is not my concern here. That said, many have doubted whether there was ever any tangible evolutionary benefit that could outweigh the enormous costliness of religion (Dawkins, 2006). If such practices work to

166

Chapter 5

the benefit of anything, then surely it is the spread of cultural memes associated with those religions, rather than enhancing the reproductive success of believers’ genes. Even so, there is evidence that strong religious believers have more children on average than those with weaker or no religious beliefs (Fieder & Huber, 2016), though the interpretation of this finding is complicated by factors such as the Roman Catholic church’s ban on artificial contraception (in theory, if not in practice), and other religious traditions that promote large families. But this introduces another critique from Dawkins (2006, pp. 203-208), which points to the indoctrination of young children as the primary means by which faith is promulgated—a sort of “meme virus” (to quote another favourite Dawkins idea) that infects susceptible juvenile brains, and thereafter leads a parasitic, selfjustifying existence at the expense of rational thought. Attend any conference of clerics, however, and casual conversations will confirm that many clergy children raised in the Christian faith either rebel or drift away from it as teenagers. The same is true in church congregations; if teaching children is indeed the only way to keep the faith alive, then Christianity would be on a hiding to nothing. That there is a steady decline in church adherence is undeniable (hardly surprising, given secular peer pressures on adolescents), but these losses are counter-balanced to a considerable extent by adult conversions to religious faith, including my own. For me, this was a gradual and essentially experiential process (“Taste and see that the Lord is good”; Psalm 34:8, NRSV), not the kind of sudden Damascus-road conversion or “falling in love” exaltation that Dawkins derides (2006, pp. 214-217). But I do not think my experience is atypical or uncommon, at least among Anglican and many other middle-of-the-road churches, nor (as this book tries to argue) does it necessarily fly in the face of rationality. Returning to our hunter/gatherer ancestors, co-operation within the group would have been essential to its survival and success. This might be strengthened and enriched through rituals that helped to bond the group together—especially if some members were not directly related to others by kinship ties. I am not arguing here for so-called “group selection” explanations of altruism and co-operation—since kin selection would clearly be important within the core group. But any outsider might feel more “included” by participating in these rituals, and might be encouraged thereby to play a fuller part in hunting or gathering food, or in fighting off animal or human attackers. Overall, it seems reasonable to suggest that such ritually bonded groups might, on average, fare better in the survival stakes than those where there was no such bonding and non-kin members felt excluded. The etymology of the word religion (from Latin religere) revealingly means “to bind together”. Robin Dunbar has suggested that

Humanity

167

such bonding rituals might have involved trance-like states—induced by music, dance, hallucinogenic drugs or other means—triggering endorphin release and promoting group well-being. When agriculture and settled communities became the norm following the Neolithic Revolution, religion became part of the social “glue” that helped to bind disparate people (often without close kinship ties) into a community—whatever its internal rivalries and divisions. It is commonly thought that religion may have helped to promote the moral codes governing ethical behaviour, although this is difficult to infer from the capricious antics of polytheistic gods in Greek or Norse mythology! A darker explanation is that religious practices such as ritual human sacrifice (widespread in many cultures, and attested in many sacred texts) may have helped to promote and sustain the development of highly stratified human societies, shifting them towards a strictly inherited class system, e.g. of kings, priests, nobles, soldiers, artisans, farmers and slaves (Watts et al., 2016). We shall look at the work of René Girard—an influential Christian thinker in this area—in § 6.8. But this “glue” was enormously expensive, as pointed out by Dawkins (2006, p. 192), in terms of the costs of building vast temples or other places of worship, and of sustaining an essentially parasitic class of priests who did not contribute directly to the economy or protection of that society (an argument that can equally be directed against a privileged aristocracy). One recent proposal is that the emergence of moralising and all-knowing gods, coupled with the threat of divine judgement and punishment in the afterlife for wrong-doers, became a powerful tool for societal control. It would encourage prosocial “good behaviour”, such as trust, co-operation and fairness towards other co-religionists—including strangers (Purzycki et al., 2016). It seems likely that this development of “moralising” gods followed, rather than preceded, the emergence of complex societies with large populations (of the order of a million; Whitehouse et al., 2019), though religious rituals emerged earlier (above). But whatever benefits might accrue in terms of societal control, there was also an inevitable downside: promotion of the in-group (followers of the same religion) came at the cost of hostility, intolerance and even genocide towards out-groups who followed other religions (as in much of the Old Testament). For tribes such as the Israelites, the military victories of leaders like King David over rival tribes such as the Philistines clearly demonstrated the innate superiority of their tribal god Yahweh over the Philistine god Dagon. The crisis came when a long-threatened Babylonian invasion destroyed the Judaean remnant of Israel, razing Solomon’s temple in Jerusalem and carrying its people off into exile in Babylon, until freed by King Cyrus of Persia to return home over half a century later. But

168

Chapter 5

rather than accepting the Babylonian god Marduk as superior, Jewish exiles came to understand Yahweh as the only God, reinterpreting their history and ritual practices accordingly by assembling and editing large parts of what we now call the Old Testament (OT). Though later adopted or adapted by both Christianity and Islam, the Jewish OT scriptures remain the bedrock of all three monotheistic Abrahamic faiths.

5.13 Consciousness and memes revisited Recent fMRI studies reinforce the conclusion (§ 5.5) that consciousness is a function—or network of functions—distributed across many regions of the brain, involving a dynamic pattern of both co-ordinated and anticoordinated signals (Demertzi et al., 2019). Normal and even minimally conscious subjects transition between several distinct patterns of active neural connectivity in the brain. However, those in a persistent vegetative state (unresponsive, hence unlikely to regain consciousness) show a basal pattern of minimal signals reflecting mainly the structural connections between brain areas. Anaesthetics increase the frequency of transitions into this basal pattern—thus anaesthesia does indeed suppress consciousness. In macaques, consciousness is mediated through connections between the thalamus and brain cortex (Redinbaugh et al., 2020). Overall, there is no single brain region that can be identified as the “seat of consciousness”— yet this faculty is not a mysterious “emergent property” of the whole brain. Daniel Dennett (2017, pp. 336-369) controversially describes human consciousness as an evolved user-illusion, generated from the vortex of memes swirling around inside our brains. This concept may seem deeply uncongenial to any kind of religious faith, but it is worth exploring what underlies this view, which is unashamedly evolutionary in its perspective. Dennett takes on board the ways in which our varied personalities develop in large part through interactions with others. We try to project a sanitised image of ourselves for public consumption (especially on social media!)— editing out our uncertainties and doubts, or our lack of confidence, and inflating our modest achievments. We are all aware of less savoury aspects of our personalities that we try our best to keep hidden, though sometimes our body language or Freudian slips let the mask down for a moment. So yes, my conscious self—and the “me” I present to the world—is indeed a user-illusion, and there are bound to be elements of self-deception in all this. In the words of Robert Burns’ 1786 poem, “To a Louse, On Seeing One on a Lady's Bonnet at Church”: “O wad some Pow'r the giftie gie us / To see oursels as ithers see us”. None of this should come as a shock to Christians, since most of us acknowledge week by week how far we fall

Humanity

169

short of what God in Jesus calls us to be, while still holding fast to the belief that such a calling is realisable, though not through our own unaided efforts. “For mortals it is impossible, but for God all things are possible” (Matthew 19:26, NRSV). All of this tends to undermine the selfproclaimed autonomous me (so beloved of self-help manuals), which determines all of my choices and directs my path in life, as in William Henley’s 1875 poem Invictus: “I am the master of my fate, I am the captain of my soul”. In truth, full human flourishing also needs both early and continuing interactions with others, with a key role for education— which can often be lifelong—as discussed by Alasdair MacIntyre (1999). Similar arguments apply to the rationales we use to justify our actions, even if we know these to have been self-seeking, impulsive, instinctive or ill-considered originally. If we have “got away” with them and lived to tell the tale, then we can usually put a fine-sounding gloss on the motives underlying those actions, and even come to believe this version ourselves (our capacity for self-deception seems boundless). Popular books on great naval, military or political blunders in the past provide a salutary lesson to set against our human hubris; we have an astonishing capacity for getting it wrong, as well as getting it right on occasion. Once again Christians need not be surprised or alarmed by this apparently low estimate of our nobility and rationality as a species; this is what has always been called human sinfulness, though in the light of evolution we can hardly blame it on the Fall (Genesis 3). The faults lie in ourselves, not in our stars—nor in fate, nor in the wiles of a talking serpent. We should not rate our abilities or motivations as more Olympian or autonomous than our (limited) selfawareness admits. It is certainly simpler—but perhaps an all-too-easy copout—to blame “bad” memes (mixed in among useful “good” ones) rather than posit some deeply embedded human propensity for evil. Atrocities are often committed by all sides in wartime, but the Nazi Holocaust against Jews was an especially brutal example, carried out with ruthless efficiency and on a vast scale. There is no reason to suppose that the German nation (hardly a “race”!) is more prone to such iniquity than any other group, yet the insidious success of Nazi propaganda memes blinded all but a few to the reality of what they were doing. Alas, much the same can be said for “holy wars”, and even for terrorist acts committed in the name of religion. Our inner thought processes also reflect this seething torrent of memes, from which we sift and consider whatever seems most relevant or useful to our purposes. In writing this book, every chapter has gone through countless drafts and edits, sometimes clarifying a sentence or two, sometimes deleting whole sections or inserting new ones. Reading

170

Chapter 5

extensively around the subject (to call this “broad” is an understatement!) has caused me to modify my views and vastly expand my horizons, yet strangely it has also clarified and sharpened the book’s underlying thrust. Section 1.1 looked briefly at the process of scientific investigation and of writing reports, but notably these latter omit all mention of the false starts, dead ends, futile revisions and endless repetitions involved in doing real science. Many works of art—in painting, sculpture, literature or music— have gone through similar processes of revision and refinement. It is perhaps instructive to look at one exception that proves (tests) this rule: the composer Wolfgang Amadeus Mozart (1756-1791), whose prodigious musical gifts are particularly well-attested. One of his notable feats was to transcribe Allegri’s 9-part Miserere from memory after hearing it sung once in the Sistine chapel (where its score was a closely guarded secret) during a visit to Rome during Holy Week in 1770, as described in a letter home by his father Leopold dated 14 th April 1770. Wolfgang did in fact revisit the chapel 2 days later on Good Friday, and afterwards made minor revisions to his score, but this hardly detracts from his achievement in notating such a complex piece from memory. He risked excommunication for illegally copying the music and taking it outside the Vatican, but in fact was honoured for his musical genius by Pope Clement XIV that July. Through much of human prehistory, the memes populating our minds have been subjected to a continual process of natural selection by trial and error, which has ensured the progressive refinement and improvement of many (not all). Whatever worked well enough (or at least, better than its antecedents) was passed on and could spread more widely—becoming in its turn the substrate for further enhancements. This need not involve any specific design intention to make such improvements, which may well have been lucky accidents, at least initially. But gradually during human evolution, we have broken decisively with our animal ancestry through intentional planning and execution of better designs (Dennett, 2017). Useful memes generated by mindless “bottom-up” variation and selection have been replaced to an ever-increasing extent by deliberate “top-down” designs. These are more complex and costly to produce—in terms of the mental effort expended—though they are still relatively inefficient, as the criteria for memes’ success at lodging in other brains remain elusive. There is no sure-fire recipe for instant memorability—and most candidate memes fail to make the grade, joining the ranks of the instantly forgettable. Many aspects of the world around us—from calculus to computers, from music to motorways—have been designed and realised by other human beings, providing us with countless new affordances that were far beyond the reach of our ancestors’ imaginations a thousand or even a hundred years ago.

Humanity

171

For many, the idea of consciousness as an illusion (however evolved) seems almost insulting. It turns our highest aspirations and achievements as a species into a kind of cultural froth—maybe adding taste and spice to the underlying slew of routine selection pressures that have shaped us—but essentially superfluous to that evolutionary story, rather than its supreme expression. This idea is nonetheless an extrapolation from the evolutionary consensus—outlined in Part 1 of this book—which views random genetic mutation and natural selection as central to life’s evolution, and eschews any notion of teleology or ultimate purpose. This does not contradict the fact that individual organisms have their own purposes in life (termed teleonomies by Jacques Monod; 1970/1972, p. 20)—which are shaped by selection in the context of that organism’s environment. It goes without saying that high aspirations are not a top priority for many humans, who would rather know where their next meal is coming from. But the recent emergence of climate change and mass extinction as looming threats to the future of life on this planet poses stark questions for all of us. Is humanity capable of rising above its selfish pursuit of individual, family or even communal well-being, in order to exercise restraint on behalf of all other living things—including future generations of Homo sapiens? Perhaps our aspirations are not so irrelevant and illusory after all, but rather provide a fitful glimmer of hope for the future of our species, and for many others…. Laland et al. (2015) call for an Extended Evolutionary Synthesis (EES) that enlarges the neo-Darwinian paradigm to incorporate insights from evo-devo (chapter 4), phenotypic and developmental plasticity (adapting to environmental exigencies), inclusive inheritance (ranging from epigenetic to cultural) and niche construction (this chapter). All of these factors, it is true, can be interpreted in neo-Darwinian terms, and do not in themselves necessitate a broader EES (as discussed by Laland et al., 2015). But in this context, one can legitimately ask what evolutionary advantages might accrue from the apparent innovation of human consciousness? This topic is discussed at length by Michael Graziano (2019). One of his key ideas is the attention schema, where our conscious awareness has evolved through focussing attention on what is currently important among the seething memes within our brains (internal stimuli) as well as sensory inputs from the outside world (external stimuli), dismissing whatever is superfluous so that we can concentrate on the task in hand. We know that various kinds of neural signals compete with each other through multiple processing layers within the brain, ensuring that we do not become distracted by extraneous irrelevancies. This clearly affords an important survival skill in the short term, but the threat of climate change underlines the fact that this same ability is also vital for collective strategic planning in the longer term,

172

Chapter 5

always provided we can set aside our short-term interests. The flipside of this same coin is that when our lives are less demanding we can relax our attention and let it wander, perhaps becoming mindful of our immediate sensory inputs, or letting our imaginations roam free—envisaging possible future courses of action and making free-will choices between them. It is fitting to close with one of Mozart’s late masterpieces, the finale of his Jupiter symphony (no. 41 in C, K. 551; 1788). This shows his mastery of old-fashioned counterpoint (combining the same or different melodies together according to strict rules), and attests to his love and respect for the music of J.S. Bach. During a later visit to the latter’s church (the Thomaskirche) at Leipzig in 1789, Mozart reputedly exclaimed “This is someone I can learn from!”. But as far back as 1782 he had transcribed 5 of Bach’s fugues from the Well-Tempered Clavier for string quartet (K. 405). The Jupiter finale ends with a coda described technically as “5-part invertible counterpoint”—that is to say, the 5 short themes on which this movement is based are combined together in various permutations of registers—so that each tune occurs, now in the treble, now in the bass, now in the inner voices. Even before this final summation, many kinds of contrapuntal ingenuity are used, including inversion (playing the same theme upside down, both literally and in variant forms). Bach also used these contrapuntal devices, but unless your ear is attuned to them (mine isn’t), it is all too easy to miss such inverted patterns. Mozart solves this problem with elegant simplicity, by using very striking brief tunes that are instantly recognisable, even upside down (Fig. 5-5A-D, showing the first and second themes plus inversions). Perhaps Mozart is simply showing off here, demonstrating that he can incorporate the fusty old counterpoint of the early 18th C CE into a vibrant classical symphony without sacrificing its élan or momentum? [Alas, many Romantic symphonies are apt to adopt an air of antique solemnity before launching into a contrapuntal finale!]. But Mozart does far more than this, illustrating how memes can influence even the finest human genius. The first theme (Fig. 5-5A) has a long pedigree, going back to the 16th C Missa Pange Lingua by Josquin des Prez. It is also used in the first movement of the second (“Der Sturz Phaetons”, circa 1781; Fig. 5-5E) of Karl Ditters von Dittersdorf’s six “Sinfonias after Ovid’s Metamorphoses”, which also features a close relative (Fig. 5-5F) of Mozart’s second theme from the Jupiter finale (Fig. 5-5C). It is as though Mozart is pointing here to his lesser contemporary’s shortcomings: “your symphony has some good ideas, but here’s what you can really do with them”. This consummate tour-de-force ending Mozart’s last symphony manages to out-ditty Dittersdorf and even out-bacchanal

Humanity

173

Bach, all with apparently effortless ease. It plays with post-modern idioms 200 years before the term was coined—using borrowed, carefully chosen memes (themes) and influences (Bach)—welding them together into a stunning musical apotheosis. There could be no finer testament to one of the greatest geniuses of Western music, despite his tragically short life. Another such short-lived genius was the composer Franz Schubert (17971828) in the early Romantic era, whose gifts for melody and harmony plumbed undreamt-of depths of emotional intensity during his last years. Memes lodge in our brains as much if not more when they pluck at our heart-strings as when they impress us through sheer ingenuity; somehow Bach, Mozart, Schubert and Shakespeare succeed brilliantly y in doingg both.

Figure 5-5. Mozart and Dittersdorf. Comparison of two themes from the finale of Mozart’s Symphony no. 41, K. 551 (A, C), plus inversions (B, D), with similar themes (E, F) from Dittersdorf’s 2nd Sinfonia after Ovid’s Metamorphoses (Der Sturz Phaetons), Kr 74. B is a variant inversion of A (contracting the first interval by a semitone and expanding the second by a tone); D is an instantly recognisable inversion of C; E is the same as A, but in a different key; while F bears obvious similarity to C despite different time signatures. Themes transcribed using Sibelius 7 software from original scores (Mozart, 1788/2008; von Dittersdorf, 1781/1899).

Figure 2-1. British and Mediterranean orchid flowers. Part P, image of “Orchis” ustulata.jpg from Flora-On by Bilou-commons wiki is licensed under CC BY-SA 3.0.

Figure 2-2. Varieties, relatives and endemics. Grateful thanks to the photo copyright holders Julia Jones (A), and Roger Key (E).

Figure 2-3. Macaronesian endemics, plus a British Echium (D) and a Mexican cactus (M).

Figure 2-4. Seasonality. Photo A is a public domain image from Flora-On (Creative Commons).

Figure 2-5. Plant families. Top, Asteraceae; middle, Gentianaceae; bottom, “Scrophulariaceae”.

Figure 2-10. Weeds. European (A-E), North American (F-H) and two invasive (J, K) weeds, plus a circumpolar Ice Age survivor (I).

Figure 2-12. Modern vegetables derived from Wild Cabbage. Photo compilation based on a figure in Steve Jones, 2017, p. 11 (original illustration copyright Rowan Clifford).

Figure 2-13. Flower mutants, Evening Primrose, Lamium hybrids. Parts F and G show the two parental species, parts H and I two polyploid hybrid species. All four Lamium flowers are magnified x 5.

Figure 9.1. Orchids imitating insects. A and B, two UK species of the genus Ophrys (Derbyshire); C to F, four Cretan species.

Figure 10-1. Arthur’s Seat and its flora. Part A, hill reflected in Hunter’s Pool; B and C, two rarities; D and E, two naturalised aliens; F to H, three calcicole plants; I and J, both species supposedly present—but yet to be found!

PART 2

CHAPTER 6 AMBIGUOUS HISTORIES

Summary § 6.1 serves as an introduction to part 2, seeking to probe beneath “received wisdom”—such as the popular myth of inevitable conflict between science and religion. The value of considering alternative viewpoints is illustrated by 2 brief musical examples, Shostakovitch in § 6.2 and the Chevalier de Saint Georges in § 6.3. Attention turns to chemistry in § 6.4, examining the legend that Wöhler’s synthesis of the “organic” compound urea from “inorganic” salts demolished the concept of a vital force unique to living organisms; in fact, he had discovered chemical isomers. Similarly, the myth that Darwin’s ideas attracted universal condemnation in Christian circles is over-simplified, since many 19th C CE clerics embraced his theory with enthusiasm, as explored in § 6.5. But fundamentalist Christians firmly rejected evolution as unbiblical; § 6.6 outlines the infamous Scopes trial of 1925, suggesting that this was occasioned in part by specious distortions of evolution masquerading as social Darwinism. Attention turns to the bible in § 6.7, with Psalm 29 as an example—a Jewish song of praise to Yahweh that may in fact have originated as a Canaanite hymn to the storm-god Ba’al—a case of inculturation typical of the way religious ideas are spread by colonising powers. § 6.8 looks at the work of René Girard, who linked violence with the sacred across many religions by describing the power of mimetic rivalry and scapegoating, leading to ritual murder of an innocent victim—a pattern challenged and nullified by God’s identification with the victim in Judaism and especially in Christianity. Finally, § 6.9 returns to scripture, focussing on the marginal figures of Doubting Thomas and Mary Magdalene—who rise to sudden prominence in the post-Resurrection narratives of John’s gospel. Perhaps Thomas should become a patron saint for scientists, while Mary challenges at least two prevalent stereotypes and emerges as “apostle to the apostles”.

Ambiguous Histories

177

6.1 Introduction to Part 2 It will seem to many Christian readers that I have fled the mythic battlefield between science and faith without so much as a token fight— waving a white flag of surrender in an effort to salvage some shreds of respectability as a scientist while apparently abandoning any pretence of following Jesus Christ and ministering to others in his name as a priest. Surely that is tantamount to betraying my faith and calling?—like those early (now forgotten) Christians who chose to pay lip-service to the Roman emperor rather than face martyrdom—which gained for at least some of their braver co-religionists the enduring fame of sainthood, albeit at the painful cost of their own lives. But this interpretation, predictable as it is, capitulates far too easily to the prevailing popular narrative that science and religion are locked in conflict, and that the latter can have no claim to plausibility—let alone truth (Dawkins, 2006; Hitchens, 2007; Coyne, 2015). In fact, Ian Barbour (1998) distinguishes four possible ways in which religion might relate to science, of which conflict is only one. Another option is independence, where each makes valid truth claims, but within non-overlapping magisteria (NOMA; Gould, 1999; Ayala, 2007). Two further possibilities are dialogue or even integration, and these twin approaches have been explored by several authors with expertise in both science and theology, such as Russell Stannard (2017), John Polkinghorne (1989, 2005), Robert Russell (2009), Arthur Peacocke, R. J. Berry, and Celia Deane-Drummond—the first 3 from a physics background and the last 3 from biology. They do not speak with one voice—some taking an evangelical line, others a liberal or catholic stance. All of these writers seek to defend cherished Christian beliefs and doctrines against the assaults of a prevalent reductionist materialism that relies heavily on what MacKay (1979) aptly termed nothing-buttery (brains are nothing but neurons, etc.). My aim in this book is rather different. I have already summarised the overwhelming evidence for evolution and its explanatory power across the whole of biology (Part 1). So, as a worst-case scenario, let us suppose that materialists like Dawkins and Dennett are in essence correct; what room might then remain for God and faith? Must both be consigned wholesale into a misty hinterland of superstition and credulousness, as Dawkins et al. would have us believe? On the contrary, I am convinced that a selfemptying God who stands aside to let the universe and life on this planet evolve according to their own laws, embracing the outcomes with love and compassion, is strikingly consonant with the good news of God’s kingdom preached by Jesus Christ, according to the gospel accounts. It is true that many New Testament scholars have cast doubt on the historicity of even

178

Chapter 6

the synoptic gospels, but their validity has also been vigorously defended by others (Eddy & Boyd, 2007). Dawkins (2006) mocks the view which I am forwarding as one that embodies (deliberate pun) a “lazy God” who makes no discernible difference to creation. But that put-down is equally apt for the earthly ministry of Jesus as seen from a worldly perspective, yet Christians believe that this Man shows us as much of God as we can humanly grasp. What if God is not some kind of irascible and omnipotent tyrant commanding every occurrence in the universe, but instead resembles the loving father who welcomes home the Prodigal Son (Luke 15:11-32)? Sometimes our image of the God whom Christians claim to worship seems to owe far more to the emperor-cult of imperial Rome than to the gospels. It is a truism that things are rarely as they seem in popular narrative or received wisdom; there is always more to be said. This chapter suggests that we can learn far more by looking at a single story from several perspectives. The first two examples are especially vivid and are drawn from music (a particular passion of mine), before turning to chemistry, evolution and scripture. It is not so much that that the simplistic mainstream version is downright wrong, but rather that it is superficial and one-dimensional. Though not strictly linked thematically, these stories together make the point that truth is multi-layered, and time spent probing beneath the surface is never wasted, but often reveals unexpected insights.

6.2 Shostakovitch—collaborator or dissident? Dmitri Shostakovitch wrote his 11th symphony in 1956-7; its title— “The Year 1905”—ostensibly commemorates the failed uprising of that year, which was brutally suppressed by the Tsarist regime. By using revolutionary songs of the time (though often sardonically), the composer assured himself of a warm reception from his critics in Russia, but it proved something of a disappointment to his Western advocates, who saw it as capitulating to the Soviet Communist authorities—coming as it did between the heroic protests of the 10th and 13th (“Babi Yar”) symphonies. But is that all that can be said about this 11th symphony? When the music was later used for a ballet, Shostakovitch reportedly told the choreographer Igor Belsky, “Don’t forget that I wrote the symphony in the aftermath of the Hungarian uprising” (1956, which was suppressed by Soviet troops). Suddenly, an almost opposite interpretation emerges, one of veiled protest against the Communist regime. This puts a wholly different complexion on, for example, the return of the quiet glacial string harmonies that open the work, after the collapse of raucous climaxes in both the 2nd and 4th

Ambiguous Histories

179

movements of the symphony. It becomes a deeply tragic work of total conviction, and indeed a worthy companion to his other late symphonies.

6.3 Chevalier de Saint-Georges – the “black Mozart” Joseph Bologne (1745-1799), better known as the Chevalier de SaintGeorges, was born of mixed race parentage in the French colony of Guadeloupe—the illegitimate son of a wealthy plantation owner and an African slave girl. Despite this inauspicious start, in Paris he became an accomplished swordsman, athlete, soldier, violinist, composer, and conductor of the prestigious Concert des Amateurs. He was fêted at the court of King Louis XVI and his queen Marie Antoinette, to whom he also taught music. Despite the failure of his first opera Ernestine in the late 1770s, he was much acclaimed as a musician, hence his later sobriquet “the black Mozart”—though in fact he was 11 years older than the latter. Some of Bologne’s music has been lost (including parts of Ernestine), but what survives is urbane and elegant in the late-18 th C CE classical galante tradition, though lacking the emotional depth and complexity of Mozart’s mature works. In his later years he joined the French revolutionaries, serving as a colonel in the Legion Saint-Georges—which was the first allblack regiment in Europe. Perhaps because of his earlier prestige in court circles, compounded by a false accusation of embezzlement, he came under suspicion during the post-revolution chaos, and was imprisoned for a time, before returning briefly to the Caribbean (also embroiled in revolution) and then back to France where he died in 1799. Slavery was abolished after the French Revolution, but was reinstated in 1802 by Napoleon Bonaparte, and Bologne’s music was banned from the French orchestral repertoire, to be rediscovered only relatively recently. While his celebrity at the court of Louis XVI may have reflected his exoticism as much as his undoubted talents, his later eclipse seems to have been a shameful example of racism. But there is a further twist to this tale, involving none other than Mozart himself. One of the most problematic aspects of Mozart’s late opera The Magic Flute is the black villain of the piece, Monostatos. While nothing can be proved for certain, it seems plausible that this character represents revenge for earlier encounters with Bologne as part of Mozart’s ill-starred visit to Paris in 1778—during which the latter’s mother died. For the struggling and grief-stricken Mozart, his older rival’s seemingly undeserved success and celebrity must have been galling, to say the least (Duchen, 2007). Even a towering musical genius can have feet of clay….

Chapter 6

180

6.4 Friedrich Wohler and the 1828 synthesis of urea Urea [chemical formula (NH2)2CO] is usually classed as an organic molecule, and is excreted by living organisms such as mammals (and also some fish) to dispose of nitrogenous waste, whereas birds and reptiles excrete mostly uric acid. In 1828, Wohler synthesised urea from two supposedly “inorganic” salts, potassium cyanate and ammonium chloride. NH4Cl

+ KOCN

ammonium ...chloride

potassium cyanate

ļ

KCl potassium chloride

+

NH4OCN ammonium cyanate

Æ

(NH2)2CO urea…..

isomerisation

The popular myth, promulgated in older textbooks on chemistry, is that this synthesis removed the distinction between organic and inorganic chemistry, and so demolished the concept of a vital force unique to living organisms—which supposedly facilitated chemical transformations that were impossible to accomplish by test-tube chemistry. In Wohler’s time there was a widely held conviction, termed vitalism, that only living systems possessed such capabilities. In an oft-quoted letter to the great Swedish chemist Berzelius, Wohler enthusiastically proclaimed: “[I] must tell you that I can make urea without need of a kidney or even an animal, be it man or dog” (cited in Ramberg, 2000). Based on this and similar statements, the Wohler “myth” takes the form of a deceptively simple syllogism: if (i) only the vital force of life is capable of producing organic compounds, but (ii) Wohler had succeeded in synthesising an organic compound (urea) from inorganic sources, then (iii) this discovery rendered the idea of a vital force redundant, consigning it to the dustbin of failed scientific hypotheses (such as the phlogiston theory of combustion). Numerous historians and philosophers of science have debunked this popular myth, amongst them Douglas McKie (1944) and in particular John Hedley Brooke (1968). In the first place, urea occupied a rather equivocal intermediate position between the classical domains of organic and inorganic chemistry, along with organic acids—which could be understood within the familiar framework of salts, acids and bases. In fact, Wohler had four years earlier used hydrolysis of the toxic gas cyanogen [(CN)2] to synthesise “organic” oxalic acid [(COOH)2], found in many plants such as its namesake, Oxalis acetosella (Wood Sorrel; Fig. 6-1A), and rhubarb. (CN)2 cyanogen

+

2 H2O

ĺ

water

(CO.NH2)2 + 2 H2O ĺ (CO.ONH4)2 oxamide

water

ammonium oxalate

(CO.NH2)2 oxamide ļ (CO.OH)2 + 2 NH3 oxalic acid

ammonia

Ambiguous Histories

181

In chemical literature of the early 19th C CE, some listings of organic compounds included such organic acids whereas others excluded them. In any case, at the time of Wohler’s synthesis of urea in 1828, cyanate itself was derived from organic sources and thus did not strictly qualify as an inorganic salt (McKie, 1944). But Brooke (1968) found this unsatisfactory as a critique of the Wohler myth. During the years immediately following Wohler’s achievement, it was not hailed as a nail in the coffin of vitalism; that claim came only in the second half of the 19 th C CE. Because the reaction conditions used by Wohler for his synthesis of urea were quite severe—as compared with normal physiological processes in living systems—it remained logically possible to maintain a vitalist position, on the grounds that organisms were capable of synthesising organic compounds under much milder conditions than those that had to be used in the laboratory. We now know that this seeming difference is due, not to some mystical vital force, but rather to the ability of protein enzymes to catalyse chemical reactions efficiently, even at physiological temperatures, by binding reactants and bringing them together at the enzyme’s active site. Brooke (1968) also points to an ambiguity in word-use that affects both French and to some extent English writings on organic chemistry during the period when Wohler was active. The French word corps (and also its English equivalent, body) was used to denote both a living organism, usually an animal, and also a chemical compound. Generally it is clear from the context which is meant, but there remains a possible conflation of both senses—whereby organic compounds are in some way uniquely identified with the organisms that produce them. This extends even to trivial matters of nomenclature—hence many plant products such as alkaloids are named after the Latin genus to which the source plant belongs, e.g. hyoscyamine from Hyoscyamus spp. (Henbanes; Fig. 6-1B), or atropine from Atropa belladonna (Deadly Nightshade; Fig. 6-1C). The significance of Wohler’s synthesis of urea, at least for contemporary and even for later generations of chemists, was very different from the Wohler myth that he had single-handedly undermined (if not destroyed) vitalism. Rather, the disappearance of ammonium cyanate (however prepared, and Wohler tried several routes) and its replacement by urea, together with proof that both shared the same overall chemical composition [N2H4CO], led to the concept of isomers—which have different spatial arrangements of the same component atoms [in this case, NH4.OCN versus (NH2)2.CO]. What Wohler had identified was in fact a spontaneous isomerisation of the unstable salt ammonium cyanate to the stable organic compound urea, a transformation of chemical identity through molecular rearrangement.

182

Chapter 6

Figure 6-1. Eponymous organic compounds and source plants. Part A, Wood Sorrel (Oxalis), a source of oxalic acid; Part B, White Henbane (Hyoscyamus), source of hyoscyamine; Part C, Deadly Nightshade (Atropa), source of atropine. Photographs by the author. Note also that hyoscyamine and atropine are isomers!

6.5 Contemporaneous theological responses to Darwin Received wisdom would have us believe that most church-goers and theologians in the later 19th C CE were appalled by Darwin’s idea that the vast diversity of modern living organisms might have evolved gradually from simpler ancestors rather than through special creation by God, and even more so by the outrageous suggestion that human beings (so beloved of God that he sent his only Son to save us) shared common ancestry with the Great Apes (chapter 5). We are frequently referred to the infamous public debate between “Darwin’s bulldog”, Thomas Henry Huxley, and the Bishop of Oxford, “Soapy Sam” Wilberforce, at the 1860 Oxford meeting of the British Association for the Advancement of Science. It is unfortunate that no detailed record of this meeting was written at the time, nor is it clear that Huxley won the day quite as easily as the popular myth would have us believe, although his lucid exposition of Darwin’s ideas elicited compliments even from clergy in the audience, much to his own surprise (Livingstone, 1984/1997, p. 34). Some clerics, such as Charles Kingsley (author of “The Water Babies”) and Frederick Temple (later Archbishop of Canterbury), embraced Darwin’s ideas with great enthusiasm—finding in them an even nobler vision than special creation by divine fiat (Kingsley). But, as David Livingstone emphasises, they were by no means alone, and many British Evangelical theologians (such as William Dallinger, a Methodist) also defended Darwin. So too did several American luminaries of the Princeton Theological Seminary, now regarded as founding fathers of modern conservative Evangelical theology, such as James McCosh (1811-1894), Benjamin Warfield (1851-1921) and Augustus Strong (1836-1921) (Livingstone,

Ambiguous Histories

183

1984/1997, pp. 106-111, 128-131). Similar views were also espoused by several contemporaneous scientists with evangelical beliefs, such as Alexander Winchell (1824-1891) and George Macloskie (1834-1920) (Livingstone, 1984/1997, pp. 85-96). Admittedly, some of their attempts to reconcile evolutionary and biblical accounts of creation, or to look for a revival of natural theology, might strike us as naïve in the early 21st C CE. Nor is this to deny the many prominent theological voices who found Darwin both profoundly anti-scriptural and scientifically unproven, for example Thomas Birks (1810-1883), John Laidlaw (1832-1906), and in the USA, Luther Townsend (1838-1922) (Livingstone, 1984/1997, pp. 132-133). But overall, the response to Darwin from clergy and theologians was by no means as uniform nor as universally hostile as the popular “science versus religion” conflict myth asserts. Equally, not all scientists at the time found Darwin’s theory adequate or convincing, though most felt that he was onto something (as discussed in § 2.9). A more determined assault on Darwinism by evangelical Christians began with a set of 12 paperback books, published between 1910 and 1915 under the series title “Fundamentals”. Among the 90 essays on all aspects of Christian belief was one entitled “The Decadence of Darwinism” by Henry Beach, matched in pugnacity by an anonymous contribution under the title “Evolutionism in the Pulpit” (seemingly the first usage of evolution as an ‘ism’). It is from this series that the modern term “fundamentalist” (often used pejoratively) is derived. The fundamentalist movement was a reaction, not just to Darwin’s theory of evolution, but to late 19th C CE developments in biblical criticism and liberal theology more generally—seeking to defend and entrench more orthodox Evangelical Protestant beliefs. Creationism, based on a literal reading of scripture, emerged strongly during the 1920s—in part through the writings of figures such as Beach, Floyd Hamilton and George Price—whose work was later taken up by Henry Morris (1918-2006), one of the founders of so-called “creation science” (Livingstone, 1984/1997, pp 146-168). The interlinked targets of “young-earth creationists”, such as Morris, are the ancient geological record and biological evolution, both of which are portrayed as anti-biblical inventions. I will not divert here into engaging with their arguments, which attempt to pick holes in the science on specious or nonexistent grounds, but which rest primarily on an unquestioning allegiance to a literal reading of scripture, e.g. God’s creation of the earth and of all living things, including mankind, in six 24-hour days (Genesis, chapter 1).

184

Chapter 6

6.6 The 1925 Scopes trial: evolution versus creationism It was my intention to gloss over this trial with only a cursory mention, but after reading Stephen Jay Gould’s “Rocks of Ages” (1999, pp. 150169)—with its surprisingly sympathetic account of the creationists’ chief protagonist, William Jennings Bryan—I realised that this too offers an ambiguous history par excellence. The case may be unfamiliar to British readers, so a brief outline of the bald facts is needed to set the scene. Much disquiet was occasioned by overt teaching of evolution in schools in the “Bible belt” of the southern USA, where fundamentalist and creationist beliefs still remain strong. In the state of Tennessee, John W. Butler had lobbied the state legislature to ban the teaching of human evolution, and the Butler Act was passed on March 25th 1925. However, several school teachers continued to teach evolution in biology classes in defiance of this new law. A substitute teacher, John Scopes, though unsure as to whether he had actually taught evolution, deliberately incriminated himself so that there would be a defendant in the inevitable trial. This was hosted as something of a publicity stunt by the small town of Dayton—largely in the open air, given enormous public interest in the case and the stifling heat inside the courtroom. Two prominent lawyers spearheaded the legal teams: Clarence Darrow defended Scopes and the right to teach evolution, while Bryan appeared for the prosecution as leader of the creationist camp—a popular grass-roots movement which had hitherto been largely disenfranchised. Local opinion, and indeed the judge (John Raulston), sided clearly with the prosecution, and several defence witnesses whom Darrow wished to bring forward were ruled irrelevant. In an unexpected twist, Darrow cross-examined Bryan about his Biblical beliefs—with a series of challenges and even “trick questions” (such as where Cain got his wife; Genesis 4:17). Whatever the adequacy or otherwise of Bryan’s responses, this examination was again ruled irrelevant by the judge and expunged from the record. One consequence of this was that Bryan never got to cross-examine Darrow, and instead the latter asked the judge to bring back the jury—which had been excluded from Bryan’s examination —to deliver the inevitable “guilty” verdict. That done, John Scopes was fined $100 by the judge. When the case went to appeal at the Supreme Court of Tennessee, the ruling that came back upheld the Butler Act as constitutional (it was not in fact repealed until 1967) but overturned Scopes’ conviction on a technicality. The amount of the fine should have been determined by the jury, since Tennessee judges were only allowed to impose fines up to $50, whereas the Butler Act specified a minimum fine of $100 for infractions. Thus both sides could claim a Pyrrhic victory, with local sympathies clearly siding with Bryan, while much of the national

Ambiguous Histories

185

press (notably H.L. Mencken) and radio coverage took the side of Darrow and the pro-evolutionist cause. Those deep divisions have not gone away. By all accounts, Darrow’s team (particularly Dudley Malone) had the better of the legal and scientific arguments. But why did Bryan come out of retirement to head the prosecution case?—indeed, he died of natural causes just 5 days after the trial (not during it) at his home in Dayton. In earlier years, he had three times been a Democratic presidential candidate (first in 1896) and had espoused progressive causes—such as the abolition of the gold standard, Philippine independence, graduated income tax, direct election of senators, and especially women’s suffrage. He also resigned as Secretary of State during World War 1, because his pacifism led him to seek neutrality rather than warmongering. Why would someone with this pedigree embrace the cause of conservative fundamentalism, however popular? One widely held opinion suggests that this trial was symptomatic of Bryan’s decline in later years, but Gould (1999) prefers an alternative view, whereby Bryan regarded the anti-evolutionist movement as a continuation of his past record of populist progressive causes. Gould avers that Bryan had misapprehended evolution in at least 3 fundamental ways, 2 of which are outlined below. First, he misunderstood natural selection—equating it in human terms with a “fight for survival” by eliminating enemies through warfare—and second, he misconstrued evolution as somehow implying that such martial struggles are morally virtuous. Both views were shaped in part by two influential books of the time (Kellogg, 1917; Kidd, 1918). Kellogg, an entomologist and teacher of evolution, found himself posted to the German General Staff during World War 1 (until the USA entered the war), where he listened to many “Darwinian” academic biologists expounding the creed of Allmacht (omnipotence). Natural selection among humans was seen in terms of violent and competitive struggle, such that “the human group which is in the most advanced evolutionary stage…. should win in the struggle for existence”, along with “the additional assumption that the Germans are the chosen race” (Kellogg, 1917, quoted in Gould, 1999, pp. 159-160). This predates the Nazis, who indeed regarded Darwin’s ideas as unGermanic. Kidd also identified Darwinism with domination by force (might is right), and held it responsible for a resurgence of paganism: “the pagan heart of the West sang within itself again in atavistic joy” (Kidd, 1918, quoted in Gould, 1999, p. 162). These sources, even though they misrepresent what Darwin had actually written over 50 years previously, clearly influenced Bryan’s contention that evolution promoted a “principle of battle” which destroyed the weak and undermined (Christian) morality.

186

Chapter 6

Bryan also fired off a salvo against the eugenic policies that were being advocated by many evolutionists at the time (see below), noting that “its only program for man is selective breeding, a system under which a few supposedly superior intellects, self-appointed, would direct the mating and the movements of the mass of mankind—an impossible system!” (quoted in Gould, 1999, p. 166). Seen in the context of “human improvement” advocated by supposedly progressive evolutionists through eugenics or even militarism (all this after the horrors of World War 1), the populist and humanitarian concerns of Bryan in siding with the creationist cause at least become understandable, even though his scientific understanding was faulty and limited. There seems to be a case for evolution to answer here. But where had these distortions of Darwinian evolution sprung from? This is not the place to delve into the murky history of so-called “social Darwinism”, a phrase which has been applied (confusingly) to everything from laissez-faire capitalism to racist imperialism to state socialism. In general terms, this phrase implies the application of “Darwinian” evolutionary ideas to human societies. One of the first to propound this hybrid field, in the 1860s, was the Victorian polymath Herbert Spencer, who could claim expertise in biology and psychology as well as sociology. Indeed, it is to Spencer that we owe the phrase “survival of the fittest”. As for eugenics, its ostensible aim was to improve the genetic stock of humanity through selective breeding, as proposed originally by Darwin’s cousin Francis Galton, also in the 1860s; it is worth noting that Darwin himself opposed this idea. However, it was promoted by many prominent geneticists in the early 20th C CE, and eugenic laws were enacted in several European countries and American states, as well as further afield. Their main purpose was to prevent mentally and/or physically disabled people from reproducing (on the questionable assumption that these conditions were hereditary), often through compulsory sterilisation. Such eugenic principles were ruthlessly enforced in Nazi Germany, with mass murder of those deemed less worthy—most tragically 6 million Jews, but also Slavs, gipsies, the disabled and the retarded, as well as homosexuals. After 1945, eugenics was largely discredited, yet several eugenic laws remained on the statute book well into the post-war era. In the view of some commentators, its spectre still haunts us under the guise of medical genetics. It is now possible to test an unborn foetus for a range of genetic diseases, many of which have devastating effects on the child’s (and thereby the parents’) quality of life. In a minority of cases, forewarned is forearmed, and the worst effects of a disease can be prevented by timely medical interventions (as e.g. in phenylketonuria). But options for “curing” such genetic diseases through gene therapy—or perhaps, in the future,

Ambiguous Histories

187

gene editing (Doudma, 2020)—still lag a long way behind our ability to diagnose their presence. Often the only realistic choice that can be offered to parents is between bearing an affected child (with all this might entail) and termination of the pregnancy—thus effectively selecting against that disease-causing gene (negative eugenics; Shakespeare, 1998). In the case of at-risk couples using in vitro fertilisation (IVF), the same end can be achieved by using preimplantation genetic testing of cells taken from early IVF embryos. All affected embryos would normally be discarded and only wild-type embryos implanted. There is a moral case to be made for these procedures on the grounds of minimising human suffering and distress, but even so the accusation of eugenics still stands, and the “right to life” of the embryo or foetus remains a contentious issue, polarising public opinion.

6.7 Multi-layered narratives in the Bible: Psalm 29 Below is the text of Psalm 29, taken from the New Revised Standard Version of the Bible (NRSV; with one alternative translation underlined). 1Ascribe to the LORD, O heavenly beings, ascribe to the LORD glory and strength. 2Ascribe to the LORD the glory of his name; worship the LORD in holy splendour. 3The voice of the LORD is over the waters; the God of glory thunders, the LORD, over mighty waters. 4The voice of the LORD is powerful; the voice of the LORD is full of majesty. 5The voice of the LORD breaks the cedars; the LORD breaks the cedars of Lebanon. 6He makes Lebanon skip like a calf, and Sirion like a young wild ox. 7The voice of the LORD flashes forth flames of fire. 8The voice of the LORD shakes the wilderness; the LORD shakes the wilderness of Kadesh. 9The voice of the LORD causes the oaks to whirl [or ‘the does to be in labour’], and strips the forest bare; and in his temple all say, “Glory!” 10The LORD sits enthroned over the flood; the LORD sits enthroned as king forever. 11May the LORD give strength to his people! [Psalm 29, NRSV] May the LORD bless his people with peace!

At first sight, this self-styled “Psalm of David” is a worship hymn addressed to the Lord God (rendered in Hebrew as the tetragrammaton YHWH, or Yahweh), expressed in terms of the natural world. But on closer inspection, it suggests a hybrid origin, with major elements (those in

188

Chapter 6

bold italic font) that may well be derived from pagan roots as a song of praise to Ba’al (Gaster, 1946). Ba’al was the storm and fertility god of the Canaanites and Phoenicians, peoples who in Old Testament times occupied much of what is now Syria and Lebanon, as well as Jordan and Israel/Palestine. Clearly this part of the psalm describes the progress of a storm as it moves inland from the Mediterranean Sea, but well to the north of Israelite territory—through Lebanon, over Mount Hermon (known as Sirion to the Phoenicians) with its cedar forests, and out into the wilderness of Kadesh (Futato, 2007, pp. 209-220). “The voice of the Lord is over the waters” in verse 3 is therefore likely to reflect the victory of the storm god Ba’al over the sea god Yam, a story that forms part of the Ugaritic Ba’al cycle myths, deciphered in the 1920s from clay tablets recovered from the tel at Ras Shamra on the Mediterranean coast of Syria. [This victory is extolled in more detail in Psalm 93—likely to have a similar hybrid origin.] Indeed, according to that cycle (unfortunately incomplete), Ba’al is later defeated and killed by his rival Mot, the god of death, who is in turn utterly destroyed by Ba’al’s sister Anath. First Ba’al and then Mot are later restored to life, after which Mot challenges Ba’al, but following an inconclusive battle between them, Mot eventually submits to Ba’al as king. All three (Ba’al, Yam and Mot) are second-tier gods and sons of the supreme god El—indeed the phrase rendered heavenly beings in verse 1 is more accurately translated “sons of god” (the Hebrew form here is El rather than YHWH). This cyclical succession of Canaanite gods might plausibly correspond to the changing of the seasons (Schwemer, 2008, p. 12). A Phoenician parallel for Psalm 29 verse 11 has been claimed (Barré, 1991), though some biblical scholars deny any such Canaanite influence in this Psalm (e.g. Barbiero, 2016). Nor is this pattern unique to Psalm 29; similar language is used in Psalm 89:5-14 and elsewhere. In Psalm 118 there is even a different form of the divine name (rendered YAH instead of YHWH), marking out what seems to be older Canaanite material derived from a hymn proclaiming the victory of Ba’al over Mot. These and other links with Ugaritic sources were promoted enthusiastically by Mitchell Dahood in his 3-volume commentary on the Psalms (Psalm 29 is in vol. 1; Dahood, 1966, 174-180). I am indebted to Dr Anja Klein (University of Edinburgh) for explaining the likely pagan origins of large parts of such Psalms during a clergy training day at New College, Edinburgh, in September 2017. Returning to Psalm 29, the bold italic text (essentially vv. 3-9) seems to have been adapted from its Canaanite model simply by substituting the tetragrammaton YHWH for the (presumed) original Ba’al. But vv. 1-2 and 10-11 evince later editorial additions (normal text) that emphasise the

Ambiguous Histories

189

incomparable superiority of Yahweh over Ba’al: “ascribe to YHWH glory and strength”, “ascribe to YHWH the glory of his name”, “worship YHWH in holy splendour” (vv. 1-2). Verse 10 makes it clear that not only does YHWH “sit enthroned over the flood” (= primordial chaos, as in Genesis 1:1-2), but he sits “enthroned as king forever” in contrast to the precarious and perhaps transient kingship of Ba’al. Similar imprints of biblical Judaism have been overlaid on other Psalm texts that seem likely to stem from Canaanite origins—they have all been carefully edited to reflect orthodox belief in Yahweh and the Mosaic Law. Tradition holds that the Psalms were composed during the days of the early kings (David and Solomon), but more likely they represent the outcome of a lengthy compositional and editorial process that occurred much later—probably during or after the exile in Babylon, as most biblical scholarship concurs. Indeed, much of what we call the Old Testament seems to have been compiled and edited over a protracted period. Four textual strands have been distinguished—respectively identified as Elohist (E), Yahwist (J), Priestly (P) and Deuteronomist (D). Material attributed to E uses El to denote God, who is often described as ruling over other gods—clearly reminiscent of the Canaanite pantheon outlined above. The J source, by contrast, insists that Yahweh (who may have started out as a tribal god of the Israelites) is the only God, a monotheistic stamp that is reinforced by the editorial activities of P and D (D is the primary source of Deuteronomy and probably the Deuteronomistic history—the books of Joshua, Judges, Samuel, Kings etc.). A brief if rather sweeping summary of this classical four-source view is given by Reza Aslan (2017), but recent scholarship has challenged this consensus, suggesting that multiple fragmentary source materials have been heavily edited and supplemented (as in Psalm 29). Numerous Old Testament passages condemn Ba’al worship, implying that such practices remained rife throughout the land over a lengthy period. There are several suggested reasons for this, but the popularity and ubiquity of Ba’al worship songs among Israelites may well underlie their adoption and transformation into Jewish psalms of praise to Yahweh. This is a classic example of inculturation—adapting elements from previous cultures or religions and then incorporating them (variously transformed) into a newer belief system, often imposed from outside (e.g. by colonial powers). Generally these adopted/adapted elements help to smooth the acceptance of otherwise alien forms of thought. Conversely, Vincent Donovan (1978/1982), a Catholic missionary working in Tanzania during the 1960s, found that he had to strip away the many cultural assumptions and accretions of Western Christianity in order to communicate the gospel effectively to the Maasai cattle-herders with

190

Chapter 6

whom he worked. Many other examples of inculturation are evident in buildings: for instance, the Pachamama or Mother-Earth fertility goddess of Andean peoples, is celebrated in details of the stone carvings by native craftspeople adorning many churches built after the 16th C CE Spanish invasion that enforced conversion to Catholicism (Fig. 6-2A to C). Even more extraordinary, perhaps, is the Breton chapel dedicated to the Seven Saints of Ephesus near Vieux-Marché in the Côtes d’Armor (France), which incorporates a Neolithic burial chamber or dolmen in its crypt (Fig. 6-2D to F), now housing statuettes of the saints. Since the story of these saints also figures in the Qu’ran (Sura 18), this modest chapel has become a focus for inter-faith pilgrimages involving both Christians and Muslims, thanks largely to the advocacy of Louis Massignon.

Figure 6-2. Inculturation exemplified in buildings. Parts A, B and C, decorative fertility motifs reflecting traditional Andean beliefs in Pachamama, from the Jesuit church in Arequipa, Peru. Parts D, E and F, the Chapelle des Sept Saints near Vieux Marché, Brittany (D), with its crypt incorporating statuettes of the 7 saints (E) and a large dolmen (capstone and supporting slabs in part F).

There is, admittedly, a fine line between inculturation that makes new beliefs accessible, and a syncretism which so dilutes their core message as to make them effectively meaningless (Newbigin, 1989). It is a moot point on which side of this fence one should classify the popular conflation of beliefs in the Pachamama and in the Virgin Mary—both venerated among Andean peoples. Arguably, the protean adaptability of Christianity is both a great strength (allowing it to spread rapidly across cultures) and a serious weakness (since almost any statement of belief will be reinterpreted or rejected by one or other grouping). This book is an attempt to inculturate Christian belief within the framework of 21 st C CE evolutionary biology— although clearly it will be rejected outright by those Christians of a creationist, or indeed fundamentalist, persuasion. For them, the literal Word of God in scripture takes precedence over, and so trumps, any form

Ambiguous Histories

191

of scientific evidence. This book will equally be rejected by materialists for whom it is inconceivable that any kind of God might actually be real.

6.8 Violence and the Sacred—the work of René Girard Atheists such as Dawkins (2006) or Hitchens (2007) never tire of reminding us that religious conflicts are endemic and often peculiarly brutal. Of course they are right, witness the Crusades, the post-Reformation wars that engulfed Europe, or the current clashes between Sunni and Shi’a factions in Islam. Even within the Bible, parts of the Old Testament condone and even glorify genocide as something commanded by God (the Deuteronomistic history books are especially repellent in this respect, but by no means unique). Yet, as pointed out by Rowan Williams (2014, pp. 37-38), even within the Old Testament there is evidence of re-evaluating certain violent acts that were formerly acclaimed as righteous, such as the massacre of King Ahab’s widow Jezebel together with his entire family at the hands of Jehu—which is celebrated in the second book of Kings (2 Kings 9:30-10:11) but later condemned by the prophet Hosea (Hosea 1:4). Understanding of morality is by no means static, and biblical interpretation needs to be nuanced accordingly. It is also worth pointing out that atheist regimes have succeeded on a far vaster scale in eliminating their (supposed) ideological opponents—witness the atrocities of Pol Pot’s killing fields, of Stalin’s gulags and Chairman Mao’s Cultural Revolution. But the Holocaust that killed 6 million Jews can to some extent be read as a religious conflict between Christianity and Judaism, given the notorious use made by Nazi propagandists of Martin Luther’s anti-Semitic rhetoric. René Girard (1923-2015), through his seminal book “Violence and the Sacred” (1972/1977) and its many sequels, developed a constellation of interlinked ideas during his long career (Girard 1978/1987, 1999/2001, 2008, 2007/2010). Starting out as a historian and literary critic, Girard claimed to have detected a common pattern in fiction and in myths from many different cultures, whereby social groups become riven by mimetic rivalries (emulating a rival to gain some limited resource), and incipient conflict can only be resolved by banding together to scapegoat an innocent victim—who is ritually murdered or driven out. In this pattern he sees the origins of most human religions (although he does not really discuss Buddhism)—thus inextricably linking violence with the sacred, since in his view such religions are all based on a founding murder that necessitates repeated ritual sacrifices in order to maintain social cohesion. For this to work effectively, it is essential for the mob to believe that the victim is truly deserving of death or exile. This he describes as a “false salvation

192

Chapter 6

through Satan”, whose power is exerted through scapegoating of innocent victims. But in Christianity, and to a lesser extent in Judaism, he sees a fundamental challenge to this false salvation. Even in the Old Testament, the “founding murder” of Abel by Cain is followed by God’s judgement but not retribution (Genesis 4:8-16). Even more strikingly, God takes the side of scapegoated Joseph and finally vindicates him publicly in the face of his conspirator brothers (Genesis chapters 37 to 48). God, in other words, is on the side of the innocent victim, not on that of the lynch mob. In the gospel of John (8:1-11), Jesus succeeds in saving the woman taken in adultery from a self-righteous crowd bent on stoning her to death, by bidding them reflect on their own sins before casting the first stone—until they sidle away shamefaced, one by one. The trial and crucifixion of Jesus expose the falsity and impotence of this scapegoating mechanism, according to Girard. God in Jesus (as the second Person of the Trinity) is identified totally with the innocent victim, scapegoated by an unholy alliance of both Roman and Jewish authorities, reviled by the crowds who had acclaimed him only days earlier on Palm Sunday, denied by Peter, abandoned by all his disciples (except John), and ritually killed. For Girard, the resurrection vindicates the self-sacrifice of Jesus on behalf of all humanity (or, as I will argue later, of all creation) and shows us “true salvation in Christ”. Satan is seen as the accuser (Job 1:6-12), who first sows disorder by inciting mimetic rivalries and then reestablishes a false order through scapegoating and ritual murder of the victim. But this semblance of order is based on a lie, for Satan is the father of lies (John 8:44). This allows us to make new sense of Jesus’ paradoxical question in Mark 3:23: “How can Satan cast out Satan?” Jesus exposes and disempowers the lies of Satan, and modern concern for victims of all kinds can be traced back to this uniquely Christian source (Girard, 1996). This should direct us towards finding new ways to resolve tensions and conflicts, and to eschew the scapegoating that has become increasingly rife in Western societies, whether through popular media hype followed by humiliating exposés of so-called celebrities, through anonymous internet bullying and “trolling”, through Machiavellian office politics, through the machinations of special interest groups, or through innumerable devious routes that allow a very few to climb the greasy pole to positions of power and influence. It may seem perverse to quote here the closing words of Richard Dawkins’ seminal 1976 book, “The Selfish Gene” (p. 215), but I think he is here suggesting something similar—that human beings should endeavour to transcend the blinkers of their evolutionary inheritance.

Ambiguous Histories

193

“We have the power to defy the selfish genes of our birth and, if necessary, the selfish memes of our indoctrination. We can even discuss ways of deliberately cultivating and nurturing pure, disinterested altruism—something that has no place in nature.. We are built as gene machines and cultured as meme machines, but we have the power to turn against our creators. We, alone on earth, can rebel against the tyranny of the selfish replicators”.

Girard claims to employ impartial “scientific” analysis of literary sources in asserting the universality of this scapegoat mechanism. But many have accused him of selectivity, elision and biased interpretation of his sources, ignoring much contrary evidence. Similarly, anthropologists are unimpressed by his attempts to shoehorn a vast range of cultural and religious practices into his universal “one-size-fits-all” model. From a theological perspective, it is doubtful whether our sense of the sacred is centred wholly round ritual sacrifice of a scapegoat (however metaphorical in nature). As Roger Scruton points out (2014, pp. 18-22), religions of all shades are more concerned with the classic “rites of passage” that mark our human lives— birth, coming of age, marriage or death—and it is hard to see where scapegoating would fit into any of these. But this lack of universality does not fundamentally undermine Girard’s insight into the insidious pervasiveness of mimetic rivalry (why else is the tenth commandment so long and detailed? Exodus 20:17; cf. James 3:14-4:3) and its inevitable culmination in the scapegoating of innocent victims. Awareness of the links between violence and religion should alert people of all faiths to their own implicit or explicit collusion in such practices. In 17th and 18th C CE Britain, many women were scapegoated, tortured and executed on merest suspicion of witchcraft (Northcott, 2014, pp. 100-102). Christians in particular should beware of using sacrificial language that implies accepting or condoning such violence, for “those who take the sword will die by the sword” (Matthew 26:52). Rather, we are enjoined to seek peace and reconciliation with our neighbour, to turn the other cheek, to give up our cloak as well as our tunic, and to go the extra mile (Matthew 5:23-24, 39-41). Scruton (2014, p. 20) also puts his finger on the singularity of Girard’s claim that “Jesus was the first scapegoat to understand the need for his own death and to forgive those who inflicted it” (cf. Luke 23:34). Scapegoating—like complex language with all its cultural offshoots— may be a uniquely human trait, or possibly one shared with other hominins. It is certainly true that competition, rivalry and aggression are widespread among animals. However, scapegoating does not seem to be used as a means for re-establishing peace and social order when conflicts break out within groups of primates (de Waal, 1989). For the most part, such conflicts are resolved through established dominance hierarchies

194

Chapter 6

within the group. Occasionally, fights will displace the existing alpha male (or female), so setting up a new hierarchy. Complex interactions likewise allow new queens to emerge among social hymenopteran insects (e.g. bees), where all of the individuals in a colony are genetically related. Superficially, the human predilection for scapegoating others (whether animal or human) might seem to find its closest animal parallel in the socalled omega wolf—the lowest in the pecking order of any wolf pack— who is often marginalised and treated viciously by other pack members of superior rank. But many anecdotal accounts suggest that the omega wolf’s role is perhaps more akin to that of a court jester in human society; certainly there seem to be elements of playfulness and even affection that do not correspond closely with scapegoating among humans. If indeed this murderous trait is unique to humans, then its origins may afford a useful re-interpretation of the Fall and the serpent’s temptation, as Girard implies.

6.9 Doubting Thomas and Mary Magdalene According to the gospel of John (11:16), the disciple Thomas was also known as the Twin. In this passage, Jesus is preparing to leave for Judaea, to visit his sick (indeed, already dead) friend Lazarus—despite having narrowly escaped stoning when he was last there. His disciples are worried at this prospect, but it is the realist Thomas who eventually states bluntly: “Let us also go, that we may die with him” (John 11:16, NRSV). Later on in John’s gospel, during the lengthy discourses of Jesus after the footwashing, it is again Thomas who dares to voice the question that must have been on all the disciples’ lips: “Lord, we do not know where you are going. How can we know the way?” (John 14:5, NRSV), eliciting one of Jesus’ most memorable sayings: “I am the way, and the truth, and the life” (v. 6, NRSV). But Thomas is best known for the famous “Doubting Thomas” episode recounted in John 20:19-29. Having been absent from Jesus’ first resurrection appearance to the other disciples on the evening of the first Easter day, Thomas cannot bring himself to believe his fellowdisciples’ claim that Jesus has risen from the dead; “Unless I see the mark of the nails in his hands, and put my finger in the mark of the nails and my hand in his side, I will not believe” (v. 25, NRSV). He is left a whole week to stew—presumably out of favour with his ten companions and with the women, who are all convinced that their Lord had indeed risen. Then Jesus again appears among them, this time with Thomas present, greeting them once more with the words “Peace be with you”. Thomas is invited to touch his crucifixion wounds and confirm that it is really Jesus who stands among them. Despite earlier vehement protestations of needing tangible proof, Thomas is so overwhelmed that he responds with the words “My

Ambiguous Histories

195

Lord and my God” (v. 29)—the first time Christ’s divinity is proclaimed so unequivocally (compare Peter—“the Messiah, the Son of the living God”; Matthew 16:16). As for his later life, tradition holds that Thomas travelled east to India on his apostolic travels, founding a unique Hebrew/ Syrian church in Kerala that still features both Jewish and Indian practices. In a celebrated essay, Lynn White (1967) lambasted the Judaeo-Christian tradition in general, and Genesis 1:28 in particular, for the human attitudes of domination and ruthless exploitation that have precipitated the ecological crisis threatening our planet (even 50+ years ago!). True enough, the Hebrew word translated dominion does not equate to domination, but rather implies stewardship responsible before God (Westermann, 1987, pp. 10-11). But in the neglected second half of his essay, White went on to nominate St. Francis of Assisi as a patron saint for ecologists— a suggestion enacted by Pope John Paul II in 1979. As for scientists in general, St. Albert the Great (Albertus Magnus, teacher of St. Thomas Aquinas) is the official Catholic patron saint, but following Karl Popper’s principle of falsifiability as decisive in science, I wonder whether Doubting Thomas might not be a more appropriate choice? Even if he did not carry out his tactile test of the risen Jesus’ identity (John’s gospel is silent on this point), he had the courage to voice his rational doubts against the reigning paradigm of belief among the disciples. If indeed he did reach India, we might commend him for his perseverance and single-mindedness (equally essential in a scientist), for this was not an easy journey in the 1st century CE—though trading routes by sea and land had linked China and India with Arabia and the Mediterranean civilisations since the 3rd C BCE. But another reason for including Thomas in this chapter is to introduce a brief mention of the “lost” Gospel of Thomas. Fragments of this text, in Greek, were unearthed at Oxyrhynchus (south-west of Cairo in Egypt) in 1898, but in 1945 a complete Coptic text was discovered in a sealed jar from a cave at Nag Hammadi in upper Egypt. This manuscript was preserved along with numerous other religious texts belonging to the socalled Gnostic tradition, which essentially emphasised secret spiritual knowledge of the divine spark within us, in contrast to a faith based on church teachings. Gnosticism was regarded as heretical by the early church, and was strongly condemned by Athanasius of Alexandria in the 4th C CE; it may be that the Nag Hammadi manuscripts were hidden by Gnostics at around this time. But the Gospel of Thomas is quite different from other Gnostic gospels and apocalypses; it contains no accounts of improbable miracles—indeed, no narratives whatsoever; rather, it is a collection of 114 sayings attributed to Jesus. Its opening proclaims that

196

Chapter 6

“these are the secret sayings which the living Jesus spoke and which Didymos [twin] Judas Thomas wrote down.” This may identify Thomas as a nickname for the otherwise obscure disciple Jude (not Judas Iscariot), whom some ancient traditions hold to be a brother of Jesus and therefore especially close to him. Certainly there was rivalry for pre-eminence among the disciples—other contenders being Peter “the Rock” and John “the beloved disciple” (in John’s gospel, uniquely). Many of the sayings in the Gospel of Thomas clearly mirror parts of the parables and teachings of Jesus as recorded in the four canonical gospels, albeit in an often briefer and less developed form (perhaps even suggesting an older origin?). Other sayings in Thomas’ Gospel have no parallel in any other part of the New Testament canon, and some of them are obscure or even downright contradictory, with an almost Zen-like quality seemingly designed to jolt hearers out of their complacency. The fact that this gospel was so revered by Gnostic sects probably contributed to its exclusion from the New Testament canon, which was outlined by Athanasius himself (in 367 CE). But others suggest that the rediscovery of this “lost” gospel is particularly apt for our time, stressing “the spirituality of incertainties” (AbrahamWilliams, 2015), as in saying 114 that ends the Coptic Gospel of Thomas. “Simon Peter said to Him, ‘Let Mary [Magdalene] leave us, for women are not worthy of Life’. Jesus said, ‘I myself shall lead her in order to make her male, so that she too may become a living spirit resembling you males. For every woman who will make herself male will enter the Kingdom of Heaven.” [Schenk, 1992]

This is, to say the least, ambiguous, although Schenk’s commentary points out that “male” is intended to denote the spiritually enlightened Gnostics (partakers of the “secret knowledge”), whereas “female” in this context denotes the “unenlightened” Christians belonging to more conventional churches. However, this same saying is given a freer and more literal contextual translation by John Henson and the ONE Community. “Simon, otherwise known as ‘Rocky’, said to the others, ‘Maggie should leave us. Life to the full is not for women!’ Jesus said, ‘I intend to train women like Maggie to do all the things that men can do and to give them the same freedoms you have. Every woman who insists on equality with men is fit to be a citizen in God’s New World.’” [Henson, 2004, p. 80]

True enough, this plays into our 21st C CE priorities about gender equality and could perhaps be construed as a wish-fulfilling rendering, but I think it stands despite that. However important historically, ancient controversies around the Gnostic movement carry very little weight for Christians today.

Ambiguous Histories

197

The proof of the pudding, as they say, is in the eating. According to John 20:1-18, it was to Mary Magdalene that the risen Jesus first appeared, an account corroborated to some extent by Matthew 28:9—though other women were also present (vv. 1-8), as they were at the empty tomb in Mark 16 (1-8) and Luke 24 (1-10). Actions speak louder than words, and the consensus that women were the initial witnesses of key events on that first Easter Sunday could hardly be mere pious invention. This was truly revolutionary in its overturning of a long-established patriarchal social order, as was so much else in the teaching of Jesus about God’s kingdom. It has taken the church 2000 years to recognise the equal ministry of women—and then only in (some) Protestant but not in Catholic or Orthodox denominations. The high regard in which Jesus held women shines through in many gospel texts, and strong hints in the Pauline epistles imply that women held leadership positions within the early church. But female role models have been largely glossed over or ignored in the history (clearly not herstory; Schussler-Fiorenza, 1983) of early Christianity, despite Paul’s assertion in Galatians 3:28 (NRSV) that “there is no longer male and female…for all of you are one in Christ Jesus.” This selfsame verse also seeks to remove distinctions between Jew and Greek, and between slave and free—yet slavery in Britain was only abolished in 1833, and racism continues unabated in many parts of the world—as do sexism and thinly disguised forms of slavery. Moreover, by implication at least, Mary Magdalene breaks another stereotype in John 20. Luke 8:2 suggests she had been afflicted by what we would now call mental illness, but was healed by Jesus. For her to be chosen as the primary resurrection witness (according to John) challenges two social stigmas simultaneously: her gender and her mental health. While prejudice against the former may be dissipating in the West as women’s equality gains ground, the latter stigma remains deeply entrenched. The seeds of these radical challenges to the established social order, with all of its implicit role-assumptions and careless pigeon-holing of people, are evident throughout the gospel teachings of Jesus. To some extent, they went on to germinate within the early church communities founded by Paul and others (e.g. Acts 2:42-47; Wright, 2018, pp. 424-427), but were later choked by the stranglehold of patriarchal authority structures. It may be true, as Pinker (2018) asserts, that these seeds have only blossomed and borne fruit in terms of human flourishing and advancement since the Enlightenment, but they were sown originally by Jesus in the unpromising soil of first-century Palestine. The epithet “Magdalene” is usually interpreted as meaning “from Magdala”—possibly denoting the sites of Magdala Nuniya (“Tower of the Fishes”) or of Magadan on the western coast of the Sea of Galilee (Taylor,

198

Chapter 6

2014). However, the root Magdala (Migdal) literally translates as “tower”, and Taylor asks whether Mary’s epithet might have been a nickname— similar to Simon Peter (petra = rock). If this is true, the use of these two nicknames within the community of Jesus’ close followers carries striking echoes of the many juxtapositions of “rock” and “tower/fortress” in the Psalms, for instance in Psalms 18:2, 31:2-3, 61:2-3, 62:2, 71:3, 94:22 and 144:1-2, with the strong connotation of “refuge” (Futato, 2007, pp. 96101). This is turn suggests that Mary was perhaps more influential than is commonly assumed among Jesus’ followers—perhaps even a leader who was later largely written out of the canonical gospels (apart from John 20:1-18) because she was a woman. Of course, it is easy to over-interpret such guesses in the absence of any real documentary evidence, but Jesus’ choice of Mary as (one of) the first witness(es) of his resurrection could hardly be fortuitous. There is a fragmentary Gnostic Gospel of Mary, perhaps dating from as early as the 2 nd C CE, that has been attributed to Mary Magdalene. It is not strictly a gospel, since it does not deal with the pre-crucifixion life of Jesus—but instead consists of dialogues between Jesus and his followers—pre-eminently Mary Magdalene herself—after his resurrection (text available online at Polebridge Press; King, 2003). At all events, the recent rehabilitation of Mary as a beloved companion of Jesus—indeed, as a disciple and even an apostle (since she witnessed his resurrection at first hand)—is long overdue. She was sent by the risen Jesus to bear witness “to the brothers” (i.e. the 11 traditional apostles; John 20:17), and so truly merits the epithet “apostle to the apostles”. My reason for prefacing part 2 of this book with a series of ambiguous and multi-layered histories is to scotch at the outset any suggestion that there is only one way of reconciling the evolutionary and biblical accounts of how humanity and the biosphere (to say nothing of the cosmos or indeed multiverse) came into being. Far from it—there are many possible ways of so doing. The next chapter outlines four contrasting approaches to such a reconciliation from key thinkers with expertise in both evolution and theology, while its successor expounds a summary of my own views.

CHAPTER 7 KEY THINKERS ON EVOLUTION AND FAITH

Summary § 7.1 briefly examines a few of the contradictions between the scientific and Christian accounts of creation, and introduces 4 key thinkers who have tried to reconcile these—albeit from very different perspectives. § 7.2 offers a critical assessment of the Jesuit palaeontologist Teilhard de Chardin, noting the long time gap between his writings and their posthumous publication. He clung to an outdated orthogenetic model of evolution, compounded by a teleology drawn towards Christ-Omega and a panpsychic view of matter—all heavily criticised by scientists. Even so, his vision of evolution as grounded and fulfilled in the cosmic Christ still remains attractive to many Christians. § 7.3 turns to Sam Berry —an evolutionary ecologist and evangelical Christian, who took both the biblical text and the science of evolution very seriously. His take on the Fall and original sin, on the Genesis creation story, on the image of God in humanity, and on the Virgin Birth of Jesus, are reviewed critically. § 7.4 surveys the contributions of Catholic biologist and theologian Celia Deane-Drummond—notably discussing the ethics around biotechnology, the biblical figure of Lady Wisdom, an expansion of von Balthasar’s concept of theo-drama to encompass evolution, and the importance of niche construction—linking ecological with human flourishing. § 7.5 considers the work of liberal Anglican Arthur Peacocke, with its distinctive adherence to emergence, panentheism and a naturalistic perspective that rejects the supernatural elements in Christian faith, while finding meaning in its sacraments. Despite its costliness, evolution can still remain a “disguised friend of faith”. Finally, § 7.6 briefly summarises salient features of these four thinkers.

7.1 How might evolution undermine Christian faith? At first sight, evolution seems to contradict any notion of a Creator God, rendering such an entity completely redundant as an “explanation” for the superabundance of life—including humanity—that populates this

200

Chapter 7

planet. I will not divert here into questions of cosmology that are beyond my expertise, but Part 1 of this book has made it abundantly clear that evolution by natural selection provides a self-consistent explanatory rationale for biodiversity at every level—from the molecular to the ecological. There is no need to posit a divine Intelligent Designer, nor a deist God who set everything going (and then sat back to watch it all unfold in fulfilment of some ineffable plan), nor even a Guide to tweak otherwise random mutations so as to promote complexity and intelligence. Given a favourable planetary environment, the self-assembly of living organisms from simple building blocks may have been a lucky accident, or may have been almost inevitable (§ 1.7). But once started, natural selection did the rest, ensuring diversification and indeed complexification of living organisms over billions of years. In the process, the biosphere has itself transformed the land, sea and air, but no species has had a greater or more rapid impact on the environment than Homo sapiens (chapters 5 and 10). Traditional Christian belief tells a very different story, claiming that God is the Creator and Sustainer of everything that exists—from nebulae to narwhals, from quarks to quail, from halogens to human beings. Yet even the timescale of God’s creative acts remains a matter of dispute— some holding to a literal six days about 6000 years ago (young-earth creationists), while others allow that our planet and the universe are vastly older than this—often conceding that creation is an ongoing process. There is also disagreement as to what is meant by the term “creation” itself, and what role (if any) can be assigned to evolution. Much depends here on how literally we interpret the written scriptures of the bible—particularly its opening book of Genesis. Unlike the other major monotheistic faiths (Judaism and Islam), the God of Christianity is Trinitarian (§ 8.4)—Father, Son and Holy Spirit—as 3 aspects or Persons of the One God. Yet this God is known personally, and is held by many Christians to intervene in the lives of individual believers, and indeed of the whole world. How far these traditional features of Christian faith might need to be recast in the light of evolution is the chief topic of both this and the next chapter. The biblical accounts of creation (note the plural, as there are several; Harris, 2013) in some cases specify separate creation by God of each kind (= species?) of plant or animal (Genesis 1:11-12, 20-25), and also confer a special status on humanity, created in the image of God (Genesis 1:26-27). Literal or even metaphorical interpretations of this chapter seem to be directly contradicted by evolution, not least by the immensities of geological time Admittedly, the notion that the biblical “days” of creation might in reality correspond to much longer time-spans can be traced back

Key Thinkers on Evolution and Faith

201

at least to St. Augustine (who noted that the sun—basis of diurnal time— did not appear until day 4; Genesis 1:14), and has been much discussed since, e.g. by Buffon in the 18th C CE, and by “old-earth” creationists more recently. But the chronology of Genesis 1 cannot easily be reconciled with the fossil record. The seas were teeming with life (including fish; day 5 in Genesis 1:20) in the Cambrian, long before plants appeared on land (day 3; Genesis 1:11) in the Silurian, or birds in the air (also day 5) in the Jurassic. Though zoologists might enjoy the image of Adam as a protoLinnaeus, naming all the animals (Genesis 2:20), from an evolutionary perspective the human Fall (as narrated in Genesis 3) cannot possibly be held responsible for the appearance of physical death on this planet (nor indeed for the origin of sin). Death is as old as life itself, while deception (which underpins so many human sins) must presumably go back to the emergence of predation in the Cambrian (§ 3.2). Even so, Genesis 3 contains profound psychological insights into the way that human beings try to shift the blame when caught out disobeying orders—likewise the story of Cain and Abel in Genesis 4. But the same could be said of many incidents in Greek, Norse, Mesopotamian or any other mythology. Such insights do not in and of themselves lend credence to the improbable stories within which they are set. We could multiply such examples ad nauseam from across the bible, including parts of the New Testament. Reading a bit further into Genesis (chapters 6-8), literal interpretations of the Flood narrative are also flatly contradicted by the findings of evolutionary science. Yet, despite this story’s inherent implausibility, there are similar flood narratives in other Middle Eastern mythologies (one figures in the Epic of Gilgamesh), suggesting that one or more great floods might indeed have affected that region within ancestral memory. The Mediterranean basin was flooded (Zanclean deluge) when the Atlantic Ocean breached the isthmus connecting Spain with North Africa, creating the Strait of Gibraltar—but this occurred ~5.3 Ma, well before the advent of modern humans. A much more recent flood that greatly expanded the Black Sea has been proposed, either about 16,000 years ago due to rapid melting of the Scandinavian Ice Sheet via the Caspian Sea, or else about 7600 years ago when the Aegean Sea broke through a sill of rock to create the Bosphorus. Both of these Black Sea suggestions remain controversial, though the time-frames look far more plausible. But none of these floods would have been world-wide, nor drowned nearly all land-based life. At the least, Christians who accept the broad truth of evolution are obliged to interpret many such biblical texts in a non-literal way. And yet, at the core of our faith is the resurrection of Jesus Christ—humanly speaking, an impossible and unprecedented event. This is a leap of faith for believers,

202

Chapter 7

because “if Christ has not been raised, your faith is pointless… If our hope in Christ has been for this life only, we are of all people the most pitiable” (1 Corinthians 15:17, 19; NRSV). Despite atheist claims to the contrary, many scientists—not all of them mere jobbing academics like myself—still maintain a faith in God, including (but not restricted to) those of a Christian persuasion. How do they reconcile the traditional doctrines of creation and the Fall—not to mention the special status accorded to human beings—with the facts of evolution? In this chapter, I will focus on the contributions made by four key thinkers in this area—all of them trained in biology or palaeontology, but also (to a greater or lesser extent) in theology as well. Inevitably, the discussion will digress to include some reference to a much broader range of thinkers, but will barely scratch the surface of the innumerable books written about science and religion. I have narrowed the field to just four by insisting on first-hand expertise in the twin fields of evolution and of theology, and also by focussing on thinkers from a European background. This is perhaps a controversial choice on my part, given the many notable contributions to this field from North America (e.g. Ayala, 2007), but the debate there has been polarised by creationist storms that have caused little more than a ripple in Europe. I will state at the outset that I disagree in some measure with both of my first two thinkers—with Pierre Teilhard de Chardin because he was fundamentally wrong about evolution, and with the late R. J. (“Sam”) Berry because I do not share his preoccupation with the veracity (even if non-literal) of the scriptures. I am generally more sympathetic to Celia Deane-Drummond—though I do not fully endorse her adherence to core Roman Catholic doctrines—and to the liberal Anglican Arthur Peacocke, though his writing could be quite dense and convoluted in places. These diminishing areas of disagreement explain the order in which I treat my four key thinkers. In defence of restricting my coverage in this way, I would maintain that all four deserve the compliment of a detailed critique, rather than just citing ideas or quotations that accord with the thrust of my overall argument, as I have done elsewhere in this book.

7.2 Pierre Teilhard de Chardin (1881-1955) 7.2.1 Brief biography Teilhard (as his name is usually abbreviated) was born in the Auvergne region of France in 1881, and was educated at a Jesuit school in the 1890s, entering the Jesuit novitiate in 1899. Two years later, a republican French government passed the Law of Associations, which effectively outlawed

Key Thinkers on Evolution and Faith

203

and confiscated the property of religious orders. Teilhard’s Jesuit training continued on the island of Jersey, which lies just off the French coast but is a Crown Dependency linked to the United Kingdom. Back in France, a licentiate in literature followed in 1902 at Caen on the Normandy coast. From 1905 to 1908, he taught physics and chemistry at a Jesuit school in Cairo, Egypt, then from 1908 to 1912 he returned to the UK, studying theology at the Jesuit training centre in Hastings. He was ordained priest in 1911, and after completing his studies, he worked from 1912 to 1914 in the palaeontology laboratory at the Musée d’Histoire Naturelle in Paris. During this period, his name became linked with the notorious Piltdown hoax of 1913 (Gould, 1980)—a supposed missing link between humans and ape-like ancestors—which was in fact a forged composite of a human skull and an orang-utan lower jaw. What role Teilhard played in this fraud is disputed (Lukas, 1981), but it is clear that he was a mere beginner in palaeontology at the time, and may well have been duped himself—unless it was, in reality, “a joke gone wrong” (Thackeray, 2012). He also worked with Abbé Breuil (see also § 5.12) in the painted caves of Castillo, Spain. During World War 1 (1914-1918), Teilhard chose not to become a chaplain to the troops, but volunteered as a non-commissioned stretcherbearer with the 4th Moroccan Regiment, where he was the only Christian among Muslims, and insisted on wearing the same khaki dress and red fez as they did. He described his wartime experiences on the front as an encounter with the Absolute, and was decorated several times for valour— including the Légion d’Honneur. He professed his final solemn vows as a Jesuit whilst on leave in May 1918. Post-war, he undertook a Natural Sciences degree at the Sorbonne, followed by a doctorate at the Catholic Institute of Paris, where he subsequently taught geology in the early 1920s. However, in 1925 two essays he had written about the Fall (see Teilhard de Chardin, 1969/1971, pp. 36-44 and 45-55) came into the hands of his superiors, and caused consternation because they appeared to cast doubt on the historicity both of Adam and Eve and of the Fall, thereby downplaying the significance of original sin. He was forced to leave his teaching post and, at the behest of the Jesuit Superior General, to recant the views he had allegedly expressed by signing a document comprising six propositions (which have only recently come to light; Grumett & Bailey, 2018) setting out official Catholic doctrine on these matters. He obeyed, rather than be expelled from the Jesuit order. This was, alas, only the start of a prolonged and futile struggle against Catholic officialdom, which effectively banned publication of all but a non-theological handful of his writings during the remaining 30 years of his life (photo, Fig. 7-1A).

204

Chapter 7

Having first visited China in 1923 with Emile Licent, he collaborated extensively with the Geological Survey of China on several subsequent geological and palaeontological expeditions, including an advisory role in the discovery and identification of Peking Man—a species initially called Sinanthropus, but now classified as Homo erectus (Fig. 7-1B). Conditions were difficult for him in France, and he spent most of his time in China from 1926 to 1946 (including all of World War 2). He also travelled extensively across many regions of China, as well as in Africa, Indonesia and the US. He pursued his own studies on the palaeontological history of naked mole rats based on Chinese fossils, as well as on human ancestry, but published rather little in scientific journals—though his last paper dates from as late as 1952 (just 3 years before his death). He was also nominated to the French Academy of Sciences in 1950. From the 1940s onwards, after failing to gain permission from Rome for publication of his major work, “The Phenomenon of Man” (Teilhard de Chardin, 1955/1959), he found his teaching activities largely curtailed, despite the advocacy of several influential Catholic figures such as Henri de Lubac (later cardinal). He died on Easter Sunday, 1955, while staying in New York. The original French text of The Phenomenon of Man was published later that year, followed in fairly rapid succession by most of his other unpublished manuscripts. Despite widespread interest in his ideas (more for their visionary than their evolutionary content, it must be said), the Catholic church remained hostile until quite recently. In 1962, shortly before the inauguration of Vatican II, the following monitum (warning) was issued by the Holy See, under the authority of Pope John XXIII: “Several works of Fr. Pierre Teilhard de Chardin, some of which were posthumously published, are being edited and are gaining a good deal of success. Prescinding from a judgement about those points that concern the positive sciences, it is sufficiently clear that the above-mentioned works abound in such ambiguities and indeed even serious errors, as to offend Catholic doctrine. For this reason, the most eminent and most revered Fathers of the Holy Office exhort all Ordinaries as well as the superiors of Religious institutes, rectors of seminaries and presidents of universities, effectively to protect the minds, particularly of the youth, against the dangers presented by the works of Fr. Teilhard de Chardin…...” [Issued by the Palace of the Holy Office; 30th June 1962; reiterated July 20th 1981].

That said, two recent Popes (Francis, and his conservative predecessor, Benedict XVI) have both referred to Teilhard in far more approving terms.

Key Thinkers on Evolution and Faith

205

7.2.2 Teilhard’s concept of evolution The rather full biography above (nothing similar will be offered for my other key thinkers) is relevant for any consideration of Teilhard’s work and its significance. Because his voice was effectively silenced and his major works only published posthumously, they were already long out of date by the time they saw the light of day. The English edition of The Phenomenon of Man appeared over 20 years after it was written (in 1938), and evolutionary science had moved on by leaps and bounds in the interim. But even acknowledging this time-lag, Teilhard took a rather sceptical view of the importance of genes and mutations—a word which is only once conjoined with the name of Mendel in the entire 313 pages of The Phenomenon of Man (Teilhard de Chardin, 1955/1959, p. 108). This is extraordinary in the light of R.A. Fisher’s influential book on genetics and evolution published in 1930. Teilhard actually says very little about genes or genetics in The Phenomenon, despite the great progress achieved during his lifetime; “Biology has not yet found a way of reconciling in phylogenesis the spontaneous activity of individuals with the blind determinism of the genes” (ibid., p. 225). Here “spontaneous activity of individuals” seems to imply a neo-Lamarckian view of evolution, whereby acquired characteristics or abilities would in some way prove heritable, providing new variations for evolution to work with. Admittedly, while drafting the Phenomenon in 1937, Teilhard may not have been aware that Theodosius Dobzhansky (1937) had already brought together genetics and evolution in what would become known as the neo-Darwinian synthesis, as popularised a few years later by Julian Huxley (1942) and by George Gaylord Simpson (1944)—who added palaeontology into the synthesis. Teilhard made little attempt to incorporate these insights when he sent his manuscript to Rome in the 1940s, although his 1948 Postscript to The Phenomenon suggests he was aware of them (below). In short, he hardly engaged at all with a consensus view of evolution that emerged after 1930. This reflects his personal commitment to a very different orthogenetic model of evolution, which still retained some vestiges of scientific credibility in the 1920s, but had become largely sidelined by the time his books were finally published. In neutral terms, orthogenesis is a tendency for evolution to proceed in definite directions. Thus far, it still remains compatible with natural selection operating in a stable environment within the evolutionary constraints imposed by phylogeny and ontogeny (see end of chapter 2). But its chief proponents often went much further than this, asserting that evolution proceeds in a linear fashion (effectively in straight lines), as if directed towards some particular endpoint or goal (teleology).

206

Chapter 7

Admittedly, in his 1948 Postscript to The Phenomenon (Teilhard de Chardin, 1955/1959, p. 302), Teilhard does make a concession to orthodox neo-Darwinian evolution: “The involuting (= evolving and complexifying) universe, considered in its pre-reflective zones, proceeds step by step by dint of billion-fold trial and error. It is this process of groping....”. Many evolutionists might say “Amen” to that, always supposing they have been persistent enough to read the previous 301 pages! But the caveat about pre-reflective zones attempts to separate off human evolution in particular from biotic evolution in general. The former involves the development of conscious thought, culture and spirituality—together termed noogenesis by Teilhard—where teleology would still in his view apply. But Dawkins’ memes and Darwinian selection (e.g. Dennett, 2017), or the Extended Evolutionary Synthesis (Laland et al., 2015), can offer cogent rationales for many seemingly unique human traits, including the emergence of culture. Teilhard’s early views were shaped in part by the vitalist philosophy of Henri Bergson’s influential book, Creative Evolution (1907/1911), whose author was later awarded the 1927 Nobel Prize for Literature. In essence, Bergson bypassed Darwinism and proposed a neo-Lamarckian (§ 2.4) version of evolution, propelled from below by a mysterious vital force (§ 6.4)—termed the élan vital—which he located in the interaction between matter and consciousness. Teilhard supplemented this perspective by incorporating his own cosmic teleological vision, envisioning evolution as a process drawn “up” towards increasing complexity and consciousness by Christ as the fulfilment or Omega Point of creation, so that God may be all in all (1 Corinthians 15:28). This flatly contradicts Bergson (1907/1911, p. 108), who had asserted that the evolution of life “is not the realization of a plan”, because “a plan is known in advance” and “ought to manifest a greater harmony the further it advances”. But Teilhard discerned precisely such a “greater harmony” in the recent emergence of human thought and spirituality (the noosphere, enveloping this planet just like the biosphere). It is hard to summarise Teilhard’s thought concisely, partly because his writing is intrinsically difficult to pin down, and partly because similar basic ideas are given different expressions in his published oeuvre, books that were constantly reworked but never finalised for publication. His scientific thinking is set out most fully in “The Phenomenon of Man”, of which I own a battered 1st edition with my father’s extensive annotations. Essentially, Teilhard saw the history of this planet in terms of geogenesis (condensation of matter, crystallization of minerals, and polymerisation of macromolecules), then biogenesis (the origin, proliferation and evolution of life), and most recently noogenesis (the birth of reflective thought and

Key Thinkers on Evolution and Faith

207

consciousness in Homo sapiens). He laid particular emphasis on human spirituality and our capacity for love (amorization)—not just in familial or kin relationships, but reaching out in the form of Christian love to embrace the whole human race and indeed the whole universe. Only in the Epilogue of The Phenomenon did he finally and explicitly mention Christ (Teilhard de Chardin, 1955/1959, pp. 291-299), despite many earlier hints. He regarded this spiritual reaching out to others as transformative, offering a definitive “best hope” for the future of humanity. But for most scientists, Teilhard overplayed his scientific hand long before this point. He made a distinction between the within and without of things, their interiority as opposed to their external appearance. The within would endow even inanimate matter with basic propensities for life and psychism: “Given that a sort of rudimentary consciousness precedes the emergence of life….” (ibid., p. 89). Even earlier in this book, he sought to distinguish two forms of energy: “a tangential energy which links the element with all others of the same order as itself in the universe; and a radial energy which draws it towards ever greater complexity and centricity—in other words forwards” (ibid., p. 65). Tangential energy, he noted, “will gradually exhaust itself, following the principle of entropy” (ibid., p. 66), whereas radial energy will increase as evolution generates more complex forms. He did not explain away this apparent paradox in terms of complex entities maintaining themselves by taking in energy (ultimately from the sun), in apparent defiance of entropy, preferring instead to invoke his own “law of complexity-consciousness” (ibid., p. 61), by which he meant an innate tendency towards increased complexification and psychism that emerges from the “radial energy” of all matter. This is not a view that finds much support in mainstream science. While most biologists might agree that evolution usually (but by no means always) tends towards increased complexity, this is explicable in far more prosaic terms through the progressive refinement of advantageous adaptations. The genetic basis for this trend, involving ever-more-complex modules for gene regulation (and alternative splicing) was outlined briefly in chapters 1 and 4—but in Teilhard’s lifetime, all this remained shrouded in mystery. The same theme resurfaced when Teilhard wrote about the evolution of life, particularly in the section entitled “Ariadne’s Thread” (ibid. pp. 142146). Here, he again equated a gradual increase in complexity through evolution with more advanced psychism. What he is proposing is in effect panpsychism, ascribing a rudimentary level of consciousness to everything that exists (though he is not alone in this; see Goff, 2019), so importing an unorthodox metaphysical idea into what claims to be a scientific treatise.

208

Chapter 7

That said, new mathematical models of consciousness are postulating just such a “proto-consciousness” in all matter, increasing in complexity as more information is transferred between component subsystems (Brooks, 2020). Overall, the thrust of Teilhard’s teleology leads us inexorably upwards through the rise of human consciousness (noogenesis) towards the ultimate Omega Point. He did admit that, “asked whether life is going anywhere at the end of its transformations, nine biologists out of ten will today say no, even passionately” (Teilhard de Chardin, 1955/1959 p. 141). Nevertheless, he sought to persuade his readers that there is indeed such a directionality in evolution, even though his sub-text is clearly more theological than scientific. It is his conflation of different ways of thinking and arguing that makes his writing so opaque to most orthodox scientists. Teilhard’s panpsychism and teleology account for the decidedly cool reception of his books by evolutionary biologists, even those who had some sympathy for his vision—such as his friends Julian Huxley (who wrote an introduction for the 1959 English edition of the Phenomenon of Man) and George Gaylord Simpson (1960). Other scientists had no time at all for Teilhard’s mysticism—notably the excoriating reviews given by Nobel prizewinners Jacques Monod and Sir Peter Medawar. To give a flavour of the latter’s forthright opinion, I will quote just one brief excerpt from his evisceration of The Phenomenon of Man: "Yet the greater part of it, I shall show, is nonsense, tricked out with a variety of metaphysical conceits, and its author can be excused of dishonesty only on the grounds that before deceiving others he has taken great pains to deceive himself." (Medawar, 1961, p. 99).

Medawar accused Teilhard of hectoring his readers and cloaking his true intent by failing to mention Christ at all until the Epilogue. In a similar vein, Richard Dawkins has dismissed this same book as “the quintessence of bad poetic science”. The poetry at least, though not the science, is much enhanced by a recent retranslation (Teilhard de Chardin, 1955/1999/2003). Given this largely negative reception, why are Teilhard’s ideas still taken seriously (mainly in church, New Age or transhumanist circles, it has to be said), and why am I bothering to include him as a “key thinker” in this chapter? The first reason—which I would endorse, albeit from a different scientific perspective—is that Teilhard saw evolution as central to Christology, as well as vice versa (see Teilhard de Chardin, 1969/1971, pp. 76-95). Admittedly, as outlined earlier, what Teilhard meant by the word evolution (with his Christ-centred teleology) was very much at odds

Key Thinkers on Evolution and Faith

209

with the neo-Darwinian synthesis that had come to dominate evolutionary science by the time his books appeared. Nonetheless, some reinterpretation of Christian beliefs and doctrine is required in the light of evolution, and this book outlines a few of the many possible options available. Teilhard was one of the first to see this clearly, and showed indomitable courage in the face of silencing and suppression by the church he loved and to which he had vowed obedience. For that, as much as for his valour in helping casualties at the front in World War 1, he deserves honour, even if most of his scientific ideas went astray or were distorted by the flame of his faith. Secondly, Teilhard attempted to integrate the humanities within an over-arching evolutionary framework—though Darwin had already taken cautious steps down this path in “The Descent of Man” (1871), as had others (less cautiously) from Herbert Spencer to Henri Bergson. Teilhard’s reflections on noogenesis and the “spiritualisation” of matter through an awakened humanity (Romans 8:18-21) stand poles apart from modern neoDarwinian interpretations of human consciousness, culture and religion (chapter 5). He postulated the coalescence of matter, the origin of life, the awakening of conscious reflection in humans, and the growth of Christian love, as key transitions in an evolutionary process that will culminate in maximum complexity and consciousness at the Omega Point in Christ. [Parenthetically, we might add in another crucial transition that generated eukaryotic cells—together with their potential for multicellularity—from symbioses between 2 or more prokaryotes; Margulis, 1970.] But he did not really embrace the idea of novel or emergent properties appearing at each of these stages. Instead he envisaged innate or incipient rudiments of life, consciousness and even spirituality as present in all matter (above; panpsychism), which still smacks of Bergsonian élan vital. Confusingly, despite insisting on maximum complexity at the Omega Point, he also reiterated the refrain of convergence towards unity at that point. But this differs radically from any of the meanings normally attached to convergent evolution (§ 3.5 and 3.6). Rather, Teilhard sought to convey a vision of humanity increasingly interconnected by love and thought, creating “a sort of super-consciousness” of “individual reflections grouping themselves together and reinforcing one another in the act of a single unanimous reflection” (Teilhard de Chardin, 1955/1959, p. 251). I will not attempt to present Teilhard’s ideas in any greater detail here (although I hope I have not distorted them too much in this outline sketch), precisely because I think his brave attempt at synthesis gets it wrong on far too many counts.

210

Chapter 7

Other commentators, both Catholic and Protestant, criticise Teilhard for a near-total lack of scriptural justification in his writings. Gareth Jones summarised the Teilhard conundrum as follows: “What Teilhard did present to the world was twofold—a synthesis of a form of evolutionism and a form of mystical Christianity, together with the personal testimony of a very remarkable and very devout man. But the mysticism he presented overrode both empirical science and biblical Christianity. While giving the appearance of being a prophet for the midtwentieth century, he rejected the science of today and the biblical faith relevant for today, and clung instead to the science and philosophy of the Greek heritage.” [Jones, 1970, p. 64].

This is admittedly written from an evangelical Christian standpoint (hence the emphasis on biblical faith!), but it also highlights the Greek roots of Teilhard’s teleology, which grates with present-day readers because it is so difficult to reconcile with modern understandings of evolutionary science. Jürgen Moltmann (1989/1990, pp. 292-297) takes Teilhard to task for his faith in progress as an evolutionary goal, ignoring its inherent ambiguity that focuses at every stage on the winners (those creatures that survive and pass on their genes) while glossing over the unnumerable losers—the “milliards of living things that fall by the wayside and disappear into evolution’s rubbish bin” (ibid., p. 294). Overall, “progress” can indeed be documented in both evolution and human history, but “the history of every form of progress has its other side in the history of its victims” (ibid., p. 296). For the most part Teilhard is silent on the multitude of these victims. Conservative Catholic critics are dismayed by his approach to the Fall, since he sees death as “the essential lever in the mechanism and upsurge of life” (Teilhard de Chardin, 1955/1959, p. 312) and evil as “a structural stress of evolutionary creation” (quoted in Jones, 1970, p. 58). Teilhard pays scant attention to human sin, and explicitly denies that all humans are descended from a single couple (monogenism), instead stemming from a single zoological branch (monophyletism; Teilhard de Chardin, 1969/1971, pp. 209-211). Teilhard focusses on Christ almost to the exclusion of the other persons of the Trinity—so falling into Christomonism—yet it is the cosmic Christ (§ 7.2.3 below) rather than the human Christ of the gospels who speaks to us in most of Teilhard’s oeuvre. In the Avant-Propos of his critique of Teilhard, Père Philippe de la Trinité (1970, p. 10) concludes caustically that “la foi teilhardienne n’est plus la foi chrétienne” (roughly translated into English as “Teilhardian faith is no longer Christian faith”).

Key Thinkers on Evolution and Faith

211

Figure 7-1. Teilhard de Chardin. Part A, public domain photograph of Teilhard in the 1950s. Part B, public domain image of a cast of Peking Man (the original is lost); image credit, Zhoukoudian Peking Man Site Museum_1 by BeautyOfChina, licensed under Creative Commons PDM 1.0. Part C, 12th C apse mosaic depicting Christ Pantocrator, Cefalù cathedral, Sicily; image copyright Lesley de Pomerai.

7.2.3 Teilhard’s mystical vision of evolution At the Council of Chalcedon in 451 CE, theologians agreed on the Chalcedonian definition of Christ as both “fully God and fully human”— the eternal Word (logos) subsisting in these two natures within one “essential existence” (hypostasis), known to us as the person of Christ. Teilhard controversially proposed a third nature, the cosmic Christ (based on Colossians 1:15-20), arising out of the union between his divine and human natures, in whom and through whom creation would attain its final fulfilment (Teilhard de Chardin, 1969/1971, p. 179; Delio, 2008, p. 76). In Teilhard’s view, the entire history of the universe (cosmogenesis) is in truth a Christogenesis—a completion of the cosmic Christ, through and for whom all things were created and in whom they will attain their final goal. This achieves perhaps its clearest and most concise expression in his last essay, dated March 1955 and entitled “The Christic” (Teilhard de Chardin, 1976/1978, pp. 82-102), in which he identifies Christ-Omega with the image of Pantocrator (ibid., p. 94), recalling the Byzantine mosaics of Christ in glory that so dominate the cathedral apses of Monreale or Cefalù in Sicily (Fig. 7-1C). Although Christian faith is (or should be) the leading shoot in this convergence towards unity, the redemptive scope of Christ is far vaster than just believers or even humanity in toto. Christ-Omega as Head will embrace the entire universe (multiverse?), which thereby becomes incorporated into the body divine—a mystical vision that Teilhard shared (albeit in a totally different religious context) with the Indian 10th/11th C Hindu teacher, RƗmƗnuja (Hunt Overzee, 1992). This greatly expands the image used by Paul in Colossians 1:18 of Christ as Head of the church (his Body), in keeping with the cosmic scope of Colossians 1:15-20. However, Moltmann again sounds a note of caution;

212

Chapter 7

by vastly expanding the time-scale of salvation history to culminate at an indefinite future Omega Point, Teilhard risks separating the cosmic Christ from the historical Jesus, leading to “a cosmic gnosticism which makes historical faith antiquated” (Moltmann, 1989/1990, p. 296). Transhumanists pick up on Teilhard’s future-focussed dynamic in his vision of convergence towards union with Christ at the Omega Point. His concepts of the noosphere (a “layer” of reflective thought and spirituality enveloping the planet, by analogy with biosphere), and of the increasing interconnectedness of humanity, are seen as foreshadowing the advent of the world-wide web—perhaps presaging some kind of global superintelligence or even the prospect of immortality in silico (Tipler, 1994; see also Graziano, 2019, pp. 138-166). Teilhard writes (1955/1959, p. 280): “We can envisage a world whose constantly increasing leisure and heightened interest would find their vital issue in fathoming everything, trying everything, extending everything…. Human vision is still diffuse in its operation, mixed up with industrial activity and war…. It will not be long before the noosphere finds its eyes” (cf. earlier quotation from p. 251 in § 7.2.2). In Teilhard’s noosphere, there is more than a hint of the biblical Lady Wisdom, who “covered the earth like a mist” (Sirach 24:3, NRSV). However, Teilhard’s Christian faith is largely glossed over by self-styled “evolutionaries” (Phipps, 2012) and transhumanists. Teilhard also offered a prescient hint of James Lovelock’s Gaia hypothesis (1979): “Taken in its totality, the living substance spread over the earth—from the very first stages of its evolution—traces the lineaments of one single and gigantic organism” (Teilhard de Chardin, 1955/1959, p. 112). By contrast, many religious mystics have been attracted precisely by Teilhard’s grand spiritual vision of all creation coming together in Christ (Teilhard de Chardin, 1957/1960, 1961/1965), and have been prepared to overlook the shortcomings of his scientific ideas. This vision goes back to his early (1923) “Mass on the World”; I quote below its 2 nd paragraph, written in a desert by a priest with no bread or wine, but facing out to the whole world: “On the horizon, the sun has just touched with light the outermost fringe of the eastern sky. Once again, beneath this moving sheet of fire, the living surface of the world wakes and trembles, and once again begins its fearful travail. I will place on my paten, O God, the harvest to be won by this renewal of labour. Into my chalice I shall pour all the sap which is to be pressed out this day from the earth’s fruits. My paten and chalice are the depths of a soul laid widely open to all the forces which in a moment will rise up from every corner of the earth and converge upon the Spirit. Grant me the remembrance and the mystic presence of all those whom the light is now awakening to the new day.” [Teilhard de Chardin, 1961/1965, p. 19].

Key Thinkers on Evolution and Faith

213

For Teilhard, the eucharist held a truly cosmic significance; each time a priest consecrates the Host (bread—compounded of matter and human work), it becomes sanctified as the very Body of Christ—according to the Roman Catholic doctrine of transubstantiation, to which Teilhard held fast despite his other unorthodoxies. In this way, bit by bit, matter becomes spirit and is thereby made holy—a part of Christ-Omega. Indeed, Teilhard focussed not so much on reception of the consecrated sacrament by a believer, but rather on adoration of that Host, for instance in a monstrance. This transformation of matter into spirit is an important—even central— aspect of his vision of the universe evolving towards the Omega point, but this precisely embodies an explicit teleology that most evolutionists reject. The French title of Teilhard’s great spiritual work, “Le Milieu Divin” (1957/1960), does not allow straightforward translation into English, since the key word milieu carries a double meaning of both “middle” (centre) and “environment”: “God is an infinite circle whose centre is everywhere and whose circumference is nowhere” (Nicholas of Cusa). In Teilhard’s view, spirit is the perfection of matter, and is thus the goal towards which the whole universe is evolving. But the universe only becomes self-aware through the human noosphere, or perhaps in other reflective creatures that may have emerged elsewhere in the vastness of the universe (Teilhard de Chardin, 1969/1971, pp. 229-236). However, Richard Bauckham (2015, p. 56) rejects “Teilhard’s identification of Christ with the immanent process of evolution and its presumed goal, [which] bears too close a resemblance to the anthropocentric progressivism of the modern age. Evolutionary science can no longer.…discern a unidirectional process in nature, with humanity and the humanization of the cosmos as its immanent telos”. For myself, I am moved by Teilhard’s reflections on the Christian spiritual life and the centrality of Christ in the material universe, yet find myself saddened by the ultimate failure of his bold but misdirected attempt to graft his visionary faith onto an evolutionary framework (but see Dodson, 1984). I wish I could offer a compelling alternative that would resonate convincingly with current understandings of both evolution and Christian belief—but that is, alas, beyond both my scientific and spiritual reach. Several recent books by self-avowed Christian mystics have engaged with the breadth of Teilhard’s vision of Christ-centred evolution without dwelling overmuch on the details of his scientific ideas. Ilia Delio (2008, pp. 66-82) devotes a chapter to Teilhard—tellingly subtitled “The Christic Universe”—as one of four spiritual guides for thinking about Christ in relation to evolution, the others being the Indian Catholic/Hindu scholar Raimon Panikkar, and the monks Thomas Merton (Cistercian Trappist)

214

Chapter 7

and Bede Griffiths (Benedictine). Beatrice Bruteau goes even further, building on Teilhard’s vision of cosmogenesis as a Christogenesis: “the growth of the ‘ever greater Christ’, [who] has been growing in ‘stature and wisdom’ (Luke 2:52; read ‘complexity and consciousness’) these last dozen or so billion years” (Bruteau, 1997, p. 12). But her account of evolution, conveyed through a sequence of vivid vignettes, is essentially orthodox, with none of the hostages to fortune that undermine the scientific credibility of Teilhard’s major works. Bruteau’s subtitle—“The Creation of a Self-Creating World”—epitomises one way of seeing the universe as an out-working of God’s creativity. To quote its main title, this is literally “God’s Ecstasy”, in the sense of God standing outside Godself. Teilhard’s evolutionary Christ also finds many resonances in the deep incarnation advocated by Niels Gregersen (2013; see also Cole-Turner, 2013), which is focussed on Christ becoming flesh (for which read matter) rather than becoming exclusively human. Matthew Eaton (2017) takes this a stage further, beyond the “human exceptionalism” (= anthropocentrism) of Teilhard, to a pan-incarnationalism whereby Christ is incarnate in all being. However, most Christians would restrict the imago dei (“likeness of God”; Genesis 1:26) to humans alone. We will return to this in § 7.3.4 and § 8.5.2 below—the latter in the context of hope for all creation’s salvation.

7.3 R.J. “Sam” Berry (1934-2018) 7.3.1 An evangelical evolutionist With Teilhard it can be difficult to fathom his meaning, but this is rarely the case with the writings of R.J. Berry (henceforward Sam Berry, though the background to this nickname is too long a story). He was Professor of Genetics at University College London from 1974 to 2000. He was an island ecologist, population geneticist, staunch defender of evolution, and lifelong committed Christian. For the last 30 years of his life he was licensed as a Reader (and hence regular preacher) in his local church, as well as serving as a lay member of the Church of England’s General Synod and as President of Christians in Science. Sam Berry came from the evangelical wing of the Anglican tradition, but was careful not to let his deep understanding of evolution get muddled with his Biblical theology. This was apparent in his first book (“Adam and the Ape”; Berry, 1975), later expanded as “God and Evolution” (Berry, 1988/2001), which offers admirably clear explanations of evolution as the how of God’s creation, alongside a careful if conservative exegesis of key Biblical texts (e.g. Genesis chapters 1-3) as the why of that creation. His writings thus provide an opportunity to explore how evolution can be reconciled with the Bible.

Key Thinkers on Evolution and Faith

215

7.3.2 The Fall Berry’s Christian faith was both evangelical and Biblical, but without insisting on a literal reading of scripture. Among the “main doctrines of the Bible”, he singles out “the fact of sin, substitutionary atonement, [and the] inevitability of judgement” (Berry, 1988/2001, p. 155). For those unfamiliar with theological jargon, the second of these statements asserts that Jesus died “in our stead”, voluntarily substituting himself to suffer the death-penalty that all of us deserve (because of our sinfulness) in God’s righteous judgement, which can have no truck with sin. This focus on sin, and on Christ as its only remedy, means that evangelical Christianity takes a keen interest in traditional doctrines of the Fall and original sin. This last is a concept developed by St. Augustine, but is based on an important aspect of Pauline theology: “for as all die in Adam, so all will be made alive in Christ” (1 Corinthians 15:22, NRSV), where “the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord” (Romans 6:23, NRSV). I should state at the outset that I do not personally share this view of the centrality of sin (though I fully acknowledge that it is a major Biblical theme), preferring to emphasise instead the love of God as the raison d’être of Christ’s incarnation. [I will doubtless stand accused by my evangelical friends of peddling a soft-focus, woolly-minded version of the Christian faith that lacks the steel of sin, repentance and judgement]. But it is worth examining how Berry achieves this careful balancing act, looking in this section at the Fall, and then at Creation in the next. Part of Berry’s concern is to scotch any notion that humanity has somehow “evolved upwards” from great ape ancestors, thereby coming to know (or at least find intimations of) God along the way—which might be one interpretation of Teilhard’s concept of noogenesis and Christogenesis. In the Bible (which is capitalised here in deference to Berry’s own usage), knowledge of God is “breathed into” the first spiritual human, called Adam, so that he becomes a “living being”. The setting of Genesis chapters 2-3 suggests a time-frame on the cusp of the Neolithic Revolution 11-13,000 years ago, since Adam and Eve were clearly gatherers (though not hunters) in the Garden of Eden, and one consequence of their later expulsion is that Adam must toil painfully to grow food from the soil (Genesis 3:17b), which obviously implies labour-intensive farming. The genetic and archaeological histories of humankind imply that there must have been large and well-established populations of modern Homo sapiens across the world by the time of the Neolithic Revolution in Mesopotamia (recall the near-simultaneous development of agriculture in Egypt, China, Amazonia and Melanesia; § 5.9). Biologically, the Adam chosen by God

216

Chapter 7

could not possibly have been the only male member of our species living at the time, as is also true of female Eve. Neither of these Biblical characters can be identified with “mitochondrial Eve” or “Y-chromosome Adam”, who both lived in Africa about 200,000 years earlier (§ 5.4). Berry concedes that “a neolithic Adam and Eve could not be the physical ancestors to the whole human species” (Berry, 1988/2001, p. 70)—indeed, the Bible itself suggests as much, since Cain found a wife who was not a daughter of Adam (Genesis 4:17). But Berry insists that God’s inbreathing into Adam (according to Genesis 2:7) was essentially spiritual. The consequence of Adam and Eve’s disobedience of God’s explicit command was not physical death as such, but rather a spiritual death in terms of separation from God—symbolised by the expulsion from Eden. This leaves the problem of how such a local act of rebellion could implicate the whole of humanity. I think this is where the model falls down somewhat, though Berry suggests that this spiritual Fall affects all human beings (including Adam’s contemporaries as well as all subsequent generations) through solidarity rather than physical descent, with Adam seen as the “federal head” of humanity (Berry, 1988/2001, p. 71). Nevertheless, this spiritual interpretation of the Fall story (Genesis 3) does at least succeed in avoiding head-on conflict with the established facts of human evolution. However, the idea that “original sin”—beginning with that first act of disobedience to God—is transmitted down the generations of humanity through sexual lust (rather like a sexually transmitted disease!) is not a Biblical concept, but rather derives from St. Augustine, who held deeply conflicted attitudes towards the body and its appetites, with a great deal of unfortunate fallout through the subsequent history of Christianity. How Christians might think today about the Fall and original sin is a topic that has exercised both Catholic and evangelical commentators and theologians (see e.g. Berry & Noble [eds.], 2009; Cavanaugh & Smith [eds.], 2017). Reading these books can be somewhat disconcerting, since contributions by philosophers and theologians are littered with caveats and cautions that seem to cast doubt on the likelihood or even credibility of evolutionary interpretations. The introduction of the 2017 book puts this in a nutshell: “The scientific theories are, of course, a moving target; new evidence is unearthed, and different theories are frequently proposed, attacked, defended and discarded. Nevertheless, there is a broad scientific consensus on some key issues that fits uneasily with biblical tradition and cannot be ignored by theologians and the wider church.” [Cavanaugh & Smith, 2017a, p. xv].

Key Thinkers on Evolution and Faith

217

Berry himself voices few such qualms in his own chapter in the earlier of these two books (Berry, 2009, pp. 30-74), where he updates his earlier accounts of human evolution while reiterating and expanding his spiritual interpretation of the Fall (see also Berry, 1996a, especially pp. 29-57). John Schneider (2012) discusses in some detail the limitations of this Augustinian account of the Fall, preferring instead an earlier model from Irenaeus, whereby the Fall was seen as inevitable, indeed foreordained, so that the Christ would come to fulfil God’s eternal plan for human salvation. As for the spread of original sin from Adam’s initial transgression, Berry points to the declining standards of moral behaviour that are documented in Genesis chapters 4 to 6, starting with Cain’s murder of his brother Abel (Genesis 4:8), through the casual murder of a young man by Cain’s descendant Lamech (Genesis 4:23), to a wholesale corruption of humanity prior to the Flood (Genesis 6:5-7)—when only Noah was counted “a good man” (Genesis 6:9). This interpretation is not implausible, since recent rationalisations of religion in early city states after the Neolithic Revolution suggest that practices such as human sacrifice developed concurrently with a highly stratified social hierarchy (Watts et al., 2016). Many texts in the Old Testament make it abundantly clear that such sacrifices were detestable to God—which is one conclusion to be drawn from the story of Abraham and Isaac (Genesis 22:1-19). For myself, in common with many liberal Christians, I find it inconceivable that even a judgemental God, to whom sin is anathema, would choose to obliterate all but a tiny remnant of the biosphere—including humanity—in a worldwide flood (Genesis 6:5-12). This smacks of wanton anger and destructiveness rather than justice, and is incompatible with the God of love. Interestingly, Berry (1988/2001, p. 121) only comments on the Flood story when criticising creationists for taking it literally, adding as a postscript: “These comments are not meant to detract from a proper interpretation of the Ark and the Flood, but only to draw attention to the distortions forced by extreme literalism”. In a later book, Berry (2003) confines his remarks to God’s covenant with Noah and the whole biosphere (Genesis 9:1-17) but does not discuss the Flood itself.

7.3.3 The Creation In analysing the creation story of Genesis 1:1-2:4, Berry (1988/2001, pp. 53-64) first asserts the classical Christian doctrine of God as creator being absolutely distinct and independent from his creation, before turning to the Biblical text. He starts with the obvious point that the six days of creation culminate in a seventh day of rest—clearly intended as an allusion to the Sabbath (Exodus 16:29). This, together with the repeated refrain,

218

Chapter 7

“And there was evening, and there was morning, the nth day”, preceded by “And God saw that it was good” from days 3 to 5, strongly suggests a liturgical use in worship, culminating in the “very good” of day 6. Berry then asks how we should interpret the “days” of Genesis 1, and suggests five possible ways—three of which are dismissed on textual rather than scientific grounds. These are: (i) the young-earth creationist position (6 literal 24-hour days), (ii) the gap theory of Thomas Chalmers (suggesting a catastrophe between Genesis 1:1 and 1:2, followed by reconstruction of the “formless void” into the world we know today), (iii) the idea of P.J. Wiseman that creation was revealed to humanity over a period of 6 days, and (iv) the concordist theory that each day of creation represents an aeon of elapsed time. Against (i), Berry’s arguments are mainly scientific, though he casts doubt on the validity of support texts used by creationists to justify a literal interpretation of “day” (e.g. comparing Exodus 31:14 to the parallel Deuteronomy 5:12-15). Against both (ii) and (iii), he notes that the word translated as made in Genesis 1 (also used in Genesis 2:2 and Exodus 20:11) cannot be translated either as remade [required for (ii)] or as made known [needed for (iii)]. Also, (ii) would require an inadmissable rendering of Genesis 1:2 as “the earth became [rather than was] a formless void”. Both interpretations therefore fall down on exegetical grounds. Against (iv), Berry agrees that day can be used to denote indefinite periods of time, both in common parlance (phrases such as “x has had its day”) and in the Bible (e.g. Psalm 95:8). However, as noted earlier in § 7.1, it is not realistic to align the Genesis days of creation with the fossil record of life on earth. Why, for example, do plants appear on day 3, yet the sun (required for photosynthesis!) and moon appear only on day 4? One suggestion is that the sun might have been hidden by a thick layer of cloud shrouding the earth (since light and darkness were separated on day 1), which only dispersed on day 4. But this would force an inadmissible translation of make on day 4 to mean reveal, as applied to sun and moon. Notice again how Berry favours exegetical over scientific arguments so as to steer evangelical readers towards his fifth and clearly preferred option. This he describes in some detail as the literary interpretation, variants of which are well attested by Biblical scholarship (including conservative evangelical commentators). Berry quotes at length from Henri Blocher (1984), but I shall only cherrypick a few highlights from this passage (Berry, 1988/2001, pp. 60-63). First, the six days of creation fall naturally into two groups of three—days 1 to 3 of separation, followed by days 4 to 6 of adornment, though one might quibble that the work of adornment starts on day 3 with the appearance of plants! Second, both day 3 and day 6 are double creations: the separation of sea from land plus the clothing of

Key Thinkers on Evolution and Faith

219

the latter with vegetation on day 3, then the creation of animal life and of human beings on day 6. Blocher (1984) suggests that the plants on day 3 function as a kind of curtain-raiser to the later days of adornment. There is a further literary symmetry noted by Berry (1988/2001, pp. 53, 64) in the use of two Hebrew words that are both translated by the one English verb to make. In Genesis 1:1, the word used is bara, to denote the creation of matter by God; this verb is used again in Genesis 1:21 and Genesis 1:27 for the creation of sea creatures (but also, by association, of birds) and of humans, respectively. Notably, bara is only ever used with God as subject, meaning create in a sense that human artists might recognise. Elsewhere in Genesis 1, the word used is asah—which carries the sense of make as in a potter shaping clay, including the sun and moon on day 4 and animals on day 6; note that a different word is used for the generation of plants on day 3. Thus the two tripartite halves of creation are framed by the use of bara on days 1, 5 and 6 only. From this verbal distinction between bara and asah, Berry (1988/ 2001, p. 64) suggests a special status of divine creation for matter, sea creatures (from which all animal groups have evolved) and human beings. But this over-neat distinction is blurred by the anomaly of plant origins on day 3 and the apparently special status conferred on birds on day 5. The carefully balanced literary structure of Genesis 1:1 to 2:4 works beautifully in its own terms, but cannot be retro-projected onto the evolutionary story as told by science. However, in a more recent review article, Berry seemed to back away from laying quite so much emphasis on bara as distinct from asah (Berry & Jeeves, 2008). Indeed, van Wolde (2009) has argued that bara actually means to separate rather than create.

7.3.4 The image of God in humanity The bulk of Berry and Jeeves’ (2008) lengthy review marshals a wealth of scientific, philosophical, psychological and theological insights into what it means to be human, covering much of the ground surveyed earlier in chapter 5, and ranging widely beyond it. Berry’s overall position remains unchanged; that we must take with utmost seriousness both the Book of God’s works—comprising scientific facts, rather than the interpretations imposed upon them—and the Book of God’s words (the Bible, for Christians)—again distinguishing between the inspired word of scripture itself and accreted layers of interpretation from different strands of Christian tradition. When apparent conflicts arise between these Books, we should go back to the Bible and look carefully at how we interpret it. If we believe that both Books are written (read inspired or directed) by God, then there cannot be any conflict between them—such was Berry’s credo.

220

Chapter 7

Berry and Jeeves (2008) proceed to ask the substantive question as to what Christians mean by asserting that humans (male and female) are “created in the image and likeness of God” (imago dei; Genesis 1:26). Following James Barr (1993), Berry and Jeeves list 5 ways in which this claim has been viewed in terms of human uniqueness vis à vis animals: (i) rationality, (ii) possession of a soul, (iii) physical distinctiveness, (iv) functionality—the nature of our interactions with the rest of the world, and (v) our human capacity for relationship—with each other, with other creatures, and above all with God. The first two of these have been dealt with briefly in chapter 5 [(ii) specifically at the end of § 5.6], while (iii) is perhaps illusory, since the majority of our physical capabilities are shared in some measure with other animals (§ 5:8). Genesis 1:26 continues with God’s first statement (repeated in Genesis 1:28) of the controversial injunction for humanity to “have dominion over the fish of the sea, the birds of the air, and over the cattle, and over all the wild animals of the earth, and over every creeping thing that creeps upon the earth” (NRSV; reiterating the ordered adornment of the earth). This was a bold if not presumptuous claim at the time these words were written down, yet as pointed out by Lynn White (1967), it has come back to haunt us with a vengeance in the 20th (and 21st) C CE, with unprecedented destruction of the environment and rapidly spiralling climate change. Indeed, as Westermann (1987) and other commentators (e.g. Berry, 2003; 1996a, pp. 85-107) have argued, a proper understanding of the word dominion should focus on stewardship—responsible before God—rather than on human domination or exploitation. We are called in scripture to act as God’s viceregents in this world, not as rapacious landlords or pillagers of its resources. Central to the imago dei in humanity is our capacity to relate to other human beings, most obviously in the context of romantic or familial love (but many animals do likewise…), often displaying altruistic behaviour in the process (explainable as kin selection?). But altruism towards humans who are unrelated to ourselves is widely documented, and is commended in scripture—notably through repeated injunctions in the Old Testament to care for “the widow, the orphan and the alien in your midst”, and in the New Testament to “love your neighbour as yourself” (Mark 12:31, quoting Leviticus 19:18). Although Dawkins (1976) avers that genuinely altruistic behaviour has no place in nature (as quoted in § 6.8), there are numerous reports of apparently altruistic behaviour in animals, for which reciprocal altruism may offer a plausible explanation. But as Berry and Jeeves (2008, p. 32) argue, “we do not need to deny the emergence of self-giving altruism in primates in order to assert the unique self-emptying sacrifice of Christ”—which is a matter of faith, not of empirical evidence.

Key Thinkers on Evolution and Faith

221

Humans also display a seemingly unique capacity to reach beyond themselves—seen most obviously in the work of pioneering artists (at least since the era of cave painting; Fig. 5-1), engineers and scientists—but also more generally in our quests for personal meaning, often though not exclusively through religion. Such self-transcendence has been termed exocentricity by Wolfhart Pannenberg. Overall, what Christians mean by the image of God within human beings is above all relational—how we interact with our environment and the biosphere, with other human beings (both kin and strangers) and with that which is beyond ourselves, whom we may call God. Gerhard von Rad (1957/1975, p. 147) points out that, according to Genesis 5:3, “Adam.…became the father of a son in his likeness, according to his image, and named him Seth”. The parallelism in wording between this verse and Genesis 1:26 clearly implies that, whatever else might have been lost during the expulsion from Eden, the imago dei was not. However we might envisage the spiritual infusion of God’s image, and whatever we might believe about original sin, these two remain as blessing and curse within us: a blessing if we use our unrivalled gifts to benefit others and the environment (whether or not we choose to do so in the name of God; cf. Deuteronomy 30:19), but a curse if we use them for purely selfish ends to exploit or harm others and the environment.

7.3.5 The Virgin Birth We may note in passing that Berry viewed the creation of Eve from Adam’s rib (Genesis 2:21-22) as being figurative rather than literal (Berry, 1996a, pp. 50-51)—but unlike the Fall and original sin, no core Christian doctrines depend on the literal (or even semi-literal) truth of this ancient myth. When it comes to the New Testament, however, Berry (1996b) is at pains to defend the classical doctrine of the Virgin Birth by insisting (as a geneticist) that it is not totally impossible, although biologically unlikely. Needless to say, Christians have to grapple with still greater implausibility in the resurrection of Jesus Christ, so if we allow that, then why not the Virgin Birth also? The miraculous birth of Jesus to Mary as a virgin mother is told in Matthew 1:18-25, but this is backed up by the words used at the Annunciation in Luke 1:26-38, and by the prophecy in Isaiah 7:14 (though the key word almah here literally means young woman). Since neither the gospels of Mark nor John feature any birth or childhood narratives concerning Jesus, their silence on the Virgin Birth proves nothing. Equally, none of the epistles of St. Paul (the earliest Christian writings that have come down to us) mentions this doctrine—which is surprising if this was a core belief of early Christians. By contrast, Paul’s writings are imbued throughout with Christ’s death and resurrection. Berry

222

Chapter 7

points out that Paul uses rather an odd word to describe Jesus’ origin in Galatians 4:4, where “God sent his son, born [but literally became] of a woman”. Likewise, John’s gospel (1:12-13) speaks pointedly, but in the plural, of the “children of God, who were born, not of blood or of the will of the flesh or of the will of man, but of God.” There is thus a Biblical case to be made for the Virgin Birth, even if it is not central to Christian faith. Theologically, rather more hangs on the Virgin Birth than at first meets the eye. In the Eastern Orthodox tradition, the Virgin Mary is named theotokos (meaning “God-bearer”)—a high title indeed, but one that arises out of her “yes” to the Angel Gabriel (Luke 1:38), a yes that changed the world in Christian thinking. Turning Jesus into a “normal” human baby, born out of wedlock, risks losing much of the mystery and power of the incarnation. In the context of original sin, seen by St. Augustine as sexually transmitted (§ 7.3.2 above), the Virgin Birth is a core doctrine necessary to proclaim Christ as sinless, since only the voluntary self-sacrifice of the One who was without sin could atone for the sins of humanity (which is the essence of substitutionary atonement; § 7.3.2). Rumours that Jesus was illegitimate can be discerned in the words used by some of his critics. Incensed Jews retorted that “we are not illegitimate children” in John 8:41 (implying by innuendo that Jesus was?), while fellow Nazarenes insulted him as “the carpenter, the son of Mary” in Mark 6:3—a demeaning phrase to use in a patriarchal society, since it cast doubt on his father’s identity. From early heretical sects to the Talmud, from Voltaire to many recent liberal clerics (including Bishop David Jenkins and Arthur Peacocke; see § 7.5 below), the doctrine of the Virgin Birth has a long pedigree of doubt and scepticism. Put bluntly, in the view of most non-Christians—and a good many professed Christians too—the notion of a Virgin Birth is quite literally inconceivable. To this, biologists would add that all male children must receive their Y chromosome paternally, from the father’s sperm, since the mother possesses two X chromosomes but no Y. Thus, even if a human oocyte or egg underwent activation without fertilisation, followed by complete development to a live-born baby and eventually an adult (a process termed parthenogenesis), the resultant child would inevitably be female, since the mother can only supply X chromosomes. Vertebrate parthenogenesis is known to occur in some fish, amphibians, reptiles, and even a very few birds, but this has never yet been observed in mammals. In response to these entirely natural doubts, Berry (1996b) points out that parthenogenetic development can be initiated in mouse embryos, even though it does not progress very far; moreover, chimaeric mice comprising

Key Thinkers on Evolution and Faith

223

mosaic mixtures of normal and parthenogenetic cells can develop even to maturity. On both grounds, human parthenogenesis is not impossible, though highly improbable. This still leaves the problem of where Jesus’ Y chromosome came from. Berry’s suggestions here are, to my mind at least, even less plausible. An X-linked genetic condition, Androgen Insensitivity Syndrome (AIS), involves a failure at the cellular level to recognise or respond to the male sex hormones (androgens—principally testosterone), such that affected individuals who are chromosomally XY develop as female intersexes, although they are usually sterile and lack a uterus. But this AIS phenotype is quite variable, so if Mary had been chromosomally XY but AIS (hence to all appearances female), and there was then a backmutation of the AIS allele in the egg that gave rise to Jesus, he could be both parthenogenetic and male. But this is surely piling Pelion on Ossa—a vanishingly improbable concatenation of many highly unlikely events. In any case, the gonads in AIS XY intersexes remain as testes, not ovaries. Another possibility cited by Berry is that Jesus might indeed have been chromosomally XX, but carrying a translocated copy of the male sexdetermining gene SRY (normally carried on the Y chromosome), which had been silenced in his mother Mary (note that one X chromosome is randomly inactivated in all female cells). Even Berry (1996b) concedes that, in outlining these implausible scenarios, he is not asserting that one or other of them was actually used by the Holy Spirit to accomplish the Virgin Birth of God’s Son Jesus Christ from his human mother Mary. Quite apart from their extreme improbability, I think there are strong theological objections to these suggestions. A justly famous phrase from Gregory of Nazianzus (329-390 CE), one of the Cappadocian Fathers, puts the matter of Jesus’ incarnate humanity in a nutshell: “What He has not assumed (= taken upon Himself), He has not healed; but that which is united to His Godhead is also saved” (Gregory Nazianzen, c. 383/2017). This aphorism asserts that Christ must be fully human in order to redeem humanity—in refutation of the Apollinarian heresy that Christ comprised a divine Mind within a human body. To the objection that Christ was male, therefore how can women also be redeemed?—human sex-chromosome constitutions come to the rescue, since all women are XX (homogametic) whereas men are XY (heterogametic). It follows that Jesus had to be male, since if born female, the human Y chromosome (and thereby all men!) would neither be assumed nor saved. [Parenthetically, if birds had evolved to consciousness and civilisation, an avian Jesus would have had to be female—since in birds the males are homogametic (ZZ) and the females heterogametic (ZW)!] Applied to Berry’s scenarios about the Virgin Birth, Gregory’s dictum rules the second out of court—since Jesus would have

224

Chapter 7

had only an SRY gene but would lack the rest of a normal Y chromosome— essentially the same objection as for a female Jesus. This also seems to cut across genuinely miraculous interventions by the Holy Spirit, whereby one of Mary’s eggs was “fertilised” with a divinely implanted male (Ybearing) haploid genome; this would not be of human origin, so how could truly human Y be redeemed? Admittedly, in the first of Berry’s scenarios Jesus would have been fully XY, but this would be an endpoint arrived at through complex abnormalities that would render him and his mother more of a genetic freakshow rather than perfect exemplars of humanity (for a different take on this topic from Arthur Peacocke, see § 7.5.2 below). Overall, Sam Berry demonstrates that it is perfectly possible to take both the Bible and evolution with the utmost seriousness, and to explore both in detail, without finding unavoidable conflicts. However, there are times when he is forced to interpret the Bible in non-literal ways (Genesis 1, parts of 2), which raises the question of why we should interpret the Fall (Genesis 3) far more literally. I remain unconvinced that this is necessarily the best route forward. Sometimes it is better to live with the ambiguity of miracles in scripture, acknowledging their unprovability yet savouring their multi-layered meanings, rather than explaining them away with rather unconvincing naturalistic scenarios. That said, Berry is more concerned to show that these scenarios could allow miraculous events to occur by God acting through “natural” means, so denying the supposed impossibility of such miracles. Examples given at the start of his article on the Virgin Birth (Berry 1996b) include the plagues of Egypt and crossing of the Red Sea (Exodus chapters 7 to 14). Berry has also made important contributions on Christian responsibility for the environment, but these relate more closely to the topics covered in chapter 10, and will be discussed there in brief.

7.4 Celia Deane-Drummond (b. 1956) 7.4.1 Botany, Biotechnology and Theology Celia Deane-Drummond has written numerous books addressing issues at the interfaces between biology and theology, being eminently wellqualified in both. She studied Botany at the University of Cambridge, graduating with a BA in 1977, then undertook a PhD in Plant Physiology at the University of Reading. Two postdoctoral research posts took her first to the University of British Columbia (1980-1982), and then back to the University of Cambridge (1982-1983). She was appointed as lecturer in Plant Physiology at the University of Durham in 1984, and might have followed a conventional academic career thereafter. Having done exactly

Key Thinkers on Evolution and Faith

225

that myself, I admire her courage in forsaking mainstream science to pursue a BA in Theology at the University of Bristol (1986-1989), then a second PhD in Systematic Theology supervised by Richard Bauckham at the University of Manchester (1989-1992). She was appointed lecturer in theology at the University of Chester in 1994, and Professor of Theology and Biological Sciences there from 2000 to 2011. Since then, she has been Professor of Theology and Director of the Center for Theology, Science and Human Flourishing at Notre Dame University, Indiana, in the USA. At the time of her appointment to Chester, the UK seemed well set to embrace genetic modification (GM) technology. GM tomato paste was first launched onto UK supermarket shelves in 1996, and sold reasonably well—partly because the cans contained an extra 20% “free” compared to the same brand of non-GM tomato paste. Allegedly this was thanks to cost savings resulting from less wastage of the slower-softening GM tomatoes, though many have surmised that it was little more than a marketing ploy. At all events, sales were halted in the wake of the Pusztai potato affair, news of which was leaked to the media in late 1998. GM tomato paste was cleared from supermarkets in the spring of 1999, and has never reappeared since. It is worth diverting briefly to describe this historical vignette, which in effect sounded the death-knell for GM food in the UK. Árpád Pusztai, a Hungarian expert on plant lectins, worked for some 30 years at the Rowett Research Institute near Aberdeen. In the late 1990s, he conducted nutritional experiments with rats fed on a diet of GM potatoes expressing an insecticidal and nematicidal snowdrop lectin, compared to non-GM potatoes. He was so worried by the evidence he found suggesting adverse effects of GM food on the gut and immune system that he leaked his findings to the media, in defiance of normal scientific procedure— which would have deferred such publicity until the draft paper had been accepted for publication. The resulting media storm alleged that all GM food was inherently unsafe—though many scientists expressed dismay at this turn of events, as they were unable to access the still-unpublished data on which Pusztai’s allegations were based. His paper was submitted to The Lancet and sent out to six reviewers (far more than customary)—some of whom went public with their criticisms, mainly on methodological and statistical grounds; this paper was not finally published until October 1999 (Ewen & Pusztai, 1999), by which time the damage was done. Pusztai’s contract at the Rowett Institute was not renewed (he later went back to Hungary), provoking accusations of an attempted establishment cover-up. It is not my task here to adjudicate on the merits of this study, which reported a rather unclear pattern of effects that can be explained in various

226

Chapter 7

ways other than an adverse response to GM food. Because of the massive investment in agricultural GM applications by multinational agri-biotech corporations, many green groups (and some scientists) maintain that real dangers from GM food are being deliberately concealed. The furore sparked by the Pusztai affair has had a strong negative impact on public views of GM in the UK and maybe Europe, but not in the United States— where many GM foods remain on sale, and are not even labelled as such because of US equivalence legislation. No widespread harm to public health from GM consumption has been reported either there or elsewhere. Deane-Drummond’s dual expertise in biology and theology made her the ideal person to review the conflicting ethical, scientific and religious perspectives on this controversial area, as evinced by the title of her first major book, “Theology and Biotechnology” (1997), which in fact preceded the Pusztai affair. However, she has returned to related themes in several more recent books, including “The Ethics of Nature” (2004), “Genetics and Christian Ethics” (2005), and “Eco-Theology” (2008), not to mention several volumes which she has edited (Deane-Drummond [ed.], 2003, on the human genome) or co-edited (Deane-Drummond et al. [eds.], 2003, on genetics more generally). She points out that much of the research on firstgeneration GM crop plants—such as herbicide-resistant varieties, or insecticidal strains expressing pest-specific Bt toxins—was carried out by scientists employed or funded by the agri-biotech industry. Nevertheless, these organisations have at least shown themselves willing to engage in ethical debates from both secular and even theological perspectives (Deane-Drummond, 2004, p. 87; see also Bruce & Bruce [eds.], 1998), although that willingness diminished markedly after the Pusztai affair. As a former genetic engineer myself, I think there are many potentially beneficial applications of this technology, and would favour consideration on a case-by-case basis. GM technology is the lingua franca of academic research in much of biology. Without it, we would have little idea of how genes become expressed in co-ordinated patterns during animal or plant development (chapter 4). Valid criticisms can indeed be raised against the commercial motives behind first-generation GM crops and the ecological damage caused by their widespread adoption. However, anti-GM attitudes have become a rallying cry and an article of faith for green campaigners, to the extent that any use of this technology in and of itself becomes a justification for condemnation and dismissal, often on specious grounds. Deane-Drummond adopts a cautious approach to biotechnology in her many publications on the subject, seeking for general ethical and theological principles by which it could be judged. These emerge largely

Key Thinkers on Evolution and Faith

227

from virtue ethics, and should include due consideration of the goodness and intrinsic value of God’s creation, as well as prudence (following the precautionary principle), the integrity of organisms (and, by implication, of their genomes), and justice for the world’s poor, for women, and for the environment. She is also highly critical of the underlying ethos of biotechnology, which sees living organisms as “things” to be manipulated, exploited and turned into profit wherever possible. All too often the heated debates between proponents and opponents of GM are undertaken in utilitarian cost/benefit terms, leading to “a form of gridlock” (DeaneDrummond, 2004, p. 101). Much the same can be said about other technologies and medical applications spawned by modern molecular genetics, ranging from genetic testing to stem-cell or gene-based therapies (Deane-Drummond et al. [eds.], 2003), or newer opportunities afforded by gene editing (Doudma, 2020). Although these were developed for the best of humanitarian motives, all too many of them raise real but often unforeseen ethical problems when used in the clinic or in the field. A wider ethical perspective is essential if biotechnology is to be applied with sensitivity to meet the broader needs of both consumers and the natural environment, instead of focussing solely on the commercial bottom line. One problem with Deane-Drummond’s all-embracing approach to GM is that it cannot easily be applied to the specifics of any given case (such as the Pusztai potatoes, above)—there are too many factors and often conflicting considerations that need to be taken into account. One way of simplifying these and of dealing with them in a consistent fashion is the ethical matrix devised by Ben Mepham (2000), which also draws on virtue ethics, alongside utilitarian and deontological ethical principles, including justice. This matrix attempts to include all “interested parties” affected by biotechnological or agricultural innovations—e.g. the organisms affected, consumers, producers, and biota in the wider environment—in terms of 3 ethical principles of well-being, autonomy and justice. But as Mepham himself admits, the downside of the ethical matrix is that even if all parties can agree on how each of its 12 “cells” might be affected by a proposed innovation, there may be disagreement as to how these cells should be weighted, obstructing any consensus decision. Deane-Drummond’s (1997, pp. 80-87) discussion of the three guises under which biotechnology can be viewed—as promise, power or threat—is especially relevant in this regard, although its context is that of first-generation GM technology. Perhaps I err too much on the side of promise! But, to be fair, she writes approvingly of a few GM crop applications that counter severe disease or pest problems, where alternative solutions are environmentally damaging or ineffective. In one such case, a rice cystatin gene was engineered into

228

Chapter 7

potatoes to combat attacks by parasitic nematodes, which often destroyed half the Bolivian potato crop. Here the GM was undertaken in consultation with local farmers (Deane-Drummond, 2008, p. 24), since broad-spectrum nematicides kill off many free-living nematodes essential for soil health. Because the GM cystatin gene is expressed in the potatoes themselves, it can only harm those parasitic nematodes that attack the roots and tubers. In discussing popular responses to GM, Deane-Drummond (2000, pp. 208-218; 2004, pp. 90-91; 2008, pp. 24-25) is inclined to credit the public with a fairly sophisticated appreciation of the intrinsic value of nature and indeed its sacredness, even if most respondents profess no overt religious faith. One key difference between GM approaches and conventional plant breeding is that the former can be patented, and thus earn royalties from those using the “invention”, whereas novel plant varieties are afforded only limited protection—with much less profit for the breeder. However, the same argument can equally be raised in the context of GM drugs (e.g. human insulin) as compared to naturally sourced drugs, yet far less public concern is raised over GM medicines—perhaps because they are not labelled as such. The UK government announced a “GM Nation” debate in July 2002, with public meetings held across the country in 2003, and a government response issued in the spring of 2004. What came through from the local views fed back from this debate was a deep suspicion about the safety of GM crops both to public health and to the environment. I can only speak for one such GM Nation meeting in a Nottingham city-centre church, which I had been invited to chair, though in the event I found myself defending GM because one speaker had cancelled. It turned out during questions (when I asked the audience directly for a show of hands) that many of those present were members of Greenpeace, Friends of the Earth or other green activist groups, who had felt motivated to make their strong views known on this sensitive topic. A cynic might argue that they had collectively hijacked the occasion, but I think their preponderance at that meeting (and probably at others) instead reflected widespread public apathy on the subject of GM. In the circumstances, it is hardly surprising that the “public responses” to this GM Nation debate largely reflected the views of green campaign groups. Deane-Drummond notes that such green groups are perceived as offering an “alternative vision” to the profitseeking multinational agri-business corporations promoting GM. But are these genuinely perceptions of the general public, or only of those segments already committed to green (and, implicitly, anti-GM) causes?

Key Thinkers on Evolution and Faith

229

7.4.2 Wonder and Wisdom A second major theme that emerges in many of Deane-Drummond’s books is the biblical figure of Lady Wisdom (Sophia), taken from the Old Testament books of Proverbs (especially chapter 8), Wisdom and Sirach (Ecclesiasticus)—though Job, the Psalms, the Song of Songs and Qoheleth (Ecclesiastes) also belong within the Wisdom tradition. Two of DeaneDrummond’s books in particular are devoted to this topic: “Creation through Wisdom” (2000) and “Wonder and Wisdom” (2006), though it reappears in several more recent books. In Proverbs 8 verse 23 (NRSV), Wisdom declares: “The Lord created me at the beginning of his work, the first of his acts of long ago”, and later (verses 29-31), “when he marked out the foundations of the earth, then I was beside him, like a master worker, and I was daily his delight, rejoicing before him always, rejoicing in his inhabited world and delighting in the human race”. This “co-worker in creation” image is echoed in the better-known prologue to John’s gospel (1:1-5, NRSV); “In the beginning was the Word [Logos]: the Word was with God and the Word was God. He was with God in the beginning. Through him all things came into being, not one thing came into being except through him. What came into being in him was life, life that was the light of men; and light shines in darkness, and darkness could not overpower it”. Both recall the Spirit/breath/wind of God sweeping over the dark waters in the beginning of creation (Genesis 1:2). One of DeaneDrummond’s aims here is to draw out the feminine aspect of the Trinity through Lady Wisdom—not as a “fourth person”, but rather as a female personification of the Son or Logos, of the Holy Spirit (Genesis 1:2; Wisdom 7:25-27), and even of the Father. Sophia thereby infuses all three persons of the Trinity, such that masculine and feminine traits (if these are in any sense applicable to the Godhead) are combined together in God. Thus Wisdom finds her place “at the very centre of theology, not just an attribute of God, but the core of who God is in God’s-self” (DeaneDrummond, 2000, p. 108). This is an arresting feminist theology, and one that can be reconciled more readily with core Trinitarian doctrines than Rosemary Radford Ruether’s (1993, p. 253) identification of Gaia as the female voice of God, who “beckons humanity into community” rather than a male translation “into laws or intellectual knowledge”. Moreover, the Wisdom tradition has deep biblical roots (in contrast to the recent concept of Gaia expounded by Lovelock, 1979), and is richly poetic in her imagery. In developing this theme, Deane-Drummond (2000, pp. 78-92) draws on Wisdom theology from the Russian Orthodox tradition, particularly the somewhat unorthodox writings of Sergius Bulgakov (1871-1944)—who

230

Chapter 7

like Teilhard was censured by senior church authorities. Indeed, there are parallels with one of Teilhard de Chardin’s essays (1965/1968, pp. 191202), entitled “The Eternal Feminine” and written during World War 1, in which he identifies Wisdom with the Virgin Mary (see Deane-Drummond, 2000, pp. 92-99). Deane-Drummond also argues for the importance of Wisdom as a basis for practical ethics (especially the virtues of restraint and prudence) in the writings of St. Thomas Aquinas (ibid., pp. 99-107). Of course, the mediaeval scholastic tradition epitomised by Aquinas is central to Roman Catholicism, and becomes a major theme in many of her books (Deane-Drummond, 2014, pp. 56-87; passim elsewhere). However, I rather doubt whether this cuts much ice among non-Catholic scientists. In her 2006 book, Deane-Drummond points to the rich use of nature imagery throughout the Wisdom literature, frequently expressing a sense of awe and wonder at details of the natural world. A few of the later Proverbs (30:18-19 and vv. 24-30) capture this sense of wonder, as do chapters 38 to 41 of the book of Job, and many of the Psalms (e.g. Psalm 29; § 6.7); so too do many love-poetry details in the Song of Songs, not to mention the hymn to the glory of God permeating all nature in Sirach 42:15-43:33. Though these passages do not offer any scientific explanation of their observations, attributing them rather to the ingenuity and providence of God, their sense of wonder echoes that which motivates many scientists to seek answers to intractable questions. Non-scientists complain that science demystifies nature by analysing it in purely reductionist terms, thereby subverting our instinctive responses of awe and wonder. Richard Dawkins (1998) has written a powerful rebuttal of this complaint, showing how science can enhance rather than undermine our appreciation of nature’s innate poetry, once we glimpse something of the underlying details and subtleties involved. Among biologists and earth scientists in particular, a childhood passion for the natural world is often the catalyst for a lifetime’s exploration of it. In my own case it was plants—witnessed by many of the illustrations in this book—whereas for my brother it was rocks and fossils. Drawing again on Bulgakov, Deane-Drummond makes a distinction between divine Wisdom and creaturely wisdom. The latter is present in the world, as exemplified in the biblical examples cited, but also in human art, ingenuity, etc. In Deane-Drummond’s view, creaturely wisdom reached its “fullest possible expression” in the Virgin Mary, whereas in Jesus, divine Wisdom and creaturely wisdom “met in a single person” (2006, p. 110). In later books (2008, pp. 125-128; 2009, pp.185-191), she takes up another theme from Bulgakov—that of shadow Sophia as the “dark face of fallen [= creaturely] Sophia” (2008, p. 126). This idea is used both implicitly and

Key Thinkers on Evolution and Faith

231

explicitly to make allowances for the “wrong turns” taken by evolution (parasitism perhaps?) and the suffering that is entailed for all living things. Admittedly, this is not spelt out in full; “shadow sophia, like wisdom more generally, is deliberately elusive as far as clear definition is concerned— for it cannot be tied down to one particular form of reasoning”. But, she allows, “in the face of the countless slaughtering of the innocents, as some have described mass extinctions, shadow sophia only goes so far”. Rather than dwell further on this, she asserts that “the weight of shadow sophia is born[e] by Christ on the cross, the wisdom of God, so an explanation of its meaning needs to take on Christological dimensions” (all three quotations from 2008, p. 127). Shadow sophia is later re-examined in the light of the atonement in her subsequent book (2009, pp. 185-191). I would echo her interpretation here, but still have some reservations about shadow sophia as the “dark face of fallen [creaturely] Sophia”, which seems predicated on some sort of pre-lapsarian state (an earthly paradise?) from which creation has “fallen”. I am far less concerned to defend traditional understandings of the Fall, especially in terms of the natural world, and I hope for a future salvation of all creation that does not exclude even the “wrong turns” attributed by Deane-Drummond to shadow sophia, otherwise the attendant suffering has largely been in vain. “Father, forgive them; they do not know what they are doing” (Luke 23:34, NRSV) surely applies here a fortiori, especially where there can be no conscious intention of evil. One might also wonder whether the suffering and wastage in evolution do not reflect greater influence from shadow sophia than from aspiring creaturely sophia.

7.4.3 Evolution interwoven into the theo-drama of salvation Deane-Drummond has also drawn on the concept of theo-drama, as expounded by Hans Urs von Balthasar his 15-volume systematic theology. I confess I have not found the time to consult these original texts, so what follows is seen through Deane-Drummond’s eyes. For von Balthasar, our personal and community histories are interlinked sub-plots within the over-arching theo-drama of salvation—centred on the incarnation, ministry, death, resurrection and ascension of Jesus Christ—whose effects ripple outward in time and space to encompass all of humanity. In her 2009 book, “Christ and Evolution”, Deane-Drummond vastly expands this approach to include the entire evolutionary history of life on this planet, as well as taking von Balthasar to task for his anthropocentrism and androcentrism. She prefaces her book with a critical examination of the various suggested roles that God might play as the author of evolution, such as “bottom-up” interference at the level of gene mutation (which would entail teleology, as God must know which “tweaks” are needed to

232

Chapter 7

realise the overall divine plan), or Arthur Peacocke’s idea of “top-down” causation—to which I shall return in §7.5 below. She then explores the possibility of God (as primary cause) working through evolution as a “secondary cause”—drawing on Aquinas and the mediaeval scholastic tradition. But she admits that this in turn raises a question as to “whether the creation of laws, including natural selection, sufficiently represents God as engaged in the creative process” (ibid., p. 28). She glances briefly at process theology: John Haught (2010), in particular, also echoes the notion of evolution as drama. It is a risky adventure of God’s creativity that shrinks neither from contingency nor costliness—shared in Jesus’ own suffering—nor setbacks along the way, though Haught still wants to retain an overall sense of directionality in evolution. Deane-Drummond (2009, pp. 33-59) goes on to explore how evolution might relate to Christology, reviewing key contributions to this field from Ian Barbour, Teilhard de Chardin (§ 7.2), Karl Rahner and Jürgen Moltmann. She suggests that all of these depend on an over-arching “grand narrative” of evolutionary history, which hardly reflects the maelstrom of interacting sub-plots that characterises evolution. In her view, this reality is far better captured in von Balthasar’s vision of theo-drama, or perhaps in a symphony of unparalleled complexity. Yet the kernel of this great drama has already unfolded in human history through Jesus Christ. I am reminded of the chorale theme crowning the turbulent second movement of Mahler’s 5th symphony, which changes the emotional trajectory of the entire work, yet only emerges into its full glory to usher in the finale’s triumphant close. Despite my preference for musical analogy, I find Deane-Drummond’s insights persuasive here, though it remains unclear how God might act to shape creation (earlier). Towards the end of her book (2009, pp. 282-283), she concedes: “While [it] is true …that biological events are constrained by physical laws, I am less convinced that we can know or define precisely how God works or acts in such contexts, even if we might want to resist forms of ‘vitalism’ that suggest there is a ‘life force’ in the biological world that tends toward particular ends in a way that is entirely different from that in the nonbiotic world.” But when it comes to the eschaton—the “Last Judgement” that will usher in God’s new creation—she writes approvingly of von Balthasar’s vision of Christ in glory still marked by the wounds of his crucifixion, so that “those who are to be judged can hope in the grace of solidarity of Christ with sinners and the lost” (p. 238). Could this perhaps apply to all creation, as at the end of Mahler’s Resurrection (2 nd) Symphony? Not for nothing is its choral climax prefaced by birdsong.

Key Thinkers on Evolution and Faith

233

7.4.4 Niche construction and human/nonhuman interactions In a more recent book, Deane-Drummond (2014) turns to insights from ecology—in particular the concept of niche construction briefly alluded to earlier in this book in § 5.8. Many organisms modify their environment to greater or lesser extent, and thereby influence others both near and far. Particular keystone species in an ecosystem can have disproportionately large effects on its biodiversity and functioning, relative to their numbers or biomass. One classic example is the sea otter off the Pacific coast of North America, whose favourite food is sea urchins; if left unchecked, the latter would wreak environmental havoc through damage to the giant seaweed forests of kelp. Similarly, in most ecosystems there are elaborate checks and balances that, for the most part, keep the abundance of different species within bounds—despite large fluctuations from year to year, depending on natural cycles and climatic or other conditions. Although human interventions usually have deleterious effects on the delicate balance of such ecosystems, there are nevertheless instances where traditional farming practices have allowed biodiversity to flourish, as in coppiced woodlands, water meadows or lightly grazed chalk downs. The Burren in County Clare of the Irish Republic is an area of bare limestone hills bordering the Atlantic, where mild wet winters and heat retention by the limestone itself allow grass growth to continue through the winter months. This in turn encouraged the unusual practice of upland winter grazing for cattle, which keeps down the ash/hawthorn scrub that would normally constitute the climax vegetation for such areas. As a byproduct of these historical factors, the Burren hosts a unique flora that combines three contrasting floristic elements: Arctic-Alpine (survivors since the last Ice Age), Atlantic and Mediterranean (thanks to the mild Gulf Stream). A few examples of this striking botanical diversity are shown in Fig. 7-2, though two others have been illustrated earlier—namely Denseflowered Orchid (Neotinea maculata) in Fig. 2-1C and Spring Gentian (Gentiana verna) in the centre of Fig. 2-5 (both in colour centrefold). This example shows, if nothing else, that biodiversity can be promoted by sensitive management—in this case using traditional farming practices that are now supported by the Burren National Park. In Mesolithic times, the whole area was covered with broad-leaved, pine and yew trees—but there was extensive deforestation by human settlers during the Neolithic period, when structures like the Poulnabrone dolmen (Fig. 5-4E) were erected. Pastoralist practices such as winter grazing were introduced later. Deane-Drummond (2014, p. 51) also cites Tim Ingold’s (2011) “notion of human cultural variation as skill grown through practice and training in a

234

Chapter 7

Figure 7-2. Some characteristic flowers of the Burren. Mountain Avens is an arctic/alpine species (as is Gentiana verna; Fig. 2-5), while Irish Saxifrage is an Atlantic species and O’Kelly’s Orchid a local speciality (perhaps only a variety). Both Carline Thistle and Rue-leaved Saxifrage are widespread limestone plants. Dense-flowered Orchid (Neotinea maculata; Fig. 2-1C) is a Mediterranean species reaching its northernmost limit (and only location in these islands) in the Burren.

particular environment and the way we inhabit that environment.” Again, the Burren provides a clear instance of this, since in most parts of the world, farmers practise transhumance by moving livestock up onto mountain pastures in the spring and back down to the valleys in autumn. Only in the Burren was the reverse pattern adopted, for good local environmental reasons (above). Deane-Drummond (2014) cites several examples of co-evolution between humans and animals, as well as comparing human morality, language and justice with animal agency, communication and fairness—drawing on material broadly similar to that discussed earlier in § 5.8. She also looks at the evolving social worlds of both animals and humans, and traces common ground between them. A related theme which emerges in many of her books is that of ecological flourishing, particularly in relation to the welfare of animals (see Deane-Drummond, 2004, 2008, 2014; Deane-Drummond & Clough [eds.], 2009). In her view, the natural world will only find its fulfilment—its shalom—in God’s new creation, but we are nonetheless called to strive in the present for environmental sustainability and justice. This intertwining of human with ecological well-being highlights the intricate links between all of the multitudinous sub-plots within the immense theo-drama of evolution. Indeed, nichebuilding itself illuminates the web of connections between apparently separate evolutionary stories in this expanded theo-drama, just as keystone species illustrate how seemingly unimportant organisms (or indeed people and events) can have far-reaching consequences. How far it might still be possible for this overcrowded planet Earth to sustain both a wide range of thriving natural ecosystems alongside flourishing human communities is an increasingly urgent question whose answers will be decided by the policies we adopt now and in the near future. National Parks and other protected habitats offer some hope here, but often they are too small

Key Thinkers on Evolution and Faith

235

and/or lack connecting “corridors” to similar refuges elsewhere. We will return to this topic in chapter 10. Recently, Deane-Drummond has edited and contributed to volumes of essays on “Religion in the Anthropocene” (Deane-Drummond et al., 2017) and “The Evolution of Human Wisdom” (Deane-Drummond & Fuentes, 2017). Both books relate to material covered in chapters 5 and 10, and are therefore not further discussed here.

7.5 Arthur Robert Peacocke (1924-2006) 7.5.1 Scientist turned theologian Arthur Peacocke was born in 1924 and studied at Exeter College, Oxford, gaining his BSc (Chemistry) in 1946 and DPhil (Biochemistry) in 1948. He lectured at the University of Birmingham from 1948 to 1959, and subsequently in Biochemistry at the University of Oxford, where he was Fellow and Tutor at St Peter’s College. His research in biophysics was centred on DNA, with pioneering work on single- and double-stranded breaks caused by radiation damage—as well as the effects of ultrasound and intercalating agents (such as acridine derivatives) on purified nucleic acids, as reviewed by Woloschak (2008). This author also suggests that one crucial factor behind Peacocke’s move from science to theology was his clash with the bleak existentialism of Jacques Monod (1970/1972), for whom evolution is largely contingent on random mutations, with no place for “animism” or religious belief. Peacocke (1977) responded by citing the work of Manfred Eigen and Ilya Prigogine, who have shown that order and organisation can emerge spontaneously in chaotic dissipative systems far from equilibrium. From this, Peacocke argued that chance mutations could interact creatively with such emergent ordering, such that selfreplicating life and its evolution become essentially inevitable, rather than contingent on random happenstance. These ideas have been taken up and developed more recently by Gregersen (1998) in terms of autopoietic (= self-generating) processes. Monod was prepared to allow teleonomy— defined as that characteristic of a living organism whereby it is “endowed with a purpose or project” (Monod, 1970/1972, p. 20)—however, the thrust of his argument ruled out any teleology, imputing overall purpose or directionality to evolution itself. Mutations “constitute the only possible source of modifications in the genetic text, itself the sole repository of the organism’s hereditary structures, [hence] it necessarily follows that chance alone is at the source of every innovation, of all creation in the biosphere” (ibid., p. 110). But, as Monod acknowledged, it is the filter of natural selection that “chooses” favourable mutations (those suited to a particular environment) and “eliminates” those that detract from the

236

Chapter 7

teleonomy of the species. By contrast, for Peacocke the idea of emergent order (see § 7.5.2) became a central theme in his attempt at reconciliation between science and theology, though this does not command universal assent. In later writings, Peacocke (2001, pp. 25-27) discusses how random mutations could underpin the overall directionality of evolution, which he sees as fulfilling God’s purposes, yet without requiring God’s intervention. In passing we may note that similar differences in philosophy (and theology) underpin Gould’s (1989, 2002) emphasis on contingency in evolution, as against Conway Morris’ (1998, 2003, 2015) insistence on convergence and overall predictability in evolution (§ 3.4 to 3.6, above). Whilst still engaged in scientific research, Peacocke undertook a Diploma in Theology at the University of Birmingham (1960) and became a Lay Reader, then gained a Bachelor of Divinity degree there in 1971; he was also ordained as deacon and subsequently as priest in the Church of England that same year. In 1973 he became Dean and Director of Studies in Theology at Clare College, Cambridge, a position he held until 1984. Apart from two years in the United States—in 1984 at Tulane University and in 1994 at Georgetown University—he spent the remainder of his life in Oxford, serving as Director of the Ian Ramsey Centre from 1985 to 1988 and again from 1995 to 1999. Among his other notable contributions, in 1972 he founded the Science and Religion Forum, serving first as its Chairman, then Vice-President and finally President. He was a founder member and Warden (1987-1992; Warden Emeritus thereafter) of the Society of Ordained Scientists—in which role I came to know him slightly after joining SOSc in 1995. Among the many awards and distinctions he received were the Lecomte de Noüy Prize in 1983, an MBE from Her Majesty the Queen in 1993, and the prestigious Templeton Prize in 2001. His life-work—developed through numerous books, contributed chapters and journal articles from 1971 until his death—was to offer a naturalistic theology that would be compatible with the scientific world-view, while retaining as much as possible of the rich heritage of Christian tradition. In what follows, I shall draw mainly upon his last major essay outlining his credo in “All That Is” (2007) and to a lesser extent on his magnum opus, “Theology for a Scientific Age” (1990), along with insights from “The Music of Creation” (Peacocke & Pederson 2006) and from the selected essays published in “Evolution: The Disguised Friend of Faith?” (2004).

7.5.2 Emergentist-Naturalistic-Panentheistic perspective These three capitalised words, or their acronym ENP, encapsulate Peacocke’s (2007, p. 26) own summary of his position. Each of them

Key Thinkers on Evolution and Faith

237

requires a certain amount of unpacking before their combination can be addressed, and comments from others are helpful in clarifying these terms. Emergentist implies a hierarchical series of nested lower- and higherorder levels of organisation—in which each level has its own emergent properties and interpretative rules that are not fully explicable in terms of lower-level phenomena. In essence, at each level the whole is greater than the sum of its parts. Most obviously, in the context of this book, cells display properties and behaviours that are not easily predicted from their underlying molecular and biochemical processes (§ 1.8). Likewise, whole organisms do not behave simply as aggregates of their constituent cells, nor ecosystems as compilations of their component species, nor brains merely as vast networks of interconnected neurons (discussed in Clayton, 2004). Peacocke qualifies his term “emergentist” with the word “monist”, meaning non-dualist in the sense discussed briefly in § 5.6—whereby “spirit” or “soul” is an emergent property of the brain and its mental processes. At each hierarchical level, varying the proportions or activities of underlying lower-level structures can produce radically different outcomes. But does this mean (as Peacocke would have us believe) that such higher-level behaviours are in principle non-reducible to (and hence unpredictable from) the lower-level entities? Hard-line reductionists argue that, if we had a sufficiently complete description of each lower level, we would be able to predict both the properties and dynamics of processes observable at higher levels. Because we lack such complete descriptions (which may be unattainable anyway in terms of limited human capabilities for measurement), this dilemma cannot be resolved one way or the other. In more abstract philosophical terms, the emergent properties of the higher level supervene upon those of the lower levels, but are not necessarily entailed by them. In this sense, perhaps a physicalist-monist spirit or soul could supervene upon the sum total of neural functions in the brain (§ 5.6). In recent decades, mathematical modelling has been used to explore characteristic features of biological systems and to make predictions about their behaviour on the basis of key kinetic parameters that encapsulate important lower-level processes, an approach known generically as systems biology. My own acquaintance with this field, involving mathematicians who modelled stress-responses in soil nematodes exposed to combinations of chemical pollutants, proved remarkably illuminating—with at least one counterintuitive prediction that was later borne out by experimental testing (Anbalagan et al., 2012). In a thoughtful commentary on Peacocke’s ideas, Philip Clayton (2008) finds broad support from his own reading of systems biology, at least as regards the importance of hierarchies. He also points

238

Chapter 7

out how outcomes are often determined by reaction stoichiometry, where small changes in reactant concentrations can have large effects on what follows. But most outcomes are predictable if initial conditions are known. Peacocke cites complex non-linear systems, far from thermodynamic equilibrium, in which order can emerge unpredictably from chaos. One such example is the Belousov-Zhabotinsky reaction (Zhabotinsky, 2007), which displays an oscillating pattern of oxidation and reduction as malonic acid reacts with a highly acidic solution of bromate (BrO3-) in the presence of a catalyst such as cerium ions, which can transition between 2 valency states—colourless cerous (Ce3+) and orange-yellow ceric (Ce4+). If stirred, the colourless Ce3+ solution turns yellow, reflecting oxidation of Ce3+ to Ce4+ by bromate; however, the Ce4+ is then reduced back to Ce3+ by the malonic acid and its bromo-derivative (bromomalonic acid), also releasing bromide ions (Br-) that powerfully inhibit Ce3+oxidation, so returning the system almost to its starting point. These oscillations continue for multiple cycles until the reactants become exhausted. What happens in a static Petri dish when the chemical solution (or gel) remains unstirred is even more remarkable: here the colour changes appear “randomly” as spots that expand and become ring-shaped as the reverse reaction kicks in. Spots and then rings arise within rings, which can merge together, generate standing waves and even form patterns reminiscent of Celtic knots (videos of both variants are accessible online). Mathematical modelling of this reaction displays transitions with chaotic behaviour, though the complex chemistry here can be simplified to just three key variables (Györgyi & Field, 1992). This particular instance is one representative of a whole family of cyclical oxidation/reduction processes (collectively termed BZ reactions), whose principal common feature is the bromate ion. Peacocke’s argument, based on the static case and other examples, is that higher-level order can emerge spontaneously from lower-level chaos. He interprets this in terms of the “higher-level” whole determining the behaviour of its “lower-level” constituents, with a flow of pattern-forming information from the former to the latter. One possibility is that these patterns arise deterministically through minute dust particles or imperfections in the surface of the vessel “seeding” new forward and/or reverse reaction centres. However, these are properties of the system-as-a-whole (including the reaction vessel itself and ambient environment), rather than intrinsic properties of the chemical reactants alone. If these patterns are truly random, their appearance (under static conditions) cannot be predicted on the basis of chemical behaviour alone. In either case, the whole is greater—and far more fascinating—than the sum of its parts. Similarly, prevailing weather or climatic conditions

Key Thinkers on Evolution and Faith

239

(such as a cold winter or drought) can have drastic effects on populations of multiple organisms within an ecosystem, mediated through a plethora of interactions between species functioning at many different levels. Living systems are indeed open, dissipative and very far from thermodynamic equilibrium, which may help to explain their self-organising properties. This much is generally agreed, but fewer scientists would be prepared to countenance the next step in Peacocke’s argument, which is to suggest that God’s action in the world is mediated through a similar whole-to-parts causation, reflecting a top-down flow of pattern-generating information. A second analogy involves the top-down relationship of conscious thought to action, but this is more controversial given the lack of consensus as to how the link might operate (§ 5.6); it is therefore not discussed further here. In any case, a transcendent God cannot be just an emergent (or supervenient) property of the universe; rather, the reverse must be true, where the entire created order becomes an emergent gift of God’s self-giving love, Similar ideas are explored in Gregersen’s (1998) view of creation as autopoiesis. Many theologians (e.g. Bielfeldt, 2001) find Peacocke’s emergentist position, combined with his monism, to be incompatible with a God who acts robustly within creation. Their arguments favour substance dualism— separating God from the created order, and analogously the human soul from the body that houses it. To this, Peacocke might respond that God can act only through natural processes. My own response, to be developed further in chapter 8, is that God might let be and love creation rather than acting to manipulate the outcomes of events. I acknowledge, as would Peacocke, that non-natural interventions are outside the scope of science. Dualism poses serious (perhaps insurmountable) problems for scientists, in that key events in the physical world, or in our brains, would essentially be uncaused by any measurable physical process—arising instead from the sovereign acts of God or of the soul, respectively. This important topic is rather beyond the scope of this book, and will not be discussed further here. For all its theological limitations, I find Murphy’s non-reductive physicalist (= emergentist) and monist account of spirit more congruent with science than the dualist alternatives (end of § 5.6; Brown et al., 1998). Naturalistic is a term that raises few concerns for scientists but can be deeply problematic for theologians, especially those of a conservative persuasion. In essence, what Peacocke means by this is that God’s actions in the world (mediated as above) never contravene the fundamental laws of nature, which are in some sense underpinned or guaranteed by God. This is seen as a self-limitation on God’s part, allowing the universe to be and to evolve according to its own laws without meddling or interference.

240

Chapter 7

This immediately rules out any literal reading of the miracles attributed to Jesus and others in the biblical narratives. Instead, we should seek out the underlying symbolism and theological messages being conveyed by these stories, which is after all what we are invited to do with the many parables told by Jesus. At least some of the supposed miracles are susceptible of naturalistic explanations—for instance, sudden healings of what may have been psychosomatic illnesses. Even those prepared to follow this line of argument might still baulk at Peacocke’s inclusion of both incarnation and resurrection among these “miracles” requiring naturalistic explanation. For Peacocke (2004, pp. 221-228), Jesus must be fully human, conceived in the usual way by Mary and (presumably) Joseph, such that he is literally “DNA of our DNA”. Some of the key arguments here have been rehearsed earlier in relation to Sam Berry’s defence of the Virgin Birth (§ 7.3.5). In what sense, then, can Jesus be described as Son of God (Son of Man at least makes literal sense)? In Peacocke’s view (2007), the human Jesus became so completely open to God’s transforming love and presence that he quite literally showed us as much of God as human minds are able to accommodate. But this is a pale and impoverished view of Jesus for many Christians; how can he be said to suffer on behalf of all humanity (let alone all creation), or to redeem us from our sinfulness? The symbolic power of the incarnation lies surely in its vision of Godself accepting the humility of human identity—the vulnerability of babyhood and childhood, followed by an adult life of service to others, leading (inevitably) to suffering and death. Is it enough simply to assert that the perfection of Jesus’ obedience to God meant that all of these human experiences are somehow taken up into the Godhead through a kind of adoption (though this can be read into some passages in the Pauline epistles)? This seems to void all meaning from the self-emptying kenosis of God in Jesus implied by any straightforward reading of Philippians 2:5-11 (see § 8.3.2 below). A similar risk of throwing out the baby with the bathwater arises in relation to the resurrection, which Peacocke (2007) interprets in a spiritual sense rather than as a physical (bodily) appearance. It must be conceded that traditional Christian views of resurrection seem incompatible with any naturalistic perspective, so Peacocke seeks to meet this challenge head-on rather than ducking it. But it is not the gospel accounts of the empty tomb and angels (as well as the risen Jesus, unrecognised at first), but rather the letters of Paul that provide the first scriptural witness to the resurrection. Though Paul’s own encounter with Jesus on the Damascus road (Acts 9) might indeed have been spiritual rather than physical (but see Wright, 2018, pp, 41-59), the Pauline epistles always stress bodily resurrection— especially 1 Corinthians chapter 15, which recounts the earliest version of

Key Thinkers on Evolution and Faith

241

a resurrection tradition received by him from Jesus’ disciples in Jerusalem. There can be no doubt that something extraordinary happened to those frightened disciples, dismayed by the death of their leader—something so powerful that it even converted the arch-persecutor Saul into Paul, zealous apostle of the gospel. It is difficult to get a clear picture of what exactly Peacocke means by a “spiritual resurrection”, but again this strips away much of the symbolic power of traditional physical interpretations. Even so, it is clear that his views did evolve over the years; earlier statements (Peacocke, 1990) seem to qualify rather than reject more orthodox beliefs. Lastly, panentheistic; this term tries to steer a middle course between pantheism, which identifies God with the whole created order (immanent within it), and traditional theism, which sees God as separate from and unmoved by God’s own creation (transcendent, and therefore impassible). Panentheism asserts that God is immanent in but also transcendent beyond the creation. Peacocke (2007, p. 22) quotes an image from St. Augustine, who likened all creation to a marine sponge—thoroughly immersed in and imbued by the sea that is God—but the sea is far vaster than the sponge. Indeed, one could extend this metaphor and hypothesise that the selfsame sea could sustain and imbue many other creatures (universes?). As such, it is arguable that panentheism is in fact a restatement of traditional Christian belief, which also holds that God is both immanent in creation and transcendent. This is more obvious in some strands of Eastern Orthodox theology (Knight, 2007, pp. 81-92), and is most strikingly expressed in the writings of Maximus the Confessor (580-662 CE). He identified the divine logos or Word with Christ (the agent of creation in the Prologue of John’s gospel), but also proposed that all created things possess their own intrinsic logoi, which are themselves manifestations of the divine logos, and represent the underlying principles and purposes of those entities— their teleonomies in Monod’s terms—as well as drawing them towards God (ibid., p. 84). This view, though couched in archaic and unfamiliar philosophical terms (Tollefsen, 2015), seems strikingly consonant with Peacocke’s panentheism. That said, for many mainstream Christians (not least Celia Deane-Drummond; § 7.4), panentheism is tarred with the same brush as pantheism—identifying God far too closely with creation and down-playing God’s transcendence. As for the traditional impassibility of God, this has been challenged by many theologians (notably Jürgen Moltmann) in recent decades. A God who both loves and suffers with creation is also evident from the bible—certainly the images of God in Jesus’ gospel parables evince a wide range of emotions—from wrath to patient, forgiving love. Further consideration of this is deferred to chapter 8.

242

Chapter 7

7.5.3 Pros and cons of Peacocke’s ENP position At the outset, it is worth hailing the intellectual honesty of Peacocke’s arguments (Jackelén, 2008). He acknowledges that his naturalistic stance contradicts the many supernatural elements that permeate scripture and theology, and in essence asks whether the Christian faith could survive the excision of these non-rational elements. He concludes that this is indeed possible, albeit at the cost (in my opinion and that of many others) of much that lends power and conviction to that faith—accounting for the “surprising emotional sense” of Christian belief (Spufford, 2013). My own view is that the multiple interpretations and layers of accreted symbolism need to be held in tension with this naturalistic stance, rather in the way that each of the ambiguous histories in the previous chapter is susceptible of multiple readings. Peacocke’s spiritual interpretation of the resurrection conveys very little of the liberating power and mystery of what happened, as encapsulated in the elusive gospel narratives that speak of numinous wonder and joy. For me, the notion that these stories are mere fabrications concocted by the early church carries little conviction (§ 8.3.1). As will be apparent from earlier chapters in this book, I believe that reality is always deeper and more complex than our attempts to describe it. As Peacocke himself concedes (2007, p. 33), “It is not at all clear that the narratives concerning the “resurrection”, taken at their face value, are sensitive to scientific considerations at all, since the end state, the “risen” Jesus, is not open even to the kind of repeatable observations science involves.” As for the incarnation (for which similar considerations of non-repeatability apply), I am a little more inclined to embrace Peacocke’s naturalistic position, whilst acknowledging that much is also thereby lost. My instinct again is to argue for “both-and” rather than “either-or”, but hard-line reductionists will say that I am simply trying to have my cake and eat it! Although Peacocke wishes to emphasise top-down, or better wholeparts, causation as a plausible model for God’s interaction with the world, this remains a controversial idea. To what extent is real pattern-generating information transmitted from the system as a whole down to its constituent parts? Other scientist-theologians, such as Robert Russell (2009), envisage God’s interaction with the world in very different terms—from the bottom up (where a degree of indeterminacy reigns at the quantum level) rather than top down. But there is no unanimity here among physicist-theologians, and John Polkinghorne (1989) is quite critical of the idea that quantum events are the locus of God’s action. In a later book, Polkinghorne (2005) points instead to the many parallels or analogies between theology and quantum physics, particularly in the ways that both deal with uncertainty

Key Thinkers on Evolution and Faith

243

and a quest for over-arching truth. Yet a God who in some sense constrains or predetermines quantum events (albeit without leaving tell-tale traces!) remains the omniscient and omnipotent micromanager of tradition. The “free-will defence” as to why God permits evil becomes null and void, and so too does its “free process” variant—which Polkinghone strongly endorses. There are several points of common ground between Peacocke and Polkinghorne, not least their shared commitment to a Christianity consonant with the scientific world-view. Both also contend, but as far as I can tell without evidence, that God sustains the entire universe in being from moment to moment, as though everything would snuff out of existence if God’s attention wandered. Really? Is this just to give God something more substantive to “do” in terms of creation? It seems odd that this is slipped in without justification (e.g. Peacocke, 2004, p. 16), when the author takes such pains to demolish any notion of an interfering “God of the gaps”, or of a deist God who simply lights the fuse and then lets everything unfold. My own, perhaps unduly naïve, view is that this unfolding of novelty is accompanied by God enfolding whatever emerges with compassion and love, suffering along with creation in all of its attendant pain and death and wastage. This too will emerge in more detail in the next chapter. There is an important theological point here: a creation that is sustained moment by moment in or by God can hardly be described as in any sense independent or free to pursue its own ends (a freedom to which evolution attests). Indeed I would argue that such a creation cannot sustain a relationship of real love between creator (however understood) and creature. If creation depends on God for its continued existence, then its freedom is merely illusory and God’s love towards it becomes controlling, even manipulative, rather than self-giving for the sake of the beloved. Yet sacrificial love is what we see lived out in the gospel of Jesus Christ (§ 8.3). Also, a wholly dependent creation could not respond to God with free-will offerings of praise, adoration and love. The emergentist views of Peacocke (et al.) raise other serious theological issues (Leidenhag, 2016), especially if Christ and the Holy Spirit are seen as emergent aspects of creation, immanent within rather than transcendent beyond it. Moreover, if the Spirit’s activity is in any sense a causal agent within creation, then a form of vitalism is reintroduced by the back door. Panentheism also raises question marks for many Christians, despite Peacocke’s valiant attempts to assert God’s transcendence over, as well as immanence within, creation. This emphasis on God’s immanence will be explored further in § 7.5.5 below, building on one of Peacocke’s favourite quotations from a 19th C CE priest and staunch Darwinian, Aubrey Moore. As to whether God is affected by what happens in the creation (God’s

244

Chapter 7

passibility), this has been explored in depth by a range of theological voices, notably Jürgen Moltmann (“The Crucified God”, 1973/1974) and W.H. Vanstone (“Love’s Endeavour, Love’s Expense”, 1977). I will return to this topic in § 8.3, since it bears closely on the core nature of the loving Trinitarian God to whom the life and teachings of Jesus bear witness.

7.5.4 Sacrament and naturalism Reflecting his Anglican heritage, Peacocke places significant emphasis on sacramental aspects of the Christian faith—particularly the eucharist or holy communion (2007, pp. 42-44). In this service the faithful gather to commemorate Jesus’ last meal with his disciples, when bread was broken and wine shared (Matthew 26:26-29; Mark 14:22-24; Luke 22:14-20). This he describes as a “natural re-enactment”, in which something new emerges from the complex webs of tradition and actuality as the liturgy unfolds. These underlying webs can be understood as encompassing obedience to Jesus’ injunction to “do this in remembrance of me”, proper authorisation of the celebrant, materiality of the consecrated elements of bread and wine, co-creation by humans with God (bread rather than wheat; wine rather than grapes), the self-emptying love of God in Jesus seen in his passion and death following on from the Last Supper, the promises of God made present in this re-enactment, and thus the presence of God as incarnate in the eucharist, a celebration that always involves the church as a community. From this rich admixture of elements emerges what Peacocke describes as the Real Presence, not as a (Catholic) physical transubstantiation of bread and wine into the body and blood of Christ, but rather as a sense of participating in a greater reality whose significance surpasses the local particularities of time and place and individual people. From my own priestly experience, I can only concur with this assessment. Unless supplemented by elaborate ancillary elements—music, incense, icons, robes and candles, for instance—the eucharist is participatory rather than a spectacle that might be watched by outsiders. Among the responses to Peacocke’s last essay is an interesting reflection by Donald Braxton (2007, pp. 104-118) which sets naturalistic views of sacrament in the context of the evolution of human religion (§ 5.12). Sacrament is seen as a “positive expression of giftedness, [acknowledging] the blessings of good community, good land, good society, and good world.” Sacrifice is the flip-side of the same coin, “a negative expression of limit, of a species that voluntarily, and for the well-being of community, land, society, and world, restricts itself to maintain right relationship with the sacred order” (ibid., p. 113). Both of these must operate in tandem, through feedback loops, in order for humans to live sustainably. Precisely because it is naturalistic,

Key Thinkers on Evolution and Faith

245

Peacocke’s sacramentality may help Christians reconnect to the natural world by rendering the “ordinary” sacred and extraordinary. In a world now threatened by overpopulation and accelerating climate change (chapter 10), this double injunction to celebrate the simple gifts of life and limit our acquisitiveness and greed for the common good, finds resonances beyond Christianity—indeed, very similar principles are intrinsic to Buddhism. Another question raised by human awareness of God, in contrast (?) to other living things, concerns the vocation of Christians to become priests of creation, representing the natural world before God, using our capacity for both empathy and rational understanding. Peacocke commends this role as ministers of grace in terms of reverencing the sacrament of nature and mediating between insentient nature and God (2007, p. 53). Indeed, this may offer one interpretation of Paul’s resonant phrase in Romans 8:19, where “the creation waits with eager longing for the revealing of the children of God” (NRSV). Ruth Page (1996, p. 162) takes issue with this version of humanity’s priestly role, on the grounds that it discounts any kind of direct relationship between God and non-human creation. Peacocke implies that creation had to wait for human consciousness to evolve before finding a voice that God can hear; this view seems unduly anthropocentric.

7.5.5 Evolution, the disguised friend of faith? This phrase serves as the title for one of Peacocke’s essay collections (2004), but actually paraphrases part of a century-older essay by Aubrey Moore (1891). It is worth repeating the full quotation that Peacocke uses as the epigraph for his 2004 collection, since in many ways it epitomises his approach to reconciling Christian faith with the world of science. “Science had pushed the deist’s God farther and farther away, and at the moment when it seemed as if He would be thrust out altogether, Darwinism appeared, and, under the disguise of a foe, did the work of a friend. It has conferred upon philosophy and religion an inestimable benefit, by showing us that we must choose between two alternatives. Either God is everywhere present in nature, or He is nowhere.” [Moore, 1891, p. 73].

In one sense, this is of course a deeply ambiguous passage; atheists should salute its frank admission that, in the light of Darwinism, God might indeed be nowhere! The “deist’s God” (above) is the prime cause needed to set the universe in motion, according to Newton and others. By the late 19th C CE, the explanations of classical physics looked unassailable, with no chinks requiring God’s subsequent intervention. What Moore could not have guessed, when writing these lines, was how soon that edifice would

246

Chapter 7

be undermined in the early 20th C CE by the twin caverns of relativity and quantum mechanics. Moore is correct in seeing two possible responses from Christians facing up to Darwinism—either to reject God altogether, or to find God permeating the totality of the astonishingly diverse living world that has emerged through evolution. Moore, Peacocke, and also myself, would all seek to embrace the second of these alternatives, but we should respect those reaching the opposite conclusion. Sometimes our embrace of evolutionary reality can feel harsh and painful: where are we to find God in the life-cycle of ichneumon flies that lay eggs inside a caterpillar, which will then be consumed from within by the hatching larvae? Another grisly case in point is the giant water bug so vividly described by Annie Dillard in her spiritual classic, “Pilgrim at Tinker Creek” (1974/2011, pp. 7-9). Nature seems vicious and cruel on the one hand, but also sublimely beautiful on the other. A keen observer must acknowledge the reality of both. Elsewhere, Moore wrote that evolution “as a theory is infinitely more Christian than the theory of ‘Special Creation.’ For it implies the immanence of God in nature, and the omnipresence of His creative power. Those who opposed the doctrine of evolution in defence of ‘a continued intervention’ of God seem to have failed to notice that a theory of occasional intervention implies as its correlative a theory of ordinary absence.” [Moore, 1893, pp. 184-185].

This is very much in tune with Peacocke’s naturalism; God is immanent in and throughout creation, while also being vastly greater than our limited senses, intelligence and spiritual awareness are able to perceive. What we need is encapsulated in the title of Sara Maitland’s 1995 book, “A BigEnough God”: “there is no other credible God; it is a God as big and as unmanageable as this or no God at all” (ibid. p. 150), a God who “cannot be spoken of, cannot be reduced to or claimed by our definitions” (ibid. p. 172), yet whose mode of expression is boundless joy in risky love. In his contribution to “Creation as Kenosis”, written in tribute to W.H. Vanstone, Peacocke (2001, p. 42) explores the vast costliness of evolution, and the untold suffering it entails both for sentient creatures and for God— as expressed most tellingly in Jesus’ last cry of dereliction from the cross, following Matthew 27:46 and Mark 15:34. Earlier in this essay he writes: “The theist cannot avoid asking, ‘If the Creator intended the arrival in the cosmos of complex, reproducing structures that could think and be free— that is, self-conscious, free persons—was there not some other, less costly and painful way of bringing that about? Was that the only possible way?’”: He then admits: “The biological parameters...discerned by science to be operating in evolution...indicate that there are inherent constraints on how

Key Thinkers on Evolution and Faith

247

even an omnipotent Creator could bring about the existence of a law-like creation that is to be a cosmos not a chaos, and thus an arena for the free action of self-conscious, reproducing complex entities and for the coming to be of the fecund variety of living organisms whose existence the Creator delights in.” [Peacocke, 2001, pp. 36-37].

This is a painfully honest non-answer, an admission that no-one has yet envisaged a more efficacious mechanism for free experimentation and the generation of jaw-dropping diversity than evolution by natural selection. Faut de mieux, perhaps not even God could come up with a less harrowing alternative. A crucial difference for Christians is that, in Jesus, Godself enters into the suffering of evolving creation, and may thereby redeem the totality of that anguish—a topic deferred to § 8.5.2. This also broaches the important question of theodicy—which seeks to defend God's love, goodness, and even plausibility, in the face of all the suffering and evil so prevalent in creation. I have no space here to explore theodicy in detail, beyond referring readers to John Hick’s magisterial work, “Evil and the God of Love” (1966/2010), which explores this issue by drawing contrasts between the explanations of the Fall given by Irenaeus and by Augustine, as well as the earlier pagan theodicy of Plotinus. Though not discussed by Hick, evolution raises the question of theodicy in a particulary acute form.

7.6 Four paths to faith through evolution The four key thinkers on whom I have focussed in this lengthy chapter exemplify four very different ways of reconciling faith with evolution. It is true that Teilhard de Chardin misjudged the evolutionary consensus of his time and pursued a cul-de-sac, building his grand synthesis on foundations of sand. But even though his ideas about evolution were fundamentally wrong, the sweep and scope of his vision have inspired others to recast his ideas in a more orthodox evolutionary framework. Whether this succeeds is perhaps a matter of taste; for mystics or visionaries, Teilhard’s synthesis remains a yardstick by which the efforts of others will be judged. Notwithstanding the negative judgements of most scientists, his vision and passion are gaining ground in church (and not only Catholic) circles. Unfortunately, many clerics and lay Christians with little knowledge of biology or geology assume that the “evolution” about which Teilhard writes is essentially identical to the modern unifying concept of evolution that makes sense of the entire biosphere. Sad to say, it is not. But those inspired by his vision are free to explore the vast vistas opened up by evolutionary science and to explore new syntheses that may bring evolution and Christian faith together more adequately than Teilhard was

248

Chapter 7

able to accomplish, given the circumstances of his life and times. There is something there, just tantalisingly out of reach, which I can sense but cannot as yet grasp—an over-arching vision of a God who crowns creation. Sam Berry came from the opposite pole of the ecclesiastical world—an evangelical who took the Bible with enormous seriousness. But he was also an evolutionary biologist by profession, and cannot be faulted for his staunch defence of Darwinism in the face of creationist over-literalism among fellow evangelicals. Though he is prepared to countenance literary interpretations of passages on which no cherished doctrines depend, he is less accommodating towards texts such as Genesis 3 that are foundational to his core Christian beliefs—in this case, human sinfulness and God’s righteous judgement. My own more liberal theology is less focussed on sin, so I find this a strange dichotomy. Nevertheless, there is much to commend in his careful expositions of key scriptural texts (often citing the original Hebrew or Greek), arguing that there is no necessary contradiction between a firm Christian faith and the major tenets of neo-Darwinian evolution. That said, he does not attempt a systematic evolutionary theology—and many biblical texts resist any kind of Darwinian gloss. Given the diverse literary and spiritual sources from which the Bible was compiled (even if Berry would maintain that all of it is God-inspired), this is hardly surprising. In my penultimate chapter, I will tackle this problem from a wider standpoint that is less narrowly directed towards scriptural exposition as an end in itself. What is remarkable is the new light that evolutionary ideas can sometimes cast on over-familiar stories and sayings whose meanings we mistakenly thought we had exhausted. Celia Deane-Drummond is different again, even if she sometimes seems to me overly deferential towards Catholic orthodoxy. But she brings to the table her professional expertise in biology as well as theology, and has an acute grasp of the pros and cons of biotechnology. Even where I might disagree with her on this topic, I can acclaim the eloquence, breadth of sympathies and careful reasoning that she brings to these often heated debates around GM, as well as controversial biomedical issues. She has perceptively pointed out links between the biblical Wisdom literature and the sense of wonder and curiosity that underlies the pursuit of science. I am intrigued but not wholly persuaded by the notion of shadow sophia distorting some (many?) directions in biological evolution. Her expanded evolutionary version of von Balthasar’s concept of theo-drama places the Christ-event at centre stage, and reinterprets the implications of evolution accordingly. To be sure, this doesn’t solve all the attendant problems—but it provides a new and dizzying perspective that might creatively feed into

Key Thinkers on Evolution and Faith

249

any attempt at a neo-Teilhardian synthesis. Likewise, her recent writing on niche construction and ecosystem flourishing provides us with models of sustainability towards which conservation efforts might usefully aspire. Lastly, Arthur Peacocke attempted to provide a thoroughly naturalistic account of a God who is still the creator, redeemer and sustainer of all that is. His proposal of top-down—or better whole-parts—causation as a model for God’s action in the world has some scientific plausibility, though the emergence of orderly behaviour in chaotic but complex non-equilibrium systems does not necessarily entail this interpretation. While his integrity in ruling out supernatural interventions by God is at least consistent, it will seem to many Christians that he vitiates (even eviscerates) the core tenets of their faith in the process. His insistence on a panentheistic God who is both immanent in and transcendent over creation attracts both praise and scepticism. There is an impressive austerity about the faith that Peacocke propounds, but I am not convinced it can attract sceptics or the unchurched. It may work best for Christians who have wrestled long with the intractable contradictions between their faith and secular versions of the way the world is. For such questioning seekers, his theology provides an intellectually honest route through the clashing rocks that beset them—between the Scylla of fundamentalist Christianity and Charybdis of militant atheism. There are elements from each of these four thinkers that inspire me, even though they come at the question of evolution and Christian belief from such radically different standpoints. If nothing else, these four accounts underline the core lesson of my previous chapter—that multiple layers of meaning and interpretation can be drawn from the careful consideration of any story from different viewpoints. The scope of my coverage here could have been broadened in many different directions, so as to include physicists such as John Polkinghorne (1989, 2005) Russell Stannard (2017), or indeed the American Robert Russell (2009). Another transatlantic omission is Franscisco Ayala (2007)—who came originally from Spain and trained as a priest, before moving to the USA and becoming a noted evolutionary biologist—although his reputation is now significantly tarnished. But the time has come for me to stop hiding behind the coat-tails of others and to present an outline sketch of my own position. I do not pretend that the following chapter is fully worked out from a theological perspective, since I am a scientist and priest rather than an academic theologian. But it is a position that I have evolved over 50 years as a convert to Christianity and as a biologist whose world makes no sense whatsoever except in the light of evolution (Dobzhansky, 1973).

CHAPTER 8 AN EVOLUTIONARY THEOLOGY

Summary § 8.1 outlines the scope and aims of this chapter, setting out my own views of how evolution and Christian faith could be reconciled. § 8.2 asks how God might be conceived as creator of a biosphere that has so clearly arisen through evolution. In particular, how might God relate to the prehuman stages of life on earth? One possibility is a God who improvises, another is a self-limited God who voluntarily refrains from interfering. I opt for a God who waits and lests be—who gifts creation with possibilities, allowing these to fulfil their own ends, embracing all that comes into being with love and compassion. This view of God is exemplified by the paradoxical figure of Christ Jesus encountered in the four gospels—as explored in § 8.3. His incarnation, baptism and resurrection are discussed briefly, before considering his divinity and self-emptying (kenosis). The kingdom teaching of Jesus turns earthly notions of status, power and worth on their heads. Instead, we are challenged to value and cherish what the world considers worthless. These paradoxes are not mere rhetoric, but rather reveal the nature of God—imbued with the costly love, undeserved compassion and abounding grace that Jesus lives out in the gospels. § 8.4 looks briefly at the Christian doctrine of God as Trinity with its key associations of community. Our churches aspire to live as flourishing communities—an ideal that is also explored in relation to the functioning of cells, ecosystems and societies. Lastly, § 8.5 turns to eschatology—where biblical threats of judgement and condemnation are contrasted with promises of rest (shalom) and redemption offered paradoxically to all. This universalist strand within the Christian tradition may afford at least the hope of salvation to non-human creation as well.

An Evolutionary Theology

251

8.1 Scope and Aims This chapter is a modest and personal attempt at a compilation (I would not dare claim a synthesis) of theological insights and ideas that are broadly compatible with evolution. It is not a comprehensively thought-through theology of evolution, nor do I claim any great originality in this presentation. The previous chapter has reviewed four contrasting attempts at synthesis, articulating faith-positions that the authors claim can be reconciled with evolution—admittedly sensu lato in the case of Teilhard. In what follows, several of these ideas will resurface, though they will not be covered at length—instead I will refer back to earlier discussions. To any academic theologian, this will seem an eclectic mix—or even a mish-mash—that cherry-picks insights from catholic (note the lower-case c), evangelical, radical and Orthodox theologies. It is also broad-brush and somewhat cavalier in its approach. My defence—perhaps little more than a fig-leaf— is that this is an exercise in practical theology, suggesting ideas that might help to reconcile Christian faith with the broad sweep of evolution, and perhaps even finding new illumination from the latter. The scope of this chapter is deliberately circumscribed, and it will be for others to pursue further theological explorations along these lines, if they are in any way fruitful. The next section (§ 8.2) will focus on the vexed question of how God might still be seen as Creator in the light of scientific accounts invoking a gradual emergence of this universe through cosmology, of the landforms and rocks of this planet through geology, and of the rich panoply of living organisms in the earth’s biosphere through evolution (the uniting thread of biology). In § 8.3 I will examine the nature of God as revealed in the person of Jesus Christ, followed by a brief consideration of God as Trinity in the context of community, church and human flourishing (§ 8.4). I apologise here to charismatic and Pentecostal Christians, who will find no separate reflection on God the Holy Spirit. Lastly, I will look more speculatively at the Christian hope of salvation (§ 8.5). Though characteristic of Christianity (despite contrasting expressions in scripture), this aspect of our faith is ultimately unprovable, and there is little shared understanding even among practising Christians. It is also vulnerable to the old jibe of “pie in the sky when you die”, as if the promise of a better afterlife (in “heaven”) could somehow excuse the painful travails of human life, or indeed those of biological evolution.

252

Chapter 8

8.2 God as Creator? 8.2.1 Theism and evolution I will doubtless be accused of ducking vitally important questions here, such as the arguments for and against the existence of God. To my way of thinking, this is a futile line of inquiry that is bound to end inconclusively. There are no knock-down arguments either way, in the sense of powerful proofs that would overwhelm all opposition; rather, they are knock-down in two alternative British senses of cheap or easily demolished. I have never yet met anyone who was converted to Christianity by the classical “proofs” of God; rather, conversions occur through personal encounter with that which is beyond our grasp, or with the presence of Jesus Christ. This is not to deny the powerful personal testimonies of scientists who profess faith (e.g. Collins, 2007), nor indeed of philosophers who have abandoned atheism to embrace belief in a supraphysical God (Flew, 2007). The previous chapter gives the lie to atheist assertions that religious (and particularly Christian) faith is incompatible with any grasp of the scope of evolution. But equally, the internal consistency and cross-reinforcement of so many geological and biological lines of evidence in support of evolution combine to demolish creationist claims for a recent 6-day creation. Such claims would need divine intervention, inter alia, to slow down drastically the rates of isotope decay—on whose constancy both rock dating and atomic clocks depend—and to order the sequences of extinct fossil species in strata laid down (presumably) during the Flood. Both of these turn the God of all truth into a forger—creating a counterfeit world that appears to be an ancient masterpiece (4+ billion years old), when in fact it was “faked” a mere 6000 years ago, according to Archbishop Ussher’s (1650/2003) biblical chronology. Why would God plant false evidence of antiquity in this world or in the even-older cosmos; is it just to condemn the hubris of scientists to eternal damnation? Sorry, I simply don’t buy that explanation. God doesn’t leave tell-tale fingerprints all over creation, unless indeed every aspect of this universe (and others?) bears testimony to God’s love and creativity. As Aubrey Moore wrote (1891, p. 73; quoted in full in § 7.5.5): “Either God is everywhere present in nature, or He is nowhere”. We cannot pick and choose here. If God creates by using the process of evolution, then the divine imprint is present as much in the ichneumon fly whose larvae consume a caterpillar from inside, as it is in that caterpillar, or indeed in the moth or butterfly that it might have become. For many, this seems to rule out any possibility of a benevolent creator God. At best, we would have a creator apparently indifferent to the cost and suffering of

An Evolutionary Theology

253

that creation. Alternatively, we could view evolution as an impersonal creative “impulse” arising from nature itself, whose end-products and byproducts are loved and cherished (and will perhaps be redeemed) by God. This last may let God off the hook, removing divine responsibility for the painful wastage inherent in evolution, but it would come at the significant cost of any claim by God to authorship of all that is. I shall argue below (§ 8.2.6) that creation could also imply a “letting be”, which might still allow for divine authorial intent—or at least divine invitation through possibility. In asserting that God leaves no fingerprints, I am also contradicting the Intelligent Design (ID) school—who hold that there are certain biological processes and structures whose irreducible complexity rules out any possibility of gradual evolutionary origin. For ID advocates, this evidence of “unevolvable” design requires God as designer (though this is usually implied rather than stated outright). A favourite and often-cited example is the bacterial flagellum, whose rotation propels many larger bacteria. It is certainly true that the assemblage of 30+ proteins in the “motor” that drives this rotation is incredibly complex, and that most of its component proteins are indispensable to its function. But even so, there are plausible evolutionary scenarios that could explain the origins of the flagellar motor—involving mergers between modular subsystems that each served its own useful function (Pallen & Matzke, 2006). Moreover, evolution can offer a far more plausible explanation for the huge variety of flagellar structures, functions and proteins among bacteria. In line with the vast majority of biologists, I reject the so-called “scientific” arguments of ID advocates and creationists as specious distortions, half-truths masquerading as science, whereas in reality they are pseudoscience (see Ayala, 2007). Evolutionary theory grows stronger, not weaker, through new findings in biology, though we should also concede that evolution provides the overarching paradigm within which all such new data are interpreted—risking circular reasoning. Surveying the vast panorama of life on earth, there are no alternatives to evolution that can afford comparable explanatory power. As far as the Book of God’s Works is concerned it would seem that God has not unambiguously asserted His (or Her) moral right to be identified as author (but see Berry, 2003). Authorship is attributed by most scientists to cosmogenesis and evolution (effectively Anon.), but maybe these are only equivalent to a word-processing program that gives definitive form to the divine author’s intentions, as many religious believers would maintain.

254

Chapter 8

8.2.2 The scriptural witness to God What then of the Book of God’s Words—the bible, or indeed other sacred texts? I am not going to consider the reliability of scripture or even the historicity of the gospels in any detail. That these are important questions for biblical scholars and theologians is beyond question, but once again there are no knock-down (= overwhelming) arguments either way. It is a paradox that the works of Roman authors attract far less scepticism than the gospel portraits of Jesus. It is true that the latter were written 40-60 years after the crucifixion—and that all 3 synoptic gospels share a common source (Q)—so it is inevitable that selective memory and post-resurrection reinterpretation of key events will have coloured these accounts. Nevertheless, a cogent case can be made for their overall broad historicity (Eddy & Boyd, 2007). In any case, we have little else to go on, though St. Paul had outlined many of the crucial themes in his epistles written two decades earlier. It goes without saying that the books currently compiled into the Christian bible, with or without the Apocrypha, comprise a somewhat arbitrary collection of texts covering a vast spectrum of different styles and genres of literature, ranging from myth (much of Genesis) to love-poetry (Song of Songs), from legal codes (Leviticus) to history (e.g. Samuel and Kings), from prophecy (e.g. Isaiah) to apocalypse (Revelation). Even if, as evangelicals such as Berry would maintain, all of these texts were divinely inspired, they have clearly been transcribed and edited and copied (with attendant errors!) by human authors—each with his (almost always) own prejudices and blinkered world-view. Little wonder, then, that observant critics can so easily pick holes in the bible, pointing to innumerable contradictions and inconsistencies—even within the same book. Modern biblical scholarship shows how disparate source materials have been woven together and (re-)edited, so that single authorship of many scriptural books looks highly unlikely. To cite just one well-known example, there were at least 3 authorial origins for the book of Isaiah, spanning a compositional period of 2-300 years, which are skilfully juxtaposed in its 66 extant chapters. Thus it is hardly surprising that joins show through in places, sometimes with abrupt changes of topic or mood. Parts of the bible are deeply offensive to modern sensibilities, even if they seemed acceptable in the past; not least among these are the genocides allegedly sanctioned by God in the takeover of the Promised Land after the Exodus from Egypt. For all of us who read the bible regularly, there are passages that inspire us and make “our hearts burn within us” (Luke 24:32), but also others that we cannot fathom or assent to—or that fill us with dread whenever we have to preach on them. Brother Roger of Taizé

An Evolutionary Theology

255

advised young Christians to focus on the former and struggle with the latter only as they grow into the faith. Once again, God’s authorship of His (Her) Book of Words is not asserted clearly and without ambiguity. Divinely inspired it may be, as judged by the human responses of love and self-sacrifice that it often provokes—but we must also confess that others have misused scripture as a pretext for unspeakable atrocities. The various fingerprints to be found in its texts are often human ones, and these at least are also fallible. It is in this light that Peacocke argues for a naturalistic reading of miracle stories, and even Berry veers from literal (Genesis 3; § 7.3.2) to literary (Genesis 1; § 7.3.3) interpretations. Nonetheless, there were sound theological reasons (sometimes lost to us) for including all of the interwoven strands of narrative and other elements within the bible. A range of hermeneutical approaches can be used to elucidate the underlying meanings (note the plural) of any given text: literal, philosophical, moral, allegorical, political, mystical or anagogical. My task in chapter 9 will be to apply an evolutionary exegesis to a personal selection of biblical texts.

8.2.3 God, humanity, and evolutionary time In Jesus’ vivid parable of the wicked tenants (Luke 20:9-16), God is pictured as an absentee landlord, although it is this selfsame landlord who originally planted the vineyard (v. 9). In any case, by sending his servants (successive prophets) and then his son (Jesus), the landlord shows ongoing care and concern for his vineyard. For Christians, this is exactly what God has done in human history—but only in the very recent past, essentially during the 12,000 years since the Neolithic Revolution. Where were God’s messengers during the billions of years when life on earth was largely or wholly microbial, or during the Cambrian explosion of animal life over 500 Ma (§ 3.2), or during the age of dinosaurs? In what ways could we conceive of God as having care for, let alone oversight of, evolution during the vast spans of time before hominins (perhaps only Homo sapiens) evolved a consciousness capable of intimations of the divine? Pursuing the parable in Luke 20 a little further, was God simply uninterested in whatever evolution produced, until such time as human beings first became conscious—analogous to the first-fruits of the grape harvest in God’s vineyard? If that is our theological assumption, then we trip headlong into the pitfall of anthropocentrism, making humankind the measure of all things, and so belittling the intrinsic value of all other living organisms. It is a bit of a cop-out to claim that this vast temporal gap would simply be irrelevant to a God who is in some sense outside of time.

256

Chapter 8

These rhetorical questions are meant to underline the real difficulties encountered in reconciling our all-too-human view of God with the immense time-spans of cosmogenesis and evolution. My aim here is to argue that the God who is revealed by Jesus, and hinted at at in the Old Testament, might be conceived as enfolding this universe—together with all its life-forms (not necessarily confined to this planet)—in an embrace of love and compassion. It is a natural corollary of this that Christ Jesus came into the world (however we envisage the incarnation), not merely to save sinners (1 Timothy 1:15), but also to offer salvation to the whole creation (cf. Romans 8:19-21). We need a much bigger God than that implied by our blinkered anthropocentric viewpoint (Maitland, 1995). In what sense can Christians continue to worship God as “creator”, when the endlessly repetitious yet never-identical sub-routines for making new stars and for evolving novel species appear to operate autonomously, with no discernible indications of either prior planning or ongoing interference?

8.2.4 God improvising? One potentially illuminating metaphor views God as an improviser without peer, weaving unpremeditated variations on the themes of stars or species. We know from contemporary accounts that J.S. Bach improvised a 3-part fugue on an unseen theme offered by Frederick the Great of Prussia in May 1747, and then improvised an astonishing 6-part fugue based on one of his own themes (Hofstadter, 1979, pp. 3-8). Not content with this, Bach later wrote a full 6-part fugue based on the original Royal Theme, and this featured as the centrepiece (Ricercar a 6) of Bach’s “Musical Offering” (Peacocke & Pederson, 2006, p. 32), together with the original 3-part fugue (Ricercar a 3) and several canons on the same theme. Given the strict contrapuntal rules governing canon and fugue, Hofstadter compared the intellectual achievement of Bach’s 6-part improvised fugue with that of playing 60 simultaneous chess games blindfold and winning them all. Although the rules and theme are constant, the precise course of an improvised piece of music cannot be predicted as it unfolds, unlike hearing the “fixed” written versions of the Ricercars and canons within the Musical Offering. Another musical parallel is afforded by jazz—where musicians improvise around a theme (e.g. a 12-bar blues progression), taking turns to feature as soloist or to retreat into the background accompaniment (Peacocke & Pederson, 2006, pp. 49-52). Beyond the basic rules—similar to the roles of genetic variation and natural selection in evolution—the only constraints on jazz or classical improvisation are the musical skills and imagination of the players. Creation as improvisation is reimagined in the first chapter of J.R.R. Tolkien’s less-read First-Age saga,

An Evolutionary Theology

257

“The Silmarillion” (1977, pp. 15-22), in which the varied voices of the “angelic host” (the Ainur) join together in making an harmonious Great Music on a theme propounded by God (Ilúvatar). Dissention and discord arise from Melkor, chief of the Ainur—Tolkein’s equivalent of the rebel angel Lucifer—in response to which Ilúvatar declares a 2nd and then a 3rd theme (the Children of Ilúvatar, Elves and Men). This Great Music is then embodied in the form of Arda, the lower world within which Tolkein’s whole mythology is set, and many of the Ainur choose to enter into it as the Valar, who thereby become Powers of Arda—for both good and evil. Another artistic analogy may help, this time in terms of the visual arts. Whether painted in watercolours or oils, works by pre-19th C CE European artists for the most part captured fine details of their subject-matter through careful brushwork. Similar techniques were used more recently by several Surrealists (such as Dalí, Magritte, or Tanguy) to realise disturbing images with great precision. Many religious believers likewise envisage God as a master painter painstakingly crafting every minute detail of creation— whether stars, species or humans. In contrast, the 19th C CE Impressionists (along with their forerunners, e.g. Turner, and Expressionist successors) used imprecise dabs of colour that make little sense when viewed at close range, yet merge into a dazzling whole with the benefit of distance. Many watercolour artists allow washes of colour to mingle and run, producing unpredictable hazes and eddies—a kind of improvisation in paint. This is taken further in marbling techniques using inks, water, size and oils to produce intricate flowing colour patterns that often provided decorative endpapers for books (Fig. 8.1A). Artistry here is a matter of working with the grain of what emerges from such improvisatory approaches, selecting patterns that look promising and discarding those that don’t. Hints of natural selection in evolution will be obvious here. Many artists mix both precision and improvisation, often in the same painting (Fig. 8.1B-D). Though the final painting is frozen in time (fixed, like a musical score once composed), the process of realising it may involve far more imprecision and improvisation than most people realise. Like jazz, the quality of the end-result is an eloquent reflection of the artist’s skill and imagination. Even so, the “flaws” and “wrong turns” of evolution, its wastefulness and attendant suffering entailed by lives cut short or unfulfilled, are either deliberate on the part of God as the meticulous master-painter (implying a lack of love towards creation?), or else they are “accidents” along the way in God’s grand improvisation. I am not sure the latter is greatly preferable to the former. A grinding unprepared discord in a classical improvisation in music, or a random mud-coloured blotch among the pastel shades of an

258

Chapter 8

Figure 8-1. Improvisation in ink and paint. Part A: a marbled endpaper from an edition of the “Poetical Works of John Dryden”, published in 1851 by Edward Moxon, London. Part B shows a mixed-media painting entitled “Lochgoilhead” by Anne Denniss (c. 1978), image © Anne Denniss 2019, used by kind permission of the artist. Part C is focussed on the lower central cottage, which is picked out quite precisely, while in Part D, the hill and sky (top right) are far more improvisatory.

evocative water-colour composition, would both reflect a lack of artistry or command of the medium by the artists concerned. If God composes or paints the whole creation in detail, then our verdict must be uncaringness. If on the other hand God improvises, then the equally devastating verdict must be carelessness. Neither verdict lets God off the hook. I am aware that this is an artificial opposition, leaving many intermediate possibilities unexplored, but it suffices to make an important rhetorical point. It is not as if evolution produces only occasional “mistakes” (like the unprepared discord above) in an otherwise steady progression towards complexity and consciousness. Instead, the majority of mutations prove deleterious—often resulting in disability or death for the affected organism—and only a tiny minority prove beneficial (§ 1.5, 1.6). A closer musical analogy might be a piece of discordant atonal music scattered with moments of brief harmony. One way of cutting the Gordian knot here is the neo-Thomist position advocated by Celia Deane-Drummond (§ 7.4), and also by Denis Edwards (1995), Herbert McCabe and Elizabeth Johnson (2014), among others. In outline, Thomas Aquinas posited God as the unique primary cause—who is the reason why anything exists at all, why there is something rather than nothing. What happens in the world results from the operation of natural laws and a system of creaturely secondary causes involving events and organisms within God’s created order. Since God endows all creatures with their own intrinsic goals and propensities (teleonomies, in Monod’s terms), granting them the freedom and independence to fulfil these, it is perfectly possible for creatures to pursue selfish or even destructive ends without God being held to blame for the waywardness of creation. As

An Evolutionary Theology

259

Johnson (2014, p. 165) points out: “while endowing creatures with their inbuilt natures and ways of acting, God leaves them free to follow the strivings of their natural inclination which aims them toward a natural good. Since all good is a participation in divine goodness, the universe as a whole tends toward the ultimate good which is God.” It is precisely at this last sentence that most scientists baulk and part company with neoThomism. Evolutionary processes (see chapters 1-5), despite their often astonishing outcomes, do not for the most part bear witness to the overarching benevolence and love of God. The good of a hunting lion pride is assured by killing an antelope—but clearly this does not serve any “good” for that antelope, unless we stand back and take a dispassionate ecosystem view, whereby the balance between predator and prey populations takes precedence. That there are indeed numerous examples of co-operation, of commensalism, of symbiosis, of mutual flourishing and even of altruism, simply underlines this objection: their relative rarity marks them out and makes them worthy of special study. So although neo-Thomism absolves God of direct responsibility for natural evil and the vicissitudes of evolution, God is still the prime cause of all that is, and the perversity of free creaturely secondary causes cannot conceal what would seem to be a flawed overall scheme. The only apparent way out of this conundrum is to propose that any less costly arrangement could not hope to be as fecund in terms of the diversity it engenders (§ 7.5.5). Since it is in Jesus’ passion and crucifixion that we glimpse this costliness, shown towards humanity in particular and creation in general, further discussion is deferred to § 8.3.

8.2.5 A self-limited God? Many religious believers hold God to be all-knowing, all-powerful, and unaffected by the passage of time or the travails of creation. The key words here are abstractions—such as infinite, omniscient, omnipotent, immortal, eternal and impassible—words we cannot readily understand except as antonyms to our own human experience as finite, unknowing, powerless, mortal, temporal beings, capable of suffering (and of empathy). An omnipotent God would be in total control of everything that happens in the universe, from the birth and death of galaxies or species to the lifeevents that affect individual humans. It is held that this God will reward the righteous and punish the wicked—such that unmerited suffering must betoken secret sins known only to God (yet the words of Job’s comforters ring hollow in our ears!). If we cannot explain why bad things afflict good people, must we then invoke the unsearchable over-arching purposes of God, within which some seem to suffer undeservedly in order to realise an invisible greater good? Could this even be how evolution realises novelty?

260

Chapter 8

The riddle of evil in general, and of unmerited suffering in particular, is explored cogently by Thomas Jay Oord (2015). If God is omnipotent, why do the prayers of faithful believers for safety or healing so often go unanswered? If God can intervene to prevent human suffering, but refuses to do so, must we then fall back on the inscrutability and ineffability of God’s purposes, or else on hidden sins of the petitioner? Of these, the first is perhaps the most convenient fig-leaf, but offers little comfort, while the second is generally discounted except in strict evangelical circles. If God sometimes chooses to intervene miraculously in the events of this world but often (usually?) elects not to, then the constancy and faithfulness of God can no longer be sustained. Again we fall back on God’s ineffable plan—where prayers that chime in with this are granted, but those that do not will never come to pass. It might be the case that God has no power to affect the course of events, but could such an impotent God merit human worship and loyalty, or effect the resurrection of Jesus Christ? Yet posing the question in that way presupposes that God is some sort of supernatural agent, which is not my assumption or intended inference. Oord’s preferred solution posits a God who voluntarily refrains from interfering in the natural unfolding of events—both in human history and in evolution. This is obviously consistent with neo-Thomist thought (above)—where God, as the prime cause of all that is, does not circumscribe or intervene in the free interactions of creaturely secondary causes in the world. The argument here is that God could intervene (and has done so, uniquely, in the resurrection of Jesus), but has chosen a consistent path of self-limitation—conferring on creation the freedom to be itself, and to evolve according to its own laws, without meddling or tweaking from on high. This stance clearly underlies the naturalistic theology of Arthur Peacocke; indeed, a similarly self-limiting God has been my underlying presupposition throughout this book. In John Hick’s (1966/2010) classic study of theodicy, God is seen as self-limiting in the sense of maintaining an “epistemic distance” between Godself and creation, such that God’s creatures are not overwhelmed by the divine presence and thereby denied the possibility of free-will choices. But if God is not needed to create individual galaxies, stars, planets, life-forms and humans, nor required as fuse-lighter to set everything going in the first place (the deist’s God), nor even as the guarantor of creation to sustain everything in being, then what do Christian evolutionists like myself believe that such an apparently lazy God is actually doing? The key insight—revealed most powerfully in the Johannine books of the New Testament (John 13:34-35; 1 John 4:7-16)—is that God is love. Many writers exploring Christian belief and evolution or the environment have

An Evolutionary Theology

261

also emphasised this fundamental truth of faith: As Johnson (2014, p. 16) puts it: “God is the incomprehensible mystery of love beyond imagining. This insight [is] itself a summary of what the [Nicene] creed confesses”. If this is so, then it is not too far-fetched to believe that God’s love reaches beyond humanity to embrace the whole creation, with all of its “mistakes” and wrong turns. If Christ is indeed the Incarnate Son and second person of the Trinity, then the suffering and death that bedevil creation have been taken up into the Godhead through his resurrection and ascension, as the epicentre of the vast theo-drama proposed by von Balthasar and expanded by Deane-Drummond to encompass evolution also (§ 7.4.3). In those core Easter events lie the deep roots of Christian hope for salvation, not just for individual believers but perhaps for the entirety of God’s creation (§ 8.5). Without arguing the case in any detail here, it is perhaps worth taking this idea of self-limitation a little further. Is God also self-limited in terms of omniscience, knowing only in broad outline how events in the future will unfold? If God knows precisely everything that will happen in the next hour, or in the next year or billion years, then all possible outcomes have already been determined and free will (§ 5.3) is an illusion. Whether this is interpreted in terms of Calvinist double predestination (holding that some are irrevocably bound for heaven and others for hellfire), or of an evolutionary process whose contingency is only apparent, this idea seems to run counter to the impression of experimentation and openness that characterises both human beings and evolution—where people can act out of character and astonishing innovations can arise—sometimes without precedent. But if God’s knowledge of the future is partial, then perhaps God too can be surprised and amazed by unexpected developments? Yet surely this would tie God into chronological real time, thereby resonating with the metaphor of God creating through improvisation, explored above (§ 8.2.4). In such a case, what becomes of eternity and of a God who is “outside time”? Perhaps there is a sense in which God is both immanent within time as well as transcendent beyond it—broadly in line with Arthur Peacocke’s panentheistic view of immanence and transcendence (§ 7.5.2). Process theology, originating from the philosophical writings of Alfred North Whitehead, and developed by Charles Hartshorne, John Cobb and others, makes precisely this point. Although God’s essential attributes (e.g. goodness and love) are immutable and eternal, in other respects God may be open to change in response to developments within the creation over time—a “neo-classical theology of becoming” that seems far more appropriate to evolution than the classical theology of static being (Hartshorne, 1962, pp. ix-x). Process theology emphasises the active

262

Chapter 8

involvement of God within the processes of cosmology, evolution and history—acting primarily as a “lure” towards better outcomes, such as increased complexity, diversity and wisdom (not only in humans). Broadly speaking I can concur with this view, so long as the word lure (which has certain negative connotations!) is replaced by love. Process theology in general adopts the panentheist position embraced by Peacocke (§ 7.5.2), so that it is incumbent on receptive humans to respond to God’s promptings— which are encouraging and inspirational, but never coercive. God has no hands, feet, eyes, ears or minds but ours through which to perceive and act in this world—a view with which I would also agree, although my theology is for the most part more mainstream. An accessible introduction to process thought is given by Mesle (1993)—though this author clearly tends towards a non-theistic process naturalism. That said, the book’s final chapter is contributed by process theist John Cobb (see also Cobb & Griffin, 1976), who argues that bringing God into the picture can vastly enrich its meanings (it is no longer meaningless), thus going beyond the utilitarian values that humanity otherwise ascribes to natural environments. A related issue—to be considered further in § 8.3—is the doctrine of divine impassibility, whereby God can neither be influenced nor moved by created entities. Yet human-like emotions of anger and love are expressed by God in the words of the Old Testament prophets (especially Hosea), suggesting rather the opposite. So too with the gospel portraits of Jesus’ passion and crucifixion, a human being who is also the pre-existent second person of the triune Godhead (Philippians 2:5-11). This theme provides the title of Jürgen Moltmann’s seminal book, “The Crucified God” (1973/ 1974). Yet W.H. Vanstone (1982, p. 93) states bluntly that “God is not passible”—in the sense of being open to manipulation by, or dependence on, persons or events within creation. But Vanstone has already explored the meanings of the English suffix “ible” or “able”, pointing out that this refers “rather to what is to be expected than to what is in fact the case” (ibid., pp 89-90). A person who is rightly regarded as unlovable may nevertheless, against all expectations, find love. So too with God’s impassibility: “Deus non passibilis sed passus: of His own free will and freedom God so acts as to enter into passion. ..…the ultimate glory of God’s creativity is the creation of His own exposure to that which He has created” (ibid., pp. 94-95; male pronoun used as in the original text). Once again we glimpse here a voluntary self-limitation by God, a vulnerability that is not intrinsic to God’s nature, but one that is freely chosen, entered into for creation’s sake. This view is also consonant with process theology.

An Evolutionary Theology

263

8.2.6 A God who waits and lets be I want to voice a slightly different but related theme, by considering creation not as making or commanding something otherwise unrealisable, but as a letting be. In the Hebrew of Genesis 1, God does not issue direct commands using the imperative mood, but rather uses the more subtle and indirect jussive mood—which can carry implied meanings ranging from mild command to strong wish, expressing a desire that something should happen. There is no jussive mood in English, but the use of a qualifying verb in forms such as let there be or may there be adequately conveys the sense. It is in this context that I must risk the ire of Hebrew scholars by suggesting that God may let be at each stage of creation. The volition or strong desire is that each element of creation should fulfil its potential—to “be fruitful and multiply” in the case of all living things, including us humans. The writers of Genesis had no conception of evolution, but perhaps within that italicised phrase there is also a call for life to diversify? The realisation of God’s desire is affirmed in Genesis 1 by the repeated refrain, “God saw that it was good”. Given the centrality of the Word in creation according to Christian theology (John 1:1), God’s repeated words of invocation or invitation in the phrase “Let there be” seem to me to take priority over God’s subsequent actions to realise each stage by creating or making (§ 7.3.2). God can in this sense intend the work of evolution, without intervening to elicit or modify or even restrain each innovation, allowing all to flourish with God’s blessing and, if needs be, forgiveness. There is perhaps a link here to the evangelical doctrine of “effectual call”, as interpreted by Vanhoozer (1998)—providing as he would see it a middle path between classical theism on the one hand and panentheism (§ 7.5.2) on the other. To quote from his conclusion (ibid., p. 250): “In fact, I have followed neither of these paths, preferring rather a communicative theism in which God is a sovereign speaker….. What God says makes a difference, but it would be perverse to describe this difference in terms of impersonal causation. If God’s call must be described in terms of causality, it would have to be of a communicative kind, and hence personal. God comes to the world in, and as, word. To be precise, God relates to the world with both ‘hands’: Word and Spirit.”

This also echoes God’s words in Isaiah 55:11 (NRSV): “so shall my word be that goes out from my mouth; it shall not return to me empty, but it shall accomplish that which I purpose, and succeed in the thing for which I sent it”, and in 45:23:“By myself I have sworn. From my mouth has gone forth in righteousness a word that shall not return: ‘To me every knee

264

Chapter 8

shall bow, every tongue shall swear’”—words re-echoed in Paul’s hymn to Christ’s kenosis (Philippians 2:10-11; § 8.3.2). God’s calling to human beings and invitations to creation do not return unanswered or unresponded to—even if some choose to ignore the call or to decline the invitation. If we interpret the days of creation as a literary device rather than literally (as even Berry concedes; § 7.3.2), then we can perhaps envision a God who waits patiently for the fulfilment of the inherent potentials in the star-dust of which all planets and all life is made. I would see this as an expansion of Vanstone’s insights expressed in “The Stature of Waiting” (1982), which explore the crucial move from activity to passivity (passion) when Jesus was “handed over” by Judas. Vanstone (ibid., pp. 104-105) cites inter alia the patience of a naturalist waiting to observe a rare animal, anticipating joy or risking disappointment as time wears on. I know that feeling well myself from many, often fruitless, plant-hunts! Similarly, a scientist may look forward with bated breath to the outcome of a crucial experiment—perhaps one that will confirm or refute some key hypothesis (§ 1.1). Again I know that feeling well from many years of experimental research. Perhaps this image can help us picture a God whose love for creation is neither coercive nor imperious, but who waits patiently and longingly for God’s best desires to be fulfilled in the fullness of time. It took the first germs of life on earth >2 billion years to attain multicellularity, generating animals that emerged in the Ediacaran and Cambrian (§ 3.1, 3.2), and another half billion-plus years before the dawn of human consciousness made it possible for Homo sapiens (and other hominins?) to experience encounters with Godself. But mere passage of time does not try the patience or the eager anticipation of the God who waits, in whose sight “a thousand years.….are like yesterday when it is past, or like a watch in the night” (Psalm 90:4, NRSV). But if God can still be surprised at what arises through improvisatory evolutionary processes, there must have been wonderful eureka moments along the way, celebrated in the very good of day 6 in Genesis 1:31. Yet setbacks, griefs and disappointments must also have abounded—moments when a promising new development was snuffed out prematurely (whether through its own inefficiency, natural disaster, mass extinction or sheer bad luck) or when an auspicious innovation turned toxic or malign. God’s selflimiting choice not to interfere or meddle must have seemed an irksome constraint at times! Despite theology’s traditional insistence on God’s impassibility (above), dare we speak of a God who sympathises (Hebrews 4:15) or even suffers with the frustrations, struggles and pain entailed by this costly evolutionary process? This is the pattern we see lived out in the

An Evolutionary Theology

265

incarnation, ministry, passion and death of Jesus Christ, but it is a pattern crowned and redeemed by his resurrection, affording hope not just to human beings but to all creation (see § 8.5). Such a God might be said to create possibility, and then to let that possibility be (indeed, to let all possibilities discover their being in the fullness of time). This view of “God’s act in creation as the gift of possibility” and freedom, is explored in greater depth by Ruth Page (1996, p. xviii; pp. 1-38). Such a God interacts with creation, not by exerting divine power imperiously, but through restraint and self-limitation, through the gentle persuasion of love offered freely and without coercion in a context of relationship (ibid., pp. 52-58). For humankind, we have some inkling of what relationship with God might entail—though this has been viewed in a multiplicity of different ways through history. But for animals, let alone plants or microbes or nonliving matter, we have no idea what this might mean. Science gives insight into the multifarious teleonomies of creatures, and philosophical theology may infer creaturely logoi in relation to the divine Logos, yet none of this enables us to know each creature from the inside (but see Foster, 2016)— as God must surely know it. “The individual organism in its individual conditions, no matter how limited these look from a human point of view, is the outcome of God’s gift of freedom and the subject of God’s love” (Page, 1996, p. 71). The relationship of God with creation is adumbrated in Page’s usage of the term pansyntheism, suggesting that “God is with…. everything and everyone, in a way which preserves divine and creaturely freedom, but connects them in divine love seeking response” (ibid., p. 40; pp. 40-52). This relationship is best described as God companioning (literally, sharing bread with) the whole of creation—which entails paying close attention to its details (concurrence, in Page’s terms), a trait we see exemplified by Jesus in gospel stories such as the widow’s mite (Mark 12:41-44)—seeing through all merely superficial appearances. Companion signifies the loving presence of God alongside all creatures, irrespective of their awareness of, or response to, that presence. Much of Page’s book is concerned with what it might mean for humans to “companion” the natural world in non-exploitative and non-directive ways, modelled on how God relates to the whole creation, made manifest in the life and words of Jesus. For Page, companioning takes priority over, and so informs, other human roles in relation to nature, such as stewardship, priesthood or co-creation (ibid., pp. 152-168). We will return briefly in § 8.5 to her thoughts on what aspects of non-human nature might ultimately be redeemed by God. Since God’s gift of possibility to creation encompasses all possible outcomes, even natural evils, then nothing can happen that is outside the will of God. My contention is that God embraces all creation in love, so I would concur

266

Chapter 8

with Steve Chalke (2019, pp. 105-117) that biblical phrases translated as the wrath or anger of God are better understood as expressing God’s deep anguish and pain at our persistent rejection of God’s ways and guidance.

8.3 Jesus, the Christ 8.3.1 Encountering Jesus: incarnation, baptism, resurrection Jesus the Christ (= Messiah, or Saviour) embodies the distinguishing belief that defines Christians, however much we may differ in how we interpret his words and deeds. While many lapsed or non- Christians might agree that Jesus was a great teacher and a re-interpreter of the traditions of Judaism, they part company with mainstream Christianity over the divine status ascribed to Jesus as the second Person of the Triune God. They would also dispute the Virgin Birth (§ 7.3.5) and the bodily resurrection of Jesus—seen as unprovable inventions concocted by the church to bolster its implausible assertion of the divinity of Christ. These issues will be examined in greater detail below. Nevertheless, as explored in § 8.3.2, this divine status was claimed for Jesus very early on—within 20 years of the crucifixion—since Paul places Christ on an equal footing beside or within the Father. Out of this, combined with veneration of the Holy Spirit, sprang the doctrine of the Trinity (§ 8.4), which is an equally distinctive and hotly disputed feature of Christian faith, though it did not emerge till much later. The word “immediately” or “straight away” (Greek eutheos) occurs no less than 40 times in Mark’s brief gospel—11 times in chapter 1 alone— compared to 15 occurrences in Matthew, 8 in Luke and 4 in John. Mark plunges straight in with the bold claim that this is “The beginning of the good news of Jesus Christ, the Son of God” (Mark 1:1, NRSV), followed by John the Baptist (vv. 3-8) and the baptism of Jesus in the Jordan (vv. 911), with a passing nod to his temptations in the wilderness (vv. 12-13). By verse 14, we arrive—breathlessly—at the start of Jesus’ ministry in Galilee, proclaiming the good news of God, and saying “The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news” (v. 15, NRSV). There are no preliminaries in Mark—no birth narratives or genealogies as in Matthew or Luke, nor any theological prologue as in John 1. This emphasis on immediacy—so characteristic of Mark’s gospel (which is also the earliest)—provides a vital clue to the enduring appeal of Jesus. Encountering him in our lives and in the gospels is how we come to accept the impossible claims made by him and about him, echoing the centurion who confessed—“Truly this man was God’s son!” (Matthew 27:34). There is a real sense of urgency in Mark—the time

An Evolutionary Theology

267

to make a choice and commit oneself is now, not after sober consideration and acquiescence (cf. Luke 9:59-62). One corollary of this is that many choose to step back from the brink and refuse the open invitation offered. It is true that paradoxical claims are made by Christians about the divinity of Christ—both fully God and fully human, about his incarnation as a human baby, and above all about his resurrection from the dead. For many, these claims beggar belief; how could any rational person subscribe to them? I can understand these objections and the questions they imply, without necessarily being able to offer a fully logical defence of my faith. Like Lewis Carroll’s White Queen (“The Annotated Alice”, 1965/1970, p. 251), I find myself “capable of believing in as many as six impossible things before breakfast”: the Trinity (that’s 3 for a start), the incarnation and resurrection of Jesus (2 more), and the hope of salvation for the whole creation. Contra Peacocke (§ 7.5), I find myself unmoved by “naturalistic” interpretations of Jesus’ incarnation, or of his resurrection as a “spiritual” experience—which lacks the galvanising power of his bodily appearances to the first disciples, so vividly attested in the New Testament. I will look first at key aspects of these birth and resurrection stories, before arguing in § 8.3.2 that Jesus was already honoured and worshipped as the Son, within or alongside the Father, by the early churches to whom Paul was writing. On the incarnation, the historical accuracy of Matthew’s and Luke’s (very different) accounts is highly questionable. Even so, they contain many details that are thoroughly consistent with the personality of Jesus as revealed in the body of all four gospels, and indeed in the Pauline epistles. Luke 1 tells the background story of John the Baptist as well as Gabriel’s annunciation to Mary, whereas Matthew 1 deals mainly with God’s justice towards Joseph. Luke 2 has a Roman census (possibly held in 6 CE?), the journey to Bethlehem, plus angels and shepherds—whereas Matthew 2 has the Magi, the massacre of innocents by order of Herod (died 4 BCE), and the flight into Egypt. The only details on which both accounts agree are that Jesus was virgin-born (conceived through the Holy Spirit), and that his birth took place in Bethlehem. We have already looked at the first of these from a biological viewpoint in the previous chapter (§ 7.3.5). But this misses the theological point: Jürgen Moltmann (1989/1990, p. 82) asserts that “The narrators’ aim [in Luke and Matthew] is not to report a gynaecological miracle. Their aim is to confess Jesus as the messianic Son of God and point at the very beginning of his life to the divine origin of his person.” In both Matthew’s and Luke’s accounts, the Christ-child is acclaimed—by Magi and a star in Matthew, or by angels (hosts of heaven) in Luke. This is vividly counterpointed against the vulnerability of Jesus’

268

Chapter 8

family situation at the time of his birth: “no room at the inn”, but only a stable in Luke; or jealous Herod wreaking vengeance on infant boys in Bethlehem, forcing Joseph to flee with Mary and Jesus to seek asylum in Egypt, according to Matthew. Even if these stories are later pious legends, they still convey important pointers to the future ministry of Jesus. Though worthy of lavish gifts and worship (the Magi), and of the angels’ song of praise (Luke 2:14), the God incarnate in Jesus Christ does not stand on ceremony, but is content (even proud?) to be born in a stable manger rather than a kingly palace. It goes deeper even than this: in the circumstances of his birth, Jesus self-identifies with the homeless sleeping rough in stables or barns; with the hard-working, down-trodden poor (shepherds, present at the stable by angelic invitation); and with refugees driven far from home by oppression in their home countries. As we shall see later, in all four gospels Jesus scandalises the priests, the scribes and the Pharisees by associating with tax-collectors and sinners, with women and children, with the sick, the unclean, the mentally ill, with Samaritans and even Romans. This future course was set irrevocably right from the time of Jesus’ birth. In Moltmann’s view, the decisive point in Jesus’s earthly life is his baptism by John in the river Jordan (compare parallel synoptic accounts; §1-6 in Throckmorton, 1992, pp. 11-14; John 1:29-34). The Holy Spirit descends on Jesus like a dove, filling him with divine power to an extent unparalleled among the Old Testament prophets or even John the Baptist. It is in this power of the Spirit that Jesus testifies, teaches and heals others throughout his ministry (Moltmann, 1989/1990, pp. 87-94). This is close to Peacocke’s view of Jesus as born naturally to human parents, but whose transparency to God allowed him to be singled out for this unique infusion of the divine Spirit. Moltmann’s view entails a kenosis or outpouring of the Holy Spirit, both moulding and empowering Jesus from his baptism onwards (ibid., pp. 91-94). In a sense, this view seems adoptionist (where Jesus is “adopted” as God’s Son), but as Moltmann also points out (ibid., p. 142), “the fact that the Spirit descends on Jesus at his baptism does not for them [Matthew and Luke] mean that the Spirit did not already act in him previously”. Luke 2:40 and 52 testify that Jesus grew in wisdom and in God’s favour throughout his childhood. It takes little psychological insight to realise that full consciousness of his divinity or of God’s unique mission for him would have overwhelmed the infant or even adolescent Jesus; these are roles he had to grow into and consciously accept, which is what we see at his baptism. Therefore, this “adoption” does not in itself contradict his pre-existent divinity; it can be viewed as the culmination of a voyage of self-discovery. What marks out Jesus’ relationship with God

An Evolutionary Theology

269

is its closeness, hence his use of Abba: not a formal Father but an intimate Daddy (ibid., pp 142-146; cf. Mark 14:36; Romans 8:15; Galatians 4:6). The resurrection narratives in the gospels are fragmentary, elusive, numinous and hard to pin down. Even so, several commonalities link all 4 accounts: the tomb of the crucified Jesus is found empty at dawn by Mary Magdalene, alone or with other women. One or two men—or angels—in white announce (or infer, in John) the resurrection and issue an instruction to go and tell the disciples; this is given (John) or reiterated (Matthew) by the risen Jesus himself. Given this congruity, it is surprising that there is no mention of the empty tomb story in 1 Corinthians 15:3-7, which is Paul’s summary of the tradition passed on to him by the apostles, probably written a mere 20-25 years after the crucifixion. Paul does mention several resurrection appearances to the disciples, and also to a much larger group (>500), but only some of these recur in the gospels. What we have instead is a series of vignettes unique to each gospel—apart from Mark, who hints at, but does not describe, such an encounter in Galilee. Matthew 28:16-20 locates this on a Galilean mountain-top, where Jesus issues the Great Commission. Luke 24:13-33 tells of the risen Christ (incognito) meeting with Cleopas and a nameless disciple on the road to Emmaus; pressed to stay with them, Jesus is recognised only when he breaks bread and shares it, whereupon he vanishes. They hasten back to Jerusalem, only to find that Peter has already met with the risen Jesus. Then Jesus himself appears among the disciples, invoking peace upon them and assuaging their doubts and fears (Luke 24:34-43). This is followed by Luke’s version of the Great Commission (set near Jerusalem, not in Galilee) and Jesus’ final ascension into heaven (vv. 44-51). John 20:19-29 doubles these appearances in Jerusalem, first to 10 disciples on Easter day (minus Thomas; § 6.9), and then to all 11 a week later—reproving Thomas for his doubts. But John follows this in chapter 21 with a Galilean appearance by the Sea of Galilee to 7 disciples, who have reverted to their former trade of fishing. In John 21:13 Jesus offers bread and fish, recalling the feeding of the 5000 (John 6:1-14 and parallels). John 21:15-19 tellingly redeems Peter’s three denials of Jesus with three affirmations of his love, in response to which Jesus enjoins Peter three times to feed (or tend) my sheep (or lambs). What are we to make of this medley of stories that partly corroborate and partly contradict one another? There is surely a core of truth here, even if overlaid by faulty memories or later embellishments. But the idea that these resurrection accounts arise out of a fraudulent conspiracy in the early (or even later) church is frankly ludicrous. If this tale had been concocted after the event, one would have expected far greater consistency between

270

Chapter 8

the different accounts; in court cases, that is what most often betrays collusion between defendants (or witnesses) in false testimony. Moreover, the resurrection appearances in the gospels (though not the empty tomb tradition) are confirmed by the much earlier epistles from St. Paul, particularly 1 Corinthians 15. Something clearly happened after the death of Jesus that emboldened a group of leaderless disciples and transformed a zealous persecutor of the infant church (Saul) into one of its most ardent advocates (Paul) (Acts 9:1-19a). Some have argued that these resurrection accounts became more elaborate as the first century CE drew to a close— scarcely featuring in the earliest gospel (Mark), slightly more developed in the next-oldest (Matthew), but with detailed additional accretions in the later gospels of Luke and John. But it is the empty tomb that features in all four gospels, yet is absent from 1 Corinthians 15, whereas the resurrection appearances attested by Paul feature mainly in the later gospels. Similarly, the testimony of the women is not mentioned at all by Paul, possibly because women were not regarded as reliable legal witnesses at that time (they were perhaps airbrushed out, according to Tom Wright). If so, why were they “invented” as unconvincing witnesses by all 4 gospel writers? More plausibly, the evangelists recorded deep-rooted oral traditions dating back to eye-witness accounts of disciples present in person at these events. Exactly what was involved in the “appearances” attested by Paul and elaborated in three of the gospel accounts is a matter for speculation, since they evidently ceased at a relatively early date—perhaps after the coming of the Spirit at Pentecost, or perhaps as late as Saul’s Damascus road experience. Though the physicality of the risen Christ is stressed by Luke and John, this does not feature in Paul; indeed, Moltmann (1989/1990, pp. 215-227) suggests that this may be an early interpretation of essentially unrepeatable and indescribable phenomena. Near the end of 1 Corinthians 15 (v. 44, NRSV), Paul writes of a dead person that “It is sown [i.e. buried] a physical body, it is raised a spiritual body”—but he does not specify what distinguishes these two forms. The fact that the risen Christ was not recognised initially by most of the witnesses (notably Mary Magdalene and the Emmaus road disciples) suggests at the very least that he was changed—not the crucified Jesus restored to physical earthly life (like Lazarus), but rather a glimpse or vision of “Christ in glory”. Even as late as the Great Commission, Matthew 28:17 concedes that some doubted. For most Christians (but not all) this is evidence enough for the resurrection of Jesus, though it can never constitute a rigorous scientific proof. Suffice it to say that no convincing Popperian falsification of Jesus’ resurrection has been demonstrated to date, despite numerous alternative suggestions. Most objections simply boil down to the assertion that “dead people don’t come

An Evolutionary Theology

271

back to life”. True enough—unless (as most Christians believe) Jesus was indeed God incarnate. As for the promised general resurrection of the dead, this clearly appertains to the fulfilment of God’s new creation, considered in § 8.5 below. Christ is above all the first-fruits from the dead.

8.3.2 The divinity and kenosis of Christ It is sometimes argued that the divinity of Christ is a late invention that only became possible within a Greek philosophical context in Roman colonial cities, and that this would have been unthinkable within the fiercely monotheistic Jewish culture that held sway in Jerusalem—and by implication, in the Jerusalem church founded by the apostles. This view is strongly contested by the late New Testament scholar, Larry Hurtado, who has summarised his own key arguments in “Honoring the Son” (2018). He emphasises firstly the importance of worship and participation in the religions of the ancient world—which for the most part tended to be syncretic and inclusive (ibid., pp. 19-26), by adopting and incorporating foreign gods into their pantheon rather than focussing on particular beliefs about them. A second point emphasised by Hurtado (ibid., pp. 27-41) is the exclusivity of ancient Jewish monotheism, taking its cue from the First Commandment (Exodus 20:2-5). Jews, and later Christians, were treated with suspicion and persecuted by the Romans, because of their vehement insistence on exclusive worship of the “one true God”. Official permission allowing this had been granted to Jews in the Roman empire, but did not automatically extend to Christians. This difference marked them out as other—as people who refused to associate or eat with other groups, let alone participate in the idolatrous worship of their gods. In particular, they singled themselves out as people who would not make obeisance to the “divinised” emperors. Little wonder they attracted intermittent persecution in the Roman empire, until the Emperor Constantine’s Edict of Milan in 312 CE proclaimed toleration of Christianity, later adopted as the empire’s official religion by Emperor Theodosius’ Edict of Thessalonica in 380 CE. Given this context during the crucial first century of Christian faith, the prominence and evident veneration given to Jesus alongside God the Father in Paul’s writings suggests a strong mutation of Jewish monotheism within the earliest Christian tradition, a mutation that had become “fixed” by the time Paul came to write his epistles (Hurtado, 2018, pp. 42-50). Wright (2018, p. 400) prefers the word within to alongside, consistent with Paul’s strict monotheism. Detailed examination of the Pauline corpus—generally recognised as the earliest extant Christian writings and dating from c. 4865 CE—reveals a wide range of phrases that seem to place Jesus Christ

272

Chapter 8

alongside (or within) God the Father as equally deserving of worship and veneration by Christians. Examples include the opening salutations in 1 Corinthians 1:3 and 2 Corinthians 1:2; “Grace and peace to you from God our Father and the Lord Jesus Christ”, where grace and peace find their joint source in both. Many similar examples could be adduced, as explored by Hurtado (2018, pp. 51-64) and in greater depth in his many other books on this topic. This “dyadic” pattern is wholly remarkable and is unique to the Christian church that emerged within (and later broke away from) Judaism after the crucifixion of Jesus. Nothing remotely similar has been found, for instance, among the Dead Sea scrolls from Qm’ran attributed by many to the Essene sect—apart from a single much-contested mention of a “Son of God” in a scroll fragment (4Q246) sometimes known as the “Aramaic Apocalypse”. These dyadic forms are far commoner in the Pauline epistles than are fully Trinitarian formulations (§ 8.4.1). Hurtado’s conclusion (ibid., p. 68) is phrased with proper academic caution, but is nevertheless striking: “….the decisive step in treating Jesus as sharing in some way in divine glory and status was taken remarkably early, and was expressed both in Christological rhetoric and….distinctively....in this dyadic devotional pattern.” By the time Paul wrote the first of his letters (Galatians, perhaps in 48 CE), Jesus had been crucified only 15 years earlier, yet already in Galatians 1:3 we see the familiar dyadic formula “Grace to you and peace from God the Father and the Lord Jesus Christ”. This pattern is also seen elsewhere in Galatians (1:1 and 3:26). Far from being a doctrine developed much later by the church after it had become established in Greek-speaking areas of the Roman empire, the divinity of Christ seems to be almost a presupposition, perhaps originating from the tradition passed on to Paul by the Jerusalem disciples (1 Corinthians 15:3). It is in this context that we can turn to the self-emptying of Jesus Christ—his kenosis—expressed most succinctly by Paul in his later (55-60 CE) Epistle to the Philippians (2:5-11). The key verses here are 5 to 8 (NRSV): “….Christ Jesus, who, though he was in the form of God, did not regard equality with God as something to be exploited, but emptied himself, taking the form of a slave, being born in human likeness. And being found in human form, he humbled himself and became obedient to the point of death—even death on a cross.” These verses capture the kernel of Paul’s theology forged during his Ephesus imprisonment (Wright, 2018, p. 273). But the translation of this passage is problematic; how are we to interpret the phrase “in the form of God” (Greek en morphe theou)? An online search using the English phrase produces multiple entries from Unitarian and Christadelphian sources arguing that these words can only mean that Jesus was not truly God, and thus contradict traditional Christian

An Evolutionary Theology

273

belief in the Trinity! In contrast, a search using the Greek phrase confirms that it is properly translated as “by his very nature, God”, citing in support other instances of morphe in the New Testament. Even more controversial is the Greek word harpagmos (NRSV, something to be exploited), whose exact meaning remains unclear because it occurs almost nowhere else in Greek sources, other than in commentaries on this very passage. In other translations, this is rendered as a thing to be grasped, as something to be used for his own advantage, as something to be held on to, or even as “a grasped thing”—as in the Authorised Version phrasing of the entire clause as [he] “thought it not robbery to be equal to God.” Varying theologies lie behind these different translations. Wright (1986) examines the Greek syntax in detail and critically compares the different translations and their theological implications, arguing (pp. 345-346) that “the pre-existent son regarded equality with God not as excusing him from the task of (redemptive) suffering and death, but actually as uniquely qualifying him for that vocation” It follows that “Calvary reveals the truth about what it meant to be God…..incarnation and even crucifixion are to be seen as appropriate vehicles for the dynamic self-revelation of God”. That, in a nutshell, is what I mean in this book by a kenotic God. In the gospel of John, there is a further development of this equality between Father and Son—claiming an unprecedented level of identity: “The Father and I are one” (10:30); “Anyone who has seen me has seen the Father” (14:9b); “Believe me that I am in the Father and the Father is in me” (14:11). According to Wright (2012, pp. 90-104), the synoptic gospels see Jesus as God returning in person to his people, and therefore as the culmination of God’s promises in the Old Testament. The idea of such equivalence between Christ and God the Father was further developed in the 4th C CE church Councils that enunciated the doctrine of the Trinity, recognising the Holy Spirit as co-equal alongside the Father and the Son (§ 8.4 below). It is not that all three Persons of the Trinity are identical; they are each distinct, yet united in love and purpose, all sharing the same essential characteristics. The point I wish to draw from this is that the kenosis, humility and suffering of Jesus Christ imbue the Father and the Spirit also, taken up into Godself by the Son’s ascension or more plausibly as eternal aspects of the triune Godhead. The nature of the Son, evinced in all four gospels, is also true of the Trinity as a whole. As mentioned above, Moltmann (1989/1990) views the Spirit-filled Jesus as a “kenosis of the Divine Spirit” throughout his kingdom-focussed ministry. It follows that this same ministry was imparted to the apostles through the Holy Spirit at Pentecost (Acts 2:1-41), and so comes at length to fallible Christians in the 21st C CE. Southgate (2008, p. 59) points to von Balthasar’s claim that it is

274

Chapter 8

the “self-emptying love (kenosis) of the Father in begetting the Son that creates the possibility that other selves can be formed.” But an important caveat must be voiced here. In the self-emptying of Jesus Christ, what is being given up? In many writings on kenosis, there is an underlying assumption that Christ—as second person of the Trinity— gave up some or all of his divine attributes in order to become “merely” human: a vulnerable baby, an adult knowing toil, rejection, suffering, and death. Surely such experiences are impossible for an impassible God? But this assumption runs counter to the Chalcedonian definition (451 CE) of Christ as both fully divine and fully human—two natures within one hypostasis. Kenosis, as described above, would surely make Jesus more human than divine? But this problem is peculiar to Western Christianity; in Eastern Orthodox theology, kenosis does not involve any diminishment of Christ’s divinity. Rather it involves surrendering the selfish will that characterises humanity, replaced by openness and obedience to the Father’s will. It is in this sense that the humanity of Jesus becomes the second, perfected Adam, the one who refuses the original sin of disobedience (1 Corinthians 15:22). [I am grateful to the Ven. Simon J. Lumby SOSc for sharing these insights.] This comes close to Peacocke’s view of Christ as the one who was transparent to the transforming love of God (§ 7.5.2)—but without losing his pre-existent divinity along the way.

8.3.3 The kingdom announced: paradox, preaching and power In “How God became King” (2012), Tom Wright challenges the way Christians of all traditions have elided much of the content of the gospels by focussing overmuch on the incarnation, death and resurrection of Christ. We buttress these by selectively quoting from Jesus’ words and actions, rather than allowing his ministry to challenge us in its entirety, afresh and in context, the way that his audiences and disciples would have experienced it 2000 years ago. It is true that in so doing, we mirror Paul’s focus on the cross and resurrection of Christ rather than on his teaching. This is even more true of the historical creeds, which omit any mention of the ministry, words or works of Jesus (ibid., pp. 5-39). Moltmann (1989/ 1990, p. 150) even dares to suggest adding 7 lines into the Nicene and Apostles’ Creeds, outlining the ministry of Jesus between his incarnation and crucifixion (also Wright, 2012, p. 63; Rohr, 2019, p. 103 ff, The Great Comma). Wright (2012, pp. 41-57) identifies six prevalent but inadequate answers to the question of what the gospels are about: (i) getting us to heaven, (ii) Jesus as ethical teacher, (iii) Jesus as moral exemplar, (iv) Jesus as the perfect sacrifice for sin, (v) providing stories Christians can

An Evolutionary Theology

275

identify with, and (vi) offering proofs of Jesus’ divinity. While there are elements of truth in all of these, even adding them together still misses the point. As Wright (2012, 90-104) sees it, Jesus embodies the Old Testament prophecies about God returning to his people. Following on from this, the gospels present us with the central claim that “the story of Jesus is the story of how Israel’s God became king” (ibid., p. 38). I find myself slightly uneasy about endorsing this statement as it stands, mainly because of the baggage associated with that key word king. For if Jesus was indeed the fulfilment of Old Testament promises, the manner in which those hopes played out in the life of Jesus was not at all what his contemporaries were expecting, affording partial mitigation of the disciples’ apparent slowness to understand (Luke 24:25). As explored below, Jesus’ teachings stand all our assumptions about power and glory on their heads; neither the kingdom Jesus proclaimed, nor the kingship manifested in his earthly life, bears any resemblance to our secular ideas of leadership or authority. It is impossible to attempt anything like an overview of the teaching of Jesus in one chapter of this book. What I shall highlight are just a few of the phrases and parables that overturn human expectations. Doubtless such paradoxes were intended for rhetorical effect—among the disciples, the religious leaders, and the uncomprehending crowds—but we should also pay attention to what they clearly imply about the nature of the God who speaks to us through the voice of the Son. Luke 4:16-21 tells how Jesus, filled with the Spirit, comes into the Nazareth synagogue and reads out a passage from Isaiah (61:1-2a), proclaiming good news to the poor, release to the captive, recovery of sight to the blind, and freedom to the oppressed. These signs usher in the year of the Lord’s favour, signifying the Jubilee year, but re-envisioned as God’s kingdom drawing near. Then Jesus makes the astonishing claim: “Today this scripture has been [is] fulfilled in your hearing” (v. 21) Note the tense here; this is a fait accompli, in the strange yet familiar person of a local carpenter’s boy, the son of Joseph. The kingdom is already here and yet still to come, both realised in the present and awaiting final fulfilment in God’s new creation. Jesus’ ministry is filled with signs of this kingdom. As Wright (2012) emphasises throughout his book, the kingdom is also inextricably interwoven with the crucifixion, so that Christ’s victory on the cross actually ushers in God’s new kingdom. What marks out Jesus’ teaching in all four gospels is its radical challenge to received wisdom, to custom and privilege, to political and religious domination, and to much that we have been taught about what is beautiful or admirable in other human beings or in the wider creation. In this respect, Jesus’ teaching is also echoed by Paul, who emphasises that

276

Chapter 8

“God’s foolishness is wiser than human wisdom, and God’s weakness is greater than human strength” (1 Corinthians 1:25). This could be seen as a purely rhetorical device, emphasising that God is incomprehensibly greater, wiser and stronger than any mere human, but based on the Greek constructions used, Barrett (1971, p. 56) insists in his commentary that “What God has done in Christ crucified is a direct contradiction [my emphasis] of human ideas of wisdom and power, yet it achieved what human wisdom and power fail to achieve.” Despite its freshness and spirit of radical challenge, Jesus’ teaching does not spring fully formed out of nowhere: it echoes Yahweh’s concerns in the Old Testament for the widow, the orphan, and the alien in your midst, and lives out the Suffering Servant songs of Isaiah (42:1-9, 49:1-7, 50:4-11, 52:13-53:12). The ministry of Jesus calls the people of Israel back into a proper relationship with God, rather than intentionally founding a new religion centred on himself. Perhaps the greatest exposition of the counterintuitive values of the kingdom is the Sermon on the Mount, comprising Matthew chapters 5 to 7, and summarised (on the Plain) in Luke 6:20-49. The first thing to note is the pre-eminence given to those who counted for nothing in the firstcentury world, or indeed in that of today: the poor and oppressed, the blind and hungry, the prisoners, and those who mourn. As for the rich, they have their consolation now (Luke 6:24), just as the religious hypocrites who indulge in ostentatious almsgiving and prayer (Matthew 6:1-4) have their reward already (cf. Mark 12:38-40). This is a group of texts we will return to in the next chapter, looking at them in an evolutionary context. Jesus here reiterates the Old Testament core theme of God’s concern for the poor—enshrined in the Mosaic Law and reiterated by the prophets. Of course, this “Bias to the Poor” (Sheppard, 1983) can become either a spur to action for social justice—which is very much the focus of Sheppard’s book—or else an instrument of social oppression, where clerics encourage disadvantaged people to accept their lot in this life with a glib pie-in-thesky promise of plentiful rewards in the afterlife. Moltmann (1989/1990, pp. 94-116) takes Jesus at his word in the first Beatitude: “Blessed are the poor [in spirit], for theirs is the kingdom of heaven” (Matthew 5:3). The poor, the suffering and the meek are founder-members of God’s kingdom; although this fact may not improve their material lot in this world, it does confer on them a new dignity and potential for co-operation and solidarity, which are key emphases in South American liberation theology. The rich, by contrast, are called to conversion if they desire to join God’s kingdom, and this will exact a heavy toll that may either be embraced (as with Zacchaeus: Luke 19:1-10) or declined (as with the rich young man; Luke 18:18-23). In the same way, those who are deemed unclean through illness

An Evolutionary Theology

277

or sinners through non-observance of the Mosaic Law are precisely those whom Jesus heals or eats with or forgives. By contrast, the influential and rich—the worldly powers-that-be—have always defined poverty, physical or mental illness, and standards of right or wrong behaviour in such a way as to place themselves (self-justifyingly) in the right, whilst placing those with whom Jesus associates in the wrong. The kingdom of God inverts this warped perspective, which is what the Beatitudes are all about. Jesus’ story of the Pharisee and the tax-collector (Luke 18:9-14) makes the point. But there is also a radical challenge in Jesus’ take on the Mosaic Law, which he came not to abolish but to complete (Matthew 5:17). Through the remainder of Matthew 5, Jesus repeatedly says (vv. 21, 27, 31, 33, 38 and 43) “You have heard it said” or “It was also said”, introducing his summary of one of the Law’s key commandments. In every case, this is followed by a more stringent injunction to a higher standard of behaviour. Not only should we refrain from murder, but also from harbouring anger (vv. 21-26); not only abjure adultery and divorce, but also lustful thoughts (vv. 27-32); likewise, our word should be our bond, without swearing by heaven or earth (vv. 33-37); we should not resist those who do us evil, let alone repay them in kind, but should act with generosity towards them (vv. 38-42). Most challenging of all, we should love our enemies and pray for those who persecute us (vv. 44-46), following the example of our Father in heaven whose providence encompasses both evil-doer and righteous alike. These resonant phrases appear to set an impossible standard for Christians; even the greatest saints struggled with failure, sin, temptation and falling short of the mark. I am sure Jesus knew we would fail time and again, yet by aspiring to these ideals we may sometimes rise up to them and mirror glimpses of the love and forbearance that God shows us through Jesus. In the Lord’s Prayer, we ask the Father to forgive our sins, even as we forgive those who sin against us (Matthew 6:12). But in this attempt to reach beyond our frequent failings, we are not alone—for this is where the community of fellow-believers (the church; § 8.4) can provide solidarity. Another theme repeated throughout all 4 gospels concerns the exercise of power. After Christ’s baptism, the Holy Spirit drives him out into the wilderness to be tempted by Satan. The substance of these temptations, as described by both Matthew (4:1-11) and Luke (4:1-13), is to seize the kingdom through exercising worldly (i.e. Satan’s) power. Jesus’ rejection of this path is most tellingly encapsulated in John’s description of him washing the disciples’ feet (John 13:1-16)—explaining his own actions by saying “You call me Teacher and Lord, and you are right, for that is what I am. So if I, your Lord and Teacher, have washed your feet, you also

278

Chapter 8

ought to wash one another’s feet” (vv. 13-14, NRSV). Foot-washing in those days was a menial task for low-ranking slaves—given that town streets were often open sewers, and sandals provided inadequate protection for the feet. This symbolic act (no mere gesture) would be extraordinary enough if undertaken by a great human teacher, but if (as Christians believe) Jesus was truly God incarnate, then it simply beggars belief. Indeed, this enactment of Jesus’ (and thus God’s) humility becomes even more staggering when we realise that the betrayer Judas Iscariot was still among the 12 at this point (making his exit only at v. 30); therefore, by implication, he must have had his feet washed along with the other 11. This action is mirrored by a phrase repeated in all of the synoptic gospels, that “the first will be last and the last, first” (Matthew 19:30, 20:16; Mark 10:31 and Luke 13:30). This trips glibly off the tongue, making us deaf to its radical implications. Jesus’ teaching, here and elsewhere, pits the new reality of God’s kingdom against the earthly power of the Roman empire. As Wright (2012) reminds us, Caesar had arrogated to himself the title Son of God, which by right belonged only to Jesus as God’s anointed Messiah. The clearest confrontation between these rival kingdoms runs through the trial and crucifixion of Jesus as described in the gospel of John. The high priest Caiaphas and the council have handed Jesus over to Pilate, the Roman governor. Knowing that accusations of blasphemy will cut no ice among Romans, the nub of the case they put forward is that Jesus claimed to be king of the Jews. Naturally, Pilate begins his interrogation by posing that claim as a question. Jesus does not answer directly until Pilate admits ignorance as to why Jesus is before him on capital charges—“I am not a Jew, am I?” Jesus’ reply (John 18:36a) is usually translated “My kingdom is not of this world” (KJV, NIV etc), or more accurately “My kingdom is not from this world” (NRSV). After all, the Lord’s Prayer asks that God’s kingdom may come….on earth, as it is in heaven. Wright (2012, pp. 228231) firmly shuts the door on any lazy interpretation of God’s kingdom as other-worldly, translating John 18:36a as “My kingdom isn’t the sort that grows in this world” (ibid., p. 229). Jesus is not trying to bring in God’s kingdom by force: “If my kingdom were from this world, my followers would be fighting to keep me from being handed over to the Jews. But as it is, my kingdom is not from here” (John 18:36, NRSV). Pilate seizes on this—“So you are a king?”, which Jesus parries with “You say that I am a king” (v. 37). It is in light of this ambiguity that we should recognise irony piled on irony as Jesus is crowned with thorns, dressed in a purple robe, and mocked by the soldiers saying “Hail, King of the Jews!” (John 19:23). Before handing Jesus over to be crucified, Pilate presents him to the angry crowd, saying “Here is your King” (v. 14), then asking the question

An Evolutionary Theology

279

“Shall I crucify your King?” (v. 15), to which the chief priests reply blasphemously (since only God should claim their allegiance) “We have no king but the emperor” [or Caesar]. Seeking to avoid a riot, Pilate allows Jesus to be taken away for crucifixion, but insists that an inscription reading “Jesus of Nazareth, the King of the Jews” should be placed on his cross in Hebrew, Latin and Greek (vv. 19 and 20b). Asked to alter this text by the chief priests, Pilate refuses: “What I have written I have written” (v. 22; all quotations from NRSV). A similar inscription is also attested in all three synoptic gospels (Matthew 27:37, Mark 15:26; Luke 23:38). Matthew and Mark record that Jesus on the cross uttered the despairing opening words of Psalm 22:1 in Aramaic (“Eli, Eli, lema sabachthani?”; “My God, my God, why have you forsaken me?”), though commentators note that this psalm ends on a note of hope and consolation (vv. 22-31). For Moltmann (1989/1990, pp. 178-181), the love of God the Father for the Son, mediated through the Spirit, experiences in this eternal moment what “God-forsakenness” truly means—the literal “com-passion” of God. John does not mention this abandonment (nor does Luke), but closes the earthly life of Jesus with a deeply paradoxical cry of triumph rather than of dereliction (John 19:30). The last word spoken by Jesus is given, not in Aramaic but in the Greek of John’s gospel, as tetelestai—meaning literally “it is finished”, or better “it is accomplished”. This distinction is subtle but real in English; in French it is far more obvious—“c’est fini!” is what a parent says to a child having a tantrum, whereas “c’est accompli” signifies the completion or end of a task. And that is precisely John’s meaning here; the mission for which Jesus became incarnate among us has now been fulfilled. God’s kingdom has not merely been announced but also made real in the person of Jesus—his victory over Satan and all the powers of darkness (however we understand or interpret these) has already been won. The resurrection that will follow on the third day is a confirmation of this victory, not some sort of afterthought on God’s part. Had the disciples taken heed of what Jesus told them many times previously, they would not have been so surprised when he rose again from the dead. The seeming defeat of Christ’s death on the cross is in fact the moment when the dam bursts and the flood of God’s new creation is released. As an evolutionist, I am bound to ask in what ways that flood might affect all the myriad other organisms that share our planet, or indeed the adherents of other religions for whom the name of Christ Jesus means nothing. Deane-Drummond (§ 7.4.3) sees these events as the epicentre or focal point of a vast theo-drama of evolution and human history. With our unidirectional sense of historical and evolutionary time, we might be tempted to dismiss the Christ-event as merely a last-minute intervention by God. But if God is also transcendent,

280

Chapter 8

and so in some sense outside of time, then this objection is less warranted. But such a conviction remains an act of faith, to be realised fully only with God’s final consummation of all things in the promised kingdom (§ 8.5.2).

8.3.4 The kingdom announced: love, grace and compassion Yahweh, the Jewish God of the Old Testament, can often seem an irate and demanding deity, yet also long-suffering and compassionate—by turns threatening disaster and imploring God’s people out of love—dismayed by their stubbornness and hardness of heart. The God to whom Jesus testifies in the gospels shares some of the strictness and unapproachable holiness of this sketch (hardly surprising, given his Jewish audience), but I think it is still fair to claim that God’s love and compassion come to the fore in the words and actions of Jesus. Among the parables, the prime exemplar is Luke’s story of the Prodigal Son (15:11-32), where the father welcomes home his long-lost wastrel son with great joy and celebration, much to the chagrin of his dutiful elder brother. God’s generosity and love for us are not predicated on what we deserve. Those who sought healing from Jesus needed no qualification for this, except insofar as they—or others acting on their behalf—showed sufficient faith (or desperation?) to initiate the request. Using section numbers (§) from Throckmorton’s (1992) synoptic Gospel Parallels plus separate references to John, these include: a leper (§ 45), a Roman centurion’s servant (§ 46), the Gerasene demoniac[s] (§ 51, 106), a paralytic brought in by friends (§ 52), the daughter of synagogue leader Jairus along with a haemorrhaging woman (§ 55, 107), the man with a withered hand healed on the sabbath (§ 70), as well as other sabbath cures (§ 163, 168; John 5:1-18), the widow’s son at Nain (§ 80), the daughter of a Syro-Phoenician woman with a chequered past (§ 116), an epileptic boy (§ 126), ten lepers—of whom only a Samaritan returned to give thanks (§ 182), a royal official’s son (John 4:46-54), a man born blind (John 9:1-38), and the raising of Lazarus (John 11:1-44). In many of these healings, the cure is also coupled with forgiveness of sins—a red rag to the Pharisees and teachers of the law, for whom such forgiveness was the sole prerogative of God. This holistic compassion for the needs of the desperate—itself a sign of the breaking-in of God’s new kingdom—is also mirrored in Jesus’ unwillingness to condemn those judged sinful by the law, including the woman taken in adultery (John 8:111), the woman who anointed Jesus’ feet with tears and ointment (Luke 7:36-50), the cheating tax-collector Zacchaeus (Luke 19:1-10), or indeed the penitent thief crucified alongside Jesus (Luke 23:39-43). Rather, these cures and absolutions reflect the unconditional love and mercy of God that

An Evolutionary Theology

281

characterise the kingdom—which is why this is “good news” for all. Jesus is frequently condemned by the religious authorities of his day for associating and even eating with “tax-collectors and sinners”, if not worse —people who were social outcasts and thus beyond the pale. Those healed by Jesus are a motley, undeserving, but truly representative cross-section of humanity: some have been sick or insane for many years, some are women or children, some Gentiles (one supplicant is a Roman!), some are blatant sinners, and some Samaritans (see also John 4:1-42, and of course the parable of the Good Samaritan in Luke 10:29-37). Not even the rich, wellconnected or influential are turned away—witness Zacchaeus, Jairus and the centurion (cf. Rohr, 2019, pp. 77-78). No-one who asks is met with refusal; the kingdom, it seems, is accessible to all—if that is what we truly desire. We cannot earn salvation by good works, as St. Paul emphasises in several epistles, but both Jesus and Paul also stress the vital role of faith. Jesus’ healings are often accompanied by the words “your faith has made you whole”; these days, we might find ourselves echoing the words of the epileptic boy’s father in Mark 9:24 (NRSV): “I believe; help my unbelief!” God’s gracious invitation into the kingdom is open to all humanity, or even all creation, but needs to be heard and accepted before it can become a reality for us, as in Jesus’ parable of the wedding guests (Matthew 22:110; Luke 14:16-24). Human free will might even extend to refusing God’s open invitation, coupled as it is with loving forgiveness freely offered. A key emphasis of the Johannine literature is the great theme of God’s love for humankind, as manifest in Jesus Christ. In John’s gospel (NRSV): “For God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life” [3:16]. “I give you a new commandment, that you love one another. Just as I have loved you, you also should love one another” [13:34]. “As the Father has loved me, so I have loved you; abide in my love” [15:9]. “This is my commandment, that you love one another as I have loved you. No one has greater love than this, to lay down one’s life for one’s friends.” [15:12-13].

The first epistle of John takes up this theme, and then vastly expands it: “We know love by this, that he laid down his life for us—and we ought to lay down our lives for one another” [1 John 3:16, NRSV]. “Beloved, let us love one another, because love is from God; everyone who loves is born of God and knows God. Whoever does not love does not know God, for God is love. God’s love was revealed among us in this way: God sent his only Son into the world so that we might live through him. In this is love, not that we loved God but that he loved us and sent his Son to be the atoning sacrifice for our sins. Beloved, since God loved us so much, we also ought

282

Chapter 8 to love one another. No one has ever seen God; if we love one another, God lives in us, and his love is perfected in us.” [1 John 4:7-12, NRSV].

Echoes of this love-theme resound also through the synoptics (e.g. Luke 6:27-28, 35-36; Matthew 5:43-48; Luke 15:11-32) and in parts of the Old Testament (e.g. Proverbs 3:12; Isaiah 40:1-5, 58:6-12; Hosea 11, 14:4). In polytheistic religions, the gods were to be honoured, worshipped and placated through ritual and sacrifice (§ 6.8), but it would never have occurred to anyone that any god (let alone the one-and-only God) might actually love them (e.g. Hurtado, 2016, p. 64). This insight, springing from Jesus himself and nurtured in early Christian communities, was therefore utterly transformational, although it was prefigured in Judaism (e.g. in the Old Testament references above). Paul’s panegyric in 1 Corinthians 13 extols love as the Christian virtue par excellence, greater even than faith or hope; verses 4-8 (NRSV) can be read as a summary of God’s very nature: “Love is patient; love is kind; love is not envious or boastful or arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice in wrongdoing, but rejoices in the truth. It bears all things, believes all things, hopes all things, endures all things. Love never ends”.

Despite outdated attitudes and assumptions, C.S. Lewis’ “The Four Loves” (1960/1963) contains invaluable insights into the love of God, as gleaned from our human experiences of affection, friendship, erotic love and caritas—this last reflecting a self-expending and over-arching love for all people—or for all creation. Far more could be said about love as the kernel of Christian faith, but this must suffice to crack open the nut that shields it. Yet God’s love for us is costly beyond our imagining. That is what we see lived out in the birth, ministry, passion and cruel death of Jesus Christ, whom we believe was God incarnate among us. Crucifixion was employed ruthlessly by the Romans as a deterrent to rebels and other criminals, but we tend not to dwell on the details of the prolonged agony experienced by a crucified victim—from which our word excruciating is derived. Stephen Cottrell (2008) re-imagines Jesus’ suffering on the cross in vivid and often harrowing detail. Since Jesus has chosen voluntarily to bear that pain and to endure the seeming oblivion of death, the Triune God knows at first hand the worst that suffering and death entail—not just for individual human beings but for all organic life, at least on earth. W.H. Vanstone’s classic “Love’s Endeavour, Love’s Expense” (1977) explores the costliness of God’s love: “The infinity of the universe must be understood, with awe, as the expression or the consequence of the limitlessness of the divine self-

An Evolutionary Theology

283

giving” (ibid., p. 59). Kenosis is not just the self-emptying of Jesus, but of God in toto: “Such is the likeness of God, wholly given, spent and drained in that sublime self-giving which is the ground and source and origin of the universe” (ibid., p. 62). What follows from this (ibid., pp. 62-63) is that: “The activity of God in creation must be precarious. It must proceed by no assured programme. Its progress, like every progress of love, must be an angular progress—in which each step is a precarious step into the unknown; ….in which, for the making of that which is truly an ‘other’, control is jeopardised, lost, and, through activity yet more intense and vision yet more sublime, regained; in which the divine creativity ever extends and enlarges itself, and in which its endeavour is ever poised upon the brink of failure. If the creation is the work of love, then its shape cannot be predetermined by the Creator, nor its triumph foreknown”.

Creation, seen in these terms, is an adventure of love fraught with risk and potential failure—summed up in Vanstone’s poem A Hymn to the Creator (ibid., pp. 119-120). We glimpse that costliness in the suffering of Jesus, but this insight is weakened by interpretations of atonement that see Christ as a scapegoat sacrificed to appease the “wrath of God” against human sin. That belittles and straitjackets the love of God, barring the gates of God’s kingdom against most of creation, apart from a saved elect of believers. This self-giving love from Godself, experienced in the lives of human persons, is what Christians mean (in the broadest sense) by the theological term grace. Again, this is a vast topic that could detain us for many pages. An eloquent account of the costliness of grace is given by Philip Yancey in “What’s So Amazing About Grace”? (1997), whose launch-pad is Isak Dinesen’s novella “Babette’s Feast” (in Anecdotes of Destiny, 1958/1986, pp. 23-68). At the end of this story, Babette is revealed as the erstwhile cook of the Café Anglais in pre-revolutionary Paris. Exiled to a remote Norwegian coastal village, she has spent the entirety of her 10,000-franc savings on preparing a lavish feast for her hosts, at whose end “it was, to each of them, blissful to have become as a small child” (ibid., p. 63). Yet, amid the aftermath of “black and greasy pots and pans”, Babette stands utterly spent, “as white and deadly exhausted as on the night when she first appeared and had fainted on their doorstep” (ibid., p. 64). The theological point here is made by one of the guests, General Loewenhielm: “We have all of us been told that grace is to be found in the universe. But in our human foolishness and short-sightedness we imagine divine grace to be finite.…. But the moment comes when our eyes are opened, and we see and realize that grace is infinite. Grace, my friends, demands nothing from us but that we shall await it with confidence and acknowledge it in gratitude.

284

Chapter 8

Grace, brothers, makes no conditions…singles out none of us in particular; grace takes us all to its bosom and proclaims general amnesty.” [ibid., p. 60]

And this is borne out by events on the magical evening of Babette’s feast, when the old animosities of an inward-looking community are forgiven and past faults admitted. But all this comes at a vast personal cost that none of the guests can guess, yet Babette offers this grace unstintingly, quite literally giving her all. Yancey (1997) uses this modern parable as his foundation for exploring the many facets of unconditional love, grace and forgiveness—both in the bible and in numerous stories drawn from contemporary life (if now a bit dated). God’s grace is unconditional and unmerited; we may choose to respond, but this is neither a precondition nor a demand placed upon us. Grace is often prevenient—meaning that it comes before any action or commitment on our part—a major theme in Wesleyan and Arminian theology. Its biblical roots include 1 John 4:10— “In this is love, not that we loved God but that he loved us.” The Scottish Episcopal Church’s eucharistic liturgy (1982/1996, p. 6) paraphrases this in its invitation to confession: “God is love, and we are God’s children. There is no room for fear in love. We love because God loved us first”. Steve Chalke (2019, pp. 61-104) points out that Martin Luther founded the Reformation understanding of salvation principally on two Latin phrases—sola fide (by faith alone) and sola gratia (by grace alone). At first sight these seem mutually contradictory. Grace—as we have just seen —is God’s free gift, whereas faith is surely something we need to work at ourselves? John Calvin’s resolution of this paradox was to see faith itself as something granted by God’s grace alone—hence his doctrine of double predestination, where a faithful elect (those to whom faith is vouchsafed) is destined for salvation in heaven, whereas those from whom this free gift is withheld are destined for damnation in hell. This resolves the conundrum —but only at the cost of God’s love, or at least of its universality. Again we fall back on the inscrutability of God’s purposes, since it is not for any merit or good works or even right beliefs that the elect are chosen. Chalke, however, believes that Luther may have misunderstood the Greek word pistis, usually translated as faith. In fact, older translations of the bible— including Tyndale’s 1522 English version—render this key word as faithfulness. Whereas faith is often (mis)understood to involve intellectual assent to a set of propositions or doctrines, the word faithfulness implies trust in the path chosen, which is followed with dogged commitment and persistence—even in face of setbacks and doubts (Wright, 2018, pp. 411413). Paul uses the phrase pistis Christou in six pivotal passages: Romans 3:22 and 26, Galatians 2:16 and 3:22, Ephesians 3:12 and Philemon 3:9

An Evolutionary Theology

285

(Chalke, 2019, 83-104). This phrase can legitimately be translated either as (our) faith in Christ, or alternatively as the faithfulness of Christ (also Wright, 2018, p. 147). There is a world of difference between these: one depends on our assent, our faith, our own effort—whereas the other trusts in Christ’s (or God’s) unwavering faithfulness, which remains constant and all-embracing despite our qualms, our doubts, and even our failures. But I have deliberately overstated the contrast here between these terms. In the experience of many (most?) believers—rather than in the imaginings of post-Enlightenment critics—faith is neither intellectual nor propositional, but rather involves being seized by an emotional commitment beyond oneself. And that, in truth, comes close to the trust implied by faithfulness, Yet how might all these pious words and phrases help us make sense of evolution in theological terms? Even Vanstone’s (1977) kenotic God— who is spent to the uttermost in the process of creation—remains in some sense an influence upon that creation; there is still a causal joint between God and created entities or processes. In the previous chapter we have looked at how some influential scientist-theologians have tried to address this problem: Arthur Peacocke advocates top-down or whole-parts causation, whereas Robert Russell (2009) favours bottom-up causation rooted in quantum indeterminacy, and Celia Deane-Drummond the free operation of creaturely secondary causes within the natural laws established and sustained by God. None of these suggestions conveys the costliness of creation, as manifested in the life and passion of Jesus, that is so movingly captured by Vanstone (1977). For my own part, I prefer a different biblical model that has been explored by many others, of a God whose influence within creation is exerted solely through love and forgiveness, a God who refrains from meddling, but who calls all creation to share in the divine fellowship of the Trinity (§ 8.4 below). Most of us have some experience of what it feels like to be loved: we feel energised, alert, on fire with new possibilities and fresh insights. It is not that the beloved is radiating energy into us nor indeed compelling us in any way; the changes are rather within ourselves, in brain chemistry and endorphin levels. But we are nonetheless changed, and the witness of countless generations of faithful believers is that God can change us for the better, and through us even make the world a better place—historically, in the abolition of slavery and the foundation of hospitals, hospices and schools (Wright, 2018, pp. 424-427). In Luke 13:21, the kingdom is likened to yeast, mixed in with the ordinary flour of society, leavening the dough so that all is (are) raised. For Christians, this involves our rational acceptance of, and response to, God’s gracious invitation—which offers us love and forgiveness through grace. But what if that same sense of God’s love in fact permeates all creation, evoking an

286

Chapter 8

unconscious and non-rational response that is also “on fire with new possibilities”? This would indeed be immensely costly for God, but would also seem to abolish any need for a causal joint between God and events in the world. Loving or forgiving someone is costly, and if reciprocated or accepted, so too is the response. But love can be unrequited, rejected or unrecognised; forgiveness can be spurned or dismissed as unneeded. In such a case, the cost to the lover or forgiver (God) makes no impact upon the beloved or forgiven—yet the possibility of recognition or acceptance still remains. Time and time again, God’s best intentions may be thwarted or blown off course, yet still the hope for a better outcome remains. All this is implied in the “letting-be” of creation. Such a role—both active and passive—resonates with Thomas Jay Oord’s title, “The Uncontrolling Love of God” (2015); 1 Corinthians 13:13 (NRSV) states it thus: “And now faith, hope and love abide, these three; and the greatest of these is love.”

8.4 Trinity, communion and community 8.4.1 Biblical allusions to the Trinity In contrast to the abundance of dyadic (Father/Son or God/Jesus) formulae in the New Testament, there is a paucity of overtly Trinitarian examples invoking the Holy Spirit as well. It is possible, albeit with rather forced or allegorical exegesis, to find hints of the Trinity even in the Old Testament. Andrei Rublev’s famous icon of the Trinity (Troitsa, c. 1410) portrays the three Persons of the Triune God as the 3 angels who visited Abraham near the oak trees of Mamre (featured in the background, along with Mount Moriah), as told in Genesis 18:1-15; this passage begins and ends with the singular voice of Yahweh, yet the apparition is of three personages who speak as one (they in vv. 5b and 9). It is possible to add a Trinitarian gloss to the Aaronic blessing of Numbers 6:24-26 with its triple invocation of the word “Lord”, or to the triple “Holy” called out by the seraphim in praise of Yahweh Sabaoth (Isaiah 6:3). In the New Testament, all three persons of the Trinity are present at the baptism of Jesus (featured in all 4 gospels): Jesus the Son—obviously, the Spirit who descends like a dove as Jesus comes up out of the water, and the Father who speaks from heaven with words of approval—“You are my Son, the Beloved; with you I am well pleased” (Mark 1:11, NRSV). At the end of Matthew’s gospel, there is an explicitly Trinitarian formulation in the Great Commission given to the disciples: “Go therefore and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19, NRSV). And in John 15:26, Jesus promises that he will send his disciples the Advocate, the spirit of truth who comes from

An Evolutionary Theology

287

the Father, and who will testify on Jesus’ behalf—a promise later fulfilled dramatically at Pentecost (Acts 2:1-41). In Paul’s letter to the Galatians (4:5), all three Persons of the Trinity are invoked together without distinction as to rank: “God has sent the Spirit of his Son into our hearts, crying, ‘Abba! Father!’”. In 2 Corinthians 13:14, the familiar dyadic formula (§ 8.2.3) is replaced by a Trinitarian variant: “The grace of the Lord Jesus Christ, the love of God and the fellowship of the Holy Spirit be with you all” (NRSV)—used by Christians the world over as the Grace.

8.4.2 Doctrine of the Trinity The brevity of the preceding subsection tells its own story: there is no explicit setting-out or explanation of the Trinity within the New Testament canon, though the veneration of Father, Son and Holy Spirit is already apparent in the early church. If all three are worthy of worship appropriate to God alone, how then are we to understand their relationship? During the first few centuries of Christianity, every conceivable permutation was mooted, debated ferociously, and nearly all found wanting. At one extreme there was tritheism with three independent gods, and at the other a single God (as Father), from whom the Son and Spirit were created as emissaries, or whose three persons were mere masks (as in Greek drama)—temporary identities adopted by the one deity in different contexts (modalism). It was not till the 4th C CE that a series of church councils (initiated by Emperor Constantine at Nicaea) tried to agree an orthodoxy of acceptable belief. It was not a pretty sight; those branded as heretics were excommunicated, anathematised, or (later) executed—so besmirching the hitherto peaceable reputation of the faith. Power, one might say, went to the heads of those whose ideas finally triumphed. Since these models of the Trinity cannot be proved unequivocally from scripture, those outside the Christian fold tend to regard this as an artificial or even unnecessary doctrine read into, or bolted onto, a biblical faith in Yahweh. But the elucidation of this doctrine, and its elegant philosophical framing by the Cappadocian Fathers (Basil the Great, Gregory Nazianzen, Gregory of Nyssa) in the 4th C CE, stands out as one of the towering achievements of early Christian theology. This is no place to unravel the convoluted history of the councils and heresies of the fourth century CE, but the “standard model” that emerged is worth setting out briefly, if only to clarify the Trinitarian basis of what follows. This standard formulation distinguishes “one substance (ousia), but three Persons (hypostases)” in the Godhead of the Trinity—hence the theological term “consubstantial”. But as John Zizioulas (1985, pp. 40-41) points out, even this is not without ambiguity. Is the unity of God simply

288

Chapter 8

one of substance (however interpreted), i.e. one of essential nature? In the Orthodox tradition, this unity springs from the Father, who begets the Son and from whom the Holy Spirit proceeds (is sent forth). Therefore, it is the Father’s free choice to create communion within the Godhead. From that understanding cascade important insights into the nature of human personhood and of church, in terms of community and of communion, as understood sacramentally in the distinctively Christian eucharistic rite. For Zizioulas (ibid., pp. 96-98), the insights of Maximus the Confessor (alluded to earlier in § 7.5.2) allow us to integrate the created order and historical— even evolutionary—time within this perspective. Christ is the divine logos (Word; John 1:1) of creation, and the logoi or teleonomies of all creatures are therefore to be found in him—a relationship that only makes sense within the dynamic movement of God’s loving will. Notably, this view does not look backwards to some supposed pre-lapsarian state of perfection, but rather looks forward towards ultimate fulfilment and rest in the shalom of God’s new creation. There are echoes here too of Teilhard’s Christ-Omega (§ 7.2), but conceived in far less triumphalist terms. This also permits a very different view of original sin—where death is the inevitable fate of individual personhood/identity, when substituted for true communion of being (ibid., pp. 46-49). In a curious paradox, this can indeed be linked to the origin of sexual reproduction. Asexual organisms often produce genetically identical progeny (clones), whereas the mixing of genes that accompanies sexual reproduction (§ 1.5) ensures that each individual is genetically unique; however, that identity will inevitably perish with the individual rather than persisting indefinitely. But sex was an innovation that vastly predated humanity—possibly by 2 billion years. The language used about the Trinity is, of necessity, cautious, indirect, steeped in tradition, and never used lightly, since we speak of what words can neither contain nor define—namely the inner nature of the Godhead who is utterly beyond comprehension. The little-used Athanasian Creed spells out—in resonant but obfuscating phrases—both the equality of the three Persons of the Trinity and also their unity: “Such as the Father is, such is the Son, and such is the Holy Ghost [Spirit]. The Father uncreate, the Son uncreate: and the Holy Ghost [Spirit] uncreate…..And yet they are not three eternals: but one eternal. As also there are not three incomprehensibles, nor three uncreated: but one uncreated, and one incomprehensible… And in this Trinity none is afore, or after other: none is greater, or less than another; but the whole three Persons are co-eternal together: and co-equal” [Quicunque Vult; Cranmer, 1662/1999, Book of Common Prayer pp. 58-59]

An Evolutionary Theology

289

The great schism between Western and Eastern Christianity in 1054 CE arose partly in response to a western papal decision, 40 years earlier, to adopt the so-called filioque clause into the Nicene Creed. In both versions the Son is “eternally begotten of the Father”, but in the western revision the Spirit “proceeds from the Father and the Son” (filioque), rather than from the Father alone—thereby implying a non-Orthodox hierarchy of Persons within the Trinity. Interestingly, the Scottish Episcopal Church has parted company with many other Anglican provinces by reverting to the original Orthodox phrasing here. So much hangs on a mere three words! Zizioulas (1985) focusses on Orthodox understanding of the Godhead, the human person and the church in terms of communion, but I would like to broaden this out by thinking in terms of community. God as Trinity can be seen as a community of Persons united and interweaving in a sublime dance of love—inviting creation to join in that dance. Human beings are of course unique, unrepeatable individuals (even identical twins)—as are all sexual organisms—but they also exist in communities and are profoundly shaped by them. In the past, each such “community” would have included animals, plants and the local environment. James Lovelock’s (1979) Gaia hypothesis seeks to foster an awareness of our innumerable links with the rest of the living world and with the great biogeochemical cycles that shape the soils and seas and atmosphere of our planet—which we stretch to breaking point at our peril, endangering innumerable other species in the process. Indeed, these cycles have themselves “evolved” through the gradual accretion of additional feedback loops that stabilise the overall system (Holmes, 2019). There are calls for humans to join their efforts to reinforce these processes by measuring environmental responses to anthropogenic changes, in order to help buffer this planet against the worst ravages of climate change (Gaia 2; Lenton & Latour, 2018). Dynamic communities arise throughout the biosphere—flourish for a time—and are replaced or renewed following recognised ecological succession patterns. Even within apparently stable ecosystems, there can be large changes from year to year in the relative abundances of food-plants and herbivores, and of predator and prey species; these variations are mirrored on ever-smaller fractal scales among the microenvironments of soils or root systems. Human beings themselves are living proof of this, witness the key roles in health and well-being now ascribed to our microbiome of commensal gut bacteria. All organisms exist in nested communities of other living things and their inorganic substrates. No individual is truly self-sufficient.

290

Chapter 8

8.4.3 Trinity, community and church If, as Zizioulas maintains, “original sin” lies in the selfish pursuit of individuality—usually at the expense of others—then the shalom or peace into which God invites us is a communion of all being: the new creation. In this view, the Son breaks into time (arguably space-time) as a foretaste of that new creation—the first-fruits from the dead. There is a key sense in which Jesus is not just an individual person, but rather a representative of all humanity, an everyman, a man for all people, indeed for all life (John 1:3). This not to deny the strong, even forceful personality that emerges in the gospel accounts, but rather to emphasise his universality, inviting all being to follow his path of selfless love and service to others. The depth of that love is revealed in his dying for all and rising again to proclaim that death does not have the final say. All creation is invited to join in timeless communion within the dance of love that is the Holy Trinity. The church is called to be Christ’s body on earth, inspired by the Holy Spirit, and offering a foretaste of that communion banquet within its eucharistic rituals, based on the Last Supper instituted by Jesus himself on the eve of his crucifixion. That the church today is much fragmented and riven by dissent is neither here nor there—its membership and its structures are all too human and suffer from the selfsame defects that mar us all. Without pretending that the church fulfils its calling, it is intended to be a meeting place for all humanity, or even all creation (§ 8.5), its members constituted as living stones built into a spiritual house, called to be a holy priesthood (1 Peter 2:5). St. Paul uses the image of a body (1 Corinthians 12:12-30), whose head is Christ and whose members (in both senses) constitute the church, with unity of purpose but diversity of functions. Perhaps, with our modern understanding of biology, a closer (and more pluralistic!) analogy might be cells—with every organ constituted by billions of such cells, each differing slightly from its neighbours while retaining a common identity. For human body cells, that identity is provided by the individual’s genome. In the promised reuniting of God’s new creation, perhaps all such identities might be subsumed and fulfilled in communion with the Holy Trinity. Mostly we cling fiercely to our individual identities and our own interests, but in loving another person unconditionally we surrender some or much of that individuality to the interests of the beloved—perhaps a pale foretaste of what is offered in communion within God’s new creation? In the early church, there was meant to be no distinction as to rank or race, status or gender. As Paul says in Galatians 3:27-28 (NRSV), “As many of you as were baptised into Christ [= have become members of the church] have clothed yourselves with Christ. There is no longer Jew or

An Evolutionary Theology

291

Greek, there is no longer slave or free, there is no longer male and female, for all of you are one in Christ Jesus”. In the eucharistic community of the church, these social distinctions of race, rank or gender are irrelevant— indeed, they are an affront to Christ. Paul upbraids the Corinthian church for disregarding this parity of status, since individuals or factions were consuming their own food and drink, leaving others hungry (2 Corinthians 11:17-21); he then passes on his own teaching about proper observance of the sacred character of this shared meal (vv. 22-26). From contemporary accounts, it is clear that Christians were often regarded with suspicion by later Roman authorities, because slaves could mingle with patricians and rich with poor converts at the eucharistic table—a practice that was seen as potentially seditious in the prevailing, highly stratified social order (cf. Hurtado, 2016, p. 32). Paul’s brief epistle to Philemon, about the runaway slave Onesimus, is also telling in this context. The early breaking-down of social barriers within the church was meant to prefigure God’s coming kingdom, where the hungry would be filled with good things and the destitute given seats of honour at heaven’s great banquet. That the church later colluded with secular power, and became acutely conscious of social rank, betrays Jesus’ own words in the gospels. It is as if—to paraphrase Dostoyevsky—the (Roman) church followed a Christ who had succumbed to Satan’s offer of worldly power, at the cost of bowing down to worship the devil (cf. Matthew 4:9). If the church is to become Christ’s body in truth, this must be realised as a community, not simply in a community (Zizioulas, 1985, p. 115). The local church represents before God each and every member of its community, whether believer or not, celebrating the eucharist on behalf of all its people, and indeed on behalf of all creation. One symptom of the churches’ retreat from any kind of representative role between God and community is the plethora of both denominational and worship-style options on offer, especially within cities. It remains the case that there is often only one church available in rural villages, though some will still choose to commute to “gathered churches” elsewhere. This fracturing of the relationship between community and church turns the Christian faith into a market-place of competing offerings, each with its own distinctive trappings or traditions. Different members of a single local community may be involved in a variety of churches (or other places of worship) or none; any semblance of a one-to-one mapping of church onto community has largely disappeared. Each church has its own liturgy for communion (sometimes infrequent, as in Presbyterian traditions), and the visible Body of Christ becomes multiplied as in a hall of mirrors. The Orthodox view of church, as described by Zizioulas (1985), is increasingly difficult to reconcile with modern urban living. Yet even within a diverse

292

Chapter 8

gathered congregation, it is possible for the communion rite to open up in worship a transient glimpse into the unity and holiness of the Triune God.

8.4.4 Flourishing in community Celia Deane-Drummond (2014; § 7.4.4) has contributed greatly to our understanding of a mutual interdependence between human and ecological flourishing, which I take to mean the well-being of communities at all levels, from social (even ecclesiastical!) and ecological to microbiological and subcellular grades of organisation. Even at a molecular level (chapter 1), cells under normal conditions express their own distinctive suites of genes at appropriate rates, but can adjust what they are doing in response to both internal and external signals. When an organism comes under stress—e.g. from heat or toxic chemicals in the environment—then normal patterns of gene activity are dampened down and eventually suppressed, while hitherto inactive stress-response genes are switched on—encoding heat-shock proteins and a range of detoxifying enzymes (see e.g. Anbalagan et al., 2012). Stress responses enable the organism to survive the threat, but at a heavy cost to normal functions such as growth and reproduction. In ecological communities, stressful conditions such as heat, drought or pollution often lead to imbalances in the relative numbers of different species, so that a few may overgrow inappropriately while others can be lost completely, making natural recovery more difficult. In human societies, including churches, tensions and ill-feelings tend to generate resentment, non-cooperation and ultimately conflict, on occasion erupting into (civil) war or schism. Orderly function requires system stability. “May you live in interesting times”, as the apocryphal Chinese curse phrases it. This is admittedly a one-sided view; stressful conditions also generate new opportunities for innovation and for doing things differently, a chance for pioneers (also invaders) to make their mark and take over. Despite the looming threat of a sixth mass extinction caused by anthropogenic climate change (chapter 10), some organisms are adapting to new niches or seizing on other unanticipated opportunities (Thomas, 2017). There will always be winners as well as losers in times when external circumstances change rapidly. The outcomes may surprise us, but will often prove unwelcome. Extinction will follow a final curtain-call for many species that we cherish. Not even with seed-banks, captive breeding or cloning biotechnologies can we hope to save more than a tiny fraction of those currently threatened. All biological systems—from cells to whole ecosystems—exhibit what is termed homeostasis: minor perturbations are compensated by internal

An Evolutionary Theology

293

regulatory mechanisms, such as sweating to cool the skin by evaporation when conditions become uncomfortably hot. More extreme temperatures activate production of heat-shock proteins (above), which prevent or repair heat-induced damage to the delicate 3D tertiary structures of many proteins (§ 1.3) on which life depends. This happens in humans during a high fever or particularly vigorous exercise. But heat-shock proteins are an emergency stop-gap, and ambient temperatures exceeding 41 °C for long periods (or 45 °C for shorter times) become lethal for human beings. The same holds true for all homeostatic systems and all communities. Pushed beyond their tolerance limits, self-regulating mechanisms break down, and disruption or complete collapse become inevitable. The bleaching of coral reefs is a case in point, decimating local biodiversity. Flourishing communities are not a luxury, but a necessity—one that may best be assured by increasing their resilience (the ability to resist perturbations through self-regulation). To some extent, we can design in resilience for human communities, though this is a tactic that only rich countries can currently afford, e.g. through building flood defences or sea walls. However, for natural ecosystems, our conservation efforts are essentially limited to patches of protected habitat. Even so, creating “wildlife corridors” as links between these can improve the chances of interbreeding between isolated populations, and might perhaps permit species to migrate into more congenial areas if and when their home ranges become uninhabitable. We must also acknowledge that our own migration corridors are strictly limited for those humans who are already fleeing climate-induced devastation in their homelands. All this may seem a far cry from church and the Trinity, but it is not. What we glimpse or infer about the Godhead—the diversity of the three Persons (hypostases), yet their unity of substance (ousia), purpose, grace, kenosis and love—is a model for the church, and also for communities more widely. Human societies seem in headlong retreat from the reality of the catastrophic climate change they have unleashed (chapter 10). Our human evolutionary history has been possible thanks to a relatively stable mild climate over the past few million years (glaciations notwithstanding). Things will be very different when—eventually—the earth’s climate settles into a new equilibrium and adaptive radiation of new species can get under way (§ 2.2, 3.4) in the wake of a sixth mass extinction. There is probably nothing we can do to avert this general course of events, but our actions now could mitigate its severity. There is a world of difference between warming scenarios of 1.5-2 °C and those of 6-8 °C (Lynas, 2008; Wallace-Wells, 2019). Climate change cannot be tackled piecemeal on a country-by-country basis, as recognised in the various international climate change agreements arrived at after so much negotiation, yet with

294

Chapter 8

so little tangible result in terms of reduced global carbon emissions. Working together to set aside our differences, listening to the voices of the poor and vulnerable (including the silent pleas of all other living things on this planet), facing up squarely to our responsibilities and taking sacrificial action to begin to make amends—these are the attitudes that are most sorely needed and also most sadly lacking. The church could begin to embody these values—modelled on the kenotic Trinity—as a basis for action on climate change, setting aside its endless wrangles over matters of doctrine or sexuality. In truth, this looks less and less likely, since far too many vested interests are at stake. We will revisit this topic in chapter 10.

8.4.5 Priests of Creation? Christians belonging to Catholic, Orthodox or Anglican traditions are familiar with three “holy orders” among the ordained clergy—deacons, priests and bishops. These were once seen as distinct callings to serve the eucharistic community of the church, but often they became a hierarchy up which clergy could “advance” by promotion: deacons were seen in many churches as trainee apprentice priests (a year-long transitional state), while exceptional priests were recognised through preferment for consecration as bishops (and beyond that, as archbishops, cardinals, metropolitans, patriarchs, or even Pope). But Orthodox, Lutheran, and increasingly other denominations have also promoted a permanent diaconate. By focussing on the 3 clerical roles in relation to the eucharist, Zizioulas (1985, pp. 215217) draws attention to the fact that all full members of the church are also ordained—by virtue of their baptism and confirmation, which involves the laying-on of hands by a bishop—to a fourth holy order, the laity. This suggests a deeper level of understanding for Peter’s description of his readers as “a chosen race, a royal priesthood, a holy nation, God’s own people” (1 Peter 2:9, NRSV)—not in any exclusive, ethnic, racial or narrowly sacerdotal sense, but with an outward-looking openness to the local and wider communities (§ 8.4.4) within which that church is set. However, my purpose here is not to explore the multiple roles of the laity within the church, but rather the calling of all Christians—and indeed all humanity—to serve as priests for that part of creation which is our home, namely this planet with its amazing diversity of landscapes and lifeforms. All of it—nothing less—from icy Antarctic oceans and snowbound mountain summits to steamy tropical rainforests and seemingly barren deserts. What might such a priesthood mean? First and foremost, we need a sense of humility and reverent awe within which God might speak to us. Southgate (2008, pp. 110-113) draws on Orthodox tradition to suggest that

An Evolutionary Theology

295

Christians should “bless and praise God” for all creation—as a “priesthood of contemplation and understanding” (ibid., p. 111). Note how this last word links with the vocation of all biologists to elucidate the living world around us; the two enterprises could and should be united in appreciating and marvelling at the workings and wonders of nature—not perpetually at loggerheads with each other. In this sense, we are “reverent-receptive priests” (ibid., p. 113), or even pastors towards creation, offering our full and undivided attention to the natural world whenever we can find time to contemplate it—much as we would listen and minister to a church member in distress. As explored further in chapter 10, the entire biosphere is already in distress—indeed in crisis. We would do well to refrain from pious platitudes about God being in charge, and not to worry unduly….. The parlous state of nature, faced with the linked calamities of climate change and mass extinction, should also spur Christians to action. Not to pontificate but to spread awareness; not to stand by as apathetic onlookers but to take responsibility for reducing our own carbon footprints and living sustainably; not to blame governments or big business interests but to live self-sacrificially so that others less fortunate than ourselves—including the natural world around us—can also flourish and prosper. This brings in two further aspects of priesthood—the sacrificial and the evangelical—this last combining love for creation with zeal for the kingdom of God. There are as many views of what it means to be a “priest of creation” as there are writers on this topic. Ruth Page (1996, pp. 161-164) argues that the role of priest should be subservient to that of companion. She criticises traditional views of a human priesthood that intercedes with God on behalf of a “voiceless” non-human creation, upbraiding both Arthur Peacocke (§7.5) and the 17 th C poet George Herbert for striking examples of this error. Three lines from the latter’s poem “Providence” will suffice to make the point: “Man is the world’s High Priest: he doth present / The sacrifice for all; while they below / Unto the service mutter an assent….” (quoted on p. 163 of Page, 1996). The inadequacies of this view are two-fold: firstly, it is far too anthropocentric, elevating the status of Homo sapiens beyond anything warranted by evolutionary history; and secondly, it ignores God’s own relationship with—and (judging from scripture) implicit delight in— the whole living world. Nature can surely plead its own cause before God—its innumerable voices blending into a passionate denunciation of human stupidity and thoughtless greed. Donald Braxton (2007) writes of the balance between celebration and sacrifice for the common good in any healthy relationship between human beings and the natural world—a simpler way of living that should encompass our priestly role in creation. Something similar is envisaged by Michael Northcott (2015), in terms of

296

Chapter 8

sustainable and environmentally sensitive local communities. Elizabeth Johnson (2014, pp. 281-284) likewise writes of our attitude towards the environment in terms of an “ecological vocation”, rather than focussing on priesthood explicitly. Alluding to the parable of the Good Samaritan (Luke 10:25-37), she echoes the call of Pope John Paul II to expand our understanding of “who is our neighbour?” beyond the human to include “all other fellow creatures in the community of creation” (ibid., p. 281). The commitment of many people to protecting the environment, in great ways or small, “bespeaks a conversion to the Earth in an ecological sense as our oikos, our inhabited house, our only home in this vast universe” (ibid., p. 281). She also suggests that “in contemplation people look on the natural world with affection rather than with an arrogant, utilitarian stare” (ibid., p. 282). Asceticism—in the sense of living more simply and sustainably—is another Christian practice with immense relevance to the ecological crisis that we all face, as are our traditions of social justice in highlighting poverty, indigenous rights or exploitative business practices, and our prophetic calling to speak truth to power (ibid., pp. 283-4). All of these are also facets of our Christian vocation to become priests of creation.

8.5 A future hope? 8.5.1 Scriptural dreams and nightmares It is not my purpose here to review—let alone explain—the biblical apocalyptic literature dealing with the endtimes. These include disturbing visions of future tribulation, and of salvation for the righteous, in many of the prophets (for instance, parts of Isaiah, Ezekiel, Zechariah, Joel or Haggai), chapters 7 to 12 of Daniel, several of the teachings of Jesus (e.g. Matthew 24 and 25:31-46; much of Mark 13 and Luke 21), some writings of Paul (e.g. 2 Thessalonians 2), and—most notoriously—the Revelation to John which closes the bible. Endless ink has been spilled about what these visions mean and who will be saved, about their symbolism and the signs we should watch out for—but that is not what I want to focus on. In all of these apocalyptic texts, the darkness and trials to come are seen as God’s wrath and judgement against human sinfulness. This might make sense in a world-view where wrongness and death originated with human sin through the Fall, but from an evolutionary perspective, that view is no longer tenable. It is far too anthropocentric, as if the only life-forms that matter to God are these Johnny-come-lately Homo sapiens—a species that has existed for a mere blink of an eye in the history of life on earth. It is more in keeping with recent science to see the impending climate apocalypse—which is real, and already under way—as something we are

An Evolutionary Theology

297

bringing upon ourselves (and incidentally visiting on the rest of the biosphere) through our own selfish greed and blindness; it can no longer be blamed on an angry God. Human sinfulness is indeed at the root of our current crisis, but this is a shared responsibility of all humanity, largely in proportion to our individual wealth and our consumption of the world’s dwindling resources. We will return to this topic in chapter 10. It is perhaps only in our Good Friday liturgies or meditations that we Christians acknowledge our corporate guilt for scapegoating Jesus (§ 6.8), and by extension for all oppressed human minorities and victims. Maybe it is high time to widen the scope of our repentance to include the natural world as well, aware that our own extravagant lifestyles are signing a death warrant for many of the other organisms with whom we share this planet. The UN IPBES Global Assessment report on Biodiversity and Ecosystem Services —published on 6th May 2019 for policymakers—suggests that one million species are now at risk of extinction from anthropogenic causes. It may be argued that Jesus himself spoke of judgement and everlasting punishment for evil-doers—most notably in Matthew 25:31-46 (the sheep and goats): according to v. 46, the former are destined for eternal life in heaven, the latter for eternal punishment. Elsewhere, he speaks of hell in terms of everlasting fire, or of being cast into the outer darkness where there will be “wailing and gnashing of teeth”. But we read these words through the filter of a lurid—and arguably warped—medieval imagination. In early Christian iconography, such as the vivid and extensive 5th-7th C CE mosaics of Ravenna, judgement rarely figures as a theme—whereas depictions of heaven are commonplace, as in the astounding apse mosaic of Sant’ Apollinare in Classe (see jacket illustration for this book). A single panel among the multitude in Sant’ Apollinare Nuovo shows Christ (remarkably young and beardless) sitting in judgement, with an angel in rose on his right taking charge of the sheep while another in blue on his left oversees the goats. Compare this with Michelangelo’s Last Judgement on the wall of the Sistine Chapel in Rome, or Hieronymus Bosch’s gruesome images of the torments of hell; something has clearly changed! In an aside from his rehabilitation of Paul, Steve Chalke (2019, pp. 217228) takes a closer look at Jesus’ words concerning hell and judgement. Two Greek words are translated by the English “hell”. One is Hades—the Greek equivalent of the Hebrew Sheol—a shadowy and dismal place of waiting, but not of torment as such. The other is Gehenna—which in Jesus’ time designated the Valley of Hinnom outside the walls of Jerusalem. In the days of Kings Ahaz and Manasseh, this valley had been used for child sacrifices to the pagan god Molech (2 Kings 16:3, 21:6; 2 Chronicles 28:3, 31:5), and was therefore turned into a municipal garbage

298

Chapter 8

dump by the reforming King Josiah (son of Manasseh; 2 Kings 23:10). It was indeed a place of stench and smouldering fires, where dogs and other animals fought over scraps. But by no means was it the everlasting pit of fiery damnation so beloved of the medieval imagination, depicted not only in religious art but also in the first part (Inferno) of Dante’s “Divine Comedy”. Three further factors undermine the traditional interpretation of Jesus’ words. Firstly, there is the prophecy in Jeremiah 31:38-40 (which would have been familiar both to Jesus and his 1st C CE Jewish audience) that Gehenna would eventually be included within the rebuilt city walls, and become holy to the Lord (v. 40). Secondly, the Greek word aiónios— usually translated as eternal—derives from the same root aion as our modern English word aeon; a long period, to be sure, but hardly eternal (Chalke, 2019, 222-226). The Greek word aidon does indeed mean everlasting—but this is not used to translate whatever Aramaic word(s) Jesus originally used. Finally, the term which aiónios qualifies is kolasis, which according to William Barclay is only ever used to signify redemptive (as opposed to retributive) punishment. Steve Chalke prefers to translate aiónios kolasis as “a time of pruning”—much closer to medieval concepts of Purgatory (see § 8.5.2 below) than to eternal damnation. Since looming climate-induced apocalypse is self-inflicted, what hope might lie beyond it—if indeed we believe in a loving and merciful God? In among the nightmare visions of the endtimes envisaged in the bible, there are also glimpses of something very different—the peace and shalom of God’s new creation. Isaiah 25:6-9 envisions Yahweh’s great banquet for all peoples, the destruction of death and the wiping away of tears from every cheek—words re-echoed in Revelation 21:1-4. Isaiah 11:6-9—later expanded in 65:17-25—speaks of God’s holy mountain where no hurt nor harm shall be done, all animal kinds live peaceably together and all human beings flourish. Different images are used elsewhere to evoke this shalom: Ezekiel 36:26 speaks in terms reminiscent of a modern heart transplant— “A new heart I will give you, and a new spirit I will put within you; and I will remove from your body the heart of stone and give you a heart of flesh” (NRSV). There is an ambiguity here, as there is in much of Jesus’ teaching about the kingdom: in one sense that kingdom is being realised here and now in all the messiness and suffering of this present world, yet in another sense it belongs in God’s future promise of a new creation. These texts are all remarkably physical rather than spiritual in tone, and elsewhere the same writers speak of the ruins (Isaiah 61:4) or the waste places (Ezekiel 36:31) being rebuilt, and of desolate land being tilled to become like the garden of Eden (Ezekiel 36:32-33). In a similar vein, Jesus speaks of the “many dwelling places” in his Father’s house (John

An Evolutionary Theology

299

14:2), where he will go to prepare a place for his disciples. While this language may be metaphorical—since it speaks of a new creation yet to be realised—it also chimes in with Paul’s emphasis on bodily resurrection, and with gospel accounts of the physicality of the risen Jesus (Acts 10:41). Teilhard saw Christ-Omega as the final culmination of all evolution, as interpreted both biologically (the biosphere) and also spiritually (the noosphere). His view now seems far too triumphalist—pressing onwards with the winners at every stage, but glossing over or even discounting the multitude who fall by the wayside. This is exactly the reason why so many Christians feel uncomfortable with evolution, which consistently backs winners but never losers, and wastes no pity on those that fail to reproduce and pass on their genes. Yet the ministry of Christ on earth was focussed precisely on losers—sinners, the sick, the poor, the disabled, the mentally ill and the lost, not to mention women and children who were of low social status in 1 st C CE Palestine—all those whom the world regards as of little or no account. As stated earlier, in Moltmann’s view (1989/1990), all these are already members of God’s kingdom—and it is the winners who need repentance in order to enter that kingdom. Evolution promotes successful gene-variants (alleles) and combinations of genes, passively weeding out those that fail to confer a selective advantage under the prevailing local environmental conditions. No doubt kdr and super-kdr mutations of insect VGSC genes (§ 1.6) have arisen by chance many times in evolution, but they were not selected (indeed, were mildly disadvantageous) until such time as pyrethroid insecticides came into widespread use. This example must stand in for innumerable trillions of other variants that have arisen, failed the test of selection and been discarded. Only a small minority have eventually reappeared (like kdr and super-kdr) in a more favourable selective context, providing them with an opportunity to survive and multiply. Failures vastly outnumber successes. It is unhelpful to saddle evolution with anthropomorphic emotive terms such as “pitiless”, but this reality underlines the need for evolution itself—along with all creatures and all of humanity—to be redeemed in and through God’s new creation. One way of reconciling evangelical Christian faith with evolution is to interpret the origins of life and humanity in Trinitarian terms as a salvation to which all creation is called (Romans 8:21), understanding the beginning in light of the end (Franklin, 2014). To me, this only makes sense if that salvation encompasses everything, without exception—a universalist view (§ 8.5.2). It is worth quoting the closing lines of T.S. Eliot’s “East Coker” (the second of his Four Quartets), whose last words underlie the italicised title of Franklin’s article: “Through the dark cold and the desolation, / The

300

Chapter 8

wave cry, the wind cry, the vast waters / Of the petrel and the porpoise. In my end is my beginning.” In the dark waters of chaos (Genesis 1:2) lie our origins—giving birth to life (§ 1.7) and later to a multitude of animals— including our chordate ancestors (§ 3.2). Without all that, we could never have evolved; neither, I contend below, can we be saved without it all.

8.5.2 Universal salvation? The question mark is necessary and deliberate. Mainstream Christian faith envisages a Last Judgement where some are found righteous through the grace of God to enjoy eternal bliss in heaven while others are adjudged unworthy and condemned to eternal damnation in hell. Stated baldly like this, questions immediately arise. On what grounds will we be judged—by our good deeds (as Jesus tells us in Matthew 25:31-46) or by our faith, as Paul reiterates in many places? And, in the latter case, is it our faith in Christ or Christ’s faithfulness to us (Chalke, 2019)? Doesn’t this dualistic vision leave God’s victory incomplete—since Satan still remains in power, even if his hellish kingdom is a ravaged wasteland? How can we affirm God’s beneficence and love if some are condemned to eternal torture in the fires of hell? One possibility is that the damned are consigned to oblivion and non-existence rather than to hell. Jesus spoke of a great gulf fixed between the damned (a rich man tormented by thirst) and the blessed (Lazarus resting in Abraham’s bosom) in Luke 16:19-31. Yet official Roman Catholic theology has, since the 12th C CE, envisaged a sort of intermediate “escalator” known as Purgatory—where the sins of imperfect believers are purged away prior to admittance into heaven. This move, a concession to the intervening shades of grey between “black” and “white”, was fiercely resisted by Orthodox churches. But the idea of a soul undergoing purification on its ascent towards God is much older—figuring prominently in the 4th C CE writings of Gregory of Nyssa (below). Most evangelicals hold firm to traditional doctrines of heaven and hell, but it is arguable that Jesus’ actual words are more consistent with Purgatory than with eternal torture in the fires of hell (§ 8.5.1; Chalke, 2019, pp. 217-228). Even so, there has long been a minority strand within Christianity that has proclaimed—or at least raised the possibility of—universal salvation, whereby all humans (all creation?) would at least be offered forgiveness and a place among the blessed “in heaven”. This is not, as some think, a pernicious dilution of the faith invented by modern liberal theologians. It has a much longer pedigree, originating as far back as Origen (?185-254 CE). Its scriptural roots go back to Paul, who states in 1 Corinthians 15:28 that “When all things are subjected to him, then the Son himself will also

An Evolutionary Theology

301

be subjected to the one who put all things in subjection under him, so that God may be all in all”; NRSV). The logical conclusion would seem to be that hell, Satan and the damned must either cease to exist (oblivion), or else will find forgiveness in God—whose reign is to be unchallenged. This is not the only seemingly universalist rabbit that Paul pulls out of his hat unexpectedly. Having spent most of his Epistle to the Romans explaining why Jews cannot be saved by obedience to the Law, he unveils a mystery in 11:26, whereby “all Israel will be saved”, because God remains faithful to his covenant promises (God’s faithfulness, note). By delaying Israel’s redemption till the Gentiles have wholly come in, the scope of salvation is vastly expanded, indeed universalised. Numerous other biblical texts also allow a universalist interpretation, though none assert this unequivocally. Early universalists include one of the Cappadocian Fathers, Gregory of Nyssa, mentioned above. However, before quoting any of his writings that imply universalism, it is worth explaining a couple of unusual features of his theology. Firstly, he held to a double creation of humanity: according to Genesis 1:26, “God said ‘Let us create humankind in our image, according to our likeness’”, but v. 27 is slightly different—“God created humankind in his image, in the image of God he created them; male and female he created them.” For Gregory, these verses are not reiterations of the same creative act; rather, v. 26 describes an ideal of humanity in toto —with neither gender nor passions—whereas v. 27 appears to imply that God had second thoughts (perhaps aware of the possibility of that humans might choose evil?), hence the mention of sexual differences and later individual identities. But why is this detail important? In Gregory’s scheme salvation must involve humanity in toto returning to its initial passionless perfection of v. 26. This is a restitution of the pristine image of God in humanity (Greek apokatastasis; Ludlow, 2000, pp. 38-44). Arcane as this may seem to us, it is not inconsistent with a God who calls or invites all the multifarious possibilities of creation into being (§ 8.2.6), as contrasted with their messy realisation through evolution, with all of its setbacks and distortions. Secondly, for this restitution to be possible, each soul must be purified from its evil and wayward passions on its journey toward God, in whose presence sin has no place. The saints may ascend directly to God, but lesser humans will first need to be purged from sin for a greater or lesser length of time—a process involving real pain and suffering, as in Gregory’s analogy of gold refined by fire from its accompanying dross. Gregory is forthright in asserting the logical consequences that follow on from the phrase “so that God may be all in all” (1 Corinthians 15:28). According to Gregory’s treatise on this text (see Brother Casimir, 1983),

302

Chapter 8

“Paul plainly speaks of the nonexistence….of evil by stating that God is in all things and present to each one of them….. It is not proper for God to be present in evil; thus, he will not be in everything so long as some evil remains” (ibid., p. 19). Earlier, he asks rhetorically what Paul is teaching us through this verse (ibid., p. 17): “It consists in saying that evil will come to nought and will be completely destroyed. The divine, pure goodness will contain in itself every nature endowed with reason; nothing made by God is excluded from his kingdom once everything mixed with some elements of base material has been consumed by refinement in fire”. This plainly refers to human reason, but may even extend to God’s non-human creation as well—since “nothing made by God is excluded from his kingdom”. While the salvation of “all that is” sounds appealing to those of a liberal persuasion, particularly in the context of evolution, it is not without its own problems. First, there is the issue of free will, which Gregory regards as the noblest and most precious of [God’s] blessings to humanity (Ludlow, 2000, p. 96). If salvation comes to all—willy-nilly, so to speak— does this abrogate creaturely freedom to reject God, and how could this be reconciled with a God whose deepest nature is uncontrolling love (Oord, 2015)? Gregory argues that human evil and rejection of God arise out of ignorance and blindness—an absence of the good. As we are taught by God through purgation (refining by fire), we will perceive that goodness and be drawn towards it (Ludlow 2000, pp. 95-111)—aligning our souls to the divine purpose that called creation into being. This implies that evil is a mere shadow—in which we may seek illusory refuge, but which has no substance to which we can cling; “to reject God is still, however obscurely and uncomprehendingly, to seek God” (Bentley Hart, 2019, p. 185). Faced with a seeming contradiction between scriptural texts promising salvation to all things and those that speak of judgement, some theologians have opted to hope for the former but stand in fear of the latter—e.g. Karl Rahner or Hans Urs von Balthasar. David Bentley Hart (2019) will have none of this equivocation. In his trenchant book, he excoriates the moral incoherence of a “God of love” who nevertheless consigns evil-doers to eternal torment; surely such a God would be a monster? Even if we invoke justice, understood in human terms, finite evil (however grave) committed by a mortal agent could never merit everlasting punishment. The ineffable incomprehensibility and superiority of God cannot cloak this injustice, at least not if we hold that God is the epitome of Love, Goodness and Mercy. With some glee, Bentley Hart labels defenders of the traditional doctrine of eternal damnation as the “infernalist” camp. He traces the origins of this travesty back to St. Augustine (354-430 CE; Roman-African theologian and bishop), who was perforce reliant on rather defective Latin translations

An Evolutionary Theology

303

of the New Testament, rather than the Greek originals. Eastern Orthodox theologians, such as Gregory of Nyssa or Isaac of Nineveh, may have understood the nuances of the Greek text with greater insight and subtlety. According to Bentley Hart (2019), the only possible resolution of the infernalist conundrum is precisely that outlined by Gregory—namely that the fires of Gehenna and the wailing outer darkness may provide necessary purgation for the vast majority of human souls (§ 8.5.1 above), but that this is transient in duration (however long it may take) and remedial or redemptive in aim. Thus the fires of hell and paradise of bliss are not two everlasting kingdoms separated by an unbridgeable chasm, but rather two stages on each soul’s ascent toward God. According to 1 Timothy 2:3-4 (NRSV), it is “God our Saviour(,) who desires everyone to be saved and to come to the knowledge of the truth”, for “the truth will set you free” (John 8:32b) If that is truly God’s intent in creation, then anything less than universal salvation would also deny Christ’s victory over sin on the cross. Jürgen Moltmann (1989/1990) makes no bones about the universality of salvation, whilst acknowledging that (among humans at least) the rich will need to repent in order to participate in God’s kingdom. “What is eschatological is the bringing back of all things out of their past, and gathering them into the kingdom of glory… It is the divine tempest of the new creation, which sweeps out of God’s future over history’s fields of the dead, waking and gathering every last created being.” This “bring[s] a redemption of the world which no evolution can ever achieve”; indeed, it “comprehends the redemption of evolution itself, with all its ambiguities” (ibid., p. 303). Scriptural warrant for such universalist assertions can be found in 1 Corinthians 15, not only in v. 28 cited earlier, but also in v. 22 (“For as all die in Adam, so all will be made alive in Christ”). The cosmic Christ also appears in Ephesians 1:9-10, invoking God’s “good pleasure that he set forth in Christ, as a plan for the fullness of time, to gather up all things in him, things in heaven and things on earth”. Colossians 1:1920 similarly asserts “For in him all the fullness of God was pleased to dwell, and through him God was pleased to reconcile to himself all things, whether on earth or in heaven” (biblical quotations from NRSV). It goes without saying that “all” has also been interpreted to mean “confined to the elect only”—but universalist readings of these texts are at least defensible. Several further texts with clear or plausible universalist implications are presented by Bentley Hart (2019, pp. 95-102), using his own translations. Other writers—focussed more specifically on evolution—have echoed Moltmann’s conclusion. Denis Edwards (1995, p. 150) boldly claims that:

304

Chapter 8 “Salvation in Christ…touches every plant, insect, animal, human being, and ecosystem on Earth. The risen Jesus is the beginning of the New Creation, and in his resurrection, the transfiguration of the material universe has begun, a process which will reach its conclusion in God’s final eschatological act of salvation”.

In a later paper, Edwards (2006, p. 106) proposes that “we can think of the Spirit of God as being present in love to each creature here and now and of each creature finding redemption in Christ.” Elizabeth Johnson concurs with this, arguing that “for God to love the whole” (as in the repeated formula of “all things” in Colossians 1:15-20) “means [also] to love every part” (Johnson, 2014, p. 230). Five propositions follow from this (ibid. p. 231): (i) the “living God creates and cares for all creatures”; (ii) this “love encompasses all creatures even in their suffering and dying”; (iii) these “creatures are part of the flesh of the world which the Word of God joined via incarnation”; (iv) the “death and resurrection of Jesus offers hope of redemption for all flesh”; (v) the “life-giving presence of the Spirit who empowers all creation is also the power of resurrected life for all beings”. She qualifies this by noting that “God relates to each creature on its own terms”, hence its “fulfilment will be one that fits its nature”, even though “scientific proof [of this hope] is out of the question” (ibid., p. 234). Christopher Southgate’s book, “The Groaning of Creation” (2008) emphasises both the beauty and the suffering of living organisms that have evolved on earth—they have value in and of themselves. He affirms that God co-suffers “with every sentient being in creation”, and that the cross of Christ is the “epitome of this divine compassion”, the moment when God takes “ultimate responsibility for the pain of creation”. Furthermore, he takes it as read (with Peacocke and others) that “an evolving creation was the only way in which God could give rise to the sort of beauty, diversity, sentience and sophistication of creatures that the biosphere now contains”. He also stresses the key importance of providing some account of salvation as “the eschatological fulfilment of creatures that have known no flourishing in this life”. Finally, he supposes that “humans are of very particular concern to God”, though this does not “exclude a sense that God delights in every creature that emerges within evolution” (all quotations ibid., p. 16). In this he discerns a high calling for humanity: to become not merely attentive observers and reverent priests, but even co-redeemers with God in healing evolved creation. I personally harbour doubts whether humanity is capable of aspiring to such a role—as discussed in chapter 10. Southgate questions whether Isaiah’s vision of God’s holy mountain, with carnivores and herbivores living peaceably together (and also with

An Evolutionary Theology

305

human beings, since “a little child shall lead them”; Isaiah 11:6), can have any meaning beyond its poetic allusions to harmony. These two categories of mammal have evolved very different abilities and strategies, and certainly no lion can eat hay like an ox (v. 7). Southgate (2008, p. 2) also quotes Holmes Rolston III: in evolutionary terms, it is “the cougar’s fang [that] has carved the limbs of the fleet-footed deer, and vice-versa”. For myself, having visited Kenya twice, I might have chosen cheetah and gazelle, but the point remains. The speed of both animals (so fascinating to us humans) in the chase is also a fundamental feature of their intrinsic natures—an essential part of what they are in God’s eyes. How could they be deprived of this in God’s new creation? Southgate (2008, pp. 88-89) quotes in full a possible resolution of this dilemma in James Dickey’s evocative poem “The Heaven of Animals” (Dickey, 1967/1978, pp. 59-60) [https://www.poetryfoundation.org/poems/42711/the-heaven-of-animals]; this poem is also reproduced by Johnson (2014, pp. 232-233). In essence, a redeemed predator continues to hunt its prey—because that is its natural instinct, not because it needs food—yet the prey suffers neither anxiety nor pain, but gets up and walks away unharmed. Of course, this begs myriad questions: if these “redeemed animals” are bodily creatures, how then are they sustained, if not by eating the foods for which their gut is adapted? There is a risk here of dematerialising resurrection, reducing life’s vibrant richness to “memories” committed forever to the mind of God (see later). Southgate (2008, p. 82) agrees in large measure with Edwards (above) about creaturely salvation, albeit with some caveats: “that simple organisms may possess little distinctive individual experience or agency, and…may be represented in the eschaton as types [species?] rather than as individuals. However, to assume that that is the situation of all creatures, including higher animals, runs the risk of not doing full justice either to the richness of individual animal experience or to the theodicy problems that evolutionary creation poses.”

Ruth Page (1996, p. 65) suggests another possible restriction on the salvation of non-human creatures in terms of their life experiences: “As far as creation is concerned, the Kingdom of God is the synthesis of those moments where freedom and love become actual, while the achievement of these purposes of God for the world are always among current possibilities… The fulfilments of God’s purposes are not lost, but are, so to speak, harvested as the fruits of creation… On the other hand, divine judgment is that, although relationship is always maintained with every creature, where there is no concurrence, or where there is no renunciation of consuming selfishness, there is nothing to harvest. These moments come under judgment, and fall into eternal oblivion.”

306

Chapter 8

While I would take issue with some of the phrasing here (can non-human organisms truly renounce consuming selfishness?), I concur with the thrust of this and similar passages in her book. She likewise writes of human salvation in terms “of moments, and their actors, which please God, rather than people who are pleasing from beginning to end” (ibid., p. 170). This at least short-circuits some of the problems posed by Catholic doctrines of Purgatory! Christians hope that God will “be merciful toward our iniquities, and will remember sins no more” (Hebrews 8:12, NRSV). Sin, with no place in God’s kingdom, must be erased by divine forgiveness. Conradie (2000/2005, pp. 283-286) explores the idea of resurrection in terms of inscription in the Book of Life (Philippians 4:3; Revelation 21:27) for individuals, or for those moments in each life that attest to fulfilment and flourishing (cf. Page, 1996). If all creation’s possibilities have been actualised through God’s love (§ 8.2.6), we should be properly cautious of limiting the scope of God’s memory, and perhaps in some sense this could be seen as a living inscription. However, this view can also be criticised on the grounds that “‘mere remembrance’ of what was created only contributes to a filling of the reservoir of divine experience” (Conradie, p. 285), granting no independence from God to creation. Paraphrasing James Nash, Conradie further suggests that a God who saves by flawless memorising is not the suffering servant embodied in Jesus, but rather a supreme ego. He goes on (ibid., pp. 286-290) to explore images of resurrection as cosmic pilgrimage or as homecoming banquet—this latter powerfully echoing Jesus’ parable of the Prodigal Son (Luke 15:11-32). However, before basking in an apparent consensus around optimistic hopes of universal salvation for animals (or perhaps for all life-forms), we should hear a sober note of caution, if not a dousing in cold water, voiced by the eminent Christian eco-theologian, Holmes Rolston III. In several books and essays he has debunked this whole comforting vision as something of a mirage, if not a delusion, asking pointedly what we think we mean by a redeemed ostrich or elephant? This “mirage” seems to him to smack of pious arm-waving—a kind of unfocussed all-inclusiveness that starts to break down and fall apart once pressed as to its details. One of Rolston III’s specific concerns with the idea of universal salvation involves what he sees as “slippage” in its use of theological terminology. It is one thing to assert that God is immanent in all matter, but quite another to claim that God is incarnate (enfleshed) in all matter. What is happening here is that an uncontroversial statement (theologically speaking), to the effect that God the Son became flesh (Greek sarx), has been vastly expanded and made all-inclusive, to encompass not just other human beings nor even other life-forms but the very stardust of which they

An Evolutionary Theology

307

are all made—thereby verging on pantheism (Rolston III, 2015, pp. 263264). He then makes the scriptural point that in John’s gospel “Jesus enfleshed” reveals “God’s solidarity with human suffering”, with no hint of any serious interest in “Jesus’ solidarity with grass or asteroids” (ibid., p. 264). To which defenders of “deep incarnation” (Johnson, 2014, quoted earlier; Gregersen, 2013) might well reply that John is writing from a human perspective for a human readership, and is addressing human concerns rather than those of modern science. Even so, we would do well not to over-stretch the biblical evidence in our desire to make grand overarching claims. Rolston III (ibid., pp. 269-275), also raises concerns about the practical details of universal salvation, concluding on p. 275: “Claim if you like that the incarnation redeems all animal flesh, but it is hard, so to speak, to ‘flesh out’ this claim with any specifics of how the work of Jesus benefitted the wild world. The claim seems vaguely reasonable so long as it is kept reasonably vague”.

Of course, he has his own axe to grind here—his concept of cruciform nature, whose “story is a passion play long before it reaches the Christ”. He continues “Since the beginning, the myriad creatures have been giving up their lives as a ransom for many. In that sense, Jesus is not the exception to the natural order, but a chief exemplification of it” (Rolston III, 2001, p. 60). Renewal of the natural world is seen in terms of flourishing, reproduction (which involves a reaching out beyond one self to another in all sexual organisms), and continuation of the species—whilst acknowledging that >98% of all species that have ever existed are extinct. But evolution’s winners are those that succeed in reproducing, while the losers are of no account except to die and become food for others, or contributions to the microbial recycling of nutrients. Though Rolston III’s environmental ethics celebrate the diversity of life and its intrinsic value, his cruciform nature offers no more final hope than the pronouncements of atheist evolutionists—except for those human beings granted redemption. Salvation becomes an exclusive club for humans, forever severed from their roots among the animals and other organisms in the vast tangled bush of evolution. While arguing forcefully against anthropocentric attitudes towards the wild world, he reinforces them in regard to eternal salvation by God. Southgate (2008, p. 50) exposes the nub of the problem here: “the ‘casualties’ of evolution…have suffering imposed on them by God for the long-term good of others…[but] without any reward to themselves.” Eaton (2017, pp. 214-215) tries to move beyond anthropocentrism by positing divinity that is “radically plural and irreducible to any one form, calling into question the imperialism of any one…species over another”. Here we are back to a God incarnate in all life, if not all matter, falling into the trap

308

Chapter 8

of unbiblical vagueness to which Holmes Rolston III takes exception, and risking accusations of pantheism—or at least of panentheism (§ 7.5.2). As a postscript, the possibility of universal salvation focusses renewed attention on the neglected Christian festival of the Ascension. Two slightly different accounts are given by Luke, one at the end of his gospel (Luke 24:50-53), the other providing rather more detail at the start of Acts (1:511). These books were conceived as a 2-part account of Jesus and the early church, but their original continuity has been dislocated by the insertion of John’s gospel between them in the New Testament canon. But the effect of the ascension is to put an end to the period of resurrection appearances by the risen Jesus and to prepare the apostles for the Holy Spirit descending at Pentecost. Though ascension is usually seen in terms of Jesus returning to the Father (whatever we might make of the qualification in heaven), it also carries the implication of Christ’s humanity becoming united with, or incorporated into, the Godhead. Peter Manley Scott takes up this idea and expands it to include not just humanity, but animals as well. In his forbiddingly titled book, “Anti-Human Theology” (2010), he seeks to bring the “anti-human” (including animals and “hybrid” GM life-forms) within the scope of God’s salvation precisely through the ascension: “Theology…knows that true humanity—that is also true animality?—is already preserved by God through the ascension of Christ. The anti-human is grounded in the ascension….. Because for God the human cannot disappear, there is no compulsion to identify the difference of the human from the animal….” And later, “Jesus’ humanity thereby participates in the shared life of God and is the ‘place’ from where he participates in God’s redeeming work in the world as God. By way of this humanity, which is constitutional for God, this Jesus is constitutive of the history of all creatures, human and non-human.” [Scott, 2010, pp. 71-72].

Scott’s theme in this book is a political theology of non-human creation rather than evolution, but this passage at least hints that the ascended Christ draws into the Godhead not just human nature, but also the natures of all the organisms with whom we are linked by innumerable variations on our shared inheritance of DNA sequences. All life-forms trace their lineage to a common ancestor in the primordial soup of the early earth (§ 1.7), diversifying into “endless forms most beautiful” (from the closing sentence of Darwin’s 1859 “Origin of Species”)—as traced through chapter 2 and in earth’s fossil history in chapter 3—by way of the myriad kindred pathways of development (chapter 4), to produce inter alia the amazing complexity and subtlety of human brains and culture (chapter 5). Not that humanity is necessarily God’s (or evolution’s) last word, but in the fullness

An Evolutionary Theology

309

of time we have been vouchsafed glimpses of the God who invites creation into being in order to explore its innumerable possibilities and fulfil its potentialities, so that all may have life, and have it to the full (John 10:10). This aim is frustrated by subjection to decay and futility (for which read entropy; Mix, 2020), but Romans 8:21 promises that all creation will finally be brought into the “same glorious freedom as the children of God”. It is perhaps appropriate to end this final section with a couplet from the closing verse of Isaac Watts’ well-known hymn “Jesus shall reign”: “Let every creature rise and bring / Peculiar honours to our king.” Peculiar—not in the sense of bizarre or unedifying—but rather in the sense of appropriate or fitting. A bird might offer its most iridescent feather, a gentian the most intense of all its blue flowers, a cheetah or an antelope its fastest-ever run, a gnarled forest tree the moment when it was transformed by veils of mist in dawn’s first light. At such moments, creation may find fulfilment—not just to our eyes, but also to the God whose image we bear.

CHAPTER 9 EVOLUTIONISM IN THE PULPIT

Summary After some brief background to the title, this chapter is framed by general discussions of scriptural interpretation (exegesis; § 9.1), also raising the question of whether science can provide illumination of biblical texts. My conclusion is a cautious yes, whilst admittng that evolutionary hermeneutics are impossible (§ 9.7) because the authors of these texts had no conception of evolution. The central sections of this chapter look at several familiar biblical texts—mostly from the gospels— in the light of current evolutionary understanding. § 9.2 asks whether, to paraphrase Jesus’ words about the rich and pious, organisms that succeed in passing on their genes “have their reward already”. § 9.3 looks back to Isaiah 45 and a God who creates both weal and woe (this last featuring prominently in evolution)—a more robust Creator than the one portrayed in the rest of this book. § 9.4 picks up on God’s care for the sparrows, and § 9.5 extends this to the lilies of the field in all their glory. Both texts imply that God values the ordinary and common creatures of this world, not merely the rare and exotic that so fascinate humans. § 9.6 applies this approach more systematically to multiple texts from the gospel of Mark—starting with Jesus’ call to another way of being, followed by the parable of the sower, then Jesus’ concern for children, how leaders should become servants, and the rejected stone being raised up as cornerstone. Themes of betrayal, suffering and death end this section, all with evolutionary resonances. The title of this chapter mirrors that of a pseudonymous essay by “An Occupant of the Pew” (1915), published in volume VIII of Fundamentals, as mentioned earlier in § 6.5. The style of the original essay (text available online at hathitrust.org) is telling—and all too typical of creationist attacks on evolution. Indiscriminate dismissals of Darwin’s arguments are based partly on conservative theology—that the uniqueness of human beings in general and of Christ in particular are thereby undermined—and partly on

Evolutionism in the Pulpit

311

opinions and comments (taken out of context) culled from contemporary academic “experts”, most of whose names are long forgotten. Two brief quotations will suffice: evolution is seen as “a system based on hypothesis only…which was, and is still after the lapse of forty years, without a single known fact to support it” (ibid., p. 27). But a faith basis for this critique later emerges; “evolutionary theory was conceived in agnosticism, and born and nurtured in infidelity” (ibid., p. 31). The remaining sections of this chapter try to counterbalance these sweeping assertions on the basis of scripture: perhaps evolutionism can indeed be preached from the pulpit. After considering a personal selection of assorted texts in § 9.2 to 9.5, I apply this approach more systematically to the gospel of Mark in § 9.6.

9.1 The task of scriptural interpretation (exegesis) There is no single “correct” way to interpret the holy writings of any religion—including Christianity. Evangelicals want to insist on priority for the plain meaning of any biblical text, except where this is absurd or selfcontradictory, in which case a non-literal interpretation may be allowed. Fundamentalists nevertheless insist on literal exegesis, which at least has the merit of clarity (“the text means exactly what it says”). We have seen earlier how Sam Berry dealt with both literal and non-literal interpretation of the early chapters of Genesis, and other instances where his evangelical faith seemed to contradict his evolutionary convictions (§ 7.3). Catholic or Orthodox interpretations of scripture temper the biblical text itself with the tradition of that church, while liberals seek to counterbalance these twin strands with an appeal to reason. In truth, all these (and other) approaches to exegesis are prone to the same error of resorting to favourite proof texts as confirmation of their validity. To cite just one example, against my own preferred liberal approach to scripture, it is easy to over-interpret Galatians 3:28 (“there is no longer Jew or Greek…slave or free….male and female”) as a clarion call for equality and tolerance between the sexes, and between those of different races or social status. But this downplays the importance of its final clause, “for you are all one in Christ Jesus”. In and of itself, this verse does not forbid sexism, racism or even slavery in society at large; it simply asserts that such attitudes are inappropriate in a Christian context. This is not the place to explore the tangled history of biblical exegesis, though anagogical (pointing heavenwards), tropological (drawing moral lessons), allegorical or mystical interpretations were commonplace in the writings of early Church Fathers We are used to written text as fixed and immutable, but comparisons between several translations of the same bible passage often reveal subtle differences of wording or emphasis, reminding

312

Chapter 9

us that the original version was written in a different language—initially without any punctuation. Thus familiar biblical phrases (memes) can only approximate to the writer’s intended meaning. Many parts of the bible (including the gospels) were written down long after the events described, and often not by the original witnesses. This betokens a prior oral tradition where selective memory must have played an important role. Details that lodged in one hearer’s mind as significant may well have been dismissed as irrelevant by another, a feature that emerges most clearly when the same events are recounted in two parallel books (e.g. Kings and Chronicles), or more (the 4 gospels). In the case of narrative passages, many elements are only sketched in briefly, while others (such as genealogies) are spelt out in tedious and unnecessary detail—at least to modern eyes. This should emphasise the importance of reading scripture with the imagination—as in Ignatian contemplation—where readers or listeners imaginatively immerse themselves in the sights and sounds of a familiar gospel story before identifying with just one of the characters, be it protagonist or bystander. By imagining oneself in different roles within the same story, different facets of the narrative emerge—with varied application to one’s own life. Karen Armstrong (2019) has argued passionately for a nuanced and multi-tiered approach to scriptural interpretation—applying this principle not only to the Christian bible, but also to the Qu’ran and texts sacred to Eastern religious traditions such as Hinduism, Buddhism or Confucianism. She confronts the fundamentalist streams within each of those religions by challenging their univocal “plain meaning” interpretation, so often used to defend oppressive doctrines that subjugate women or advocate violence against dissenting voices or infidels. In her view, the sparse texts used as justification for these stances are of peripheral significance, or can bear alternative interpretations—they are not axiomatic dogmas without which the entire edifice of religious faith would collapse, as is so often claimed. Scripture should reclaim its proper role as a spiritual tool-set for enabling believers to enter into relationship with the divine. Ignatian contemplation, mentioned above, is a case in point—as are many other spiritual practices. Indeed, scriptural interpretation goes hand in hand with—and frequently emerges out of—religious ritual and praxis. She calls for a rediscovery and re-evaluation of myth—not as something false or invented, but “as a timeless truth that in some sense happened once but which also happens all the time” (Armstrong, 2019, p. 8), e.g. the Fall. Our modern emphasis on reason (logos) has made mythos, and scripture in particular, difficult to accommodate or give ear to. It is far simpler to dismiss its emotive power as a dangerous delusion, as secular atheists are fond of reminding us. But just as both the left and right brain are required for full human functioning

Evolutionism in the Pulpit

313

(see McGilchrist, 2009), so too are their prevalent domains of logos and mythos, respectively. “Because it does not conform to modern scientific or historical norms, many people dismiss scripture as incredible and patently ‘untrue’ but they do not apply the same criteria to a novel, which yields profound and valuable insights by means of fiction” (Armstrong, 2019, p. 9). I don’t believe that she is here equating scripture (or even myth) with invented fiction, though “fictional” elements and embellishments do undoubtedly occur in all holy writ. Sifting these out from the core truths contained in these ancient texts is a task for scriptural scholars within each faith tradition. But “fictitious” details enhance the overall impact of any narrative, though some of the faithful may find these aspects distracting or unhelpful; Peacocke’s rejection of miracles (§ 7.5.2) is a case in point. But it is worth adding that one person’s fiction is another’s core tenet of faith. The power and appeal of scripture transcend differences of interpretation. Among the ambiguous histories in chapter 6, we glanced briefly at Psalm 29 (§ 6.7), and at the shadowy figures of Doubting Thomas and Mary Magdalene (§ 6.9). In all these cases, there seems to be more going on than meets the eye—even if we do not buy into the Canaanite model for this Psalm (and others), or the Gnostic gospels attributed to both Mary and Thomas. Most preachers make extensive use of biblical commentaries to illuminate a sermon with background details and underlying meanings that may be unfamiliar to the congregation. But it is always good practice to ask first what any given text might have meant to its original readers or listeners (hermeneutics), before applying its lessons to current issues or situations. In this chapter, I am attempting a risky combination of current and allegorical interpretations, omitting any in-depth exploration of the original meaning of each text. The “allegorical” truth that I am expounding is evolution—but I make no claim that these scriptural passages provide evidence favouring evolution, nor that they were written with any such interpretation in mind. Even so, they often find unexpected resonances in the light of evolutionary science, which may suggest new ways in which they could be understood. I am not arguing that these interpretations are any more valid or relevant than many others available, nor would they ever have occurred to either readers or listeners during most of Christian history. My purpose here is simply to show that evolutionary interpretation or exegesis of certain biblical texts can, on occasion, prove illuminating.

314

Chapter 9

9.2 Rewards in this life and beyond “And whenever you pray, do not be like the hypocrites: for they love to stand and pray in the synagogues and at the street corners, so that they may be seen by others. Truly I tell you, they have received their reward.” [Matthew 6:5, NRSV]

“But woe to you who are rich, for you have received your consolation.” [Luke 6:24, NRSV] Matthew applies this warning specifically to those who strut their piety ostentatiously (most likely aimed at the Pharisees and other religious authorities), whereas Luke applies it more generically to the rich. Both groups have received their reward (or consolation) already in this life. By contrast, those whose piety or possessions are more modest will receive their reward from the Father in heaven. Both texts bear an obvious parallel with the thrust of evolution by natural selection, where those that succeed in passing on their genes have their reward already, in a very real sense. But what of the multitudes that fall by the wayside, the evolutionary and reproductive dead-ends whose hopes for any kind of genetic future are dashed by the luck of the draw, with huge odds stacked against them? Humans faced with a diagnosis of complete infertility know the score here, where even the gift of a child by adoption or surrogacy or gamete donation can never quite compensate for a lack of genetic relatedness—since one’s own familiar traits will never crop up unexpectedly (even embarrassingly!) in such children. The vast numbers of organisms that fail to reproduce successfully, due to the exigencies of natural selection, may seem of little concern to humans—yet infertile people experience what this actually feels like, though not all are necessarily distressed by a lack of children in their lives. Many creatures without issue may likewise be unconcerned, but for others there might indeed be frustration, sadness, and even a sense of loss. Moltmann (1989/1990), as discussed earlier in § 8.5.2, believes that the poor and oppressed are already members of God’s kingdom, and will receive their reward or consolation beyond this life. This can be read as pie in the sky when you die, though he also points to the dignity and solidarity conferred now by kingdom membership. It is the rich (or pious hypocrites) who need to repent in order to enter God’s kingdom—otherwise they will be sent away empty (Luke 1:53). Moltmann also holds that the countless victims of evolution’s “killing fields” will find salvation in the eschaton— the final fulfilment of all things. As noted at the end of § 8.5.2, this must be counted as hope rather than as certainty; the appealing grandeur of Moltmann’s overall vision may dazzle us into glossing over the very real

Evolutionism in the Pulpit

315

problems that such universal salvation entails, as pointed out by Holmes Rolston III. If some aspects of creation or experience (as Ruth Page would see it; 1996, p. 171) are to be consigned to oblivion as incompatible with God’s kingdom, then the twin texts at the head of this section could be read rather differently—along the lines of Jesus’ story about the rich man and Lazarus (Luke 16:19-31), where a great chasm has been fixed between the blessed and the damned. There are also hints in the Old Testament that God’s judgement against the “rich” may extend beyond the human realm, though passages such as Ezekiel 34:15-24 clearly refer to the lost sheep of Israel rather than literal flocks of livestock. God promises in this text that: “I will seek the lost, and I will bring back the strayed, and I will bind up the injured, and I will strengthen the weak, but the fat and the strong I will destroy. I will feed them with justice.” [v. 16, NRSV].

Then, four verses later: “Therefore, thus says the Lord God to them: I myself will judge between the fat sheep and the lean sheep. Because you pushed with flank and shoulder, and butted all the weak animals with your horns until you scattered them far and wide, I will save my flock, and they shall no longer be ravaged: and I will judge between sheep and sheep.” [vv. 20-22, NRSV].

And, lest we miss the link here to Jesus’ later picture of the sheep and goats at the Last Judgement (Matthew 25:31-46), Ezekiel 34:17 states: “As for you, my flock, thus says the Lord God: I shall judge between sheep and sheep, between rams and goats” (NRSV). Of course animals are not aware of God’s “code of conduct”, and can only follow the dictates of their own innate natures (teleonomies), hence they cannot be condemned for doing so, however unpleasant the end result may look to human sensibilities. But at the least, it would not be inconsistent with scripture to suggest that God might save whatever in a creature’s life speaks of joy or fulfilment, of flourishing or even altruism (insofar as such capacities are open to it), yet consign to oblivion all the suffering and cruelty and selfishness of that life (Page, 1996, pp. 65, 170-171; discussed in § 8.5.2). Taken as written, all these biblical texts apply first and foremost to human beings and the ways they behave towards each other and before God. But, by extension into an evolutionary context, similar behaviours characterise animals and perhaps other organisms too—hence the appropriateness of Ezekiel’s imagery in this passage. Jesus’ earthly ministry was focussed on the poor, oppressed and marginalised, so might we not expect a similar bias toward the losers in evolution’s “struggle” to survive and reproduce? Sexual selection (§ 2.8) commonly entails violent, sometimes fatal, conflicts between males to

316

Chapter 9

secure a mate or mates—where it is the winner who takes all. Similar considerations apply to the pecking order when social animals gather to feed together; dominant individuals get the richest pickings, while those lowest on the social scale have to make do with the scraps—if anything. All these behaviours are reminiscent of Ezekiel’s sleek and well-fed sheep, butting aside and scattering the weaker animals. God sides with the latter, not the former—who have indeed had their reward already in terms of reproductive success and plentiful food. Rich pastures and abundant water, under the protection of the caring shepherd (God), are promised to the weak or needy, reversing whatever social hierarchies existed here on earth.

9.3 A sovereign God? “I am the Lord, and there is no other. I form light and create darkness. I make weal and create woe; I the Lord do all these things.” [Isaiah 45:6c-7, NRSV]

Given my arguments for a non-interventionist God of love as set out in § 8.2 and 8.3, this might seem an odd choice of text. But I am well aware that, for many Christians, the picture I have painted earlier is too wan and impotent to be recognisable as the Almighty God whom they worship. This short section therefore looks at the traditional view of God’s power permeating the entire universe. The context here is important: Isaiah 45 as a whole is addressed to Cyrus, king of Persia, who liberated the people of Judah from their Babylon captivity in 539 BCE, as is also told in the book of Ezra. According to Isaiah, Cyrus is an unwitting tool in God’s hands, raised up to effect a liberation of God’s own people. On this reading, God’s punishment against idolatry and corruption during the reigns of most of David’s successors in Judah had run its course after 50+ years of exile, and the captives could at last return to their homeland. Isaiah 45:13 clarifies the instrumental role of Cyrus: “I have aroused Cyrus in righteousness, and I will make all his paths straight: he shall build my city and set my exiles free, not for price or reward, says the Lord of hosts” (NRSV). This whole chapter provides a concise statement of God’s rule over all things— brooking no questioning or opposition: “Woe to you who strive with your Maker, earthen vessels with the potter! Does the clay say to the one who fashions it, ‘What are you making’? or ‘Your work has no handles’?” (v. 9, NRSV). The verse quoted at the start of this section offers an alternative view of God’s role in evolution, directing or overseeing the entire process, whether or not humanity is truly its final culmination. This could even entail the micromanagement of every detail, so long as the greater good of God’s purposes in creation justifies the immense attendant costs along the

Evolutionism in the Pulpit

317

way. Arthur Peacocke (2001, p. 36) asked whether evolution by natural selection (however cruel to our eyes) is the only way in which the diversity and richness and adaptability of life on this planet could possibly have arisen. Though this makes a telling point, I remain uncomfortable with the idea of God as “director” of the evolution epic—especially if only humans are to be saved, such that the whole preamble of life on earth up until our belated appearance would count for nothing in God’s eyes (§ 8.2.3 above). One way or another, all of my key thinkers in chapter 7 have argued for some sort of “causal joint” allowing God to act in the world—though Peacocke at least seeks to locate this within the natural processes that science detects and measures. Berry would doubtless argue for miraculous interventions as well, though these can be explained (often implausibly!) in naturalistic terms. Teilhard would point to the teleological attraction of the cosmic Christ drawing all things towards the Omega Point, while Deane-Drummond might infer that God’s purposes find fulfilment in the theo-drama of creaturely secondary causes within the framework of God’s over-arching primary cause. But a God who acts in or on creation is also in some sense responsible for whatever happens in that creation. And while some creaturely suffering may be more apparent than real, there is a heavy cost involved, albeit one that is mitigated by Christ’s identification with, and redemption of, that suffering. At least Isaiah 45:7 comes clean about this, with no beating about the bush: “I make weal and create woe”, says God. I think this text can allow a robust defence for evolutionists who want to proclaim an interventionist God, whose purposes are beyond our comprehension (exemplified by the book of Job). My “hands-off” God of uncontrolling love is unlikely to appeal to such people (too wishy-washy!), even if it offers an alternative for those who find it difficult to reconcile the process of evolution with the God of love attested by Christianity. And in the last analysis, the contrast here is not quite as stark as I have drawn it, because a God who calls possibilities into existence and allows them to find their own fulfilment, yet refrains from interfering when developments go awry, still retains overall responsibility for everything that is. In that sense, nothing happens outside God’s will, even though such a God does not actively cause woe, suffering or evil. Nevertheless, out of God’s free choice, God the Son came into this world to show the extent of God’s love for humans and for all creation, even to the extent of dying with and for us, showing us through resurrection that death does not have the final say.

318

Chapter 9

9.4 God’s care for the non-human creation “Are not five sparrows sold for two pennies? Yet not one of them is forgotten in God’s sight. But even the hairs of your head are all counted. Do not be afraid; you are of more value than many sparrows.” [Luke 12:6-7, NRSV].

The Greek word translated here as “forgotten” is HSLOHOƝVPHQRQ, and consulting a Greek lexicon reveals three further meanings that modify and expand the usual sense of forgotten: these are (i) neglected, (ii) uncared for, and (iii) given over to oblivion. The first two of these additional qualifying senses point towards God’s ongoing concern and care for the non-human creation, while the third suggests a possibility of ultimate redemption (as opposed to the oblivion of nothingness) in God’s kingdom. Sparrows—an unremarkable species of bird by any standard—here stand in as proxies for all living organisms. Nevertheless, the last clause of v. 7 implies that there is some kind of “scale of value” for God, where sparrows rank lower than humans. We should not presume to guess what value God assigns to any given species or individual within that species, or whether indeed some “lower” life-forms such as microbes may be redeemed by God as kinds or species. It is unlikely that God’s valuations correspond to the instrumental values allocated by humans to the animals and plants we have domesticated. As for wild creatures, humans find some more aesthetically pleasing or value them more highly (so affording them better protection) than those viewed with less favour (see Sandler, 2012, on the ethics of species). God might conceivably value species according to their ecological importance as functional elements within ecosystems, but this is a biocentric ranking that does not privilege humans over other species—perhaps contradicting Luke 6:7. All we can hope is that God loves all creatures for what they truly are, in and of themselves. The natural world figures rather little in the New Testament, apart from some of the illustrations used by Jesus in his sayings and parables. However, it is more prominent as a scriptural theme in the Hebrew Old Testament. Keen observation of nature informs much of the Wisdom literature (see § 7.4.2), as typified by God’s answer to Job’s protestations (Job 38:39-39:30; 40:15-41:34). It seems legitimate to infer that God takes delight in non-human creation, as well as in human beings. In and of itself, that is no guarantee of salvation for animals, let alone other creatures— though the peaceable co-habitation of predator and prey envisaged in Isaiah 11:6-9 and 65:25 could bear such an interpretation. Moreover, the whole created order—from mountains and rivers to cedar forests—joins together with humanity in praising God (Psalms 65:12-13, 98:8, 148:7-10,

Evolutionism in the Pulpit

319

150:6; Isaiah 44:23, 55:12). Maybe that praise also resounds through God’s redeemed creation, the kingdom announced and embodied in Jesus?

9.5 Glory to God? “‘Consider the lilies, how they grow: they neither toil nor spin; yet I tell you, even Solomon in all his glory was not clothed like one of these. But if God so clothes the grass of the field, which is alive today and tomorrow is thrown into the oven, how much more will he clothe you—you of little faith!’” [Luke 12:27-28, NRSV; cf. Matthew 6:28-30].

I confess I slipped in this text as a self-indulgence—since it has little relevance to evolution or to the fate of non-human creation—even though the earlier parallel saying about the ravens (Luke 12:24) reinforces § 9.4 in terms of God’s care for the world of nature, whilst according greater value to human beings than to birds. I have of course used v. 27 as the epigraph for this book, not least because so many of its illustrations are photographs of flowers, reflecting my 60-year fascination with botany. But my reason for commenting on this passage here is that it seems to say something important and unexpected about God’s own view of glory and beauty. The scriptural word-pictures of Almighty God become increasingly opulent as we read onwards through the bible. The God who sought Adam and Eve in the garden in the cool of the day (Genesis 3:8), or who called to Moses from an unconsumed burning bush (Exodus 3:1-6) and to Elijah as a “still small voice” (1 Kings 19:11-13), becomes enthroned and wreathed in smoke for the call of the prophet Isaiah (6:1-8), and is seated on a throne resembling sapphire when calling Ezekiel (1:26-28). In the Old Testament royal annals, vast riches flooded in from across the known world to the court of King Solomon (2 Chronicles 1 to 9), in tribute to his legendary wisdom. So it is telling that Jesus makes an unfavourable comparison between the glory of Solomon’s clothing and that of “lilies of the field” (possibly the Asian Buttercup, Ranunculus asiaticus). In choosing such a common flower, or common birds such as ravens and sparrows, Jesus finds beauty and significance—even glory—in the ordinary and unremarkable, just as he does in human beings (see § 8.3). We humans are all too easily dazzled by gold and jewels and rich fabrics—or indeed by exotic rare animals or flowers—but perhaps these have no greater significance for God than do many pedestrian species. We should look afresh at overfamiliar weeds or pests, marvelling at the intricacy of their structures and at their sheer resilience and adaptability, which have allowed them to colonise disturbed or polluted habitats, and which may increase their chances of surviving a sixth mass extinction (chapter 10); they may in time

320

Chapter 9

be all we’re left with. Examples include the intricate flowers of 4 common weeds, the Red, Henbit, Northern and Intermediate Dead-Nettles (Lamium purpureum, L. amplexicaule, L. confertum, L. hybridum) in Figure 2-13F-I. The fact that the glory of these lilies is transient—here today and gone tomorrow—reminds us of our own mortality, especially in relation to our youth or any beauty we may once have possessed. Its passing does not in any way diminish us—and maybe, following Page (1996), all this will be saved from oblivion by God. Jesus’ words also suggest that true glory can be glimpsed only in the moment of perception—in the sinuous motion of a fish underwater, in a glorious sunset, or in the spreading of a butterfly’s wings before it flutters off. These are true treasures—perhaps laid up for us in heaven—not the false permanence of precious stones and metals, the “treasures on earth , where moth and rust consume and where thieves break in and steal” (Matthew 6:19, NRSV). Perhaps we fail to glimpse God’s glory, not so much because of our sinfulness, but because our blinkered vision pays so little close attention to what is all around us. Given the urgency of curbing our profligate consumerism (chapter 10), we might usefully ponder the many layers of meaning in this passage from Luke—inviting us to see humble and ordinary things in a different light.

9.6 Evolution according to Mark 9.6.1 Finding another way In the rest of this chapter, I shall take readers on a journey through the gospel of Mark, offering brief evolutionary perspectives on a series of familiar stories and sayings. The words of Jesus’ proclamation in Mark 1:15 are translated in the NRSV as: “The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news”. But the Greek root of the imperative verb “repent” is metanoeite, which literally means “change your mind”, or even “enlarge your world view” (Rohr, 2019, pp. 92-93)—a far cry from the usual sense of regret and doing penance for our sins. We are called to seek another way—God’s way. Although Mark gives no details about the temptations proffered by Satan during the 40 days Jesus spent in the wilderness after his baptism, he does mention that Jesus was with the wild beasts (Greek thérion) and that angels waited on him. The former is usually taken to underline the solitude and very real danger from large predators (probably including lion and leopard) in the rugged terrain of southern Judaea. An alternative view is that Jesus, as the second perfected Adam, related naturally and without fear to animals (and they to him), just as Adam had once named them in

Evolutionism in the Pulpit

321

Genesis 2:19-20. Without overstretching the meaning of the word “with” (Greek meta), one can infer an element of sojourning or communing with the wild beasts. The term “companioning” (Page, 1996) seems to fit the bill exactly here. Elsewhere, Mark uses meta of the 12 disciples whom Jesus called to be with him (Mark 3:14); likewise, once restored to his right mind, the Gerasene demoniac pleads to be with Jesus (Mark 5:18). Once again, we glimpse another way of being in the natural world. Mark 2:1-12 tells how the resourceful friends of a paralysed man circumvented the crowds and let him down through a hole dug in the roof so that Jesus could heal him. They too found another way to keep faith with their paralysed companion. This is a case of inspired improvisation, the kind of thing that surfaces time and again in evolution, where bizarre adaptations and novel structures have arisen through the modification and exaggeration of familiar developmental processes, by dint of changes in the regulation of genetic modules from the standard repertoire (as outlined in chapter 4). Faced with seemingly insurmountable challenges, such as living in the extreme cold of Antarctic seas or the heat of hydrothermal vents, life finds ways of coping, even thriving—since both environments offer nutritional bonanzas to organisms that find another way to survive.

9.6.2 Paradox of the sower “‘Listen! A sower went out to sow. And as he sowed, some seed fell on the path, and the birds came and ate it up. Other seed fell on rocky ground, where it did not have much soil, and it sprang up quickly, since it had no depth of soil. And when the sun rose, it was scorched; and since it had no root, it withered away. Other seed fell among thorns, and the thorns grew up and choked it, and it yielded no grain. Other seed fell into good soil and brought forth grain, growing up and increasing and yielding thirty and sixty and a hundredfold.’ And he said, ‘Let anyone with ears to hear listen.’” [Mark 4:3-9, NRSV].

As told to a “very large crowd” (v. 1), these words describe a familiar agricultural situation. English translations of the Greek gospel text have fortuitously introduced a telling double meaning for ears—both heads of seed (stachus) and organs for hearing (ota), though this is absent from the original. But this passage can also illustrate the contingency of evolution. For simplicity’s sake, let us assume a genetically uniform population of seed grains. Some are simply wasted, becoming food for other creatures— a common fate for many organisms and their reproductive stages. Others fail to find a suitable environment in which they can thrive, while yet others are outcompeted by more vigorous life-forms. Only a few are able

322

Chapter 9

to find an optimal niche and survive to reproduce in turn. All this reflects the initial dispersal of the seeds—which was casual if not exactly random. If there were genetic differences between seeds (likely), some may have had propensities to develop shallow root systems—resulting in droughtand heat-sensitivity—while others may have grown more slowly, allowing competitors the edge. Only those with genotypes suited to the prevailing environment would flourish and multiply. Needless to say, Jesus’ parable was never intended to illustrate evolution, and his own explanation of this parable to his followers (Mark 4:14-20) is both succinct and pointed.

9.6.3 Children versus progeny “[A Gentile woman…of Syrophoenician origin] begged him [Jesus] to cast the demon out of her daughter. He said to her, ‘Let the children be fed first, for it is not fair to take the children’s food and throw it to the dogs.’ But she answered him, ‘Sir, even the dogs under the table eat the children’s crumbs.’ Then he said to her, ‘For saying that, you may go—the demon has left your daughter.’” [Mark 7:26-30, NRSV] “…[The disciples] were silent, because on the way they had argued with one another about who was the greatest. He [Jesus] sat down, called the twelve, and said to them, ‘Whoever wants to be first must be last of all and servant of all’. Then he took a little child and put it among them; and taking it in his arms, he said to them, ‘Whoever welcomes one such child in my name welcomes me, and whoever welcomes me welcomes not me but the one who sent me.’” [Mark 9:34-37, NRSV] “People were bringing little children to him [Jesus] in order that he might touch them; and the disciples spoke sternly to them. But when Jesus saw this, he was indignant and said to them, ‘Let the little children come to me; do not stop them; for it is to such as these that the kingdom of God belongs. Truly I tell you, whoever does not receive the kingdom of God as a little child will never enter it.’ And he took them up in his arms, laid his hands on them, and blessed them.’” [Mark 10:13-16, NRSV]

These three rather disparate passages all centre around children— indeed, Mark 9:17-29 about the healing of an epileptic boy could also have been included. Like women, children in Jesus’ day were of low social standing—perhaps because so many of them would succumb to disease or accidental mishap. Likely survivors would be difficult to pick out, and too great a parental investment in any given child might prove a risky strategy. But fairness and good nourishment for children remain natural concerns, as Jesus’ apparent dismissal (or testing?) of the Syrophoenician woman suggests (Mark 7:27). Her perceptive reply (v. 28) incidentally illustrates a

Evolutionism in the Pulpit

323

key feature of evolution and of ecology in general: that nothing much ever goes to waste. The leftover scraps on a carcass are stripped by vultures and maggots, even excreta are dealt with by dung beetles and other soil organisms—and ultimately by the microbes that complete the processes of nutrient recycling. Of course, this is by the by—not the point of the story. Some commentators have seen this as a pivotal point in Mark’s gospel, where Jesus opens up God’s kingdom to all nations, his mind perhaps changed and his horizons even broadened by the woman’s skilful answer. The other two passages quoted, from Mark 9 and 10, emphasise the high regard in which Jesus held children. Welcoming children in his name is an essential part of our calling as Christians—not to indoctrinate them so as to perpetuate the church, but to listen to them and learn from them. Psalm 8:2 contains the startling sentence: “Out of the mouths of babies and infants you have founded a bulwark [or established strength] because of your foes, to silence the enemy and the avenger” (NRSV). This has entered common parlance as pointing to the insightfulness of children— sometimes they see things more clearly than cynical adults, and perhaps they also notice more because they are not blinkered by prejudice as to what they should expect to find. These are qualities essential in scientists —not to dismiss the errant outlier that annoyingly implies the inadequacy of current models or hypotheses (§ 1.1). To welcome and pay attention to children recognises their frequent insights and openness to the world around them. This is perhaps why we adults are called to receive God’s kingdom like little children—with both wonder and gratitude—wherever we may glimpse it. As pointed out by Deane-Drummond (§ 7.4.2), wonder and curiosity are hallmarks of scientists too, refusing to rest content with received wisdom. One general lesson from these texts is their focus on the future—the next generation—who will inherit not only our insights but also the mess we bequeath them through short-sighted greed and selfishness— as highlighted recently (2019) by youthful Extinction Rebellion protesters. Evolution focusses instead on progeny, providing raw genetic material for natural selection to act on. This stands in contrast to Jesus blessing of the children—his welcome and compassion set over against the “pitiless” winnowing by evolution of embryos and larvae and juvenile forms that never make it to maturity, finding no opportunity to flourish, let alone to reproduce and see their genes passed on to future generations. Since Jesus is the good shepherd, who lays down his life for the sheep (John 10:11), how should we interpret his statement of intent in John 10:10, whereby he came “that they may have life, and have it abundantly”? Among humans, and even among faithful Christians, not all children have “abundant life”.

324

Chapter 9

If we believe in a “universal Christ” who offers salvation to the whole of creation (discussed in § 8.5.2 above), will those myriads of juvenile lives cut short by selection or happenstance in this world find true flourishing in the eschaton, in the promise of God’s new creation? Rohr (2019, pp. 4648) calls for a ‘paradigm shift’ away from an individualistic focus on personal salvation by Christ towards a universal salvation in Christ that embraces all of humanity—or indeed all of creation.

9.6.4 Servanthood “So Jesus called them [the disciples] and said to them, ‘You know that among the Gentiles those whom they recognize as their rulers lord it over them, and their great ones are tyrants over them. But it is not so among you; but whoever wishes to become great among you must be your servant, and whoever wishes to be first among you must be slave of all. For the Son of Man came not to be served but to serve, and to give his life as a ransom for many’”. [Mark 10:42-45, NRSV]

This is another passage in which Jesus illustrates evolutionary themes by contradiction—calling his followers to live out a more enlightened and all-embracing calling. What he says about human rulers or tyrants applies equally to many social animals—where the queen or alpha male, pack chieftain or clan matriarch, exercises leadership prerogatives over the rest of the group. The roles and freedoms allowed to subordinates vary from species to species, or even (to an extent) from group to group—but human societies seem little different from this familiar pattern. Democracy has not diminished the importance of elected leaders, nor did communism ever succeed in establishing common ownership of the means of production in a classless society. Despite egalitarianism in the earliest church (Acts 2:4447, 11:29-30), recognised leaders soon emerged within it—not least Peter and Paul. The original institution of 3 (or 4) ordained vocations in the church—as laity, deacons, priests or presbyters, and perhaps bishops (§ 8.4.5)—soon became a hierarchy, with attendant privileges of increasing power that have frequently been misused—leading all too often to abuse of the weak or disenfranchised. We Christians have thus been “conformed to this world” (despite Paul’s injunction in Romans 12:2), at least in terms of church power-structures and assumptions of privilege. Recent emphasis on servant leadership in clergy training circles has only begun to address this imbalance. It is possible to take on leadership responsibilities and yet remain essentially humble, as the examples of Mahatma Gandhi, Nelson Mandela, Desmond Tutu and Pope Francis attest in recent times. But it is rare to find this at the top of the greasy pole of preferment and promotion,

Evolutionism in the Pulpit

325

and even then, the phrase “slave of all” is rarely if ever applicable. Yet this is exactly what Jesus enacted for us by washing his disciples’ feet (§ 8.3.3). A fortiori, since humanity exerts reckless domination over most of the earth’s ecosystems—as opposed to the exercise of responsible stewardship (dominion; Genesis 1:28)—such servant leadership offers the only realistic hope for the future of the natural environment. This calls for moderation, for a curbing of our “will to power” in Nietzsche’s apt but ominous phrase. We may note that Nietzsche (1887/2003) also decried the slave mentality of Christians, which he viewed as a breeding ground for resentment and fantasies of revenge (cf. Psalm 137:9), as exemplified in the whole notion of hell. While he has a point here, the unbridled exercise of our human “will to power” has brought this entire planet to the brink of ecological catastrophe. What is sorely needed now is a voluntary move towards that much-derided “slave mentality” in the service of the natural world and its biodiversity, thereby curbing our will to power. We will return to looming threats from climate change and from a sixth mass extinction in chapter 10. But evolutionary science can also provide us with illustrations a-plenty of symbioses, commensal lifestyles and co-evolved adaptations that seem to tell a rather different story from the prevalent competition for survival. One example might be the ancient symbioses between three bacterial ancestors that gave rise to the cells of green plants—with different origins for the energy-supplying mitochondria, for the photosynthetic chloroplasts and for the larger host cell with its membrane-bounded nucleus (§ 1.2). Another might be the polyphyletic lichen group—where diverse fungi harbour algal (or sometimes cyanobacterial) symbionts—allowing these novel bipartite organisms to colonise and thrive in diverse and sometimes extreme habitats, from damp forest trees to exposed rocks or arctic tundra. Within hierarchical social groups of animals, co-operation yields tangible dividends, not least in the hunting strategies used by packs of predators. Such examples imply that evolutionary benefits do arise from co-operation, at least under specific conditions (see Laland, 2017), but how far this can be extrapolated to help understand altruism is a moot point. Many insights in this area have emerged from mathematical analyses using game theory, identifying conditions under which altruism might be favoured by natural selection. Nowak and Coakley [(eds.), 2013] provide an overview of this intriguing field, with a wide-ranging series of essays encompassing ethical, philosophical and theological—as well as scientific—reflections.

326

Chapter 9

9.6.5 Unanticipated turns of events “‘The stone that the builders rejected has become the cornerstone; this was the Lord’s doing, and it is amazing in our eyes.’” [Mark 12;10-11]

Evolution is full of unexpected twists and turns, though often we find these repeated in variant forms. The ancient symbioses between different archaeal and bacterial cells that gave rise to eukaryotic cells happened, not once, but multiple times—as did the invention of multicellularity (Conway Morris, 2015). Wings (but not feathers), eyes and other specialisations (§ 3.5 and 3.6) have appeared in multiple animal groups, such that evolution is replete with examples of convergence—some of which cannot be glibly demoted to the lesser status of parallel evolution (i.e. dependent on the same basic genetic circuitry). In Mark 12:1-9, Jesus directs the parable of the wicked tenants against the chief priests, scribes and elders (Mark 11:27), and his point is that they—the builders of Israel—should have recognised him (Jesus) as the cornerstone, but rejected him because of their blinkered vision, blind to the coming retribution that they were bringing upon themselves. Similarly, evolutionary innovations that seem at first sight amazing or unexpected turn out to have a certain inevitability, their genetic foundations laid long before in the (inferred) genomes of their ancestors. The fibrous but flexible skin protein keratin is used in reptiles to produce scales, in birds (and many theropod dinosaurs) to make feathers, and in mammals to create hair or fur. [Fish scales are rather different, sharing a common origin with teeth]. But convergence teaches us that whatever crops up once in evolution—provided it works reasonably well— will probably recur multiple times in different lineages living in similar environmental niches or facing similar challenges. And yet, there are some evolutionary developments that seem genuinely unprecedented, not least that which led to the co-evolution of human brains and culture (chapter 5). Since we see nothing comparable elsewhere in the animal kingdom, we might indeed agree that this is “amazing in our eyes”, even though atheists would reject any notion that “this was the Lord’s doing”. There is of course a more literal sense in which to interpret the phrase “the stone that the builders rejected has become the cornerstone” —in terms of evolutionary exaptation, or the re-use of old inventions (which may or may not have become redundant) for new purposes. As described in § 3.7, birds excrete nitrogen as uric acid (uricotelic) rather than as urea (ureotelic, as in mammals); as a corollary, two or more of the key ureacycle enzymes required to synthesise urea from ammonia are missing in birds. This effectively makes the remaining urea-cycle enzymes (and their

Evolutionism in the Pulpit

327

genes) redundant—so perhaps we should not be too surprised to find that one—argininosuccinate lyase (ASL)—has been redeployed for a different purpose. Through exaptation and later gene duplication, one copy of the original ASL gene has become a major contributor to the avian eye lens, coding for its principal protein, į crystallin. As we saw in chapter 4, established genetic modules are adapted and re-used by evolution for a multiplicity of novel roles. It is simpler and less costly to tinker with preexisting genetic resources than to reinvent the wheel from scratch—though clearly evolutionary innovations can and do arise, albeit much more rarely.

9.6.6 All-consuming sacrifice Before turning to the Last Supper below, we may note in passing how the later destruction of the Jerusalem Temple by the Romans in 70 CE— foretold by Jesus in Mark 13:1-2—finds a parallel in the history of mass extinctions in the fossil record. Just as there were several of these, so too one could point to previous disasters in the Deuteronomistic history of the people of Israel—including their enslavement in Egypt, frequent defeats by the Philistines, the fall of the northern kingdom to Assyria, and later of the southern kingdom leading to the exile in Babylon, plus their subsequent oppression by Seleucid Greeks and later Romans. Most histories of weaker human groups follow a similar pattern—squeezed between powerful neighbours or invaded by colonial powers. Just as the chequered history of Israel can be read in terms of inevitable consequences of wrong decisions and unwise policies—rather than as divine judgement against their sinfulness per se—so mass extinctions follow on (though not entirely predictably) from combinations of identifiable causes such as bolide impact and flood vulcanism, or in the present time rapid global warming. At each such lurch in history, much that was precious is lost—just like the large stones and large buildings of the Temple. Yet the Wailing Wall in Jerusalem still bears witness to the colossal foundations of that Temple, just as fossils from past geological epochs bear silent testimony to some of the strange and wonderful creatures that were lost during each mass extinction. Indeed, one could press the comparison with Mark’s gospel even further. Challenged about the seeming wastefulness of the alabaster jar of very costly ointment of nard poured over his head by an un-named woman (Mark 14:3b), Jesus responds by saying “She has done what she could; she has anointed my body beforehand for its burial. Truly I tell you, wherever the good news is proclaimed in the whole world, what she has done will be told in remembrance of her” (Mark 14:8-9, NRSV). Each fossil that helps us piece together the evolutionary past is likewise worthy of remembrance—even if later generations have occasion to reinterpret it.

328

Chapter 9

In a sense, that fossil has been embalmed (quite literally so, for organisms trapped in amber) and subsequently buried in stone, till we uncover it. “While they were eating, he [Jesus] took a loaf of bread, and after blessing it he broke it, gave it to them, and said, ‘Take; this is my body’. Then he took a cup, and after giving thanks he gave it to them, and all of them drank from it. He said to them, ‘This my blood of the [new] covenant, which is poured out for many.” [Mark 14:22-24, NRSV]

These words are so familiar to Christians from eucharistic services that many will have automatically inserted the word “eat” after “Take” (cf. Matthew 26:26; slightly different wording is used in Luke 22:19-20, and in 1 Corinthians 11:23-25). Yet to non-Christians, there are cannibalistic undertones in this talk of eating the body and drinking the blood of Christ. In vain we protest that the language here is symbolic. For some, at least, what we do in the eucharist is simply a remembrance of Jesus, proclaiming his death until he comes (1 Corinthians 11:24-26). But others insist on the Real Presence of Christ—in spirit if not bodily—in the consecrated bread and wine. The challenge—even scandal—of these words becomes clearer in John 6:48-59, in the context of Jesus teaching in the synagogue at Capernaum rather than at the Last Supper in Jerusalem. Even his disciples find this difficult (v. 60), and some turn away from following him (v. 66). Yet when asked if he too wished to go away, Simon Peter responds “Lord, to whom can we go? You have the words of eternal life. We have come to believe and know that you are the Holy One of God” (vv. John 6:68-69, NRSV). We Christians need to be scandalised anew by the language that Jesus uses, both in John 6:48 ff. and in the words of consecration used by Paul and by the synoptic writers. We should find them deeply shocking for their rawness and earthiness—in their evocation (albeit indirectly) of a darker, atavistic past when human sacrifice and cannibalism were acceptable practices. Rohr (2019, pp. 130-131) draws attention to the fact that Jesus says, in effect, “Eat me”—“the vehicle [of the sacrament], the medium, and the final message here are physical, edible, chewable, yes digestible human flesh. Much of ancient religion portrayed God eating or sacrificing humans or animals, which were offered on the altars, but Jesus turned religion and history on their heads, inviting us to imagine that God would give himself as food for us.” Similarly, to drink blood was anathema to any Jew—for whom mere contact with blood entailed ritual impurity (a major facet of Levitical regulations). As Rohr (ibid., pp. 133-134) further points out, the invitation to drink wine as his blood links us in bodily solidarity with all those whose blood is shed unjustly (Matthew 25:35), from the beginning of time till its end. Last but not least, the invitations to eat and drink of Jesus are deeply personal: given for you, my body broken

Evolutionism in the Pulpit

329

for you, my blood shed for you (ibid., pp. 135-138). Repetition over countless Sundays has dulled most Christians to the startling import of these words, challenging us to give ourselves likewise in love and service. This is, of course, the commonplace pattern throughout evolution and ecology. For most species (excepting humans and top predators), the vast majority of individuals are indeed consumed—digested to provide energy for the next level up in the food chain. There is no justly or unjustly about the shedding of blood in the natural world; this is, quite literally, the way of all flesh—and even the apparent victors (ourselves and predators) will in turn provide nourishment for a host of small organisms and microbes during bodily decomposition processes. The non-human natural world is not merely cruciform (as Holmes Rolston III sees it; § 8.5.2), but even— dare I say it?—eucharistic. We cannot accuse God of inconsistency here; if God allows the wastage, suffering and mass slaughter that evolution entails, because there is no other way, then this is what we should expect from a God who shows solidarity with all life by embracing everything in love, and who even offers Godself as food and drink for all in communion.

9.6.7 Betrayal, suffering, renewal The rest of Mark’s gospel is devoted to the betrayal, trial, crucifixion, burial and resurrection of Jesus—though this last is only hinted at in the original version of Mark 16 (vv. 1-8). Insofar as pain and suffering are inevitable concomitants of evolution, we may note that Godself knows what these feel like from the inside—since Jesus the Christ was put to death on trumped-up charges for political and religious (John 11:50) convenience—enduring both the psychological agony of Gethsemane (Mark 14:32-42) and physical agony of crucifixion (Mark 15:25-38). In between came betrayal—first by his disciple Judas (Mark 14:12, 43-47), then by his second-in-command Peter (Mark 14:66-72). But this cuts both ways: Joseph of Arimathea was both a respected member of the council (Sanhedrin) of Jewish priests and elders, but also a secret follower or admirer of Jesus—since he was “waiting expectantly for the kingdom of God” (Mark 15:43, NRSV), and he later took Jesus’ body for burial (vv. 42-46). Such betrayals may also occur on occasion among mammals with complex social hierarchies, but in more general terms, deception is rife across the board in evolution and ecology. Aposematism describes the use of bright warning coloration—often reds, oranges or yellows—by an animal to warn potential predators that it is in fact highly toxic (e.g. the Yellow-Spotted Tiger Moth caterpillar shown in Fig. 2-6H). Other species —though actually non-toxic and therefore good to eat—have evolved

330

Chapter 9

similar colour-schemes as a deceptive defence. Many orchids of the genus Ophrys possess extraordinary flowers that mimic certain insects—as a false sexual lure to those insects so as to ensure the orchid’s pollination (Darwin, 1862; Fig. 9-1, centrefold). Each Ophrys species emits volatile allomones, chemically identical to the sex pheromone secreted by virgin females of the pollinating insect species, in addition to which the flower’s labellum sufficiently resembles a female abdomen for males to attempt pseudo-copulation with it, becoming covered with pollen (as coherent masses, termed pollinia) in the process. This fascinated Darwin, whose detailed observations confirmed that Ophrys apifera is self-pollinated in Britain (though it is pollinated by Eucera or Tetralonia solitary bees in the Mediterranean), whereas Ophrys insectifera is fertilised by insects (two species of Argogorytes digger wasp in Britain). Appearances can be deceptive, not least among those many organisms that utilise camouflage. Mark’s brief prelude to the resurrection conveys a sense of mystery and awe; chapter 16 ends with the women fleeing from the empty tomb—“for terror and amazement had seized them; and they said nothing to anyone, for they were afraid” (Mark 16:8, NRSV). But immediately prior to this, there is a clear promise from the white-robed man (angel) sitting in the empty tomb: “He [Jesus] has been raised; he is not here. Look, there is the place they laid him. But go, tell his disciples and Peter that he is going ahead of you into Galilee; there you will see him, just as he told you” (Mark 16:6-7, NRSV). There is a blend of certainty and uncertainty here, of promises made but not yet wholly fulfilled, which rings true with Jesus’ proclamation of God’s kingdom throughout Mark’s gospel, starting with 1:15 (§ 8.3.1). Jesus himself uses the analogy of a grain of wheat, which must fall into the earth and (to all appearances) die before it can spring up as a new wheat plant that yields much fruit (John 12:24). Some wheat grains will indeed die and fail to germinate, or suffer any of the mishaps mentioned in the parable of the sower (§ 9.6.2), but some will usually survive. This pattern repeats over and over throughout the natural world in the renewal of spring, or in the recovery of habitats after flood, fire, storm or drought. On a larger and much slower scale, the same resilience of life emerges during adaptive radiation—as when new islands are colonised, or in the wake of mass extinctions. But these are less predictable than the sprouting of wheat or pageant of spring. Vacant niches are filled, but not necessarily with species similar to the previous occupants of that niche. Sometimes evolution comes up with radically new departures—something unprecedented like a hairless ape that hunts in bands with primitive stone tools. So too, the resurrection hinted at in Mark 16:6-7 emerges from leftfield, unexpected despite the many predictions from Jesus himself. This is

Evolutionism in the Pulpit

331

indeed the kingdom of God—not merely drawing near, but actually embodied in the risen Christ, yet Mark chooses to leave us with tantalising hints rather than a fully fleshed description of any resurrection appearance. Similarly, we might hazard informed guesses as to which species might survive a sixth mass extinction, and even infer the likely evolutionary trajectories of their descendants. But we will often be wrong, on many counts, for we see only “in a mirror, dimly” (1 Corinthians 13:12), based on past trends following previous mass extinctions. Perhaps, as Rohr (2019), Moltmann (1989/1990) and many others have argued, we are similarly blinkered in our expectations of God’s kingdom, basing them on an individualistic view of salvation that has only become prevalent since the Reformation. Yet there are grounds for hope that God’s kingdom will embrace, not just some or even all humans, but also the whole universe or multiverse of creation (§ 8.5.2)—finally returning to its source in God. A recurrent refrain throughout this book has been our need for a BigEnough God (Maitland, 1995). We humans create gods in our own image, reducing them to pettifogging lawyers bent on catching people out in some misdemeanour, so justifying our own prejudices and self-righteousness, confirming us in our greed and superiority over “lesser breeds without the Law”, and all too often bringing out the worst rather than the best in us. It was precisely on these grounds that Jesus condemned the religious leaders of his own day: “‘Woe to you, scribes and Pharisees, hypocrites! For you tithe mint, dill, and cumin, and have neglected the weightier matters of the law: justice and mercy and faith. It is these you ought to have practised, without neglecting the others” (Matthew 23:23, NRSV). Such nit-picking observances are a far cry from—indeed the very antithesis of—the mission and ministry of Jesus described in the gospels (§ 8.3). He had no time for pettiness, but had all the time in the world for genuine need—making no distinctions as to worthiness or unworthiness. We seem to have lost the universality of God’s over-flowing love and resurrection promise— operating instead on what Richard Rohr (2019) calls a “scarcity model” of salvation—where our place in the kingdom must be earned, or even bought (via indulgences, large donations, etc.) like some high-end luxury commodity. But Jesus operated out of an abundance model—whereby the kingdom of God came near to all through him, even to the places or people who rejected him (Luke 10:11). We cling to our petty squabbles on points of doctrine, but lose sight of the bigger picture—that all who follow Christ are called to be one, as Christ is one with the Father (John 17:20-21).

332

Chapter 9

9.7 Evolutionary exegesis, or hermeneutics? The question posed in this section title requires some unpacking. It is certainly possible to undertake an evolutionary exegesis of scriptural texts, following the example of William P. Brown (2017) in two chapters on Old Testament exegesis in the light of science (referring mainly to the early chapters of Genesis; ibid., pp. 201-227) and of ecology (ibid., pp. 229245). But it is more doubtful whether one can really speak of evolutionary hermeneutics—since this term deals not only with the reception of texts by readers or listeners, but also with the intentions (insofar as they can be ascertained) of the authors—in other words, the whole two-way process involved in written communication (Thiselton, 2009, pp. 1-16). For much of their history, the Israelites were a people living under oppression, hence one can usefully apply the critical hermeneutics of liberation theologies (ibid., pp. 255-278). Likewise, though most of the bible was written by men, and even largely for men, women’s reactions to and interpretations of its texts afford several distinctive feminist hermeneutics (ibid., pp. 279305). But since biblical authors clearly had no concept of evolution, this can only be something read into or grafted onto the reception process in today’s world. It was never part of the intended meaning of any biblical passage, nor is it relevant to the prevailing context at the time of writing. It is of course very risky to assume or read into any biblical text the presuppositions of one’s own time. Steve Chalke (2019, pp. 46-48) cites the misuse of Paul’s epistles by Martin Luther as a justification for his anti-Semitic views—which were later seized on by Nazi propagandists to incite the Holocaust. It is vital to look first at the context and historical setting of any scriptural text—appositely summarised by Chalke as “a text without a context becomes a pretext” (ibid., p. 23). So why have I often ignored this sage advice in the preceding sections of this chapter? Since this is a book about evolution rather than biblical exegesis, I have taken the liberty of omitting all but the briefest sketch of context for the biblical passages covered earlier in this chapter. Some are devoid of any context whatsoever, but in other cases such context provides a useful counterpoint. The evolutionary insights and implications offered are in no way meant as definitive, as they are all “read into” texts that were written with no such interpretation in mind. If properly contextualised, I hope some of the ideas outlined above may suggest possible directions worth exploring, which are relevant to present-day understandings of the natural world around us, rather than historical world-views that were current 2000 years ago. This is especially urgent in view of the problems of impending climate change and species loss (chapter 10). If nothing else, the idea that science is

Evolutionism in the Pulpit

333

inherently inimical to faith needs to be challenged and its falsity exposed. No doubt, as scientific understanding develops, much of what I have written in this chapter will be superseded and become irrelevant, but the same or different texts will doubtless acquire new evolutionary resonances for future preachers, for readers, and indeed for “occupants of the pew”. It is my contention that even a modicum of scientific knowledge can provide unexpected illumination of familiar scriptural texts. I will close with one particularly vivid example drawn from physics—as well as from biology—which was kindly shared with me by the Rev’d Mark Gallagher SOSc. Consider the following two verses from Psalm 139 (11-12, NRSV): “If I say, ‘Surely the darkness shall cover me, and the light around me become night,’ / even the darkness is not dark to you: the night is as bright as the day, for darkness is as light to you.” The take-home message is that you can’t hide from God, and the cover of darkness is no protection at all. But we are apt to take that phrase about “darkness is as light to you” as a mere rhetorical flourish—betraying our anthropomorphic view of God as having eyes like ours. Are we made in the image of God, or have we rather envisioned a God with merely human eyesight? Human eyes are sensitive only to certain wavelengths of light—those in the so-called visible spectrum—ranging from red to violet. But the sense of sight in other animals can extend outside this range into the ultra-violet (in many insects, but also in certain mammals, birds and fish). As for detecting infra-red radiation, we have become familiar with nocturnal animals through films obtained using sophisticated heat-sensitive cameras. Special heat-sensing organs (though not eyes as such) have evolved in two groups of snakes and also in vampire bats, allowing warm-blooded prey to be caught even in total darkness. Human instruments such as radio telescopes can detect radiation across a much broader bandwidth, enabling us to pick up even the faint isotropic microwave background from the Big Bang itself. If we believe in a God who is attentive to every possibility that unfolds in creation (concurrence, in Page’s terms), why would that God be “blind” to any part of the whole electromagnetic spectrum? Surely all wavelengths would impart some useful and distinctive information? Maybe the author of Psalm 139 was inspired to grasp a poetic truth that could not have been conceptualised in any categories available at the time. This combination of physical and biological insights should give us pause for thought, encouraging us to expand our preconceptions and catch a fleeting glimpse of that “Big-Enough God”. This example does not merely cast a new light on biblical verses, but rather expands our very definition of “light”. I believe this is something to which all preaching should aspire, or else we will find that our well-researched sermons fall increasingly on deaf ears.

CHAPTER 10 ENVOI: THE SIXTH MASS EXTINCTION

Summary § 10.1 admits my own failure to live a truly sustainable life-style in the context of rapid climate change and the likelihood of a sixth mass extrinction triggered by anthropogenic causes. § 10.2 draws some intriguing parallels between development in music and in biological systems, and also with the slower processes of evolutionary change. § 10.3 asks whether God too grieves at the destruction we humans are wreaking on the rest of the biosphere. Warnings from climate scientists today recall those of the Old Testament prophets—and are likewise being widely dismissed, particulary by evangelical churches. § 10.4 calls on Christians to wake up to this urgent crisis, which has become increasingly muddied by climate-change denial and ineffectual international action. Some possible ways in which churches could help, and our Christian witness make a difference, are explored in § 10.5. The most appropriate response is one of restraint, a challenge developed in § 10.6. This section points to the self-sacrificial ministries of Jesus himself and of many Christians since—as a counterbalance to the crass excesses of consumerism: how much do we really need to live a good life? Reverting to the format of chapter 9, § 10.7 casts our environment in the role of importunate friend in Jesus’ Luke 11 parable, hammering at the door of humanity as sleepy householder. § 10.8 concludes this book on a note of pessimisim, though COVID-19 has at least proved to us that we can change our behaviours when confronted with an urgent need to do so. It is still unclear whether we will yet do likewise for climate change.

Envoi: The Sixth Mass Extinction

335

10.1 Mea culpa Retiring to Edinburgh has brought me many benefits, only some of which I had anticipated beforehand. Needless to say, I knew of its elegant yet quirky architecture, and also of its vibrant cultural life as a capital city —not just during the summer Festival, but throughout the year. I chose a flat within easy walking distance of the Royal Botanic Gardens (a must for any amateur botanist!), but found myself close to a wide range of other facilities, including a major hospital. Within a few months of my arrival, I became part of the ministry team at the local Scottish Episcopal church (Anglican), just 200 metres from my home, and unexpectedly joined the staff of New College at my alma mater, the University of Edinburgh, as an Honorary Fellow contributing to a Masters course in Science and Religion —for the first time combining my twin interests in biology and faith. Only in a country as small as Scotland could I have spoken at length to a serving government minister over breakfast—this after a bitterly cold mass sleepout to raise funds for the homeless in December 2017. My genes, if not my known family history, suggest Scottish roots: this feels like coming home. Perhaps less celebrated than its crenellated and turreted roof-scapes, Edinburgh’s skyline of natural landforms is equally spectacular—Calton Hill with its follies, the castle crowning its forbidding crag, and above all the steep-sided miniature mountain known as Arthur’s Seat (Fig. 10-1A, centrefold). There is also the wooded valley (in parts a ravine) of the Water of Leith, cutting a green groove across the city from south-west to north-east, beyond whose headwaters stretch the rolling Pentland Hills, which are more popular with locals than with tourists. Even less familiar are the wild inhabitants of these green spaces, including a range of unusual plants. Arthur’s Seat is particularly notable in this respect, in part because its base-rich basalts harbour calcicole (lime-loving) species, illustrated in Fig. 10-1F to H (centrefold). For me, it is sheer delight to wander the many lesser paths that snake around the hill’s flanks, discovering secret hollows heady with the scent of gorse. I have found there a few famous rarities (Fig. 10-1B, C), as well as plants that were unexpected (Fig. 10-1D, E), though others reputed to grow on the hill still elude me (Fig. 10-1I, J). While I have been writing this book, prognostications for the future of planet Earth have worsened steadily (Steffen et al., 2018). A sixth mass extinction looks inevitable; more immediately, climate change may render sizeable regions of the globe uninhabitable by 2100, along with large rises in sea level from melting ice-caps, perhaps by several metres (Lynas, 2008; Wallace-Wells, 2019)—inundating coastal cities and much agricultural

336

Chapter 10

land. There is also the likelihood of far-reaching changes in terrestrial vegetation cover (Nolan et al., 2018). Humanity’s current greed and shortsightedness seem set to blight the lives of future generations, and risk halting or even reversing the cumulative ratcheting-up of human culture over time (Laland, 2017). Technological fixes may still be possible, but it is doubtful whether the political will currently exists to invest in them and implement any that prove effective. In the meantime, we are confronted with an ever-shrinking “window of opportunity” for taking remedial action with any hope of success. Despite increasing urgency in the dire warnings from the vast majority of climate scientists, we seem hell-bent on ignoring them, distracted by siren-calls of climate-change denial and consumerism. Even those who acknowledge this are all too liable to give up in despair at the sheer scale of the problems we are facing globally. More of this later. When I look at my own lifestyle, I realise that it falls a long way short of the simplifications and even sacrifices that are called for if humanity is ever to live sustainably and in harmony with the rest of the biosphere. I should eschew meat for both ethical and ecological reasons, as well as all foods imported from distant countries—instead buying seasonal local produce. I should refuse to purchase anything that is wrapped in plastic packaging, and I should also recycle far more assiduously than I currently do. I should invest in more efficient insulation and in self-generated renewable energy, wear clothes made of natural fibres, and renounce leather. I should economise on my water and energy use—all this with the aim of minimising my carbon footprint. Truth to tell, I do far too few of these, or do them only half-heartedly. I should walk or cycle more, and give up travelling by car. Why drive for hours to track down a rare plant on a distant Scottish mountainside, when there are still species that elude me on Arthur’s Seat—within walking distance (Fig. 10-1I, J)? And yet, with my daughter living in western Canada, I know full well that I am never likely to refrain completely from long-distance air travel. But when all is said and done, there is a lot more that I could do in terms of living sustainably, and it is high time I made a start….. I am calling for churches and theologians to grapple seriously with evolution—neither denying nor ignoring it, but rather embracing it and rediscovering the God of Jesus’ kingdom teaching in an evolutionary context (chapter 9). True enough, I have devoted the first five years of my retirement to researching and writing this book, but beyond that, how often do I preach in church or even engage in casual conversation on a scientific topic? And when I do so, it is all too apparent that my words fail to communicate with some in the audience—far too many seem to glaze over as soon as science is mentioned. As Christian faith and religion in general

Envoi: The Sixth Mass Extinction

337

have come increasingly under bombardment from atheist battle lines, there has been an inevitable retrenchment, with uneasy alliances between different church denominations that scarcely see eye to eye on anything. We naturally wish to affirm what unites us—our belief in Jesus and the Triune God—rather than dwelling on what divides us. But in truth, there are several largely unacknowledged fault lines running through that thin veneer of unity, and evolution is only one of them. I fear that this may be symptomatic of a much deeper divide—between inclusive and exclusive versions of Christianity. My own personal conviction is that God became incarnate among us in Jesus, not merely as a remedy for human sinfulness, but as an act of love towards creation as a whole, in line with Franciscan spirituality (e.g. Delio, 2008, pp. 53-65). Romans 8:19-22 claims that the entire cosmos (or even multiverse) is awaiting its salvation and final fulfilment in the glorious freedom of the children of God—a theme explored earlier in § 8.5.2. But other Christians believe—with equal sincerity, it has to be said—that salvation is offered only to the elect, however construed: those whose faith is unimpeachable or who live Godfearing lives—as is indeed implied later by Paul in Romans 8:29-30. I have to ask myself how often I stand up to be counted for my universalist convictions, and how often I choose instead to keep a safer silence. On all these fronts, I could do better—a lot better. Mea culpa indeed!

10.2 Complexity—in music, biology and evolution Among the pretentious epigraphs that preface all 8 chapters of my PhD thesis, my personal favourite is the following quotation attributed to the philosopher George Santayana—although I have been unable to trace its original source; it may indeed be misquoted or wrongly accredited, as this wording produces no matches across numerous online sources consulted: “Prodigious complexity is something to which Nature is not averse, like a human artist, but on the contrary is positively prone.”

I would myself dispute the clause about “a human artist”. Simplicity or economy may characterise certain pinnacles of artistic achievement—as for instance in many Chinese paintings or Japanese haiku—but in the hands of other notable writers and artists, the complexity of their greatest works bears at least modest comparison with that shown by living organisms. The detailed mythological or futuristic fictional worlds created by J.R.R. Tolkein or Frank Herbert (and expanded by their sons) provide obvious examples, as do the Ring cycle music-dramas of Richard Wagner and certain late-Romantic symphonic works—for instance Mahler’s 8th

338

Chapter 10

symphony, Schoenberg’s “Gurrelieder”, or the vast “Gothic Symphony” of Havergal Brian; a page from the score of this last is reproduced as Fig.102A. But complexity is not confined to particular styles or lengths—think for instance of Thomas Tallis’ astounding 40-part motet “Spem in Alium”, or of the multitudinous resonances of a Gerard Manley Hopkins sonnet. There are several intriguing parallels between music, time, theology and biology, explored by writers such as Jeremy Begbie (2000) and Arthur Peacocke (Peacocke & Pedersen, 2006). Fig. 10-2B shows one example of a gene regulatory network (GRN)—a concept developed by the late Eric H. Davidson (1937-2015) for encapsulating the interactions of multiple signalling systems, transcription factors (TFs), and target genes involved in specifying particular cell fates (chapter 4). The GRN shown in Fig. 102B is that which designates mesendodermal (or endomesodermal) fates in sea urchin embryos, and was generated from multiple experimental manipulations of each interaction shown (Davidson et al., 2002). Without commenting in detail on this example, it is noteworthy that the major pathways are buffered—with multiple switches for each key gene, such that local failures can be compensated. Another general point is that such GRNs are not static, but unfold dynamically over time; of the links in Fig. 10-2B, those in the upper box involve maternal factors, while the rest of the figure follows the unfolding of genetic circuits controlling zygotic gene expression in the emerging territories of early embryos up to 24 hours: in micromeres (Mic), in the primary mesenchyme cells (PMC) to which they give rise, or in the mesodermal and two endodermal lineages descended from the macromeres (Fig. 4-2). In an analogous way, the musical notation shown in Fig. 10-2A also unfolds in time (less than a minute for this page!). Part of the fascination of both music and animal development (chapter 4) lies in this gradual emergence over time, often trending towards greater complexity. Over longer time-scales this also characterises evolution, despite the setbacks occasioned by mass extinctions (Fig. 3-6). A subsidiary theme in Jeremy Begbie’s book “Theology, Music and Time” (2000) is the relationship between actual time in music and the times or contexts in which that music is performed—also reflected in the theological contrast between historical or clock time (chronos) and God’s time (kairos). Many acknowledged musical masterpieces were ignored or poorly received at their first performances—or in some cases were not performed at all until rediscovered or reconstructed more recently (e.g. Bach’s Mass in B minor). Indeed, there is a fashion for completing works left unfinished by their composers: among symphonies, we now have full versions of both Schubert’s and Mahler’s 10th, Bruckner’s 9th, Elgar’s 3rd, and de Falla’s vast cantata Atlantida. Sometimes the context of a particular

Envoi: The Sixth Mass Extinction

339

performance can make an indelible impression on the audience. One such occasion for me was a searing account of Czech composer Josef Suk’s Asrael (Angel of Death) symphony—written in the aftermath of the deaths first of his father-in-law 'YRĜiN and then of his own wife Otylka. This doom-laden work was played by the Brno Philharmonic Orchestra from former Czechoslovakia in Leeds Town Hall, shortly after Soviet tanks had rolled into Prague in August 1968. In one sense, music exists for all time as written (symbolically) in the score, but it only truly comes to life when heard or performed in real time. Similarly, the developmental programmes specified by GRNs (e.g. Fig. 10-2B) are implicit in the genome, but need to be realised or read out in real time, into the context of prevailing environmental conditions. In evolutionary terms, subtle changes affecting the regulation or outputs of these GRNs may occasionally afford selective benefits that then allow them to spread more widely within the gene pool. Evolution also unfolds in real time, albeit on a scale far vaster than a human lifespan, at least for macroscopic organisms. [For bacteria, adaptive evolution has been convincingly demonstrated across >60,000 generations in Richard Lenski’s epic 35-year, and still ongoing, experimental study; Tenaillon et al., 2016]. Some parallels can be drawn between evolutionary changes and musical development, or indeed between the broader patterns that shape the history of life and the form of large-scale musical structures. For any given melody or even brief motif, there will be numerous potential variations that require filtering and selection in the mind of the composer, choosing (often unconsciously) those that best express the desired emotion and/or advance the musical argument. In some such cases, a composer’s sketchbook records the many iterations and subtle changes that transform a fairly pedestrian idea into something truly inspired. This is not dissimilar to natural selection operating among innumerable slight variants of a species’ genome; some work well in a particular context while others fail to make the cut, thereby generating fewer or no progeny. The Finnish composer Jean Sibelius was adept at drawing striking melodies out of a welter of seemingly unrelated short motifs, so that the music seems to emerge—or even evolve—as an inevitable fulfilment of whatever has gone before. But this did not always come easily, as instanced by the composer’s long struggle to find a final form for his epic 5th symphony, which sounds so organic and unforced to listeners today. So too for the emergence of novelty in evolution—made possible by combining and/or tinkering with genetic circuits that had originally evolved for quite different purposes.

340

Chapter 10

Figure 10-2A. Complexity in music. Penultimate page of the first movement (“Te Deum Laudamus”) of Part II of Havergal Brian’s Gothic Symphony (1932/1976, p. 147). Extract from Symphony No. 1 (originally no. 2), “The Gothic”, by Havergal Brian, reproduced by kind permission of the trustees of the Havergal Brian Estate, and by United Music Publishers.

Envoi: The Sixth Mass Extinction

341

Figure 10-2B. Genetic complexity. The GRN for endomesoderm specification in sea urchin. Original colour diagram published as Fig. 3 in Davidson et al. (2002). Copyright permission kindly granted by AAAS on behalf of Science journal. Note key roles played by gene orthologues familiar from chapter 4, such as Eve, Krox, Otx, Wnt(8), Hox11/13b, Delta and Notch. Small arrowheads (ŷŹ) denote TF interactions that promote transcription of target genes (൛Ź), whereas the symbol

ŏ denotes repression. Note that endomesoderm is now rendered as mesendoderm.

342

Chapter 10

Building on earlier techniques of thematic variation, in which slowmoving melodies often become embellished with increasingly fleet and elaborate decoration, Sibelius also developed a distinctive style in which different elements of the music progress in very different time-frames or tempos. This is exemplified in the rapid foreground figuration of much of his 3rd symphony, superimposed over long-held pedal notes in the bass that move with glacial slowness yet bind the whole fabric together. Again, there are parallels here with evolution, whereby new species (or indeed larger phyletic groups) emerge at a much slower tempo than the random mutations producing small-scale variations on which natural selection can act. Of course, it is easy to overstate such parallels between musical forms and evolutionary processes. To cite just one obvious exception, the socalled development section of a classical sonata-form movement plays with variations on the theme(s) presented initially in the exposition. So far, the analogy with natural selection seems to hold good, at least in broad outline. But, by musical convention, this development section culminates in a restatement or recapitulation of the initial theme(s)—which clearly does not correspond with anything that happens in evolution. Species do not reappear in their original form after diversifying into different daughter species—unless selective pressures change to favour the proliferation of a few survivors belonging to the original species. Conversely, convergence starts from very different origins yet ends up with something strikingly similar (§ 3.5). I find myself wondering whether convergence could maybe provide a novel pattern for constructing a satisfying musical structure…. Parallels have been drawn (e.g. by Ursula Goodenough, quoted in Peacocke & Pederson, 2006, p. 28) between the structure of music and the intricate interlinking of biochemical processes within a living cell. However, there is a minimum level of complexity in any living cell, which does not strictly apply to music. Analogous parallels can also be drawn between music and whole ecosystems, but here I think the comparisons are more apt, since both can vary enormously in complexity—from harsh environments where very few species are able to survive (similar to an unsupported melody or rhythm) to the lush prolixity of species in tropical rainforests or coral reefs (analogous to the complex wash of sound in Fig. 10.2A). At all events, what climate change portends is a drastic thinning down of the whole texture of the biosphere’s vast symphony. Elimination and total silence still seem vanishingly unlikely, even in the worst-case scenarios. Some life—probably including human life—will undoubtedly survive, and earth’s homeostatic systems will in time re-establish a new climate equilibrium, allowing novel species to evolve and to occupy the vacated niches as living organisms re-diversify after a sixth mass extinction.

Envoi: The Sixth Mass Extinction

343

Climate change has become so urgent and so all-encompassing that a brief outline of its scope, and of possible Christian responses to it, will occupy the rest of this chapter, and will close the book on a more sombre note. However, I will not attempt to review the vast literature that documents the extent and causes of global warming, beyond a few popular summaries. The pattern of repeated mass extinctions punctuating the history of evolution (§ 3.4) is paralleled in a few large-scale musical structures. One such example is the lengthy finale of Mahler’s 6th (“Tragic”) symphony. March rhythms predominate throughout, tramping grimly on towards three pivotal catastrophes, each (in the original version) crowned by a hammerblow that leaves the music reeling. After the third of these (later deleted by the composer for personal reasons), the music does not recover but subsides into a slow dirge for trombones and a final howling chord above the fading drum rhythm that has haunted this symphony. As a musical portrayal of repeated struggle and disaster, ending in ultimate defeat—this movement bears eloquent witness to what mass extinctions might feel like. It may seem perverse to close this book on evolution and Christian faith with an apparent digression into the ongoing debates round climate change. The long-term consequences of current global warming (over hundreds, if not thousands, of years) threaten Earth’s biodiversity with a sixth mass extinction. This gloomy prognosis is reinforced by other ancillary causes —such as pollution, habitat destruction and human overpopulation. Species are going extinct at a rate 1000-fold above background, and up to a million species are now threatened with extinction, according to the 2019 IPBES report mentioned earlier. My justification for including this chapter is that biodiversity loss on such a scale is part and parcel of the vast evolutionary narrative, in which mass extinctions (§ 3.4) act as gigantic punctuation marks to terminate its chapters. Taking up a musical analogy, they likewise function as the closing candences and final chords of each movement in evolution’s long symphony. Mass extinctions are not uniform in their effects on biodiversity, and even the great Permian-Triassic event proved far less lethal for land plants than for marine life (§ 3.4). Indeed, several major biotic transitions seem to have occurred without the intervention of mass extinctions. The recent rapid rise of humanity—in terms of population numbers, resource consumption and niche construction —has undoubtedly triggered the sixth mass extinction we now face. But the severity of this will depend on how far we allow global temperatures to rise, which in turn will reflect the mitigating actions taken now or in the next few years. Sibelius’ one-movement 7th symphony contains elements of the traditional four symphonic movements, yet with almost seamlesss

344

Chapter 10

joins. We might aim for something similar by limiting the severity of climate change, but this will require unprecedented levels of international co-operation and investment, neither of which is yet apparent in terms of effective action. It will also necessitate concerted action from all humanity.

10.3 A God’s-eye perspective? If the God in whom Christians believe is neither impossible (as atheists aver) nor impassible (§ 8.3), then the environmental apocalypse unfolding in slow motion before our eyes must surely be distressing for Godself too. Without shrugging off or belittling the significance of individual sins, many of the human traits that have contributed so notably to our success as a species (chapter 5) are now sounding the death-knell for countless other living organisms with whom we share this planet. This is a collective human responsibility, an aggregate summation of trillions of individual choices that in most cases (with some honourable exceptions) boil down to living unsustainably well beyond our ecological means. How far our children’s thriving or even survival will be imperilled by climate change and biodiversity loss, depends in part on how willing we are to work together now to mitigate greenhouse gas emissions and minimise global warming. For my own part, I cannot believe that God remains unmoved by all this. The fact that mass extinctions have happened before (§ 3.4) in no way lessens the impact of our current crisis, even if God promises that all creation will be redeemed. Since “Jesus wept” (John 11:35) at the death of his friend Lazarus—even though the latter would later be restored to life— how much more might God feel sorrow at all the destruction and loss wrought by humans in heedless pursuit of short-term advantage? The fact that we are so clearly culpable, and now recognise our own responsibility, only compounds the hurt we knowingly inflict on God. We have trampled heedlessly on our planet, treating whatever we cannot exploit as worthless, only to realise too late how far we depend on its resources for our survival, especially its ecosystem services such as water, forests or soil, whose value to humans is revealed by global modelling (Chaplin-Kramer et al., 2019). All this might remind Christians of the dire warnings of Old Testament prophets like Jeremiah or Amos, who predicted disaster unless the people mended their ways. Exactly when these prophecies were written relative to their fulfilment is open to question, but many of them were indeed borne out by historical events. Catastrophes such as the Babylonian exile or later fall of Jerusalem (70 CE) embody not so much God’s wrath vented against the people of Judah (in both cases), but rather the inevitable outcome of their pursuing unwise, short-sighted policies that contravened the Law of

Envoi: The Sixth Mass Extinction

345

Moses or defied God’s instruction. As then, so now; we must live with the consequences of our choices and actions. The uncomfortable relationship between God, prophet and people is aptly captured by John Goldingay: “The prophets share God’s dreams. But before they speak of these dreams, they share God’s nightmare vision of how things will turn out if the people do not change.” (Goldingay, 2015/2016, p. 359).

Note that the people here is a collective noun, not just a group of individuals. Today, it is climate scientists who prophesy catastrophe. Their rhetoric may be less extreme, but their predictions simply extrapolate from what we already see happening. Like the people of Judah and Israel of old, we turn a deaf ear to the words we do not wish to hear—words that disturb and discomfort us, insisting that we are currently living in an unsustainable and ultimately unreal bubble of inflated living standards. But the longer we carry on as normal, the more surely we lock our collective future into a trajectory that none of us wishes to see realised. What we will reap are the inevitable consequences of what we sow now. This might suggest a less vengeful interpretation of Yahweh’s self-description in Exodus 20:5 (NRSV): “for I the LORD your God am a jealous God, punishing children for the iniquity of parents, to the third and the fourth generation of those who reject me.” The consequences of global warming and of a sixth mass extinction will persist far beyond the fourth generation of our children.… The attitude of right-wing evangelicals towards this and more political “Armageddon scenarios” can be summed up in three words: “bring it on”. They see disasters and threats of disaster as hastening the endtime—the Second Coming of Jesus, bringing judgement on the world. I personally do not interpret the apocalyptic writings of both Old and New Testaments in such literal terms, but even if these threats were realised it is far from clear that those who incited catastrophe would earn God’s commendation, as they seem to believe. Jesus himself warns explicitly against trying to guess the day or hour of judgement, which is known only to God (Matthew 24:36). The task of his followers is to stay awake and alert, indeed to hold our heads high (Luke 21:28)—so that we can see further and more clearly. Christians should therefore be in the vanguard of climate-change activism and mitigation, not denying or opposing it at every turn. In fact, many evangelicals no longer deny the reality of global warming, since the evidence from increasing levels of CO2 and melting ice-caps is incontrovertible. Rather, they seek to shift the blame away from human activities and pin it on natural causes, such as spikes in greenhouse gas emissions from volcanic activity. There is scant scientific support for this

346

Chapter 10

scenario, as opposed to straightforward calculations of total CO2 output from anthropogenic sources (transport, industry, agriculture, etc.), which clearly point the finger at humanity. However, their “alternative scenario” gains added credence from the four End Time “Christian fiction” novels by Tim Lahaye and Craig Parshall (published between 2010 and 2014)— which remain runaway bestsellers in evangelical circles (Ronan, 2017). Their plot-line portrays inter-religious and intergovernmental attempts to limit global CO2 emissions as a vast conspiracy centred around an AntiChrist figure, with the express aim of weakening US economic power by curbing its free-market economy. The potency of this conspiracy fiction (theory would dignify it too much) lies in its frequent recourse to detailed fulfilments of apocalyptic scriptures—mainly those in Revelation (§ 8.5.1). For people who take such prophecies very literally, the End Time plot-line carries an illusory air of conviction; it is all too believable if you want to believe it. Conveniently, it also plays into the popular Prosperity Gospel— where riches are seen as a mark of God’s blessing—despite Jesus’ explicit warning that “you cannot serve both God and money” (Matthew 6:24). Furthermore, if greenhouse gas levels have risen simply because of natural rather than anthropogenic causes, then this is not our fault but is clearly God’s doing—as a prelude to the Apocalyspse and Last Judgement. Profligacy and excessive consumption can only hasten the endtime: bring it on indeed! Unfortunately, no amount of scientific data will undermine this false conviction. All blame is shifted from human greed onto nature beyond our control and thence to God’s implacable will. We could usefully ponder the story of the Fall (Genesis 3; § 7.3.2)—where nobody was willing to admit responsibility for choosing to sin. Jesus reminds the Pharisees in Matthew 23:23 that their punctilious observance of the finer points of the Law conceals a neglect of weightier matters—“justice, mercy, good faith”. Similar attitudes among many church leaders vitiate what should be a united front to combat climate change and protect the natural environment.

10.4 A path of repentance? In two trenchant critiques of the causes and attitudes underlying climate change, Michael Northcott (2007, 2014) lambasts the values and implicit assumptions of neo-liberal market-led economics—which now transcend national boundaries through multinational corporations that move their operations around the world to exploit cheap labour and natural resources whilst minimising their tax liabilities. Northcott shows how these have led with tragic inevitability to our current plight. He argues for a return to the wisdom of older cultures that lived, for the most part, in harmony with their local environment. And therein lies a crucial point; modern economic

Envoi: The Sixth Mass Extinction

347

systems throughout the world have increasingly divorced the goods and foods we buy from the places and people that produce them—a trend that began with the industrial revolution, but now applies equally to agriculture or fisheries. Natural catastrophes—including famines that might have been provoked by poor farming practices or over-exploitation of the land’s resources—were “blamed” by ancient cultures on the wrath of their God or gods, but became opportunities for communal grieving and repentance (“sackcloth and ashes”)—with a concomitant mending of their ways and restoration of traditional observances. Of course, we now recognise that these catastrophes often arise by chance due to natural causes—such as earthquakes or tsunamis, volcanic eruptions or flash floods, mud slides, avalanches, droughts or forest fires. But in so doing, we deny or at least abdicate our own responsibility—in whole or in part—for many such events. Examples include the wanton overuse of scarce water resources and pollution of aquifers, deforestation and loss of topsoil exacerbating floods and mud slides—plus global warming contributing directly to forest fires, desertification, droughts (Williams et al., 2020), soil salinisation, extreme weather events, avalanches, and the melting of ice-caps—from the tropics (Kilimanjaro) to Greenland and Antarctica. While single incidents can be blamed on a multiplicity of factors, the overall trends and their underlying causes are now abundantly clear. We all too conveniently forget our own responsibility as individuals for participating or at least acquiescing in the rampant consumer profligacy that is literally consuming our planet. Northcott (2007, pp. 71-80) compares two bible stories in Genesis that address issues linked to climate change. First he cites Noah (Genesis 6-9) —taken metaphorically rather than literally—who acts on God’s warnings and probably courts disbelief from those who can see no cause for alarm. Before the Flood, Noah devotes time to careful preparations—not only building the ark, but also provisioning it to sustain the multifarious animals who will join him. Jewish rabbinic commentators draw out from this story not only the culminating covenant between God, humanity and all creation, but also (as Northcott emphasises) an implicit dedication of human effort—or even servanthood—to all those creatures with whom we share this planet. This is a humble, thankless servitude, most likely earning ridicule for Noah from his contemporaries. We can read into this text a message of gratitude for all those who have dedicated their lives to the cause of conservation and the natural environment, from pioneers like John Muir (founding father of the National Parks movement) to the myriad unsung volunteers who mend fences and paths in small reserves and keep a watchful eye on the animals and plants they are trying to protect. This pattern of self-sacrifice and service towards the natural world is truly a

348

Chapter 10

parable for our time, if we can but shake off our naïvely literal picture of animals entering the Ark two by two by two, with Captain Noah steering. Whether they would acknowledge it or not, such volunteers are serving God by cherishing the creation which God beheld as good (Genesis 1). Northcott contrasts this story with that of Joseph (Genesis 37-48). Promoted to a powerful position by the Pharaoh whose dreams he had interpreted, Joseph is able to invest the surplus from 7 years of plenty and store it in readiness for the 7 years of famine that will follow—which eventually draw his brothers down from Canaan to seek food aid from him. This story is a kind of early “techno-fix” solution—building great granaries to store the surplus grain and then rationing it out carefully (even rationally) so that it would last through the predicted famine. Many people today place a similar reliance on technological developments to mitigate or cope with climate change. But their trust may prove misplaced; ideas abound, yet few have been fully safety-tested, and none may prove adequate to the scale of the task ahead. Northcott clearly favours the Noah model, but notes that this cannot be achieved without a real and deliberate sacrifice of much that we take for granted in our spendthrift Western standard of living—particularly in terms of transport, food and energy use. Only thus can we hope to achieve justice for the poor (a recurrent theme through the bible), or for the natural world that surrounds and sustains us. The blunt truth is that we need to repent of our wastefulness, our greed and our collusion with the monstrous consumer juggernaut we have built for ourselves but don’t know how to stop—even if we recognise the harm it is causing to our planet. Many people do repent to a greater or lesser extent (see § 10.1 for my own failings in this regard), and recent publicity around key environmental problems has led to belated action at national and international levels, as well as increased awareness and local involvement. A good example of this is the issue of plastics contamination in marine and other aquatic habitats—so starkly highlighted in the final episode of the Blue Planet II series, broadcast on the 10 th December 2017 by the BBC, and narrated by Sir David Attenborough. But mitigation of current emissions—whether of greenhouse gases or of plastic waste in all its forms—does not address the huge backlog already present in the environment, whose effects will long outlast us. Much of the damage we have already wrought is likely to prove irreparable—cause indeed for repentance and fresh resolve to do better. Christianity, like most religions, has rituals and even seasons (especially Lent) for self-examination and repentance, but these are utterly alien to our secular consumer religion and its worship of the wealth-idol Mammon (Matthew 6:24). Consumerism rarely questions its own assumptions or implicit values, and at best pays

Envoi: The Sixth Mass Extinction

349

lip-service to social ideals such as justice, sustainability, or the value and integrity of the natural world. Nor can it acknowledge its dependence on ecosystem services beyond the most cursory kind of financial calculus. Northcott (2007) argues cogently for a radical rethinking of our prevailing political and economic models, and for reclaiming real power (both administratively and in energy terms) from multinational corporations— not back to centralised nation states, but very much further—to local communities that both know and respect their immediate environment. This theme is further developed in the same author’s more recent book, “Place, Ecology and the Sacred” (Northcott, 2015; see also § 10.6 below). But localism can run up against the selfsame betrayals that have so paralysed international efforts to mitigate climate change. As Northcott (2014, pp. 161-168) points out, the negotiations leading from the 1992 United Nations Framework Convention on Climate Change to the Kyoto Protocol 5 years later (though not implemented until 2005), and on to the Paris Climate Change Agreement of 2015 and Katowice Climate Package in late 2018, have all been vitiated by a succession of slippery concessions and compromises favouring developed nations and multinational business interests—yet have signally failed to address pressing justice issues for the developing world. The core problem here arises from the monetarisation of greenhouse gas emissions, so that carbon trading and carbon offsets allow industries to carry on largely as before, with little incentive to change their prodigal ways. These devices are compared by Northcott (2014, pp. 120139) to the sale of indulgences by the medieval Catholic church. It is also abundantly clear in global terms that no net reduction in carbon emissions had been achieved by 2019. On current trends, this planet may be heading for a temperature rise of 4 to 7 °C by the year 2100, rather than the 1.5 to 2 °C considered “safe” (Lynas, 2008; Juniper, 2016; Hoegh-Guldberg et al., 2019). On the plus side, more widespread adoption of green technologies such as solar and wind power has greatly reduced their capital costs, making them far more competitive, even without government subsidies. However, the iron-mailed hand of the global market still steers political decision-making, and there is a tacit assumption that it will be easier and cheaper to deal with the negative effects of global warming as and when they arise, rather than taking radical action now to slash carbon emissions and reduce the likely scale of future global warming—since this would entail a significant reduction in the living standards of richer countries. An exactly opposite conclusion was reached by a UK government-sponsored report published by economist Nicholas Stern in 2007 (online in 2006), who estimated that the future costs attendant on most climate-change scenarios would vastly outweigh those of reducing current carbon emissions

350

Chapter 10

in the short term. A further common assumption is that current free-market economic models can continue indefinitely into the future so long as they gradually go green by reducing their carbon footprint, albeit not so rapidly as to threaten business as usual. Short-term profits always win out over long-term damage to the environment. A new calculus is long overdue, in which the wider interests both of future human generations and of the natural world can emerge from the wings and take centre-stage. Historically, the present excess of CO2 and other greenhouse gases in the atmosphere came largely from industrialised nations, though growing emissions from developing countries such as India, Indonesia, Brazil and China are already changing this balance. Yet it is amongst the poorest nations and people on earth that the greatest impacts of climate change will be felt. Mass migrations caused by flooding, rising sea levels, deforestation or desertification are already starting and can only get worse. Northcott (2007, pp. 181-185) makes no bones about describing this inequitable situation as “structural sin”. In traditional, locally-based economies, goods and services were for the most part bartered between individuals within an implicit social framework. Other goods—such as water, soil or fuel resources—were held in common, and many foodgathering activities (e.g. collecting, harvesting, hunting or fishing) were communal. It was not in the interests of anyone to pollute or over-exploit these limited local resources, because flourishing of the whole community was dependent on their sustainability. Cheats would rapidly be exposed, shamed and ostracised, if not expelled. There is still of course the “tragedy of the commons”—whereby slight over-exploitation goes unnoticed at first, until disaster strikes. But industrialisation has severed those links between communities and the basic necessities of life, such that water, soils and other environmental services can be polluted or over-exploited without cost to distant consumers, who do not see the damage caused. Hence vast tracts of rainforest are being felled and replaced by oil-palm plantations in Borneo, or by cattle ranches in Brazil, decimating local biodiversity and displacing many indigenous communities. Such examples could be multiplied a thousand-fold, and serve only to bolster accusations of structural sin. Compounding this, the market economy is not content merely to sell us commodities and services that we need; it also seeks to foist on us unnecessary luxury items that we do not need for a decent standard of living (Northcott, 2007, pp. 152-156), and to persuade us that we will be missing out if we do not succumb to temptation and buy into the fantasy “good life” depicted by advertising. Insofar as we all fall prey to this pervasive ethos (FOMO—the fear of missing out), we also stand convicted of that communal sin. It may well be “easier for a camel to go

Envoi: The Sixth Mass Extinction

351

through the eye of a needle than for someone who is rich to enter the kingdom of God” (Mark 10:25, NRSV). Arguably, it is advertising agents and promoters, rather than innovators or CEOs, who are the high priests of consumerist religion. Clever and ever-more-subtly targeted advertising creates fashions through a combination of memes that lodge in our minds and the power of mimetic rivalry—seducing us into desiring the not-quiteattainable—luring us into debt in the process. All grist to the capitalist mill. In truth, since climate change first came to public attention in the 1990s, the international response has been half-hearted at best, while its predicted likely consequences have escalated from gloomy possibilities to full-blown apocalyptic warnings (Northcott, 2014, p. 12 ff.), reminiscent of the books of Revelation or parts of Daniel—or indeed some sayings of Jesus before his arrest and trial. Part of the problem is that this catastrophe is unfolding in slow motion (ibid., pp. 4-7), such that the overall trends can easily be denied or attributed to “natural cycles”—anything rather than accepting our own responsibility for what is happening. Climate scientists often find themselves dismissed as lobbyists rather than impartial reporters of the best inferences drawn from accumulating data. The fact that science plays a central role in our technology-dominated internationalist ideology tragically undermines its core claim to impartiality in its predictions about global warming—promoting suspicion among climate-change sceptics that this is merely a conspiracy promulgated by big business and international agencies. It is also blatantly obvious that this provides a shameless cover for multinational business interests, such as the opportunistic oil industry, which in turn help to fund climate change denial (Northcott, 2007, p. 112). There is a double whammy here, because the greenhouse-gas-producing technologies on which modern life relies (e.g. road and air transport) are themselves the products of applied science from earlier generations. Scientific progress in large measure lies at the root of the problem of global warming, in addition to generating an avalanche of dire predictions about its likely consequences. Northcott (2014, pp. 15-23) also explains why recent climate science has become ever more politicised, identifying the interlinked factors that underlie widespread scepticism—even when faced with overwhelming scientific evidence. As discussed earlier (§ 10.3), a further twist is introduced by those evangelical Christians who blame climate change on natural causes instigated by God as a preparation for the endtime; for them, all such science-based warnings are irrelevant. In view of increasing human influences over the land-masses, aquatic habitats and atmosphere of this planet, some are calling for this present epoch in earth’s history to be renamed the Anthropocene (Crutzen, 2002; Zalaciewicz et al., 2011). Opinions differ as to when this period was

352

Chapter 10

inaugurated: perhaps with the Neolithic revolution that gave birth to agriculture and permanent human settlements, perhaps with the industrial revolution that first saw fossil carbon released from coal on a huge scale, or perhaps from 1950 onwards (my own lifetime!) when atmospheric CO2 levels began to rise steeply. Northcott (2014) develops his arguments into a radical political theology of climate change. Thus the biblical Fall (Genesis 3) can be viewed as an unprecedented choice by (some) human beings to exert control over their environment, rather than relying as their hunter/gatherer ancestors did on what that environment was able to provide (§ 7.3.2). No other species in the 3.7 billion-year evolutionary history of life on this planet has been able to construct such elaborate and complex niches to further its own ends, nor to plunder the biosphere and natural resources of the earth so ruthlessly, apparently impervious to the long-term consequences. First came farming, tailoring a range of crop and livestock species for human benefit through selective breeding, together with deforestation, irrigation and enclosure of land. Then came mining, for metals initially, but increasingly for coal—and then oil—to fuel the burgeoning industries that satisfy our craving for manufactured consumer goods. Now, finally, our collective profligate greed is catching up with us—and without drastic action by both individuals and governments, the likely outcomes towards the end of this century will threaten human civilisation, and even survival, in many parts of the world. Atmospheric CO2 levels have risen from pre-industrial levels of 280 to over 400 parts per million (ppm). The last time such conditions were experienced (3-5 or possibly even 15-20 Ma), the Arctic was ice-free and sea levels were 20+ metres above those seen at present. It is true that CO2 levels peaked at 5fold higher levels (2000+ ppm) during the Devonian (~400 Ma) and Triassic (~200 Ma) periods, but they were closer to 300 ppm during parts of the Carboniferous (~300 Ma) era, when so much fossil carbon was sequestered as coal (Foster et al., 2017). A long period of relative climate stability allowed the evolution of Homo sapiens and the development of a technological culture, but that equilibrium is now becoming destabilised. The future still remains shrouded. At best, humanity might find the self-sacrificial resolve to curb its collective carbon emissions and so reduce the extent and impact of global warming. But the 21st C CE has seen efforts in this direction derailed by a worldwide economic recession starting in 2007, and more recently by right-wing populist nationalism that tends to go hand in hand with climate-change denial. The global political omens do not look promising, nor are there obvious “techno-fix” solutions of proven safety in the offing, other than massive tree-planting projects (Bastin et al., 2019), which may be of limited effectiveness (Anderegg et

Envoi: The Sixth Mass Extinction

353

al., 2020). As sea levels rise and vast tropical areas become marginal for agriculture (e.g. through desertification), so mass migrations of displaced people will come knocking at the borders of more developed nations. Current trickles will become floods and then tides of humanity, but the response of richer countries is unlikely to be welcoming. “Carbon wars” in the coming century could even dwarf the global conflicts of the 20th C CE (Northcott, 2014, pp. 7-12). In extreme scenarios, law and order may well break down within the richer countries. Certainly there is already a strong survivalist movement among eco-activists—those preparing to become self-sufficient on small-holdings of land at safe altitudes, and also to defend themselves against marauders. This betokens an individualistic, hard-nosed response where only the “fittest” can hope to survive, and the weak may go to the wall. In Lovelock’s “The Revenge of Gaia” (2006), the planetary super-organism is seen as preparing to slough off and get rid of its troublesome parasite, Homo sapiens. Even if some humans survive the impending catastrophes, they may be greatly reduced in numbers and technological reach—such that survivors would perforce live with greater regard for a hostile environment. Our hubris will have over-reached itself and failed us. All this may happen sooner than we think, as global warming is now accelerating due to mutually reinforcing processes (Xu et al., 2018). René Girard points to a mimetic escalation of violence in the modern world (Steinmair-Pösel, 2017). Christian faith clearly shows the impotence of the classic scapegoating mechanism (§ 6.8), but paradoxically removes a key restraint on violence—so facilitating its escalation. The only solution on offer is radical conversion, following Christ’s costly example of love and service to others. A propos of climate change, Girard writes: “There is an indissoluble link between global warming and the rise in violence. I have repeatedly emphasized the confusion of the natural and the artificial, which is perhaps the strongest thing in apocalyptic texts. Love has ‘cooled down’. Of course, we cannot deny that it works in the world as it has never worked before, that the awareness of the innocence of victims has progressed. However, charity is now facing the worldwide empire of violence.” [Girard, 2007/2010, p. 216]. “Humanity is more than ever the author of its own fall because it has become able to destroy the world.” [ibid., p. 217].

Violence in turn is underwritten and justified by greed; those of us who are materially prosperous resort to violent means to defend our possessions and privileges, turning a deaf ear—if not the barrel of a gun—towards the poor and dispossessed flocking to our borders, often entering by illegal means. Immigration into our countries is so difficult and bureaucratic that

354

Chapter 10

it fosters bitter resentment among refugees. Terrorism becomes virtually inevitable, as Girard (2007/2010) discusses at some length in his Epilogue. If our nomadic hunter/gatherer ancestors lived mostly off the bounty of the environment, and if the biblical Fall symbolises our first faltering steps towards controlling and manipulating that environment for our own ends, then the codified rules for land use set out in the Mosaic Law (principally in the book of Leviticus) can be read as God’s attempt to mitigate the worst excesses of early agriculture and of the city-states that it supported. Northcott (2014) points to the Sabbath rest prescribed for the land every seventh year (Leviticus 25:1-7), and for human labourers (including even slaves) every seventh day. Land was meant to be apportioned equitably among the 12 tribes following the conquest of Canaan. Moreover, in each 50th year of Jubilee, all land was to be returned to its original owner (Leviticus 25:8-17), and those fellow-countrymen who had become slaves or indentured servants were to be freed (Leviticus 25:54-55). These measures set limits on the accumulation of land and wealth by a small minority of powerful landowners, just as fallow years allowed the land itself to recover its fertility. Other detailed regulations—for instance about not moving boundary markers or leaving field margins unharvested so that the poor (and indeed animals!) could benefit from the gleanings—seem designed to promote a more equitable society than was the norm among Israel’s neighbours. During their early years under the Judges, the Israelites eschewed monarchy, and when kingship was eventually established (albeit reluctantly)—first under Saul and then the House of David—the king was supposed to act as the steward of his people, responsible before God. Very few of the kings met these exacting standards (even Hezekiah and Josiah fell short on occasion), and the vast majority “did evil in the sight of the Lord”. It is also noteworthy that rediscovering the Mosaic Law (in which all of the above regulations were enshrined) was accompanied by public acts of repentance both during the reign of Josiah (2 Chronicles 34:14-33), and later when the temple in Jerusalem was rebuilt—supervised by Ezra and Nehemiah—following the exile in Babylon (Nehemiah 8). In terms of land use, politics and citizens’ rights, Israel was meant to set an example of good practice and sustainability to its neighbours, but all too often it failed to live up to these ideals—allowing idolatry, injustice, exploitation and avarice to become rife, all of which were roundly condemned by the Old Testament prophets. Their call for repentance—a fundamental change of heart and mind and practice (Greek metanoia)—is one that should loom large today in relation to climate change, and especially so for Christians.

Envoi: The Sixth Mass Extinction

355

10.5 How might Christians help? It goes without saying that church leaders and congregations would do well to stop denying climate change and human culpability for it, and instead join forces with green campaign groups to work towards a sustainable future for the entire biosphere. The Anglican Communion has at least made a start by including this as its 5th mark of mission, adopted in 1990 by the Anglican Consultative Council: “to strive to safeguard the integrity of creation, and sustain and renew the life of the earth”. Other denominations have also made similar statements among their mission priorities. Many churches are now adopting a liturgical season of Creation Time, stretching from 1st September to 4th October (feast-day of St. Francis of Assisi) each year, often including traditional Harvest Festivals. This initiative was launched originally by the Eastern Orthodox churches in 1989, but has since been widely adopted in Protestant, Catholic and Anglican circles. A rich variety of creation-centred liturgical resources is now available, which encourage congregations to think more deeply about environmental issues. But having sat on many church committees over 40+ years, this 5th mark of mission is often ignored or given a low priority, and Creation Time is also viewed with scepticism. Reducing the carbon footprint of churches to zero is obviously a longer-term aim—which may be hampered in practice by poorly insulated buildings and other factors. These changes are modest but feasible, if given sufficient priority by clergy, laity and key funders. Organisations such as Eco Church (facilitated by A’Rocha in England) or EcoCongregations exist to help diverse church communities realise these aims, encouraging members to join together in caring for creation. Broader themes are explored by Pope Francis in his 2015 encyclical Laudato Si’, on care for the natural world. Unfortunately there are many right-wing Christian groupings who still deny the reality of climate change, or at least of human responsibility for it. A draft of what became the “Evangelical Declaration on the Care of Creation” (Anon., 1994; republished 1995) was met with condemnation from several quarters (e.g. Beisner, 1993), prompting a fuller and more considered evangelical response from a range of theologians and scientists (in Berry [ed.], 2000). Peter Harris comments as follows: “Over recent years, the fall has been the most convenient get-out for evangelical leaders looking for scanty rags of theology to cover naked free-market greed…. The conventional argument is that now that creation is fallen, God has lost interest in everything but salvaging the souls of human beings; all we need to know is how to live in the creation in the meantime, and to extract what we can of God’s good gifts from it before it all burns in the final judgement.” [Harris, 2000, p. 134].

356

Chapter 10

Harris takes the Declaration to task for citing as a key text Genesis 1:31, which “records God’s satisfaction with all he has made, but refers to creation before the fall”—so leaving this particular escape hatch wide open. Jürgen Moltmann (2000, p. 111), emphasises instead the covenant established after the Flood, and therefore within “fallen” creation, between God, humanity and the natural world, spelt out in Genesis 9:6b-11 (NRSV): “ ‘for in his own image God made humankind. And you, be fruitful and multiply, abound on the earth and multiply in it.’ Then God said to Noah and to his sons with him. ‘As for me, I am establishing my covenant with you and your descendants after you, and with every living creature that is with you, the birds, the domestic animals, and every animal of the earth with you, as many as came out of the ark. I establish my covenant with you, that never again shall all flesh be cut off by the waters of a flood, and never again shall there be a flood to destroy the earth.’”

Note how the opening of this quotation also reaffirms the imago dei of humanity (Genesis 1:26; § 7.3.4) as well as the injunction to be fruitful and multiply (Genesis 1:28), suggesting that the divine ordering of creation was not abrogated after the Fall. However, there is a stark change in the terminology used to describe humanity’s “dominion” over the creatures of the world. Instead of this rather ambiguous term, with its overtones of stewardship responsible before God, we have these far more chilling (but realistic) words in Genesis 9:2 (NRSV): “The fear and dread of you shall rest on every animal of the earth, and on every bird of the air, on everything that creeps on the ground, and on all the fish of the sea; into your hand they are delivered.” How ruthlessly we have pursued that path since Neolithic times! Calvin DeWitt (in Berry [ed.], 2000, pp. 60-73) outlines 7 ways in which Homo sapiens is degrading and contaminating the natural world—in terms of its atmosphere, land and soil, deforestation, species extinction, fresh and marine water-quality, toxic waste disposal, and loss of indigenous cultures. However, each of these can be restored to some extent through protection, and by natural processes of renewal (7 provisions of creation). His point is that earth’s repair systems have only a limited capacity, which is already being strained or exceeded on all fronts. Time, and holding back, are essential in order to let the planet mend itself. As mentioned earlier, there has been a powerful evangelical backlash — particularly in the USA—that makes a show of acknowledging climate change as real, whilst denying that human beings make any significant contribution towards this natural (indeed, divinely ordained) trend, which will usher in the endtimes predicted in scripture. This implies that business can carry on as usual, with no need to mend our ways. Christians should

Envoi: The Sixth Mass Extinction

357

rightly be wary of such an easy path, when the gospels are unanimous that we cannot escape the costliness of taking up our cross to follow Jesus.

10.6 The practice of restraint Herein lies a deeper and more personal sense in which Christians can engage with environmental issues and sustainability. From the outset, our faith has been profoundly counter-cultural—cutting across divisions of race, gender, ethnicity and economic status. At least, that is what the Jesus we meet in the gospels shows us by his words and deeds. All too often, this counter-cultural aspect has been turned on its head by institutional churches, embracing a moral agenda that rejects contemporary “liberal” values and denies the inclusiveness of Jesus’ own ministry among social outcasts—the tax collectors, prostitutes and sinners, even Samaritans and Romans—which so outraged the scribes and Pharisees and Law-teachers. One recurrent manifestation of Christianity’s counter-cultural tendency has been a rejection of worldliness and an identification with the poor and destitute. From early times, zealous Christians have sought solitude as hermits in the desert, or joined remote monastic communities (none more extreme than Skellig Michael off the Iveragh peninsula in the Irish Republic), or served as missionaries in distant outposts of various European empires (from Roman to British). It is true that many monastic communities grew rich and self-indulgent, and that mission efforts were compromised by collusion with colonial powers and insensitivity to local beliefs or customs (a form of cultural imperialism, often amounting to cultural genocide). But a common thread uniting many of these men and women of faith was their commitment to renouncing everything worldly in order to follow the call of Jesus Christ (Matthew 8:18-22; 19:21-22). This is a theme taken up by Sallie McFague (2013) in “Blessed are the Consumers”, which challenges Christians to live lives of genuine restraint in view of climate change and widespread poverty in the developing world. Her examples, including Simone Weil (who virtually starved herself to death), are perhaps extreme—but they jolt us into an awareness of how little we really need in order to lead full and fulfilling lives. If we take heed of Christ’s call to serve others, following his own kenotic example (Philippians 2:5-11), then our material possessions become vain distractions. Indeed, we begin to see them for what they truly are—mere flotsam in the relentless tides of consumer marketing, trying to turn a profit by selling us goods we don’t really need. In the meantime, whatever the economic rationale for such a senseless state of affairs, we are slowly strangling our planet with pollution (plastics, especially), with greenhouse

358

Chapter 10

gases, and with insatiable demands for non-renewable resources—despite untold costs to the rest of the biosphere and to other, less fortunate human beings. Although we are at last recognising the necessity of recycling as much waste as possible, the complex composites of varied materials used in many manufactured goods pose problems in terms of disassembly and sorting—usually farmed out to cheap labour in poor developing countries. A lack of proper protection or disposal facilities vitiates the health of such workers and pollutes their environment. Moreover, built-in obsolescence, compounded by ever-accelerating rates of technological innovation, always favours replacement over refurbishment or repair. It is far simpler and less time-consuming to buy a brand-new computer than to upgrade an old one with extra memory plus the latest operating system and software. Christians are called to live Christ-like lives in the service of others— showing our love for God through loving them, even those whom we count as enemies. Conspicuous consumption has no place in this call to service, and Christians could potentially offer leadership by example, if we were more willing to live lives of real restraint in material terms, yet of generosity with our time, money and talents. Such a movement—if it were sufficiently widespread—could help counter the age-old accusations of hypocrisy and of behaving in ways that belie the central tenets of our faith. It might even prove more attractive to the idealism of the young, who are conspicuous by their absence in so many churches. But we would need to embrace this change of lifestyle wholeheartedly, and not by half-measures, as Sallie McFague (2013) makes clear. Ideally, this should become a hallmark of all Christian communities—so that we become known for our restraint as well as for the love we show to others, for in so doing we make known the example of Christ (1 John 3:16-18). Environmental awareness and sustainable living should be integral to our practice of righteousness. There are biblical precedents, as in the Torah’s insistence on a fallow year: “but the seventh year you shall let it [your land] rest and lie fallow, so that the poor of your people may eat; and what they leave the wild animals may eat. You shall do the same with your vineyard, and with your olive orchard.” [Exodus 23:11; NRSV].

The same injunction is made in Leviticus 25:2-7, but here it is clear that God’s intention for this 7th fallow year is to become a sabbath rest for the land itself (Moltmann, 2000, p. 112)—an early example of ecological wisdom. The consequences of failure to obey this instruction (ibid., p. 113) are spelt out in the following chapter, where God warns: “I will scatter you among the nations….your land shall be a desolation and your cities a waste. Then the land shall enjoy its sabbath years as long as it

Envoi: The Sixth Mass Extinction

359

lies desolate …it shall have the rest it did not have on your Sabbaths when you were living on it.” [Leviticus 26:33-35; NRSV].

We have long recognised that soils eventually become depleted, and unable to sustain high levels of agricultural production, when we ignore traditional practices such as crop rotation or a fallow year. Intensive chemical inputs of fertilisers and pesticides can provide at best a stopgap solution to this problem. We have also come to recognise that levels of pest infestation are often lower under organic farming practices, where a greater variety of predator and parasite organisms helps to keep pest numbers in check. I am not advocating organic farming as a solution to the travails of agriculture—it is hard to see how current levels of food production could be maintained without using intensive methods—but merely pointing out that this is yet another instance where we literally reap what we have sown. Widespread resistance to pesticides (see § 1.6), soil depletion and erosion, water shortages and biodiversity losses are all-butinevitable consequences of the intensive farming approaches we have adopted across much of the world. For subsistence farmers in sub-Saharan Africa and elsewhere, integrated pest management (IPM) solutions offer a realistic alternative. These often emerge from local traditions, buttressed by detailed analyses of the volatile chemicals that are emitted by crop plants and act as attractants to insect pests. IPM usually involves inter-planting crops with non-crop species whose volatiles actively deter those pests, as well as enclosing crop fields with “trap” margins planted with species that are even more attractive to the pests than the crop itself (Push-Pull systems; Pickett et al., 2014). Other approaches include some ingenious applications of second-generation genetic modification (GM) in key crop plants (Pickett & Khan, 2016). But the potential of GM technology needs to be freed from the stranglehold of the big multinational agri-business corporations that monopolised first-generation GM applications (§ 7.4.1). The church remains one of the few societal institutions that still maintains a foothold in rural communities (true in much of Africa, as well as in Europe and the Americas). It also has no particular axe to grind in the polarised arguments around farming, land use, agrochemicals, GM or food production, so it could potentially act as an honest broker to promote informed debate around the issues involved. Indeed, this could encompass both outreach into local communities and engagement with environmental sustainability. But the church’s motivation must be transparent here: it is not primarily about making converts, but rather about following Christ’s own injunction to act as yeast in the dough of society (Luke 13:20-21). Christians are called to lives of restraint and service as an unostentatious model for others—who may not share our faith but who feel (however

360

Chapter 10

tentatively) that we should all be doing more to cherish the environment. In this we should be making common cause with conservation and green pressure groups, and with the many non-religious people who respond to E.O. Wilson’s (1984) call for humanity to embrace biophilia (meaning love for the living world). It is also abundantly clear that addressing global warming requires concerted action from below, as well as from national and international agencies. If we Christians cannot set aside our differences (and our thinly masked agendas!) to join in this common cause, then we forgo any claim to moral authority and consign ourselves to irrelevance. We betray the God whom we profess to love by failing to exercise proper stewardship towards God’s earthly creation (see Berry [ed.], 2000; Berry, 2003)—whether we choose to interpret this phrase metaphorically or even literally. Wilson (2016), at least, has not given up hope of saving the world’s biodiversity, though his radical proposal to devote half the earth’s surface to wildlife conservation will seem wildly over-ambitious to many. Northcott (2015) envisages human beings living increasingly in smallscale, sustainable, morally and environmentally responsible communities. Doubtless this utopian vision will also seem hopelessly idealistic to most people, yet it may represent the only long-term solution that can reestablish harmonious relationships between humanity and the natural environments we inhabit. At the end of his 2014 book (pp. 307-312), Northcott cites the hopeful movement known as the Transition Network (see TransitionNetwork.org), which started at Kinsale in Ireland and was pioneered in the UK by the small Devon town of Totnes—coincidentally close to the ancestral lands taken over by my own de la Pommeraye ancestors in 1066 CE (the Norman castle at nearby Berry Pomeroy). The aim of Transition Network is to encourage the development of bottom-up community initiatives—so that towns, villages and even cities become more self-sufficient in terms of energy, water and other resources. This is in part a response to, and a preparation for, climate change—but it has also proved empowering and creative for the communities involved. At all events, this concept has been adopted widely across the UK and elsewhere in recent years. If we do not embrace such a programme voluntarily, we may find it forced upon us willy-nilly by the exigencies of global warming. Of course, most of us are now urban dwellers, and many of the villages in developed countries have become little more than commuter dormitories for well-to-do escapees from bustling cities, seeking an illusory rural idyll. Such changes in community life are compounded by changing patterns of work: life-time jobs (like mine before retirement) are largely a thing of the past, while temporary, freelance or self employment has become the norm. But, in a sense, this is nothing new for Christians. Jesus himself said that,

Envoi: The Sixth Mass Extinction

361

while “Foxes have holes, and birds of the air have nests….the Son of Man has nowhere to lay his head” (Luke 9:58, NRSV). As Hebrews 13:14 (NRSV) phrases it, “For here we have no lasting city, but we are looking for the city that is to come”. Yet wherever we may find ourselves living, and however transiently, we will still form part of a community to which each of us can contribute, set in an environment whose flourishing we can foster and promote. The well-being of the former is linked inextricably with the health of the latter—a wisdom that was familiar to our ancestors but is increasingly lost from view amid the frantic pace of 21st century CE living. Churches could again lead by example here, modelling restraint as a Christian virtue alongside zeal for our beliefs, plus a commitment to cherish our local community and its environment through unconditional love and compassion for others—thereby living out our calling to proffer glimpses of God’s counter-intuitive kingdom. But we should ask ourselves for how long this option can still remain open to us. As in any hard-hitting sermon, these reflections come home to roost in myself—and what more I could do personally to live sustainably and in harmony with the environment. I come full-circle back to where I started this chapter, but with a renewed resolve to do better, having at least made a start. If all Christians, and the churches to which they belong, could do the same—then bit by bit we might start to make a difference. If other religions joined in (as many already aspire to do), then that difference might become truly significant. But it will still take a worldwide mass movement from below to break the stranglehold of consumerism and the climate change which it foments. Maybe this is special pleading: too little, too late. But if we humans cannot bring our spirituality into play as a motivating force for restraint in our attitudes and way of life, then we have already lost the battle to limit global warming. We may only realise the true value of what we have lost once it has vanished irretrievably, never to reappear. Future generations will not forgive us for our short-term thoughtlessness and greed in these crucial years of the early 21st C CE, when we realised the scale and consequences of climate change, yet could not find the inner motivation to change our ways—as young eco-activist Greta Thunberg made clear in her address to the United Nations General Assembly in September 2019. The manifold temptations of our wasteful lifestyles may prove harder to resist than the lure of the proverbial apple that betrayed Adam and Eve in Genesis chapter 3, but if we cannot find the resolve to turn our backs on them, then our second Fall as a species could prove far more catastrophic than the first. Judgement will again follow, as an inevitable consequence of our choices. For Christians and other religious believers, it may be seen as God’s judgement; for others, it

362

Chapter 10

will be the revenge of Gaia or of a destabilised planetary climate. However we choose to interpret it, what is looming ahead looks ominous or worse (Wallace-Wells, 2019). Our age may come to be seen with hindsight as an Eden that this generation will have squandered, an inheritance we despised and traded for a mess of pottage, as Esau once sold his birthright to his cunning younger brother Jacob (Genesis 25:29-34). The writing is on the wall, as it was long ago for King Belshazzar: “MENE, God has numbered the days of your kingdom and brought it to an end; TEKEL, you have been weighed in the scales and found wanting; PERES, your kingdom is divided and given to the Medes and the Persians” (Daniel 5:26-27, NRSV).

10.7 The importunate friend “And he said to them, ‘Suppose one of you has a friend, and you go to him at midnight and say to him, “Friend, lend me three loaves of bread; for a friend of mine has arrived, and I have nothing to set before him.” And he answers from within, “Do not bother me; the door has already been locked, and my children are with me in bed; I cannot get up and give you anything.” I tell you, even though he will not get up and give him anything because he is his friend, at least because of his persistence he will get up and give him whatever he needs.’” [Luke 11:5-8, NRSV]

Reverting to the format used in chapter 9, it is illuminating to cast the human race in the role of the sleepy householder, his door safely locked (or so he imagines), tucked up cosily in bed with his children, cocooned in his creature comforts and surrounded by his immediate concerns of family, career, status—or indeed, where the next meal is coming from. Most of us are pretty well insulated from the environment outside our walls, yet that is what comes knocking at our door at dead of night. Indeed, through floods or wildfires or mudslides, it might literally batter our doors down. Interestingly, on this interpretation, we are asked by Jesus to identify not with the householder but with the environment, which is supposed to be our friend. Of course, for our hunter/gatherer ancestors, or for indigenous peoples in Australasia and the Americas and much of the non-European world, that friendship was real and hallowed by ritual—since their local environment was the source of bounty and scarcity alike. Needless to say, we are far too sophisticated for such irrational nonsense in the 21 st C CE. Or are we? The environment is still out there, hammering at our barred and locked doors with increasing volume and persistence. We may choose to wear ear-muffs, or listen to a recording of some deluded climate-changedenying rant—but sooner or later we will have to wake up and pay proper attention. As Jesus says, “at least because of his [the environment’s] persistence he [the human race] will get up and give him whatever he

Envoi: The Sixth Mass Extinction

363

needs.” We can choose the path of selective deafness, until such time as wildfires burn our houses to the ground (as in Australia, late in 2019), and till the flood defences of our coastal cities are overwhelmed by rising sea levels—or we can act decisively now to curb our carbon emissions and get a grip on climate change before it spirals out of control. We are starting to realise how much our well-being as a species depends on the diversity of other organisms on this planet, and on its essential ecosystem services. Human friendship with the environment is sorely in need of renewal! We tend to take our natural environment (however modified) for granted, and fail to appreciate or give proper thanks for its bounteous gifts and blessings of unparalleled beauty and insight. We might recall Jesus’ healing of the ten lepers in Luke 17:11-19. All 10 are healed, yet only one returns to thank Jesus in person, “praising God with a loud voice” (v. 15)—and he a Samaritan, a “foreigner” in Jesus’ terms. The final words in this story are worth pondering, where Jesus says “Your faith has made you well” (v. 19, NRSV)—or more literally “Your faith has saved you” (Morris, 1988, p. 283). It seems to me that a contrast is being drawn here between physical healing—which all 10 received—and salvation, offered paradoxically (for any orthodox Jew at that time) only to this heretical Samaritan. Of course, we can spiritualise this in terms of recognising Jesus as the living God incarnate—but I think it is also permissible to make a distinction here between physical health or healing and the wider concept of well-being, which has mental and spiritual as well as physical dimensions. We can experience true well-being only when we live in harmony with ourselves, with other humans, with our environment and, dare I say it, with God. Herein we find a foretaste of God’s shalom—the Sabbath rest of the kingdom in which all creation finds ultimate rest and fulfilment.

10.8 Afterword In a conversation between two of the greatest symphonists of the early 20th C CE, Jean Sibelius and Gustav Mahler, the former spoke of the strictness and profound logic of symphonic form, but the latter declared “A symphony must be like the world; it must embrace everything!” So too for evolution: it provides a disciplined and logical way of thinking about the riotous profusion of the living world, asking always “What is it for?” (since adaptations are favoured for good reasons) and “How did it come to be this way?” (since nothing springs into existence ready-made). But evolution is also all-embracing in its scope: not just the neo-Darwinian synthesis of genetics (chapter 1) and natural selection (chapter 2), but also insights from palaeontology (chapter 3), evo-devo (chapter 4), and from

364

Chapter 10

human culture (chapter 5). The challenge for Christians is to see evolution, not as a threat, but rather as an expression of God’s creativity—enfolded in love, compassion and mercy. If we can discern God in and through and companioning evolution, then we have nothing whatsoever to fear from it. Except that such understanding now comes with a sting in the tail; anthropogenic climate change threatens the whole planet with a sixth mass extinction, perhaps comparable to the five that have already punctuated the course of evolution, each time with devastating effects on biodiversity. We who benefit from prosperous lifestyles risk finding ourselves numbered among the goats rather than the sheep (Matthew 25:31-46), if we fail to take urgent action to minimise our carbon footprint. We cannot presume that God will intervene to bail us out from impending disaster, for we will reap the whirlwind of what we have sown (Hosea 8:7). Without the crucial motivation of hope (with its deep Christian connotations of resurrection; Conradie, 2000/2005), it is all too easy to fall into despair or anomie in the face of climate change—the sheer scale of the problem crushes and defeats us. Yet far too many Christians stand aside from this global calamity as though it had nothing to do with them, instead of seeing it as the joint responsibility of all humanity. Isaiah had a stark warning for those who ignored the signs of the times and simply carried on as normal: “In that day the Lord God of hosts called to weeping and mourning, to baldness and putting on sackcloth; but instead there was joy and festivity, killing oxen and slaughtering sheep, eating meat and drinking wine. ‘Let us eat and drink, for tomorrow we die.’ The Lord of hosts has revealed himself in my ears: surely this iniquity will not be forgiven you until you die, says the Lord God of hosts.” [Isaiah 22:12-14, NRSV]

The theme that underpins every facet of this book is best summed up as interconnectedness—a concept central to both ecology and Buddhism. As Part 1 has tried to make clear, evolution links together every aspect of biology—from molecules to ecosystems. As outlined in chapter 8, I also suggest that a universalist conception of the Christian God offers an even broader embrace (I choose this word deliberately, with all of its intimate associations)—encompassing all that was or is or ever shall be in God’s unfathomable love. This is, I concede, a hope rather than a certainty, but one that is grounded in scripture and a venerable (if minority) tradition within Christianity (§ 8.5.2). That embrace will ultimately lead us into the life and interweaving dance of the Holy Trinity, interconnecting us with all creation as one community in endless communion with God’s very self. Of course, this provides no answer for atheists such as Dawkins, Hitchens or more recently Jerry Coyne (2015): I have adduced not one shred of

Envoi: The Sixth Mass Extinction

365

evidence for the existence of God, whose fingerprints are either everywhere (and thus indistinguishable from natural causes) or nowhere. I believe that a universe imbued with love and compassion will be more astonishing in its creativity and innovation than the bleak alternative of purposeless blind chance. But my belief is in itself an unprovable assertion, indeed a giant leap of faith. The God I have outlined does not meddle in the cosmos, but enfolds it in love, offering grounds for hope that all will be redeemed and made right in the kingdom promised by scripture, and brought near to all in Jesus. Perhaps this is just wishful thinking on the part of those (like me) too weak to face up to the grim reality that life has no meaning, and that human ideals of love, virtue, honour, loyalty and courage are just comforting fictions with which we cosset ourselves. The problem with this gloomy existentialism—espoused by many atheists in the wake of Jacques Monod (1970/1972)—is that it can offer little or no leadership in the current environmental crisis. If we human beings have no ultimate purpose beyond the dictates of our genes, memes and personal ambitions (Monod’s teleonomies), then what value can we ascribe to the natural world, beyond a crude calculus of its instrumental benefits? Species are merely transient identities in the great evolutionary flux, so why bother to conserve those that are probably doomed anyway? Some humans will doubtless survive the coming catastrophe (and those who live in temperate climes may be best placed to do so), so why should we not strengthen our borders as a bulwark against less fortunate migrants? I am not saying that even fervent atheists necessarily countenance this cynical view, but it is not an unreasonable extrapolation from their arguments. Many of them also advocate a reliance on future technological advances to save the day, appearing over the horizon—like the US cavalry—just in the nick of time. The Christian calling is, I believe, radically different—demanding yet hopeful. As set out earlier in this book, our faith need not contradict the current scientific world-view. If God indeed intends that all creation shall be redeemed (§ 8.5.2), then there is no necessity for Christians to convert the world to their faith. Rather, we should follow the example of Jesus the Christ, living modest lives of genuine restraint, in the service of others and of the natural world—as yeast in the dough of humanity, working for the kingdom in which all shall be raised. Thus far, we have made a poor show of leading by example, since the most vocal Christians are those preaching an exclusive faith that frequently denies human responsibility for climate change. For such churches, saving souls through conversion always takes priority. But I believe the more open, liberal, radical and inclusive faith that I have outlined in chapter 8 is also well grounded in scripture—and offers hope for all, not just for the elect. Perhaps that hope and faith will

366

Chapter 10

prove misplaced (we will no longer be around to find out!), but at the least the example of Jesus should guide us into lives well lived. We are called to work tirelessly for the disadvantaged, the poor and the voiceless—which must now include the environment as a core priority. We should be known for our love—not just within the church community, but for all people and all creation. As faith becomes increasingly marginalised, there is no shame in being labelled counter-cultural and even subversive. We need to ask of our own lifestyles, of our technological dependency, and of the economic system which sustains them, the same two inter-related questions that I raised earlier in the context of evolution: “what is it for?”, and “how did it come to be this way?”—but perhaps adding a third: “who pays the cost?” Pope Francis’ recent encyclical letter Laudato Si’ (2015, p. 59) highlights an inadequate anthropology, taught even by the church, that has focussed on domination and bequeathed us “a Promethean vision of mastery over the world, which gave the impression that the protection of nature was something that only the faint-hearted cared about.” We must learn better, as a matter of urgency: future generations depend upon our choices now. I intended to end my book at this point. But major heart surgery and a lengthy indexing process have dragged on until July 2020, and our world has been turned upside down by the coronavirus pandemic, on a scale not seen since the Spanish ‘flu a hundred years ago. The COVID-19 virus has ironically achieved what 30 years of climate change negotiations have signally failed to do: 2020 will see the first substantial annual reduction in carbon dioxide emissions (Tollefson, 2020), given the virtual shutdown of air travel and of many industries across the planet. Of course, a one-year dip will not materially affect the concentration of CO2 in the atmosphere. Given the inertia of climatic and geochemical cycles, many sustained years of emission reductions will be needed to turn the tide of global warming. Evolution has also played a role in this pandemic. The single-stranded RNA coronavirus has itself adapted genetically, making the leap from illdefined animal origins (perhaps bats?) to infect human hosts with alarming efficiency and high lethality—at least among vulnerable groups. Humans have also adapted through cultural memes—from unfamiliar protocols in the health service to a widespread (though alas not universal) adoption of social distancing. This is evolution in action, with top-down memes pitted against bottom-up genes. Our behavioural responses to COVID-19 might also give us pause for thought. Could working from home actually increase our creativity or productivity? Might tele-conferencing prove less costly and time-wasting than face-to-face business meetings? It is clear that innumerable jobs will be lost worldwide, especially in tourism-related

Envoi: The Sixth Mass Extinction

367

industries—as restaurants, hotels, travel agents, tour operators and airlines are forced out of business through lack of demand, which may well last for a year or more. Will we be forced to cut back on our foreign travel in the future—due to a lack of capacity and therefore higher prices? Or will new enterprises spring up like mushrooms to replace those lost, like adaptive radiations after a mass extinction? In short, will we just return as quickly as possible to our profligate old ways, turning our backs on the trials of this pandemic? Or will we at last take heed and learn lessons from this unforeseen yet foreseeable (in general terms) turn of events? Might we even start to tackle global warming with the seriousness it truly deserves? Insofar as any firm predictions can be made in the current uncertainty, some forms of social distancing will have to remain in place until mass vaccination against coronavirus becomes possible, maybe a year from now. This will restrict our social interactions, impacting on travel and on public gatherings—from church services to concerts and theatre. Live streaming and impromptu virtual groups have already sprung up to fill the gaps—and no doubt these will become ever more imaginative as the pandemic continues. But the flip-side is that those who are not digitally connected (especially the elderly and infirm) will largely miss out on these novel opportunities and become ever more isolated. The human and economic costs of this pandemic are eye-watering if not indeed incalculable— saddling future generations with debts far greater than those incurred by the financial crisis of 2007-8. Our recent progress in tackling plastic waste has now been thrown into reverse, with a hygiene-enforced reliance on single-use plastic items such as masks, gloves and drink cups. As the current lockdown is eased, there may well be a hell-for-leather race to stimulate economic growth, whatever the costs in terms of future global warming. Yet, at the least, we have been given pause for thought, and an opportunity to adopt a different way of being in the world (§ 9.6.1). For myself, I have found a dozen flowers new to me by paying closer attention to plants in my local area (especially along the aforementioned Water of Leith)—as many as I would normally have found on more distant rambles! Indeed, the pandemic restrictions on our lives have enabled many of us to reconnect with nature and to find there both solace and mental equilibrium. But I am not optimistic that we will seize this chance and truly change our ways. Old habits die hard, and we treasure our familiar creature comforts… Jonathan Sacks (2020) has described a parallel “climate change” in morality, turning from shared community values and obligations towards increased emphasis on individual autonomy, rights and choices. As part of this, we have largely outsourced community care and compassion to the

368

Chapter 10

state and to the market. Care of the infirm elderly is a particularly flagrant case in point—passed from families to the state and now increasingly to the private sector. But as health and public services across the world struggle to cope with coronavirus, and as vulnerable groups are advised to self-isolate for long periods of time, so spontaneous local initiatives are springing up to help those in quarantine or isolation for their own protection. Some offer physical assistance with shopping for food or medications, others offer online group activities—from virtual choirs to exercise regimes. Though social distancing has imposed unwelcome restrictions on our gregarious habits, we are finding communities (whether actual or virtual) reborn in unanticipated and often novel guises. That seems an apt note on which to end this book; our interconnectedness will find ways to cope. Coronavirus has proved that we can change our habits once we grasp the urgent need to do so, notwithstanding the enormous human and economic costs to society across the planet. Concerted action on climate change is at least feasible, however difficult to implement. On that note, I rest my case.

ABBREVIATIONS (EXCLUDING GENE NAMES)

A = Adenine (DNA and RNA base). A1 to A9/10 = Abdominal segments. AI = Artificial intelligence. AIS = Androgen insensitivity syndrome. AND = Androstadienone (candidate male pheromone). ANTC = Antennapedia gene complex. A/P = Anterior/posterior (head to tail) axis. ASL = Argininosuccinate lyase (urea-cycle enzyme). ATP = Adenosine triphosphate (energy currency of cells). BCE = Before Common Era (formerly BC). BMP4 = Bone morphogenetic protein 4. bp = base pair(s). Bt = Bacillus thuringiensis (bacterial source of specific insecticidal toxins). BV = Brain volume. BXC = Bithorax gene complex. BZ = Belousov/Zhabotinsky reaction. bZIP = Leucine zipper domain (family of dimeric transcription factors). C = Cytosine (DNA and RNA base). or C = Century. or C terminus = Carboxy terminus (end of a protein chain). CE = Common Era (formerly AD). CIs = Confidence intervals (commonly stated as the limits within which we can be 95% confident that the true value lies). CNS = Central nervous system. COVID-19 = Coronavirus disease 2019. CTCF = Transcriptional repressor with insulator function. DDT = Dichlorodiphenyltrichloromethane (pesticide). DNA = Deoxyribonucleic acid. D/V = Dorso/ventral (front to back) axis. DZ = Dizygotic (twins).

370

Abbreviations

EES = Extended evolutionary synthesis. ENP = Emergentist-Naturalistic-Panentheistic (Arthur Peacocke). EST = Estratetraenol (candidate female pheromone). EU = European Union. F0 = Founder (parental) generation. F1, F2, F3 = First-, second- and third-generation progeny. FGF = Fibroblast growth factor (a family of related signalling proteins). fMRI = Functional magnetic resonance imaging. G = Guanine (DNA and RNA base). G1, G2, G3 = Generations within a family tree. GABA = Ȗ-Aminobutyric acid (a neurotransmitter). GM = Genetic modification (or genetically modified). GPCR = G protein-coupled (7-transmembrane) receptor. GST = Glutathione S-transferase. H1, H2A, H2B, H3, H4 = Histone proteins in nucleosomal chromatin. HES = Hairy/Enhancer of Split transcriptional repressor. HLH = Helix-loop-helix domain (family of dimeric transcription factors). HOMC = Homeobox gene cluster in Tribolium. Hox = Homeobox-containing gene (or gene-cluster). ID = Intelligent design. IPM = Integrated Pest Management. IVF = In vitro fertilisation. KJV = King James Version of the Bible (published 1611). lac operon = 3 linked E. coli genes encoding lactose-processing enzymes. LCA = Last common ancestor. lncRNA = Long non-coding RNA. L/R = Left/right axis. Ma = Million years ago. MADS box = Gene sequence encoding a DNA-binding domain in plants, named after the genes in which it was first identified [MCM1 (yeast)/ AGAMOUS (Arabidopsis)/DEFICIENS (Antirrhinum)/SRF (Homo)]. microRNA = Short regulatory RNA (non-coding). MRI = Magnetic resonance imaging. mRNA = Messenger RNA. mtDNA = Mitochondrial DNA.

Redundant God? Christian Faith in the Light of Evolution

371

mtMRCA = Mitochondrial most recent common ancestor. MZ = Monozygotic (twins). MZA = Monozygotic twins reared apart. MZT = Monozygotic twins reared together. or MZT = Maternal to zygotic transition (embryology). N, 2N, 4N = Haploid, diploid, tetraploid (number of chromosome sets). or N terminus = Amino terminus (start of a protein chain). NIV = New International Version of the Bible. NOMA = Non-overlapping magisteria. NRSV = New Revised Standard Version of the Bible. OT = Old Testament. P/D = Proximo-distal (centre to periphery) axis. PET = Positron emission tomography. pol I = RNA polymerase 1 (transcribes 18S/5.8S/28S rRNA in eukaryotes). pol II = RNA polymerase 2 (transcribes pre-mRNA in eukaryotes). pol III = RNA polymerase 3 (transcribes eukaryotic tRNA and 5S rRNA). ppm = Parts per million. ps = Parasegment. r1 to r7 = Rhombomeres in embryonic hindbrain. r8 to r11 = Crypto-rhombomeres in medulla oblongata. RA = Retinoic acid. RNA = Ribonucleic acid. RP = Readiness potential. rRNA = Ribosomal RNAs (distinguished by size in Svedberg units [S]). S = Svedberg unit, a measure of sedimentation rate and thus size. SAZ = Segment addition zone. SC = Spinal cord. SF = Science fiction. snRNA = Small nuclear RNA (involved in pre-mRNA splicing). SSSB = Same-sex sexual behaviour. T = Thymine (DNA-only base, equivalent to U in RNA). T1 to T3 = Thoracic segments (in insects). TBP = TATA-binding protein. TF = Transcription factor. tRNA = Transfer RNA.

372

Abbreviations

U = Uracil (RNA-only base, equivalent to T in DNA). UK = United Kingdom. USA = United States of America v. = verse. VGSC = Voltage-gated sodium channel. vv. = verses W = Avian sex chromosome carried only by females. X = Sex chromosome present in males (1 copy) and females (2 copies). Y = Sex chromosome carried only by males. Y-MRCA = Y-chromosome most recent common ancestor. YHWH = Yahweh or Jehovah (the tetragrammaton, as used in Hebrew). Z = Avian sex chromosome present in females (1 copy) and males (2). ZPA = Zone of polarising activity.

BIBLIOGRAPHY

Abe, Masanori, and Reiko Kuroda. 2019. “The development of CRISPR for a mollusc establishes the formin Lsdia1 as the long-sought gene for snail dextral/ sinistral coiling.” Development 146: dev175976. doi:10.1242/dev.175976. Aboobaker, Aziz, and Mark Blaxter. 2003. “Hox gene evolution in nematodes: novelty conserved.” Current Opinions in Genetics and Development 13: 593598. doi:10.1016/j.gde.2003.10.009. Abraham-Williams, Gethin. 2015. Why the Gospel of Thomas Matters; The Spirituality of Incertainties. Alresford, UK: Christian Alternative Books. Aguinaldo Anne Marie A., J.M. Turbeville, L.S. Linford, M.C. Rivera, J.R. Garey, R.A. Raff, J.A. Lake. 1997. “Evidence for a clade of nematodes, arthropods and other moulting animals.” Nature 387 (6632): 489-493. doi:10.1038/387489a0. Akam, Michael. 1998a. “Hox genes, homeosis and the evolution of segment identity: no need for hopeless monsters." International Journal of Developmental Biology 42 (3): 445-451. PMID: 9654030. Akam, Michael. 1998b. “Hox genes: From master genes to micromanagers.” Current Biology 8: R676-678. http://biomednet.com/elecref/09609822008R0676. Alexander, Tara, C. Nolte, R. Krumlauf. 2009. “Hox genes and segmentation of the hindbrain and axial skeleton.” Annual Review of Cell and Developmental Biology 25: 431-456. doi:10.1146/annurev.cellbio.042308.113423. Al-Khalili, Jim, and Johnjoe McFaddem. 2014. Life on the Edge: The Coming of Age of Quantum Biology. London, UK: Black Swan, Transworld Publishers. Allison, Anthony C. 1954. “Protection afforded by sickle-cell trait against subtertian malarial infection.” British Medical Journal 1 (4857): 290-294. http://www. jstor.org/ stable /20327729. Alves, Joel M., M. Carneiro, J.Y. Cheng, A. Lemos de Matos, M.M. Rahman, L. Loog, P.F. Campos et al. 2019. “Parallel adaptations of rabbits to myxoma virus.” Science 363 (6433): 1319-1326. doi:10.1126/science.aau7285. An Occupant of the Pew. 1915. “Evolutionism in the pulpit.” In The Fundamentals: A Testimony to the Truth, by Compliments of Two Christian Laymen, vol. VIII: 27-35. Chicago, Illinois, USA: Testimony Publishing Company. Anbalagan, Charumathi, I. Lafayette, M. Antoniou-Kourounioti, M. Haque, J. King, B. Johnsen, D. Baillie et al. 2012. “Transgenic nematodes as biosensors for metal stress in soil pore water samples.” Ecotoxicology 21 (2): 439-455. doi:10.1007 /s10646-011-0804-0. Anderegg, William R.L., A.T. Trugman, G. Badgley, C.M. Anderson, A. Bartuska, P. Ciais, D. Cullenward et al. 2020. “Climate-driven risks to the climate mitigation potential of forests.” Science 368 (6497): eeaz7005.

374

Bibliography

doi:10.1126/science.aaz7005. Anon. 1995. “Evangelical Declaration on the Care of Creation.” Perspectives on Science and Christian Faith 47 (2): 110-111. Araújo, Rúbia A., M.S. Williamson, C. Bass, L.M. Field, I.R. Duce. 2011. “Pyrethroid resistance in Sitophilus zeamais is associated with a mutation (T929I) in the vROWDJHဨgated sodium channel.” Insect Molecular Biology 20: 437-445. doi:10.1111/j.1365-2583.2011.01079. ArchaeoGLOBE Project (Stephens, Lucas, D. Fuller, N. Boivin, T. Rick, N. Gauthier, A Kay, B. Marwick et al.) 2019. “Archaeological assessment reveals Earth's early transformation through land use.”. Science 365 (6456): 897-902. doi:10.1126/science.aax1192. Archbishops Council. 2000. Common Worship: Services and Prayers for the Church of England. London, UK: Church House Publishing. Arenas-Mena, Cesar, A.R. Cameron, E.H. Davidson. 2000. “Spatial expression of Hox cluster genes in the ontogeny of a sea urchin.” Development 127: 46314643. PMID: 11023866. Arendt, Detlev. 2018. “Hox genes and body segmentation.” Science 361 (6409): 1310-1311. doi:10.1126/science.aav0692. Aria, Cédric, and Jean-Bernard Caron. 2019. "A middle Cambrian arthropod with chelicerae and proto-book gills". Nature 573 (7775): 586-589. doi:10.1038/s41586-019-1525-4. Armstrong, Karen. 2019. The Lost Art of Scripture: Rescuing the Sacred Texts. London, UK: The Bodley Head. Ashton, Benjamin J., A.R. Ridley, E.K. Edwards, A. Thornton. 2018. “Cognitive performance is linked to group size and affects fitness in Australian magpies.” Nature 554 (7692): 364-367. doi:10.1038/nature25503. Aslan, Reza. 2017. God: A Human History. London, UK: Bantam Press. Athanasius of Alexandria. 367. 39th Festal Latter. http://www.ccel.org/ccel/schaff/npnf204. xxv.iii.iii.xxv. html. Ayala, Francisco J. 2007, Darwin's Gift: To Science and Religion. Washington DC, USA: Joseph Henry Press. Barbiero, Gianni. 2016. “The two structures of Psalm 29.” Vetus Testamentum 66 (3): 378-392. doi:10.1163/15685330-12341238. Barbour, Ian G. 1998. Religion and Science: Historical and Contemporary Issues. London, UK: SCM Press. Barnard, Chris. 2004. Animal Behaviour. Harlow, UK: Pearson Education. Barnard, Chris J., and Jerzy M. Behnke. 1990. Parasitism and Host Behaviour. Abingdon, UK: CRC Press, Taylor & Francis Group. Barr, James. 1993. Biblical Faith and Natural Theology. Oxford, UK: Clarendon Press. Barré, Michael L. 1991. “A Phoenician parallel to Psalm 29.” Hebrew Annual Review 13: 25-32. Barrett, Charles K. 1971. A Commentary on the First Epistle to the Corinthians. Second Edition, edited by Henry Chadwick. London, UK: A & C Black. Barrett, Rowan D.H., S.M. Rogers, D. Schluter. 2008. “Natural selection on a major armor gene in Threespine Stickleback.” Science 322 (5899): 255-257.

Redundant God? Christian Faith in the Light of Evolution

375

doi:10.1126/ science.1159978. Bastin, Jean-Francois, Y. Finegold, C. Garcia, D. Mollicone, M. Rezende, D. Routh, C.M. Zohner, T.W. Crowther. 2019. “The global tree restoration potential.” Science 365 (6448): 76-79. doi:10.1126/science.aax0848. Bateman, Richard M. 2006. “How many orchid species are currently native to the British Isles?” In Current Taxonomic Research on the British and European Flora, 89-110. London, UK: Botanical Society of Britain and Ireland. Bauckham, Richard. 2015. “The incarnation and the cosmic Christ.” In Incarnation: On the Scope and Depth of Christology, edited by Niels H. Gregersen: 25-57. Minneapolis, Minnesota, USA: Fortress Press. Baynes-Rock, Markus. 2017. “In the Minds of Others”. In The Evolution of Human Wisdom, edited by Celia Deane-Drummond and Agustín Fuentes: 4767. London, UK: Lexington Books. Becker, Sidney, J. Feldmann, S. Wiedemann, H. Okamura, C. Schneider, K. Iwan, A. Crisp et al. 2019. “Unified prebiotically plausible synthesis of pyrimidine and purine ribonucleotides.” Science 386 (6461): 76-82. doi:10.1126/science.aax2747. Begbie, Jeremy S. 2000. Theology, Music and Time. Cambridge, UK: Cambridge University Press. Behe, Michael J. 1996. Darwin's Black Box: Biochemical Challenges to Evolution. New York, USA: Free Press. —. 2007. The Edge of Evolution: The Search for the Limits of Darwinism. New York, USA: Free Press. Beisner, E. Calvin. 1993. “Are God's resources finite?” World (27th November issue):10-13. Bentley Hart, David. 2019. That All shall be Saved: Heaven, Hell, and Universal Salvation. New York, USA: Yale University Press. Berglund, Hans, P. Lindström, I. Savic. 2006. “Brain response to putative pheromones in lesbian women.” PNAS 103 (21): 8269-8274. doi:10.1073/pnas.0600331103 . Bergson, Henri. 1907/1911. Creative Evolution, translated by Arthur Mitchell. New York, USA: Henry Holt and Company. Berry, Robert J. 1975. Adam and the Ape. London, UK: Falcon Books. —. 1988, republished 2001. God and Evolution: Creation, Evolution and the Bible. Vancouver, Canada: Regent College Publishing. —. 1996a. God and the Biologist: Faith at the Frontiers of Science. Leicester, UK: Apollos (IVP). —. 1996b. “The Virgin Birth of Christ.” Science & Christian Belief 8 (2): 101-110. —. 2003. God's Book of Works: The Nature and Theology of Nature. London, UK: T&T Clark Ltd. —. 2009. “Did Darwin dethrone humankind?” In Darwin, Creation and the Fall: Theological Challenges, edited by Robert J. Berry and T.A. Noble: 30-74. Nottingham, UK: Apollos (IVP). Berry, Robert J. (ed.). 2000. The Care of Creation: Focussing Concern and Action. Leicester, UK: Inter-Varsity Press.

376

Bibliography

Berry, Robert J., and Malcolm Jeeves. 2008. “The Nature of Human Nature.” Science & Christian Belief 20 (1): 3-47. Berry, Robert J., and T.A. Noble (eds.). 2009. Darwin, Creation and the Fall: Theological Challenges. Nottingham, UK: Apollos (IVP). Bielfeldt, Dennis. 2001. “Can western monotheism escape substance dualism?” Zygon: Journal of Religion and Science 36 (1): 153-178. doi:10.1111/0591-2385.00345. Blocher, Henri. 1984. In the Beginning. Leicester, UK: InterVarsity Press. Blomenkemper, Patrick, H. Kerp, A. Abu Hamad, W.A. DiMichele, B. Bonfleur. 2018. “A hidden cradle of plant evolution in Permian tropical lowlands”. Science 362 (6421): 1414-1416. doi:10.1126/science.aau4061. Blount, Zachary D., C.Z. Borland, R.E. Lenski. 2008. “Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli”. PNAS (USA) 105 (23): 7899-7906. doi:10.1073/pnas.0803151105. Blount, Zachary D., R.E. Lenski, J.B. Losos. 2018. “Contingency and determinism in evolution: Replaying life's tape”. Science 362 (6415): eaam5979 (summary, p. 655). doi:10.1126/science.aam5979. Bobrovskiy, Ilya, J.M. Hope, A. Ivantsov, B.J. Nettersheim, C. Hallman, J.J. Brocks. 2018. “Ancient steroids establish the Ediacaran fossil Dickinsonia as one of the earliest animals.” Science 361 (6408): 1246-1249. doi:10.1126/ science.aat7228. Boesch, Christophe, and Hedwige Boesch. 1990. “Tool use and tool making in wild chimpanzees.” Folia Primatologica 54: 86-89. doi:10.1159/ 000156428. Bohle, Uta-Regina, H.H. Hilger, W.F. Martin. 1996. “Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae).” PNAS (USA) 93: 11740-11745. doi:10.1073/pnas.93.21.11740 Bonnet, Timothée, M.B. Morrissey, A. Morris, S. Morris, T.H. Clutton-Brock, J.M. Pemberton, L.E.B. Kruuk. 2019. “The role of selection and evolution in changing parturition date in a red deer population.” PLoS Biology 17 (11): e3000493. doi:10.1371/journal.pbio.3000493. Bonneville, Steeve, F. Delpomdor, A. Préat, C. Chevalier, T. Araki, M. Kazemian, A. Steele et al. 2020 “Molecular identification of fungi microfossils in a Neoproterozoic shale rock”. Science Advances 6: eaax7599. doi:10.1126/sciadv.aax7599. Boos, Alena, J. Distler, H. Rudolf, M. Klingler, E. El-Sherif. 2018. “A re-inducible gap-gene cascade patterns the anterior-posterior axis of insects in a thresholdfree fashion.” eLife 2018: 7: 41208. doi:eLife.41208.001. Boycott, A.E., C. Diver, S. L. Garstang, F. M. Turner. 1931. “The inheritance of sinistrality in Lymnæa peregra (Mollusca, Pulmonata).” Philosophical Transactions of the Royal Society of London. Series B, Containing Papers of a Biological Character 219: 51-131. http://www.jstor.org/stable/92173. Bramhall, David, and Zoe Bramhall. Second edition, 2001. Wild Flowers of the Canary Islands. Madrid: Editorial Rueda. Brawand, David, C.E. Wagner, Y.I. Li, M. Malinsky, I. Keller, S. Fan, O. Simakov et al. 2014. “The genomic substrate for adaptive radiation in African cichlid fish.” Nature 513 (7518): 375-381. doi:10.1038/nature13726.

Redundant God? Christian Faith in the Light of Evolution

377

Braxton, Donald M. 2007. “Sacrament and sacrifice: The feedback loops of religious community.” In All That Is: A Naturalistic Faith for the Twenty-First Century: A Theological Proposal with Responses from Leading Thinkers in the Religion-Science Dialogue, by Arthur R. Peacocke, edited by Philip Clayton: 104-118. Minneapolis, Minnesota, USA: Fortress Press. Bray, Sarah J. 2016. “Notch signalling in context.” Nature Reviews Moecular Cell Biology 17: 722-735. doi: 10.1038/nrm.2016.94. Brian, Havergal. 1932, republished 1976. Symphony no. 1 (originally no. 2), "The Gothic". Bury St Edmunds, Suffolk, UK: Cranz (Brian's music now administered by United Music Publishers). Britten, Roy J., and Eric H. Davidson. 1969. “Gene regulation for higher cells: a theory.” Science 165 (3891): 349-357. doi:10.1126/science.165.3891.349. Brockmann, Axel, and Moushumi Sen Sarma. 2009. “Honeybee dance language: is it overrated?” Trends in Ecology and Evolution 24 (11): 583. doi:10.1016/j.tree. 2009.06.005. Brooke, John Hedley. 1968. “Wöhler's urea, and its vital force?—a verdict from the chemists.” Ambix 15 (2): 84-114. doi:10.1179/amb.1968. 15.2.84. Brooks, Michael. 2020. “Here, there, everywhere? ” New Scientist 246 (3280): 4044. doi: 10.1016/SO62-4079(20)30864-2. Brother Casimir. 1983. “When (the Father) will subject all things to (the Son), then (the Son) himself will be subjected to him (the Father) who subjects all things to him (the Son)—a treatise on First Corinthians 15:28 by Saint Gregory of Nyssa.” The Greek Orthodox Theological Review 28 (1): 1-25. Brown, Warren S. 1998. “Cognitive Contributions to Soul.” In Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature, edited by Warren S. Brown, N. Murphy, H.N. Malony: 99-125. Minneapolis, Minnesota, USA: Fortress Press. Brown, Warren S., N. Murphy, H.N. Malony (eds.). 1998. Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature. Minneapolis, Minnesota, USA: Fortress Press. Brown, William P. 2017. A Handbook to Old Testament Exegesis. Louisville, Kentucky, USA: Westminster John Knox Press. Bruce, Donald, and Ann Bruce (eds.). 1998. Engineering Genesis: The Ethics of Genetic Engineering in Non-Human Species. Abingdon, Oxford, UK: Earthscan Publications Ltd. Brusatte, Stephen L. 2017. “A Mesozoic aviary.” Science 355 (6327): 792-794. doi:10.1126/ science.aal2397. Bruteau, Beatrice. 1997. God's Ecstasy: The Creation of a Self-Creating World. New York, USA: Crossroad Publishing Company. Büchel, Claudia. 2019. “How diatoms harvest light: Light-harvesting systems in a group of microalgae differ from those in plants.” Science 365 (6452): 447-448. doi: 10.1126/science.aay3036. Bucher, Gregor, and Martin Klingler. 2004. “Divergent segmentation mechanism in the short germ insect Tribolium revealed by giant expression and function.” Development 131: 1729-1740. doi:10.1242/dev.01073 .

378

Bibliography

Burr, A.H. Jay, D. Wagar, P. Sidhu. 2000. “Ocellar pigmentation and phototaxis in the nematode Mermis nigrescens: changes during development.” Journal of Experimental Biology 203: 1341-1350. jeb.biologists.org/content/jexbio/203/8/ 1341. Butlin, Roger K., J. Galindo, J.W. Grahame. 2008. “Review. Sympatric, parapatric or allopatric: The most important way to classify speciation?” Philosophical Transactions of the Royal Society, Series B (Biological Sciences) 363 (1506): 2997-3007. doi:10.1098/rstb2008.0076. Buttler, Karl P. Second edition, 1991. Field Guide to Orchids of Britain and Europe. Swindon, UK: The Crowood Press. Callaway, Ewen. 2019. “Siberia's ancient ghost clan starts to surrender its secrets.” Nature 566 (7745): 444-446. doi: 10.1038/d41586-019-00672-2. Cao, Chen, L.A. Lemaire, W. Weng, P.H. Yoon, Y.A. Choi, L.R. Parsons, J.C. Matese et al. 2019. “Comprehensive single-cell transcriptome lineages of a proto-vertebrate.” Nature 571 (7765): 349-354. doi:10.1038/s41586-019-1385-y. Carroll, Lewis (Dodgson, Charles L.). 1965, revised edition, 1970. The Annotated Alice (comprising "Alice's Adventures in Wonderland" and "Through the Looking Glass"). Edited by Martin Gardner. Harmondsworth, Middlesex, UK: Penguin Books Ltd. Carroll, Sean B. 2006, republished 2011. Endless Forms Most Beautiful: The New Science of Evo-Devo and the Making of the Animal Kingdom. London, UK: Weidenfeld & Nicolson, republished by Quercus Books. Carson, Rachel. 1962. Silent Spring. New York, USA : Houghton Mifflin. Cavanaugh, William T., and James K.A. Smith (eds.). 2017. Evolution and the Fall. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. —. 2017a. “Beyond Galileo to Chalcedon: resources for reimagining evolution, human origins, and the Fall.” In Evolution and the Fall, edited by William T. Cavanaugh and James K.A. Smith: xv-xxix. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. Cerny, Alexander C., G. Bucher, R. Schröder, M. Klingler. 2005. “Breakdown of abdominal patterning in the Tribolium Krüppel mutant jaws.” Development 132: 5353-5363. doi:10.1242/dev.02154. Cerny, Alexander C., D. Grossmann, G. Bucher, M. Klingler. 2008. “The Tribolium ortholog of knirps and knirps-related is crucial for head segmentation but plays a minor role during abdominal patterning.” Developmental Biology 321: 284294. doi:10.1016/ j.ydbio.2008.05.527. Chalke, Steve. 2019. The Lost Message of Paul: Has the Church Misunderstood the Apostle Paul? London, UK: SPCK. Chan, Eva K.F., A. Timmermann, B.F. Baldi, A.E. Moore, R.J. Lyons, S.-S. Lee, A.M.F. Kalsboek et al. 2019. “Human origins in a southern African palaeowetland and first migrations.” Nature 575 (7781): 185-189. doi:10.1038/s41586-019-1714-1. Chaplin-Kramer, Rebecca, R.P. Sharp, C. Weil, E.M. Bennett, U. Pascual, K.K. Arkema, K.A. Brauman et al. 2019. “Global modeling of nature’s contributions to people.” Science 366 (6462): 255-258.

Redundant God? Christian Faith in the Light of Evolution

379

doi:10.1126/science. aaw3372. Chen, Jun-Yuan, D.-Y. Huang, Q.-Q. Peng, H.-M. Chi, X.-Q. Wang, M. Fen. 2003. “The first tunicate from the Early Cambrian of South China.” PNAS (USA) 100 (14): 8314-8318. doi:10.1073/pnas.1431177100. Chen, Zhe, C. Zhou, X. Yuan, S. Xiao. 2019. “Death march of a segmented and trilobate bilaterian elucidates early animal evolution.” Nature 573 (7774): 412415. doi:10.1038/s41586-019-1522-7. Chen, Jin, A.-D. Bonner, J.Z. Cogan, J.K. Nuñez, A.P. Fields, B. Adamson, D.N. Itzhak et al. 2020. “Pervasive functional translation of noncanonical human open reading frames.” Science 367 (6482): 1140-1146. doi:10.1126/science.aay0262. Chen, Lu, A.B. Wolf, W. Fu, J.M. Akey. 2020. “Identifying and interpreting Neanderthal ancestry in African individuals.” Cell 180 (4): 677-687.e16. doi: 10.1016/j.cell.2 020.01.012. Chimpanzee Sequencing and Analysis Consortium. 2005. “Initial sequence of the chimpanzee genome and comparison with the human genome.” Nature 437 (7055): 69-87. doi:10.1038/nature04072 . Chiori, Roxanne, M. Jager, E. Denker, P. Wincker, C. Da Silva, E. Le Guyader, M. Manuel, E. Quéinnec. 2009. “Are Hox genes ancestrally involved in axial patterning? Evidence from the Hydrozoan Clytia hemisphaerica (Cnidaria).” PLoS ONE 4: e4231. doi:10.1371/journal.pone.0004231 . Chipman, Ariel D. 2009. “On making a snake.” Evolution & Development 11: 3-5. doi:10.1111/j.1525-142X.2008.00295.x. —. 2010. “Parallel evolution of segmentation by FRဨRSWLRQ of ancestral gene regulatory networks.” BioEssays 32: 60-70. doi:10.1002/bies.200900130. Chipman, Ariel D., D.E.K. Ferrier, J. Qu, D.S.T. Hughes, R. Schroder, M. TorresOliva, N. Znassi et al. 2014. “The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima.” PLoS Biology 12 (11): e1002005. doi:10.1371/journal.pbio.1002005. Choe, Chong Pyo, S.C. Miller, S.J. Brown. 2006. “A pair-rule gene circuit defines segments sequentially in the short-germ insect Tribolium castaneum.” PNAS (USA) 103 (17): 6560-6564. doi:10.1073/pnas.0510440103. Clark, Eric, and Michael Akam. 2016. “Odd-paired controls frequency doubling in Drosophila segmentation by altering the pair-rule gene regulatory network.” eLife 2016: e18215. doi:10.7554/eLife-18215. Clark, Eric, A.D. Peel, M. Akam. 2019. “Arthropod segmentation.” Development 146: dev170480. doi:10.1242/dev.170480. Clarke, Julia A. 2019. “Evolution of flight loss caught in the act.” Nature 572 (7768): 182-184. doi:10.1038/d41586-019-02234-y. Clayton, David F. 2019. “Learning birdsong by imitation: Transforming sensory information into vocal imitation allows young finches to sing.” Science 366 (6461): 33-34. doi:10.11226/science.aaz1552. Clayton, Philip. 2004. Mind and Emergence: From Quantum to Consciousness. Oxford, UK: Oxford University Press.

380

Bibliography

—. 2008. “Hierarchies: The core argument for a naturalistic Christian faith.” Zygon: Journal of Religion and Science 43 (1): 25-39. doi:10.1111/j.1467.2008.00896.x. Clement, Hal. 1955, republished 1976. Mission of Gravity. London, UK: New English Library SF Master Series. Cobb Jr., John B. and David R. Griffin. 1976. Process Theology: An Introductory Exposition. Louisville, Kentucky, USA: Westminster John Knox Press. Cole-Turner, Ronald. 2013. “Incarnation deep and wide: A response to Niels Gregersen.” Theology and Science 11 (4): 424-435. doi:10.1080/14746700.2013.836886. Collins, Francis S. 2007. The Language of God: A Scientist Presents Evidence for Belief. London, UK: Pocket Books, Simon & Schuster UK Ltd. Conklin, Edwin G. 1895. “The organization and cell lineage of the ascidean egg.” Journal of the Academy of Natural Sciences Philadelphia 13: 5-118. Conradie, Ernst M. 2000/2005. Hope for the Earth: Vistas on a New Century. Eugene, Oregon, USA: Wipf & Stock Publishers. Conway Morris, Simon. 1998. The Crucible of Creation: The Burgess Shale and the Rise of Animals. Oxford, UK: Oxford University Press. — . 2003. Life's Solution: Inevitable Humans in a Lonely Universe. Cambridge, UK: Cambridge University Press. —. 2015. The Runes of Evolution: How the Universe Became Self-Aware. West Conshohocken, Pennsylvania, USA: Templeton Press. Conway Morris, Simon, and Jean-Bernard Caron. 2014. “A primitive fish from the Cambrian of North America.” Nature 512 (7515): 419-422. doi:10.1038/nature13414. Cottrell, Stephen. 2008. The Things He Carried: A Journey to the Cross: Meditations for Lent and Holy Week. London, UK: SPCK. Couso, Juan Pablo. 2009. "Segmentation, metamerism and the Cambrian explosion." International Journal of Developmental Biology 53: 1305-1316. doi:10.1387/ijdb.072425jc. Coyne, Jerry A.. 2015. Faith vs. Fact: Why Science and Religion are Incompatible. New York, USA: Viking. Cramer, Patrick. 2019. “Organization and regulation of gene transcription.” Nature 573: 45-54. doi:10.1038/s41586-019-1517-4. Cranmer, Thomas. 1662, republished 1999. The Book of Common Prayer; And Administration of the Sacraments and Other Rites and Ceremonies of the Church According to the Use of The Church of England, Together with the Psalter or Psalms of David Pointed as They are to be Sung or Said in Churches. London, UK: Everyman Classics. Crutzen, Paul J. 2002. “Geology of mankind.” Nature 415 (6867): 23. doi:10.1038/415023a. Cunningham, John A., A.G. Liu, S. Bengtson, P.C.J. Donoghue. 2016. “The origin of animals: can molecular clocks and the fossil record be reconciled?” Bioessays 38: 981-990. doi:10.1002/bies.201600120. Currie, Mark. 1998. Postmodern Narrative Theory. New York, USA: St Martin's Press.

Redundant God? Christian Faith in the Light of Evolution

381

Curry, Andrew. 2013. “Archaeology: the milk revolution.” Nature 500 (7460): 2022. doi:10.1038/500020a. —. 2018. “Early Mongolians ate dairy, but lacked the gene to digest it.” Science 362 (6415): 626-627. doi:10.1126/science.362.6415.626. Dahood, Mitchell. 1966. "Psalm xxix". In Psalms 1-50: pp. 174-180. Garden City, New York, USA: Anchor Bible vol. 16. Danowitz, Melinda, R. Domalski, N. Solounias. 2015. “The cervical anatomy of Samotherium, an intermediate-necked giraffid.” Royal Society Open Science 2: 150521. doi:10.1098/rsos.150521. Darroch, Simon A.F., E.F. Smith, M. Laflamme, D.H. Erwin. 2018. “Ediacaran extinction and Cambrian explosion.” Trends in Ecology and Evolution 33 (9): 653-663. doi:10.1016/j.tree.2018.06.003. Darwin, Charles. 1859, republished 1998. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. Ware, Hertfordshire, UK: Wordsworth Editions Ltd. —. 1862. On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects, and on the Good Effects of Intercrossing. London, UK: John Murray. —. 1871. The Descent of Man, and Selection in Relation to Sex. London, UK: John Murray. —. 1975. Charles Darwin's Natural Selection: Being the Second Part of his Big Species Book Written from 1856 to 1858, edited by R.C. Stauffer. Cambridge, UK: Cambridge University Press. Davidson, Eric H., J.P. Rast, P. Oliveri, A. Ransick, C. Calestani, C.-H. Yuh, T. Minokawa. 2002. “A genomic regulatory network for development.” Science 295 (5560): 1669-1678. doi:10.1126/science.1069883. Dawkins, Richard. 1976. The Selfish Gene. Oxford: Oxford University Press. —. 1982. The Extended Phenotype. Oxford, UK: Oxford University Press. —. 1986. The Blind Watchmaker. Harlow, Essex, UK: Longmans Scientific & Technical. —. 1996. Climbing Mount Improbable. London, UK: Viking Books. —. 1998. Unweaving the Rainbow. London, UK: Allen Lane. —. 2004. The Ancestor's Tale: A Pilgrimage to the Dawn of Life. London, UK: Weidenfeld & Nicolson. —. 2006. The God Delusion. New York, USA: Bantam Books. de la Trinité, Père Philippe. 1970. Pour et Contre Teilhard de Chardin, Penseur Religieux. Paris, France: Editions St. Michel. de Pomerai, David. 1985 (Second Edition, 1990). From Gene to Animal: An Introduction to the Molecular Biology of Animal Development. Cambridge, UK: Cambridge University Press. —. 2008. “Biological mechanisms in homosexuality: a critical review.” In The Anglican Communion and Homosexuality: A Resource to Enable Listening and Dialogue, edited by Philip Groves: 267-292. London, UK: SPCK. de Pomerai, David I., W.K. Ip, M. McLaughlin, K.C. Perry. 1991. “Expression in non-lens tissues of an enzyme activity related to the ‘lens-specific’ protein, delta crystallin.” Development 111 (1): 181-190.

382

Bibliography

de Pomerai, David I., C. Daniells, H. David, J. Allan, I. Duce, M. Mutwakil, D. Thomas et al. 2006. “Retraction: Non-thermal heat-shock response to microwaves.” Nature 440 (7083): 437. doi:10.1038/440437a. De Robertis, Edward M., and Hiroki Kuroda. 2004. “Dorsal-ventral patterning and neural induction in Xenopus embryos.” Annual Review of Cell and Developmental Biology 20: 285-308. doi:10.1146/annurev.cellbio.20. 011403.154124. de Rosa, Renaud , B. Prud'homme, G. Balavoine. 2005. “caudal and HYHQఆVNLSSHG in the annelid Platynereis dumerilii and the ancestry of posterior growth.” Evolution & Development 7: 574-587. doi:10.1111/j.1525-142X.2005.05061.x. de Vries, Hugo. 1905. Species and Varieties: Their Origin by Mutation. Chicago, USA: Open Court Publishing Co. de Waal, Frans. 1989. Peacemaking Among Primates. Cambridge, Massachusetts, USA: Harvard University Press. Deane-Drummond, Celia E. 1997. Theology and Biotechnology: Implications for a New Science. London, UK: Geoffrey Chapman. —. 2000. Creation Through Wisdom: Theology and the New Biology. Edinburgh, UK: T&T Clark Ltd. —. 2004. The Ethics of Nature. Oxford, UK: Blackwell Publishing. —. 2005. Genetics and Christian Ethics. Cambridge, UK: Cambridge University Press. —. 2006. Wonder and Wisdom: Conversations in Science, Spirituality and Theology. London, UK: Darton, Longman and Todd Ltd. —. 2008. Eco-Theology. London, UK: Darton, Longman and Todd Ltd. —. 2009. Christ and Evolution: Wonder and Wisdom. London, UK: SCM Press. —. 2014. The Wisdom of the Liminal: Evolution and Other Animals in Human Becoming. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. Deane-Drummond, Celia E. (ed.). 2003. Brave New World? Theology, Ethics and the Human Genome. London, UK: T&T Clark. Deane-Drummond, Celia E., R. Grove-White, B. Szerszynski (eds.). 2003. Reordering Nature: Theology, Society and the New Genetics. London, UK: T&T Clark. Deane-Drummond, Celia E., and David Clough (eds.). 2009. Creaturely Theology: On God, Humans and Other Animals. London, UK: SCM Press. Deane-Drummond, Celia E., S. Bergmann, M. Vogt (eds.). 2017. Religion in the Anthropocene. Eugene, Oregon, USA: Wipf and Stock Publishers. Deane-Drummond, Celia E., and Agustín Fuentes (eds.). 2017. The Evolution of Human Wisdom. London, UK: Lexington Books. Delio, Ilia. 2008. Christ in Evolution. Maryknoll, New York, USA: Orbis Books. Demertzi, Athena, E. Tagliazucchi, S. Dehaene, G. Deco, P. Barttfeld, F. Raimondo, C. Martial et al. 2019. “Human consciousness is supported by dynamic complex patterns of brain signal coordination.” Science Advances 5: eeat7603. doi:10.1126/sciadv.aat7603. Dennett, Daniel. 1995. Darwin's Dangerous Idea: Evolution and the Meanings of Life. New York: Simon & Schuster. —. 2003/2004. Freedom Evolves. London, UK: Penguin Books.

Redundant God? Christian Faith in the Light of Evolution

383

—. 2017. From Bacteria to Bach and Back: The Evolution of Minds. London, UK: Allen Lane. DePalma, Robert A., J. Smit, D.A. Burnham, K. Kuiper, P.L. Manning, A. Oleinik, P. Larson et al. 2019. “A seismically induced onshore surge deposit at the KPg boundary, North Dakota.” PNAS (USA) 116 (17): 8190-8199. doi:10.1073/pnas.1817407116. Détroit, Florent, A. Salvador Mijares, J. Corny, G. Daver, C. Zanolli, E. Dizon, E. Robles et al. 2019. “A new species of Homo from the Late Pleistocene of the Philippines.” Nature 568 (7751) : 181-186. doi:10.1038/s41586-019-1067-9. DeWitt, Calvin B. 2000. “Creation's environmental challenge to evangelical Christianity.” In The Care of Creation: Focussing Concern and Action, edited by Robert J. Berry: 60-73. Leicester, UK: Inter-Varsity Press. Dickey, James. 1967, reissued 1978. “The Heaven of Animals.” In Poems 19571967, 59-60. Middletown, Connecticut, USA: Wesleyan University Press. Dillard, Annie. 1974/2011. Pilgrim at Tinker Creek. London, UK: Canterbury Press. Dinesen, Isak (Karen Blixen). 1958/1986. Anecdotes of Destiny. London, UK: Penguin Books Dobzhansky, Theodosius. 1937. Genetics and the Origin of Species. New York, USA: Columbia University Press. Dobzhansky, Theodosius. 1973. “Nothing in biology makes sense except in the light of evolution.” American Biology Teacher 35 (3): 125-129. Dodson, Edward O. 1984. The Phenomenon of Man Revisited. New York, USA: Columbia University Press. Donovan, Vincent J. 1978, republished 1982. Christianity Rediscovered. London, UK: SCM Press. Doudma, Jennifer A. 2020. “The promise and challenge of therapeutic genome editing” Nature 578 (7794): 229-236. doi:10.1038/s41586-020-1978-5. Dowd, Michael. 2007. Thank God for Evolution! How the Marriage of Science and Religion Will Transform Your Life and Our World. Tulsa, Oklahoma, USA: Council Oak Books Dray, Nicolas, K. Tessmar-Raible, M. Le Gouar, L. Vibert, F. Christodoulou, K. Schipany, A. Guillou et al. 2010. “Hedgehog signaling regulates segment formation in the annelid Platynereis.” Science 329 (5989): 339-342. doi:10.1126/science.1188913 . Duboule, Denis. 2007. “The rise and fall of Hox gene clusters.” Development 134: 2549-2560. doi:10.1242/dev.001065 . Duchen, Jessica. 2007. “Marie Antoinette's Pop Idol.” The Independent, 21 May. www.jessicaduchen.co.uk/pdfs/indi-2007/st.georges-may21.pdf. Dudman, Clare. 2003. Wegener's Jigsaw. London, UK: Sceptre Books, Hodder & Stoughton. Dufour, Suzanne C., and Duncan McIlroy. 2017. "Ediacaran pre-placozoan diploblasts in Avalonian biota: the role of chemosynthesis in the evolution of early animal life". In Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier, edited by Alexander T. Brasier, D. McIlroy, N.

384

Bibliography

Mcloughlin. London, Geological Society London Special Publ. 448: 211-221. doi:10.1144/SP448.5. Dunn, Frances S., and Alex G. Liu. 2017. “Fossil focus: The Ediacaran biota.” Palaeontology Online 7: Article 1: 1-15. Dunn, Frances S., A.G. Liu, P.C.J. Donoghue. 2018. "Ediacaran developmental biology". Biological Reviews 93: 914-932. doi:10.1111/brv.12379. Dyonisius, Michael N., V.V. Petrenko, A.M. Smith, Q. Hua, B. Yang, J. Schmitt, J. Beck et al.. 2020 "Old carbon reservoirs were not important in the deglacial methane budget". Science 367 (6480): 907-910. doi:10.1126/science.aax0504. Eaton, Matthew. 2017. "Beyond human exceptionalism: Christology in the Anthropocene". In Religion in the Anthropocene, edited by Celia DeaneDrummond, S. Bergmann, M. Vogt: 202-217. Eugene, Oregon, USA: Wipf and Stock Publishers. Eddy, Paul R., and Gregory A. Boyd. 2007. The Jesus Legend: A Case for the Historical Reliability of the Synoptic Jesus Tradition. Grand Rapids, Michigan, USA: Baker Academic. Edwards, Denis. 1995. Jesus the Wisdom of God: An Ecological Theology. Maryknoll, New York, USA: Orbis Books. —. 2006. “Every sparrow that falls to the ground: the cost of evolution and the Christ-event.” Ecotheology 11 (1): 103-123. doi:10.1558/ecot.2006.11.1.103. Eldredge, Nils, and Stephen Jay Gould. 1972. “Punctuated equilibria: an alternative to phyletic gradualism.” In Models in Paleobiology, edited by T.J.M. Schopf: 82-115. San Francisco, USA: Freeman, Cooper & Co. Endler, John A. 1980. “Natural selection on colour patterns in Poecilia reticulata.” Evolution 34 (1):76-91. doi:10.1111/j.1558-5646.1980.tb04790.x Erwin, Douglas H., and James W. Valentine. 2013. The Cambrian Explosion: The Construction of Animal Biodiversity. Greenwood Village, Colorado, USA: Roberts & Co. Evans, Patrick D., S.L. Gilbert, N. Mekel-Bobrov, E.J. Vallender, J.R. Anderson, L.M. Vaez-Azizi, S.A. Tishkoff et al. 2005. “Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans.” Science 309 (5741): 1717-1720. doi:10.1126/science.1113722 . Ewen, Stanley W.B., and Arpad Pusztai. 1999. “Effects of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine.” The Lancet 354 (9187): 1353-1354. doi:10.1016/S0140-6736(98)05860-7. Faith, J. Tyler, J. Rowan, A. Du, Paul L. Koch. 2018. “Plio-Pleistocene decline of African megaherbivores: No evidence for ancient hominin impacts.” Science 362: 938-941. doi:10.1126/science-aau2728. Fiddes, Ian T., G.A. Lodewijk, M. Mooring, C.M. Bosworth, A.D. Ewing, G.L. Mantalas, A.M. Novak et al. 2018. “Human-specific NOTCH2NL genes affect Notch signaling and cortical neurogenesis.” Cell 173: 1356-1369. doi:10.1016/j.cell. 2018.03.051. Fieder, Martin, and Susanne Huber. 2016. “The association between religious homogamy and reproduction.” Proceedings of the Royal Society, Series B (Biological Sciences) 283 (1834): 20160294. doi:10.1098/rspb.2016.0294.

Redundant God? Christian Faith in the Light of Evolution

385

Finn, Julian K., T. Tregenza, M.D. Norman. 2009. “Defensive tool use in a coconut-carrying octopus.” Current Biology 19 (23): R1069-R1070. doi:10.1016/j.cub.2009.10.052. Finnerty, John R., K. Pang, P. Burton, D. Paulson, M.Q. Martindale. 2004. “Origins of bilateral symmetry: Hox and Dpp expression in a sea anemone.” Science 304 (5675): 1335-1337. doi:10.1126/science. 1091946 . Fisher, Ronald A. 1930. The Genetical Theory of Natural Selection. Oxford, UK: Clarendon Press. Flew, Anthony, with Roy A. Varghese. 2007. There Is a God: How the World's Most Notorious Atheist Changed His Mind. New York, USA: HarperOne, HarperCollins Publishers. Fortey, Richard. 2001. Trilobite! London, UK: Flamingo Press. Foster, Charles. 2016. Being a Beast: An Intimate and Radical Look at Nature. London, UK: Profile Books Ltd. Foster, Gavin L., D.L. Royer, D.J. Lunt. 2017. “Future climate forcing potentially without precedent in the last 420 million years.” Nature Communications 8: Art. no. 14845. doi:10.1038/ncomms14845. Fox, Douglas. 2016. “What sparked the Cambrian explosion?” Nature 530 (7590): 268-270. doi:10.1038/530268a. Fraga, Mario F., E. Ballestar, M.F. Paz, S. Ropero, F. Setien, M.L. Ballestar, D. Heine-Suñer et al. 2005. “Epigenetic differences arise during the lifetime of monozygotic twins.” PNAS (USA) 102 (30): 10604-10609. doi:10.1073/pnas.0500398102. Franklin, Patrick. 2014. “Understanding the beginning in light of the end: eschatological reflections on making theological sense of evolution.” Perspectives on Science and Christian Faith 66 (3): 154-170. Fu, Dongjing, G. Tong, T. Dai, W. Liu, Y. Yang, Y. Zhang, L. Cui et al. 2019. “The Qingjiang biota—a Burgess Shale-type fossil lagerstätte from the early Cambrian of South China.”. Science 363 (6433): 1338-1342. doi:10.1126/science.aau8800. Futato, Mark D. 2007. Interpreting the Psalms: An Exegetical Handbook, edited by David M. Howard Jr.. Grand Rapids, Michigan, USA: Kregel Publications. Futuyama, Douglas. 2015. “Can modern evolutionary theory explain macroevolution?” Interdisciplinary Evolution Research 2, in Macroevolution: Explanation, Interpretation and Evidence, edited by Emanuele Serrelli and Nathalie Gontier: 29-85. Cham, Switzerland: Springer International. doi:10.1007/978-3-319-15045-1_2. Gabi, Mariana, K. Neves, C. Masseron, P. Ribeiro, L. Ventura-Antunes, L.Torres, B. Mota et al.. 2016. “No relative expansion of the number of prefrontal neurons in primate and human evolution.” PNAS (USA) 113 (34): 9617-9622. doi:10.1073/pnas.161078113. Galton, Francis. 1889. Natural Inheritance. London, UK: Macmillan. Ganna, Andrea, K.J.H. Verweij, M.G. Nivard, R. Maier, R. Wedow, A.S. Busch, A. Abdellaoul et al. 2019. “Large-scale GWAS reveals insights into the genetic architecture of same-sex sexual behavior.” Science 365 (6456): eaat7693 (summary p. 882). doi:10.1126/science.aat7693.

386

Bibliography

Gastaldo, Robert A. 2019. “Plants escaped an ancient mass extinction.” Nature 567 (7746): 38-39. doi:10.1038/d41586-019-00744-3. Gaster, Theodor H. 1946. “Psalm 29.” Jewish Quarterly Review 37 (1): 55-65. https://www.jstor.org/stable/i263338 . Gaunt, Stephen J. 2015. “The significance of Hox gene collinearity.” International Journal of Developmental Biology 59 (4-6): 159-170. doi: 10.1387/ijdb.150223sg. Gavelis, Gregory S., S. Hayakawa, R.A. White III, T. Gojobori, C.A. Suttle, P.J. Keeling, B.S. Leander. 2015. “Eye-like ocelloids are built from different endosymbiotically acquired components.” Nature 523 (7559): 204-207. doi:10.1038/nature14593. Geoffroy Saint-Hilaire, Etienne. 1822. “Considérations génèrales sur la vertèbre.” Memoires du Museum national d'histoire naturelle 9: 88-119. Gibbs, H. Lisle, and Peter R. Grant. 1987. “Oscillating selection on Darwin's finches.” Nature 327 (6122): 511-513. doi:10.1038/327511a0. Gilbert, Walter. 1986. “Origin of life: The RNA world.” Nature 319 (6055): 618. doi:10.1038/319618a0. Girard, René. 1972, English translation 1977. Violence and the Sacred, translated by Patrick Gregory. Baltimore, Maryland, USA: John Hopkins University Press. —. 1996. “Satan.” Chapter 13 in The Girard Reader, edited by James G. Williams: 195-210. New York, USA: Crossroad Publishing Company. —. 1999, English translation 2001. I See Satan Fall Like Lightning, translated by James G. Williams. Maryknoll, New York, USA: Orbis Books. —. 2007, English translation 2010. Battling to the End: Conversations with Benoît Chantre, translated by Mary Baker. East Lansing, Michigan, USA: Michigan State University Press. Girard, René, with J.-M. Oughourlian and G. Lefort. 1978, English translation 1987. Things Hidden Since the Foundation of the World, translated by Stephen Bann and Michael Metterer. London, UK: the Athlone Press. Girard, René, with P. Antonello, J. Cezar and C. de Castro Rocha. 2008. Evolution and Conversion: Dialogues on the Origin of Culture. London, UK: Continuum Publishing. Godfrey-Smith, Peter. 2016. Other Minds: The Octopus and the Evolution of Intelligent Life. London, UK: HarperCollins. Goethe, Johann W. von. 1790. Versuch der Metamorphose der Pflanzen zu Erklären. Gotha, Germany: C.W. Ettinger. Goff, Philip. 2019. Galileo's Error: Foundations for a New Science of Consciousness. New York, USA: Pantheon Books. Goldingay, John. 2015/2016. An Introduction to the Old Testament: Exploring Text, Approaches and Issues. London, UK: SPCK. Gould, Stephen Jay. 1980. “The Piltdown conspiracy.” Natural History 89 (8): 828. —. 1989. Wonderful Life: The Burgess Shale and the Nature of History. New York, USA: W.W. Norton.

Redundant God? Christian Faith in the Light of Evolution

387

—. 1999. Rocks of Ages: Science and Religion in the Fulness of Life. New York, USA: Ballantine Books. —. 2002. The Structure of Evolutionary Theory. Cambridge, Massachusetts, USA: Bellknap Press of Harvard University Press. Grant, Peter R., and B. Rosemary Grant. 2018. “Role of sexual imprinting in assortative mating and premating isolation in Darwin's finches.” PNAS (USA) 115 (46): E10879-E10887. doi:10.1073/pnas.1813662115. Grasby, Stephen E., X. Liu, R. Yin, R.E. Ernst, Z. Chen. 2020. “Toxic mercury pulses into late Permian terrestrial and marine environments.” Geology 48 (8): 830-833. doi:10.1130/G47295.1. Graziano, Michael S.A. 2019. Rethinking Consciousness: A Scientific Theory of Subjective Experience. New York, USA: W.W. Norton & Company. Green, Joel B. 1998. “'Bodies—that is, human lives'; A re-examination of human nature in the Bible.” In Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature, edited by Warren S. Brown, N. Murphy, H.N. Malony: 149-173. Minneapolis, Minnesota, USA: Fortress Press. Greenfield, Susan. 2016. A Day in the Life of the Brain. London, UK: Allen Lane. Gregersen, Niels H. 1998. “The idea of creation and the theory of autopoietic processes.” Zygon: Journal of Religion and Science 33 (3): 333-367. doi:10.1111/0591-2385.00154. —. 2013. “Cur deus caro: Jesus and the cosmos story.” Theology and Science 11 (4): 370-393. doi:10.1080/14746700.2013.836891. Gregory Nazianzen. Original text c. 383; posted online 2017. “Epistle 101: Second Epistle to Cledonius the Priest Against Apollinarius.” Edited by Kevin Knight, New Advent. www.newadvent.org/fathers/3103a.htm. Accessed September 27, 2018. Grumett, David, and Paul Bentley. 2018. “Teilhard de Chardin, original sin, and the six propositions.” Zygon: Journal of Religion and Science: 53 (2): 303-330. doi:10.1111/zygo.12398. Guo, Huili, N.T. Ingolia, J.S. Weissman JS, D.P. Bartel. 2010. “microRNAs predominantly act to decrease target mRNA levels.” Nature 466 (7308): 835840. doi:10.1038/nature09267. Guttman, Mitchell, and John L. Rinn. 2012. “Modular regulatory principles of large non-coding RNAs.” Nature 482 (7385): 339-346. doi:10.1038/nature10887. Györgyi, Laszló, and Richard J. Field. 1992. “A three-variable model of deterministic chaos in the Belousov-Zhabotinsky reaction.” Nature 355 (6363): 808-810. doi:10.1038/ 355808a0. Hafner, Anne-Sophie, P. Donlin-Asp, B. Leitch, E. Herzog, E. Schuman. 2019. “Local protein synthesis is a ubiquitous feature of neuronal pre- and postsynaptic compartments.” Science 364 (6441): eaau3644 (summary, p. 650). doi:10.1126/science.aau3644. Hagadorn, James W., S. Xiao, P.C J. Donoghue, S. Bengtson, N.J. Gostling, M. Pawlowska, E. C. Raff et al. 2006. “Cellular and subcellular structure of Neoproterozoic animal embryos.” Science 314 (5797): 291-294. doi:10.1126/science.1133129.

388

Bibliography

Halder, Georg, P. Callaerts, W.J. Gehring. 1995. “Induction of ectopic eyes by targeted expression of the eyeless gene in Drosophila.” Science 267 (5205): 1788-1792. doi:10.1126/science.7892602 . Han, Jian, S. Conway Morris, Q. Ou, D. Shu, H. Huang. 2017. “Meiofaunal deuterostomes from the basal Cambrian of Shaanxi (China).” Nature 542 (7640): 228-232. doi:10.1038/nature21072. Hansen, Thomas B., T. I. Jensen, B.H. Clausen, J.B. Bramsen, B. Finsen, C.K. Damgaard, J. Kjems. 2013. “Natural RNA circles function as efficient microRNA sponges.” Nature 495 (7441): 384-388. doi:10.1038/ nature11993. Harrap, Anne, and Simon Harrap. 2009. Orchids of Britain and Ireland. Second Edition. London, UK: A. & C. Black. Harris, Mark. 2013. The Nature of Creation: Examining the Bible and Science. Durham, UK: Acumen Publishing Ltd. Harris, Peter. 2000. “A new look at old passages.” In The Care Of Creation: Focussing Concern and Action, edited by Robert J. Berry: 132-139. Leicester, UK: Inter-Varsity Press. Hartshorne, Charles. 1962. The Logic of Perfection. La Salle, Illinois, USA: Open Court Publishing Company. Harvati, Katerina, C. Röding, A.M. Bosman, F.A. Karakostis, R. Grün, C. Stringer, P. Karkanas et al. 2019 Apidema Cave fossils provide earliest evidence of Homo sapiens in Eurasia.” Nature 571 (7766): 500-504. doi:10.1038/s41586-019-1376-z. Haughn, George W., and Chris R. Somerville. 1988. “Genetic control of morphogenesis in Arabidopsis.” Developmental Genetics 9 (2): 73-89. doi:10.1002/dvg.1020090202. Haught, John F. 2010. Making Sense of Evolution: Darwin, God and the Drama of Life. Louisville, Kentucky, USA: Westminster John Knox Press. Hayakawa, Shiho, Y. Takaku, J.S. Hwang, T. Horiguchi, H. Suga, W. Gehring, K. Ikeo, T. Gojobori. 2015. “Function and evolutionary origin of unicellular camera-type eye structure.” PLoS ONE 10 (3): e0118415. doi:10.1371/journal.pone.0118415. He, Shuonan, F. del Viso, C.-Y. Chen, A. Ikmi, A.E. Kroesen, M.C. Gibson. 2018. “An axial Hox code controls tissue segmentation and body patterning in Nematostella vectensis.” Science 361 (6409): 1377-1380. doi:10.1126/science.aar8384. Heisenberg, Martin. 2009. “Is free will an illusion?” Nature 459 (7244): 164-165. doi:10.1038/459164a. Held, Lewis I. 2017. Deep Homology?: Uncanny Similarities of Humans and Flies Uncovered by Evo-Devo. Cambridge, UK : Cambridge University Press. Henderson, James Cleaves II, C. Butch, P.B. Burger, J. Goodwin, M. Meringer. 2019. “One among millions: the chemical space of nucleic-acid-like molecules.” Journal of Chemical Information and Modeling 59 (10): 42664277. doi:10.1021/acs.jcim. 9b00632. Hendry, Andrew P. 2009. “Ecological speciation! Or the lack thereof?” Canadian Journal of Fisheries and Aquatic Sciences 66: 1383-1398. doi:10.1139/F09-074.

Redundant God? Christian Faith in the Light of Evolution

389

Henson, John. 2004. Good As New: A Radical Retelling of the Scriptures. Alresford, UK: O Books. Hick, John. 1966, reissued 2010. Evil and the God of Love. Basingstoke, UK. Palgrave Macmillan. Hitchens, Christopher. 2007. God is Not Great: How Religion Poisons Everything. London, UK: Atlantic Books. Hoegh-Guldberg, Ove, D. Jacob, M. Taylor, T. Guillén-Bolaños, M. Bindi, S. Brown, I.A. Camilloni et al. 2019. “The human imperative of stabilizing global climate change at 1.5°C.” Science 365 (6459). eaaw6974 (summary, p. 1263). doi:10.1126/ science. aaw6974. Hoffmann, Ary A., and Carla M. Sgrò. 2011. “Climate change and evolutionary adaptation.” Nature 470 (7335): 479-485. doi:10.1038/nature09670. Hoffmann, Dirk L., C.D. Standish, M. García-Diez, P.B. Pettitt, J.A. Milton, J. Zilhão, J.J. Alcolea-González et al. 2018. “U-Th dating of carbonate crusts reveals Neandertal origin of Iberian cave art.” Science 359 (6378): 912-915. doi:10.1126/science. aap7778. Hofstadter, Douglas R. 1979. Gödel, Escher, Bach: An Eternal Golden Braid. New York, USA: Basic Books. Holland, Linda Z., M. Kene, N.A. Williams, N.D. Holland,. 1997. “Sequence and embryonic expression of the amphioxus engrailed gene (AmphiEn): the metameric pattern of transcription resembles that of its segment-polarity homolog in Drosophila.” Development 124 (9): 1723-1732. Holmes, Bob. 2019. “The Goldilocks planet.” New Scientist 241 (3222): 34-37. doi:10.1016/ S0262-4079(19)30514-7. Hörstadius, Sven. 1928. “Uber die determination des keimes der Echinodermen.” Acta Zoologica Stockholm 9: 1-192. Hoyal Cuthill, Jennifer F., and Conway Morris, Simon. 2014. “Fractal branching organizations of Ediacaran rangeomorph fronds reveal a lost Proterozoic body plan.” PNAS (USA) 111 (36): 13122-13126. doi:10.1073/pnas.1408542111. Hoyal Cuthill, Jennifer F., and Conway Morris, Simon. 2017. “Nutrient-dependent growth underpinned the Ediacaran transition to large body size.” Nature Ecology & Evolution 1: 1201-1204. doi:10.1038/s41559-017-0222-7. Hull, Pincelli M., A. Bornemann, D.E. Penman, M.J. Heneha, R.D. Norris, P.A. Wilson, P. Blum et al. 2020. “On impact and volcanism across the CretaceousPaleogene boundary.” Science 367 (6475): 266-272. doi:10.1126/aay5055. Hunt Overzee, Anne. 1992. The Body Divine: The Symbol of the Body in the Works of Teilhard de Chardin and 5ƗPƗQXMD Cambridge, UK: Cambridge University Press. Hurtado, Larry W. 2016. Destroyer of the Gods: Early Christian Distinctiveness in the Roman World. Waco, Texas, USA: Baylor University Press. —. 2018. Honoring the Son: Jesus in Earliest Christian Devotional Practice, edited by Michael E. Bird. Bellingham, Washington, USA: Lexham Press. Huxley, Julian. 1942. Evolution: The Modern Synthesis. London, UK: Allen & Unwin.

390

Bibliography

Imachi, Hiroyuki, M.K. Nobu, N. Nakahara, Y. Morono, M. Ogawara, Y. Takaki, Y. Takano et al. 2020. “Isolation of an archaeon at the prokaryote-eukaryote interface.” Nature 577 (7791): 519-525. doi: 10.1038/s41586-2019-1916-6. Ingold, Tim. 2011. The Perception of the Environment: Essays on Livelihood, Dwelling and Skill. London, UK: Routledge. International Human Genome Sequencing Consortium. 2001. “Initial sequencing and analysis of the human genome.” Nature 409 (6822): 860-921. doi:10.1038/35057062. Ivantsov, Andrey Y. 2009. “New reconstruction of Kimberella, problematic Vendian Metazoan.” Palaeontological Journal 43 (6): 601-611. doi:10.1134/ S003103010906001X. Jackelén, Antje. 2008. “An intellectually honest theology.” Zygon: Journal of Religion and Science 43 (1): 43-55. doi:10.1111/j.1467-9744.2008.00897.x. Jacob, Francois, and Jacques Monod. 1961. “Genetic regulatory mechanisms in the synthesis of proteins.” Journal of Molecular Biology 3 (3): 318-356. doi: 10.1016/ S0022-2836(61)80072.7. Jacobs, David K., C.G. Wray, C.J. Wedeen, R. Kostriken, R. DeSalle, J.L. Staton, R.D. Gates, D. Lindberg. 2000. “Molluscan engrailed expression, serial organization, and shell evolution.” Evolution & Development 2 (6): 340-347. doi:10.1046/j.1525-142x.2000.00077.x. Jarvis, Erich D. 2019. “Evolution of vocal learning and spoken language”. Science 366 (6461): 50-54. doi:10.1126/science.aax0287. Jeffares, Daniel C., A.M. Poole, D. Penny. 1998. “Relics from the RNA world.” Journal of Molecular Evolution 46:18-36. doi:10.1007/PL00006280. Jessen, Timm H., R.E. Weber, G. Fermit, J. Tame, G. Braunitzer. 1991. “Adaptation of bird hemoglobins to high altitudes: Demonstration of molecular mechanism by protein engineering.” PNAS (USA) 88 (15): 6519-6522. doi:10.1073/pnas.88.15.6519. Johnson, Elizabeth A. 2014. Ask the Beasts: Darwin and the God of Love. London, UK: Bloomsbury Continuum. Jones, D. Gareth. 1970. Teilhard de Chardin. Westmont, Illinois, USA: InterVarsity Press Academic. Jones, Steve. 1996. In the Blood: God, Genes and Destiny. London, UK: HarperCollins. —. 2017. Evolution. London, UK: Ladybird Expert Books (series 117). Jukes, Thomas H., and Syozo Osawa. 1990. “The genetic code in mitochondria and chloroplasts.” Experientia 46 (11-12): 1117-1126. doi:10.1007/BF01936921. Juniper, Tony. 2016. What's Really Happening to Our Planet? The Facts Simply Explained. London, UK: Dorling Kindersley Limited, Penguin Random House. Kellogg, Vernon. 1917. Headquarter Nights. Boston, Massachusetts, USA: Atlantic Monthly Press. Khaitovich, Philipp, I. Hellmann, W. Enard, K. Nowick, M. Leinweber, H. Franz, G. Weiss et al. 2005. “Parallel patterns of evolution in the genomes and transcriptomes of humans and chimpanzees.” Science 309 (5742): 1850-1854. doi:10.1126/science.1108296.

Redundant God? Christian Faith in the Light of Evolution

391

Kidd, Benjamin. 1918. The Science of Power. New York, USA: G.P. Puttnam's Sons. King, Karen L. 2003. Gospel of Mary. Polebridge Press. Accessed May 21, 2018. http://www.maryofmagdala.com/GMary_Text/gmary_text.html. Kirkpatrick, Mark. 2019. “Sex chromosomes manipulate mate choice.” Nature 570 (7761): 311-312. doi:10.1038/d41586-019-01714-5. Klingler, Martin, and John Peter Gergen. 1993. “Regulation of runt transcription by Drosophila segmentation genes.” Mechanisms of Development 43 (17761): 3-19. doi:10.1016/0925-4773(93)90019-T. Kmita, Marie, N. Fraudeau, Y. Hérault, D. Duboule. 2002. “Serial deletions and duplications suggest a mechanism for the collinearity of Hoxd genes in limbs.” Nature 420 (6912): 145-150. doi:10.1038/nature01189. Knight, Christopher C. 2007. “Emergence, naturalism, and panentheism: An Eastern Christian perspective.” In All That Is: A Naturalistic Faith for the Twenty-First Century: A Theological Proposal with Responses from Leading Thinkers in the Religion-Science Dialogue, by Arthur R. Peacocke, edited by Philip Clayton: 81-92. Minneapolis, USA: Fortress Press. Knope, Matthew L., A.M. Bush, L.O. Frishkoff, N.A. Heim, J.L. Payne. 2020. “Ecologically diverse clades dominate the ocean via extinction resistance.” Science 367 (6481): 1035-1038. doi:10.1126/science.aax6398. Koenig, Kristen M., P. Sun, E. Meyer, J.M. Gross. 2016. “Eye development and photoreceptor differentiation in the cephalopod Doryteuthis pealeii.” Development 143 (17): 3168-3181. doi:10.1242/dev.134254 . Korstrom, Glen. 2017. “Musqueam's YVR pact could be native partnership template.” Business in Vancouver. 04 July. https://biv.com/article/2017/07/ musqueams-yvr-pact-could-be-native-partnership-tem. Krause, Johannes, C. Lalueza-Fox, L. Orlando, W. Enard, R.E. Green, H.A. Burbano, J.-J. Hublin et al. 2007. “The derived FOXP2 variant of modern humans was shared with Neandertals.” Current Biology 17 (21): R917-R919. doi:10.1016/j.cub. 2007.10.008. Krebs, Jocelyn E., Elliott S. Goldstein, Stephen T. Kilpatrick. 2018. Lewin's Genes XII. Burlington, Maine, USA: Jones & Bartlett Learning. Kremen, Claire and Adina M. Merenlender. 2018. “Landscapes that work for biodiversity and people.” Science 362 (6412): eaau6020 (summary, p. 304). doi:10.1126/ science.aau6020. Kriesell, Hannah J., S.H. Elwen, A. Nastasi, T. Gridley. 2014. “Identification and characteristics of signature whistles in wild Bottlenose Dolphins (Tursiops truncatus) from Namibia.” PLoS ONE 9: e106317. doi:10.1371/journal.pone. 0106317. Kuhn, Thomas. 1962. The Structure of Scientific Revolutions. Chicago, USA: University of Chicago Press. Kulakova, Milana, N. Bakalenko, E. Novikova, C. E. Cook, E. Eliseeva, P.R.H. Steinmetz, R.P. Kostyuchenko et al. 2007. “Hox gene expression in larval development of the polychaetes Nereis virens and Platynereis dumerilii (Annelida, Lophotrochozoa).” Development, Genes and Evolution 217 (1): 3954. doi:10.1007/s00427-006-0119-y.

392

Bibliography

Lawler, Andrew 2020. “Dawn of the chicken revealed in Southeast Asia.” Science 368 (6498): 1411. doi:10.1126/science.368.6498.1411. Lai, Cecilia S., S.E. Fisher, J.A. Hurst, E.R. Levy, S. Hodgson, M. Fox, S. Jeremiah. 2000. “The SPCH1 Region on Human 7q31: Genomic charactsrization of the critical interval and localization of translocations associated with speech and language disorder.” American Journal of Human Genetics 67 (2): 357-367. doi:10.1086/ 303011. Lai, Cecilia S.L., S.E. Fisher, J.A. Hurst, F. Vargha-Khadem, A.P. Monaco. 2001. “A forkhead-domain gene is mutated in a severe speech and language disorder.” Nature 413 (6855): 519-523. doi:10.1038/35097076. Lakatos, Imre. 1978. The Methodology of Scientific Research Programmes. Cambridge, UK: Cambridge University Press. Laland, Kevin N. 2017. Darwin's Unfinished Symphony: How Culture Made the Human Mind. Woodstock, Oxfordshire, UK: Princeton University Press. Laland, Kevin N., J. Odling-Smee, S. Myles. 2010. “How culture shaped the human genome: Bringing genetics and the human sciences together.” Nature Reviews Genetics 11 (2): 137-148. doi:10.1038/nrg2734. Laland, Kevin N., T. Uller, M.W. Feldman, K. Sterelny, G.B. Müller, A. Moczek, E. Jablonka, J. Odling-Smee. 2015. "The extended evolutionary synthesis: its structure, assumptions and predictions. Proceedings of the Royal Society, Series B (Biological Sciences) 282: 2015-1019. doi:10.1098/rspb.2015.1019. Lambert, Jonathan. 2019. “Scientists glimpse oddball microbe that could help explain rise of complex life.” Nature 572 (7769): 294. doi:10.1038/d41586-019-02430-w. Lambert, Olivier, G. Bianucci, R. Salas-Gismondi, C. Di Celma, E. Steurbaut, M. Urbina, C. de Muizon. 2019. “An amphibious whale from the Middle Eocene of Peru reveals early South Pacific dispersal of quadrupedal cetaceans.” Current Biology. doi:10.1016/j.cub.2019.02.050. Lamichhaney, Sangeet, J. Berglund,, M.S. Almén, K. Maqbool, M. Grabherr, A. Martinez-Barrio, M. Promerová et al. 2015. “Evolution of Darwin's finches and their beaks revealed by genome sequencing.” Nature 518 (7539): 371-375. doi:10.1038/nature14181. Leidenhag, Joanna. 2016. “A critique of emergent theologies.” Zygon: Journal of Religion and Science 51 (4): 867-882. doi:10.1111/zygo.12300. Lenton, Timothy M., and Bruno Latour. 2018. “Gaia 2.0: could humans add some level of self-awareness to Earth's self-regulation?” Science 361 (6407): 10661068. doi:10.1126/science.aas0427. Lenton, Timothy M., R.A. Boyle, S.W. Poulton, G.A. Shields-Zhou, N.J. Butterfield. 2014. “Co-evolution of eukaryotes and ocean oxygenation in the Neoproterozoic era.” Nature Geoscience 7 (4): 257-265. doi:10.1038/NGEO2108. Lewis, Clive S. 1960/1963 (paperback). The Four Loves. London, UK: Fontana Books. Lewis, Ed B. 1978. “A gene complex controlling segmentation in Drosophila.” Nature 276 (5688): 565-570. doi:10.1038/276565a0.

Redundant God? Christian Faith in the Light of Evolution

393

Li, Yan, J.H.I. Haarhuis, A.S. Cacciatore, R. Oldenkamp, M.S. van Ruiten, L. Williams, H. Teunissen et al. 2020. “The structural basis for cohesin-CTCFanchored loops.” Nature 578 (7795): 472-476. doi:10.1038/s41586-019-1910-z. Libet, Benjamin, A. Freeman, K. Sutherland (eds.). 1999. The Volitional Brain: Towards a Neuroscience of Free Will. Thorverton, UK: Imprint Academic. Liegertová, Michaela, J. Pergner, I. Kozmiková, P. Fabian, A.R. Pombinho, H. Strnad, J. 3DþHV et al. 2015. “Cubozoan genome illuminates functional diversification of opsins and photoreceptor evolution.” Scientific Reports 5: 11885. doi:10.1038/srep11885 Lindgren, Johan, D.-E. Nilsson, P. Sjövall, M. Jarenmark, S. Ito, K. Wakamatsu, B.P. Kear et al. 2019. "Fossil insect eyes shed light on trilobite optics and the arthropod pigment screen." Nature 573 (7772): 122-125. doi:10.1038/s41586-019-1473-z. Lineweaver, Charles H., and Aditya Chopra. 2019. "The biological overview effect: Our place in nature." Journal of Big History III (3): 109-122. doi:10.22339/jbh.v3i3.3360. Linnaeus, Carolus. 1753. Species Plantarum. Stockholm, Sweden: Laurentius Salvius. —. 1758. Systema Naturae tome I. Stockholm, Sweden: Laurentius Salvius. —. 1759. Systema Naturae tome II. Stockholm, Sweden: Laurentius Salvius. Liu, Alexander G., J.L. Matthews, L.R. Menon, D. McIlroy, M.D. Brasier. 2016. “Haootia quadriformis n. gen., n.sp., interpreted as a muscular cnidarian from the Late Ediacaran period (approx. 560 Ma).” Proceedings of the Royal Society, series B (Biological Sciences) 281: 20141202. doi:org/10.1098/rspb.2014.1202. Livingstone, David N. 1984, republished 1997. Darwin's Forgotten Defenders: The Encounter Between Evangelical Theology and Evolutionary Thought. Vancouver, Canada: Regent College Publishing. Locke, Devin P., L.W. Hillier, W.C. Warren, K.C. Worley, L.V. Nazareth, D.M. Muzny, S.P. Yang et al. 2011. “Comparative and demographic analysis of orang-utan genomes.” Nature 469 (7331): 529-533. doi:10.1038/nature09687. Lombardo, Umberto, J. Iriarte, L. Hilbert, J. Ruiz-Pérez, J.M. Caprilles, H. Veit. 2020. “Early Holocene crop cultivation and landscape modification in Amazonia.” Nature 581 (7807): 190-193. doi:10.1038/s41586-020-2162-7. Loron, Corentin C., C. François, R.H. Rainbird, E.C. Turner, S. Borensztajn, E.J. Javaux. 2019. “Early fungi from the Proterozoic era in Arctic Canada.” Nature 570 (7760): 232-235. doi:10.1038/s41586-019-1217-0. Losos, Jonathan. 2017. Improbable Destinies: How Predictable is Evolution? London, UK: Allen Lane. Losos, Jonathan B., and Robert E. Ricklefs. 2009. “Adaptation and diversification on islands.” Nature 457 (7231): 830-838. doi:10.1038/nature07893. Losos, Jonathan B., K.I. Warhelt, T.W. Schoener. 1997. “Adaptive differentiation following experimental island colonization in Anolis lizards.” Nature 387 (6628): 70-73. doi:10.1038/387070a0.

394

Bibliography

Lovelock, James E. 1979. Gaia: A New Look at Life on Earth. Oxford, UK: Oxford University Press. —. 2006. The Revenge of Gaia: Why the Earth is Fighting Back and How We Can Still Save Humanity. London, UK: Allen Lane. Ludlow, Morwenna. 2000. Universal Salvation: Eschatology in the Thought of Gregory of Nyssa and Karl Rahner. Oxford, UK: Oxford University Press. Lukas, Mary. 1981. “Teilhard and the Piltdown "Hoax".” America: The Jesuit Review 144 (20): 424-427. Lumsden, Andrew. 1999. “Closing in on rhombomere boundaries.” Nature Cell Biology 1: E83-E85. doi:10.1038/12078. Luo, Shiyu, C.A. Valencia, J. Zhang, N.-C. Lee, J. Slone, B. Gui, X. Wang et al. 2018. “Biparental inheritance of mitochondrial DNA in humans.” PNAS (USA) 115 (51): 13039-13044. doi:10.1073/pnas.1810946115. Lyell, Charles. 1830. Principles of Geology, vol. 1. London, UK: John Murray. —. 1832. Principles of Geology, vol. 2. London, UK: John Murray. —. 1833. Principles of Geology, vol. 3. London, UK: John Murray. Lynas, Mark. 2008. Six Degrees: Our Future on a Hotter Planet. London, UK: Harper Perennial. MacColl, Andrew D.C. 2011. “The ecological causes of evolution.” Trends in Ecology and Evolution 26: 514-522. doi:10.1016/j.tree.2011.06.009. MacIntyre, Alasdair. 1999. Dependent Rational Animals: Why Human Beings Need the Virtues. Chicago, Illinois, USA: Open Court Publishing Company. MacKay, Donald M. 1979. Human Science and Human Dignity. London, UK: Hodder & Stoughton. Maguire, Eleanor A., D.G. Gadian, I.S. Johnsrude, C.D. Good, J. Ashburner, R.S.J. Frackowiak, C. Frith. 2000. “Navigation-related structural change in the hippocampi of taxi drivers.” PNAS (USA) 97 (8): 4398-4403. doi:10.1073/pnas.070039597. Maitland, Sara. 1995. A Big-Enough God: Artful Theology. London, UK: Mowbray. Margulis, Lynn. 1970. Origin of Eukaryotic Cells: Evidence and Research Implications for a Theory of the Origin and Evolution of Microbial, Plant, and Animal Cells on the Precambrian Earth. New Haven, Connecticut, USA: Yale University Press. Maricik, Tomislav, V. Günther, O. Geogiev, S. Gehre, M. ûXUOLQ C. Schreiweis, R. Naumann et al. 2013. “A recent evolutionary change affects a regulatory element in the human FOXP2 gene.” Molecular Biology and Evolution 30 (4): 844-852. doi:10.1093/molbev/mss271. Marlétaz, Ferdinand, P.N. Firbas, I. Maeso, J.J. Tena, O. Bogdanovic, M. Perry, C.D.R. Wyatt et al. 2019. “Amphioxus functional genomics and the origins of vertebrate gene regulation.” Nature 564 (7734): 64-70. doi:10.1038/s41586-018-0734-6. Marshall, John A., J. Lakin, I. Troth, S.M. Wallace,-Johnson. 2020. “UV-B radiation was the Devonian-Carboniferous boundary terrestrial extinction kill mechanism.” Science Advances 6 (22): eaba0768. doi:10.1126/sciadv.aba0768.

Redundant God? Christian Faith in the Light of Evolution

395

Martin, William F., F.L. Sousa, N. Lane. 2014. “Energy at life's origin.” Science 344 (6188): 1092-1093. doi:10.1126/science.1251653. Martín-Durán, Jose M., Y. J. Passamaneck, M.Q. Martindale, A. Hejnol. 2017. “The developmental basis for the recurrent evolution of deuterostomy and protostomy.” Nature Ecology and Evolution 1: 0005. doi:10.1038/s41559-016-0005. Martinez-Arias, Alfonso, and Peter E. Lawrence. 1985. “Parasegments and compartments in the Drosophila embryo.” Nature 313 (6004): 639-642. doi:10.1038/313639a0. Martin-Ordas, Gema, D. Haun, F. Colmenares, J. Call. 2010. “Keeping track of time: evidence for episodic-like memory in great apes.” Animal Cognition 13 (2): 331-340. doi:10.1007/s10071-009-0282-4. Matloff, Laura Y., E. Chang, T.J. Feo, L. Jeffries, A.K. Stowers, C. Thomson, D. Lentink. 2020. “How flight feathers stick together to form a continuous morphing wing” Science 367 (6475): 331-340. doi:10.1126/science.aaz3358. Matsuda, Mitsuhiro, Y. Yamanaka, M. Uemura, M. Osawa, M.K. Saito, A. Nagahashi, M. Nisho et al. 2020. “Recapitulating the human segmentation clock with pluripotent stem cells” Nature 580 (7801): 124-129. doi:10.1038/s41586-020-2144-9. McClintock, David, and R.S.R. Fitter. 1956. Pocket Guide to Wild Flowers. London, UK: Collins. McComb, Karen, L. Baker, C. Moss. 2006. “African elephants show high levels of interest in the skulls and ivory of their own species.” Biology Letters 2 (1): 2628. doi:10.1098/rsbl.2005.0400. McFague, Sallie. 2013. Blessed are the Consumers: Climate Change and the Practice of Restraint. Minneapolis, Minnesota, USA: Fortress Press. McGilchrist, Iain. 2009. The Master and His Emissary: The Divided Brain and the Making of the Western World. New Haven, Connecticut, USA: Yale University Press. McGinnis, William, M.S. Levine, E. Hafen, A. Kuroiwa, W.J. Gehring. 1984. “A conserved DNA sequence in homoeotic genes of the Drosophila Antennapedia and bithorax complexes.” Nature 308 (5958): 428-433. doi:10.1038/308428a0. McGrath, Alister E. 2011. Darwinism and the Divine: Evolutionary Thought and Natural Theology. Chichester, UK: Wiley-Blackwell. McKie, Douglas. 1944. “Wöhler's ‘Synthetic’ Urea and the Rejection of Vitalism: A Chemical Legend.” Nature 153 (3890): 608-610. doi:10.1038/153608a0. Medawar, Peter B. 1961. “The Phenomenon of Man by Pierre Teilhard de Chardin.” Mind 70 (277): 99-106. doi:10.1093/mind/LX.277.99. Mekel-Bobrov, Nitzan, S.L. Gilbert, P.D. Evans, E.J. Vallender, J.R. Anderson, R.R. Hudson, S.A. Tishkoff, B.T. Lahn. 2005. “Ongoing adaptive evolution of ASPM, a brain size determinant in Homo sapiens.” Science 309 (5741): 17201722. doi:10.1126/science.1116815. Memczak, Sebastian, M. Jens, A. Elefsinioti, F. Torti, J. Krueger, A. Rybak, L. Maier et al. 2013. “Circular RNAs are a large class of animal RNAs with regulatory potency.” Nature 495 (7441): 333-338. doi:10.1038/nature11928.

396

Bibliography

Mendel, Johann G. 1866. “Versuche über pflanzen-hybriden.” Verhandlungen des naturforschenden Vereines in Brünn BD IV: 3-47. http://www.mendelweb.org/ Mendel.html. Mepham, T. Ben. 2000. “A framework for the ethical analysis of novel foods: the ethical matrix.” Journal of Agricultural and Environmental Ethics 12: 165176. doi:10.1023/A:1009542714497. Mesle, C. Robert. 1993. Process Theology: A Basic Introduction. Final chapter by John B. Cobb, Jr. St. Louis, Missouri, USA: Chalice Press. Meyer, Kyle W., S.V. Petersen, K.C. Lohmann, J.D. Blum, S.J. Washburn, M.W. Johnson, D. Gleason et al. 2019. “Biogenic carbonate mercury and marine temperature records reveal global influence of late Cretaceous Deccan Traps.” Nature Communications 10 (1): article no. 5356. doi:10.1038/ s41467-019-13366-0. Mills, Melinda C. 2019. “How do genes affect same-sex behavior?” Science 365 (6456): 869-870. doi:10.1126/science.aay2726. Mix, Lucas J. 2015. Thinking Fair: Rules for Reason in Science and Religion. North Charleston, South Carolina, USA: self-published using CreateSpace. —. 2020. “The ends of the world (or don't blame evolution, blame entropy).” God and Nature Magazine (published by the American Scientific Affiliation): Winter 2020. Moltmann, Jürgen. 1973/1974. The Crucified God, translated by R.A Wilson and John Bowden. London, UK: SCM Press Ltd. —. 1989/1990. The Way of Jesus Christ: Christology in Messianic Dimensions, translated by Margaret Kohl. London, UK: SCM Press. —. 2000. “God's covenant and our resposibility.” In The Care of Creation: Focussing Concern and Action, edited by Robert J. Berry: 107-113. Leicester, UK: Inter-Varsity Press. Monk, Julia D., E. Giglio, A. Kamath, M.R. Lambert, C.E. McDonough. 2019. “An alternative hypothesis for the evolution of sane-sex sexual behaviour in animals.” Nature Ecology and Evolution 3: 1622-1631. doi:10.1038/s41559-019-1019-7. Monod, Jacques. 1970/1972. Chance and Necessity: Essay on the Natural Philosophy of Modern Biology, translated by Austryn Wainhouse. London, UK: Collins. Moore, Aubrey L. 1891. “The Christian doctrine of God.” In Lux Mundi, edited by Charles Gore: 57-109. London, UK: John Murray. Moore, Aubrey L. 1893. Science and the Faith: Essays on Apologetic Subjects with an Introduction, 4th edition. London, UK: Keegan Paul. Moroz, Leonid L., K.M. Kocot, M.R. Citarella, S. Dosung, T.P. Norekian, I.S. Povolotskaya, A.P. Grigorenko et al. 2014. “The ctenophore genome and the evolutionary origins of neural systems.” Nature 510 (7503): 109-114. doi:10.1038/nature13400. Morris, Leon. 1988 (revised edition). Luke: An Introduction and Commentary. Leicester, UK: Inter-Varsity Press.

Redundant God? Christian Faith in the Light of Evolution

397

Morwood, Michael J., R.P. Soejono, R.G. Roberts, T. Sutikna, C.S.M. Turney, K E. Westaway, W.J. Rink et al. 2004. “Archaeology and age of a new hominin from Flores in eastern Indonesia.” Nature 431 (7012): 1087-1091. doi:10.1038/nature02956. Mozart, Wolfgang Amadeus. 1788, score republished 2008. Symphony no. 41 in C, K 551. Mainz, Germany: Ernst Eulenberg & Co. GmbH. Muchowska, Kamila B., S.J. Varma, J. Moran. 2019. “Synthesis and breakdown of universal metabolic precursors promoted by iron.” Nature 569 (7754): 104107. doi:10.1038/s41586-019-1151-1. Muralidhar, Pavitra. 2019. “Mating preferences of selfish sex chromosomes.” Nature 570 (7761): 376-379. doi:10.1038/s41586-019-1271-7. Murphy, Nancey. 1998. “Human nature: Historical, scientific and religious issues.” In Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature, edited by Warren S. Brown, N. Murphy, H.N. Malony: 1-29. Minneapolis, Minnesota, USA: Fortress Press. Musilova, Zuzana, F. Cortesi, M. Matschiner, W.I.L. Davies, J.S. Patel, S.M. Stieb, F. de Busserolles et al. 2019. “Vision using multiple distinct rod opsins in deep-sea fishes.” Science 364 (6440): 588-592. doi:10.1126/science.aav4632. Naiche, L.A., N. Holder, M. Lewandoski. 2011. “FGF4 and FGF8 comprise the wavefront activity that controls somitogenesis.” PNAS (USA) 108: 4018-4023. doi:10.1073/pnas1007417108. Nakamura, Tetsuya, A.R. Gehrke, J. Lemberg, J. Szymaszek, N.H. Shubin. 2016. “Digits and fin rays share common developmental histories.” Nature 537 (7619): 225-228. doi:10.1038/nature19332. Newbigin, Lesslie. 1989. The Gospel in a Pluralist Society. Grand Rapids, Michigan, USA: Eerdman's Publishing. Ng, Medard, and Martin F. Yanovsky. 2001. “Function and evolution of the plant MADS-box gene family.” Nature Reviews Genetics 2 (3): 186-195. doi:10.1038/35056041. Nietzsche, Friedrich. 1887, republished 2003. On the Genealogy of Morality: A Polemic, edited by T.N.R. Rogers; translated by Horace B. Samuel. Mineola, New York, USA: Dover Thrift Publications. Nolan, Connor, J.T. Overpeck, J.R.M. Allen, P.M. Anderson, J.L. Betancourt, H.A. Binney, S. Brewer et al. 2018. “Past and future global transformation of terrestrial ecosystems under climate change.” Science 361 (6405): 920-923. doi:10.1126/science.aans5360. Northcott, Michael S. 2007. A Moral Climate: The Ethics of Global Warming. London, UK: Darton, Longman and Todd, in association with Christian Aid. —. 2014. A Political Theology of Climate Change. London, UK: SPCK. —. 2015. Place, Ecology and the Sacred: The Moral Geography of Sustainable Communities. London, UK: Bloomsbury Academic. Nowak, Martin, and Sarah Coakley (eds.). 2013. Evolution, Games and God: The Principle of Cooperation. Cambridge, Massachusetts, USA: Harvard University Press.

398

Bibliography

Nüsslein-Volhard, Christiane, and Eric Wieschaus. 1980. “Mutations affecting segment number and polarity in Drosophila.” Nature 287 (5785): 795-801. doi:10.1038/287795a0. Nutman, Allen P., V.C. Bennett, C.R.L. Friend, M. J. Van Kranendonk, A.R. Chivas. 2016. “Rapid emergence of life shown by discovery of 3,700-millionyear-old microbial structures.” Nature 537 (7621): 535-538. doi:10.1038/nature19355. Olmstead, Richard G. 2002. “Whatever happened to the Scrophulariaceae?” Fremontia 30 (2): 13-22. Onai, Takayuki, J.-K. Yu, I.L. Blitz, K.Y.W. Cho, L.Z. Holland. 2010. “Opposing Nodal/Vg1 and BMP signals mediate axial patterning in embryos of the basal chordate amphioxus.” Developmental Biology 344 (1): 377-389. doi:10.1016/j.ydbio.2010.05.016. Oord, Thomas Jay. 2015. The Uncontrolling Love of God: An Open and Relational Account of Providence. Downers Grove, Illinois, USA: InterVarsity Press. Pace, Ryan M., M. *UELü L.M. Nagy. 2016. “Composition and genomic organization of arthropod Hox clusters.” EvoDevo 7: 11. doi:10.1186/s13227-016-0048-4. Page, Roderic D.M., and Edward C. Holmes. 1998. Molecular Evolution: A Phylogenetic Approach. Oxford, UK: Blackwell Science. Page, Ruth. 1996. God and the Web of Creation. London, UK: SCM Press Ltd. Paley, William. 1802. Natural Theology: Or, Evidences of the Existence and Attributes of the Deity; Collected from the Appearances of Nature. London, UK: R. Faulder. Pallen, Mark J., and Nicholas J. Matzke. 2006. “From The Origin of Species to the origin of bacterial flagella.” Nature Reviews Microbiology 4 (10): 784-790. doi:10.1038/ nrmicro1493. Parker, Hugo J., M.E. Bronner, R. Krumlauf. 2019. “An atlas of anterior hox gene expression in the embryonic sea lamprey head: Hox-code evolution in vertebrates ” Developmental Biology 453 (1): 19-33. doi: 10.1016/j.ydbio.2019.05.001. Paterson, John R., D.C. Garcia-Bellido, M.S. Lee, G.A. Brock, J.B. Jago, G.D. Edgecombe. 2011. “Acute vision in the giant Cambrian predator Anomalocaris and the origin of compound eyes.” Nature 480 (7376): 237-240. doi:10.1038/nature10689. Peacocke, Arthur R. 1977. “Chance and necessity in the life-game.” Trends in Biological Sciences 2 (5): N99-100. doi:10.1016/0968-0004(77)90160-8. —. 1990. Theology for a Scientific Age. Oxford, UK: Basil Blackwell Ltd. —. 2001. “The cost of new life.” In The Work of Love: Creation as Kenosis, edited by John Polkinghorne: 21-42. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. —. 2004. Evolution: The Disguised Friend of Faith? West Conshohocken, Pennsylvania, USA: Templeton Foundation Press. —. 2007. All That Is: A Naturalistic Faith for the Twenty-First Century, edited by Philip Clayton. Minneapolis, USA: Fortress Press.

Redundant God? Christian Faith in the Light of Evolution

399

Peacocke, Arthur R., and Ann Pederson. 2006. The Music of Creation. Minneapolis, Minnesota, USA: Augsburg Fortress. Penney, David, C. Wadsworth, G. Fox, S.L. Kennedy, R.F. Preziosi, D.A. Brown. 2013. “Absence of ancient DNA in sub-fossil insect inclusions preserved in ‘Anthropocene’ Colombian copal.” PLoS ONE 8: e73150. doi:10.1371/journal.pone.0073150. Pennisi, Elizabeth. 2019a. “Algae suggest eukaryotes get many gifts of bacteria DNA:.” Science 363 (6426): 439-440. doi:10.1126/science.363. 6426.439-b. —. 2019b. “Did neurons arise from an early secretory cell?” Science 363 (6424): 212-213. doi:10.1126/science.363.6424.212. —. 2019c. “Plant genomics unearths Africa's 'fertile crescent;.” Science 364 (6439): 422-423. doi:10.1126/science.364.6439.422. Percival, Lawrence M., M. Ruhl, S.P. Hesselbo, H.C. Jenkyns, T.A. Mather, J.H. Whiteside. 2017. “Mercury evidence for pulsed volcanism during the endTriassic mass extinction.” PNAS (USA) 114 (30): 7929-7934. doi:10.1073/pnas.1705378114. Pérez-Gómez, Rocio, E. Hara, M. Fernández-Guerrero, M.F. Bastida, M.A. Ros. 2018. “Role of Hox genes in regulating digit patterning.” International Journal of Developmental Biology 62: 797-805. doi:10.1387/ijdb.180200mr. Peters, Shanan E. 2008. “Environmental determinants of extinction selectivity in the fossil record.” Nature 454 (7204): 626-629. doi:10.1038/nature07032. Peterson, Kevin J., S.Q. Irvine, R.A. Cameron, E.H. Davidson. 2000. “Quantitative assessment of Hox complex expression in the indirect development of the polychaete annelid Chaetopterus sp.” PNAS (USA) 97 (9): 4487-4492. doi:10.1073/pnas.97.9.4487. Phipps, Carter. 2012. Evolutionaries: Unlocking the Spiritual and Cultural Potential of Science's Greatest Idea. New York, USA : Harper Perennial. Piatigorsky, Joram. 1993. “Puzzle of crystallin diversity in eye lenses.” Developmental Dynamics 196: 267-272. doi:10.1002/aja.1001960408. Piatigorsky, Joram, and Graeme Wistow. 1991. “The recruitment of crystallins: new functions precede gene duplication.” Science 252 (5009): 1078-1079. doi:10.1126/ science.252.5009.1078. Pickett, John A., and Zeyaur R. Khan. 2016. “Plant volatile-mediated signalling and its application in agriculture: successes and challenges.” New Phytologist 212: 856-870. doi:10.1111/nph.14274. Pickett, John, C.M. Woodcock, C.A.O. Midega, Z. Khan. 2014. “Push-pull farming systems.” Current Opinion in Biotechnology 26: 126-132. doi:10.1016/j.copbio.2013.12.006. Pineda, David J., J. Gonzalez, P. Callaerts, K. Ikeo, W.J. Gehring, E. Salo. 2000. “Searching for the prototypic eye genetic network: Sine oculis is essential for eye regeneration in planarians.” PNAS (USA) 97 (9): 4525-4529. doi:10.1073/pnas.97.9.4525 . Pinker, Steven. 2018. Enlightenment Now: The Case for Reason, Science, Humanism, and Progress. London, UK: Allen Lane. Plotnik, Joshua M., F.B.M. de Waal, D. Reiss. 2006. “Self-recognition in an Asian elephant.” PNAS (USA) 103 (45): 17053-17057.

400

Bibliography

doi:10.1073/pnas.0608062103. Polderman, Tinca, B. Benyamin, C. De Leeuw, P. Sullivan, A. Van Bochoven, P. Visscher, D. Posthuma. 2015. “Meta-analysis of the heritability of human traits based on fifty years of twin studies.” Nature Genetics 47 (7): 702-709. doi:10.1038/ng.3285. Polkinghorne, John. 1989. Science and Providence: God's Interaction with the World. London, UK: SPCK. — . 2005. Quantum Physics and Theology: An Unexpected Kinship. London, UK: SPCK. Pope Francis. 2015. Laudato Si': On Care for our Common Home. Encyclical Letter. London, UK: The Incorporated Catholic Truth Society. Popper, Karl. 1968. The Logic of Scientific Discovery. New York, USA: Harper & Row. Powell, Daniel L., M. Garcia-Olazábel, M. Keegan, P. Reilly, K. Du, A.P. DíazLoyo, S. Banerjee et al. 2020. “Natural hybridization reveals incompatible alleles that cause melanoma in swordtail fish.” Science 368 (6492): 731-736. doi:10.116/science. aba5216. Price, Tabitha, D.L. Cheney, R.M. Seyfarth, K. Hammerschmidt, J. Fischer. 2015. “Vervets revisited: A quantitative analysis of alarm call structure and context specificity.” Scientific Reports 5: 13220. doi:10.1038/srep13220. Prud’homme, Benjamin, R. de Rosa, D. Arendt, J.-F. Julien, R. Pajaziti, A. W.C. Dorresteijn, A. Adoutte et al. 2003. “Arthropod-like expression patterns of engrailed and wingless in the annelid Platynereis dumerilii suggest a role in segment formation.” Current Biology 13: 1876-1881. doi:10.1016/j.cub.2003.10.006. Prüfer, Kay , K. Munch, I. Hellmann, K. Akagi, J.R. Miller, B. Walenz, S. Koren et al. 2012. “The bonobo genome compared with the chimpanzee and human genomes.” Nature 485 (7404): 527-531. doi:10.1038/nature11128. Prüfer, Kay, F. Racimo, N. Patterson, F. Jay, S. Sankararaman, S. Sawyer, A. Heinze et al. 2014. “The complete genome sequence of a Neandertal from the Altai Mountains.” Nature 505 (7481): 43-49. doi:10.1038/nature12886. Purzycki, Benjamin G., C. Apicella, Q.D. Atkinson, E. Cohen, R.A. McNamara, A.K. Willard, D. Xygalatas et al. 2016. “Moralistic gods, supernatural punishment and the expansion of human sociality.” Nature 530 (7590): 327330. doi:10.1038/nature16980. Quiring, Rebecca, U. Walldorf, U. Kloter, W.J. Gehring. 1994. “Homology of the eyeless gene of Drosophila to the Small eye gene in mice and Aniridia in humans.” Science 265 (5173): 785-789. doi:10.1126/science.7914031 . Rahbek, Carsten, M.K. Borregaard, R.K. Colwell, B. Dalsgaard, B.G. Holt, N. Morueta-Holme, D. Nogues-Bravo et al. 2019. “Humboldt's enigma: What causes global patterns of mountain biodiversity?.” Science 363 (6458): 11081113. doi:10.1126/science.aax0149. Ramberg, Peter J. 2000. “The death of vitalism and the birth of organic chemistry: Wohler's urea synthesis and the disciplinary identity of organic chemistry.” Ambix 47 (3): 170-195. doi:10.1179/amb.2000.47.3.170.

Redundant God? Christian Faith in the Light of Evolution

401

Raup, David M., and J. John Sepkowski. 1982. “Mass extinctions in the marine fossil record.” Science 215 (4539): 1501-1503. doi:10.1126/science.215.4539.1501. Redinbaugh, Michelle J., J.M. Phillips, N.A. Kambi, S. Mohanta, S. Andryk, G.L. Dooley, M. Afrasiabi et al. 2020. “Thalamus modulates consciousness via layer-specific control of cortex.” Neuron 106 (1): 66-75. doi: 10.1016/ j.neuron.2020.01.005. Remeseiro, Silvia, and Ann Losada. 2013. “Cohesin, a chromatin engagement ring.” Current Opinion in Cell Biology 25: 63-71. doi:10.1016/ j.ceb.2012.10.013. Retallack, Gregory J. 2013. “Ediacaran life on land.” Nature 493 (7430): 89-92. doi:10.1038/nature11777. Reznick, David A., H. Bryga, J.A. Endler. 1990. “Experimentally induced lifehistory evolution in a natural population.” Nature 346 (6282): 357-359. doi:10.1038/346357a0. Roberts, Neil. 2019. “How humans changed the face of the earth.” Science 365 (6456): 865-866. doi:10.1126/science.aay4627. Robinson, Gene E. 2004. “Beyond nature and nurture.” Science 304 (5669): 397399. doi:10.1126/science.1095766 . Rodríguez-Vidal, Joaquin, F. d’Errico, F.G. Pacheco, R. Blasco, J. Rosell, R.P. Jennings, A. Queffelec et al. 2014. “A rock engraving made by Neanderthals in Gibraltar.” PNAS (USA) 111 (37): 13301-13306. doi:10.1073/pnas.1411529111 . Rohr, Richard. 2019. The Universal Christ: How a Forgotten Reality can Change Everything we See, Hope for and Believe. London, UK: SPCK. Rolston III, Holmes. 2001. “Kenosis and nature.” In The Work of Love: Creation as Kenosis, edited by John Polkinghorne: 43-65. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. —. 2015. “Divine presence—causal, cybernetic, caring, cruciform: From information to incarnation.” In Incarnation: On the Scope and Depth of Christology, edited by Niels H. Gregersen: 255-287. Minneapolis, Minnesota, USA: Fortress Press. Ronan, Marisa. 2017. "American evangelicalism, apocalypticism, and the Anthropocene." In Religion in the Anthropocene, edited by Celia DeaneDrummond, S. Bergmann, M. Vogt: 218-231. Eugene, Oregon, USA: Cascade Books. Ruether, Rosemary Radford. 1993. God and Gaia: An Eco-Feminist Theology of Earth Healing. London, UK: SCM Press. Runnström, J. 1928. “Plasmabau und determination bei dem ei von Paracentrotus lividus, LK.” Wilhelm Roux' Archiv fur Entwicklungsmechanik der Organismen 113: 556-581. Russell, Robert J. 2009. “Divine action and quantum mechanics: A fresh assessment.” In Philosophy, Science and Divine Action, edited by F. LeRon Shults, N. Murphy, R.J. Russell: 351-403. Leiden, The Netherlands: Brill. Ryan, Joseph F., K. Pang, C.E. Schnitzler, A.-D. Nguyen, R.T. Moreland, D.K. Simmons, B.J. Koch et al. 2013. “The genome of the ctenophore Mnemiopsis

402

Bibliography

leidyi and its implications for cell type evolution.” Science 342: 1242592 (summary, p. 1336). doi:10.1126/science.1242592. Sacks, Jonathan. 2020. Morality: Restoring the Common Good in Divided Times. London, UK: Hodder & Stoughton. Sackton, Timothy B, P. Grayson, A. Cloutier, Z. Hu, J.S. Liu, N.E. Wheeler, P.P. Gardner et al. 2019. “Convergent regulatory evolution and loss of flight in paleognathous birds.” Science 364 (6435): 74-78. doi:10.1126/science.aat7244. Sanders, Alan R., E.R. Martin, G.W. Beecham, S. Guo, K. Dawood, G. Rieger, J.A. Badner et al. 2015. “Genome-wide scan demonstrates significant linkage for male sexual orientation.” Psychological Medicine 45 (7): 1379-1388. doi: 10.1017/S0033291714002451. Sandler, Ronald L. 2012. The Ethics of Species: An Introduction. Cambridge, UK: Cambridge University Press. Sankararaman, Sriram, S. Mallick, M. Dannemann, K. Prüfer, J. Kelso, S. Pääbo, N. Patterson, D. Reich. 2014. “The genomic landscape of Neanderthal ancestry in present-day humans.” Nature 507 (7492): 354-357. doi:10.1038/nature12961. Sansom, Robert S., S.E. Gabbott, M.A. Purnell. 2010. “Non-random decay of chordate characters causes bias in fossil interpretation.” Nature 463 (7282): 797-800. doi:10.1038/nature08745. Satoh, Noriyuki. 2019. “A deep dive into sea-squirt development". Nature 571 (7765): 333-334. doi: 10.1038/d41586-019-01967-0. Savic, Ivanka, H. Berglund, P. Lindström. 2005. “Brain response to putative pheromones in homosexual men.” PNAS (USA) 102 (20): 7356-7361. doi:10.1073/pnas.0407998102. Scally, Aylwyn, J.Y. Dutheil, L.W. Hillier, G.E. Jordan, I. Goodhead, J. Herrero, A. Hobolth et al. 2012. “Insights into hominid evolution from the gorilla genome sequence.” Nature 483 (7388) : 169–175. doi:10.1038/nature10842. Scharff, Constance, and Jana Petri. 2011. “Evo-devo, deep homology and FoxP2: implications for the evolution of speech and language.” Philosophical Transactions of the Royal Society of London, Series B (Biological Sciences) 366 (1574): 2124-2140. doi:10.1098/rstb.2010.0409. Scheele, Ben C., F. Pasmans, L.F. Skerratt, L. Berger, A. Martel, W. Beukema, A.A. Acevedo et al. 2019. “Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity.” Science 363 (6434): 1459-1463. doi: 10.1126/science.aav0379. Schenk, Craig. 1992. The Gospel of Thomas. Amazon Books, available online, courtesy of Paul Halsall; [email protected]. Schiffbauer, James D., T. Selly, S.M. Jacquet, R.A. Merz, L.L. Nelson, M.A. Strange, Y. Cai, E. Smith. 2020. “Discovery of bilaterial-type through-guts in cloudinomorphs from the terminal Ediacaran Period ” Nature Communications 11 (1): 205. doi:10.1038/s41467-019-13882-z. Schneider, John R. 2012. “The Fall of 'Augustinian Adam': Original fragility and supralapsarian purpose.” Zygon: Journal of Religion and Science 47 (4): 949969. doi:10.1111/j.1467-9744.2012.01307.x.

Redundant God? Christian Faith in the Light of Evolution

403

Schreiweis, Christiane, U. Bornschein, E. Burguière, C. Kerimoglu, S. Schreiter, M. Dannemann, S. Goyal et al. 2014. “Humanized Foxp2 accelerates learning by enhancing transitions from declarative to procedural performance.” PNAS (USA) 111 (39): 14253-14258. doi:10.1073/pnas.1414542111. Schroeder, Mark D., C. Greer, U. Gaul. 2011. “How to make stripes: Deciphering the transition from non-periodic to periodic patterns in Drosophila segmentation.” Development 138: 3067-3078. doi:10.1242/dev.062141. Schulze, Jens, and Einhard Schierenberg. 2009. “Embryogenesis of Romanomermis culicivorax: An alternative way to construct a nematode.” Developmental Biology 334 (1): 10-21. doi:10.1016/j.ydbio.2009.06.009. Schussler-Fiorenza, Elisabeth. 1983. In Memory of Her: A Feminist Theological Reconstruction of Christian Origins. New York, USA: Crossroad Publishing Company. Schwemer, Daniel. 2008. “The storm-gods of the ancient Near East: summary, synthesis, recent studies, part II.” Journal of Ancient Near Eastern Religions 8 (2): 1-44. Scott, Peter Manley. 2010. Anti-Human Theology: Nature, Technology and the Postnatural. London, UK: SCM Press. Scottish Episcopal Church. (1982/1996). Scottish Liturgy 1982 with Alternative Eucharistic Prayers. Edinburgh, UK: General Synod Office of the Scottish Episcopal Church. Scruton, Roger. 2014. The Soul of the World. Princeton, New Jersey, USA: Princeton University Press. Sczepanski, Jonathan T. and Gerald F. Joyce. 2014. “A cross-chiral RNA polymerase ribozyme.” Nature 515 (7527): 440-442. doi:10.1038/nature13900. Seaver, Elaine C., D.A. Paulson, S.Q Irvine, M.Q. Martindale. 2001. “The spatial and temporal expression of Ch-en, the engrailed gene in the polychaete Chaetopterus, does not support a role in body axis segmentation.” Developmental Biology 236 (1): 195-209. doi:10.1006/dbio.2001.0309. Seehausen, Ole, R.K. Butlin, I. Keller, C.E. Wagner, J.W. Boughman, P.A. Hohenlohe, C.L. Peichel et al. 2014. “Genomics and the origin of species.” Nature Reviews Genetics 15: 176-192. doi:10.1038/nrg3644. Seilacher, Adolf. 2007. "The nature of Vendobionts". In The Rise and Fall of the Ediacaran Biota, edited by Patricia Vickers-Rich and Patricia Komarower. London, UK: Geological Society Special Publications 286: 387-397. Service, Robert T. 2015. “Origin-of-life puzzle cracked.” Science 347 (6228): 1298. doi:10.1126/science.347.6228.1298. Shakespeare, Tom. 1998. “Choices and rights: Eugenics, genetics and disability equality.” Disability & Society 13 (5): 665-681. doi:10.1080/ 09687599826452. Shapiro, Michael D., M.E. Marks, C.L. Peichel, B.K. Blackman, K.S. Nereng, B. Jonsson, D. Schluter, D.M. Kingsley. 2004. “Genetic and developmental basis of evolutionary pelvic reduction in threespine sticklebacks.” Nature 428 (6984): 717-723. doi:10.1038/nature02415. Sheppard, David. 1983. Bias to the Poor. London, UK: Hodder & Stoughton Ltd.

404

Bibliography

Simpson, George G. 1944. Tempo and Mode in Evolution. New York, USA: Columbia University Press. —. 1960. “The remarkable testament of the Jesuit palaeontologist Pierre Teilhard de Chardin.” Scientific American 202 (4): 201-207. doi:jstor.org/stable/24940457. Slimak, Ludovic, J. Fietzke, J.-M. Geneste, R. Ontanon. 2018. “Comment on "UTh dating of carbonate crusts reveals Neandertal origin of Iberian cave art".” Science 361 (6408): eaau1371. doi:10.1126/science.aau1371. Smith, Mark. 2019. “The trans twins.” The Times Magazine, 2 February: 16-21. Sokal, Alan, and Jean Bricmont. 1998. Intellectual Impostures: Postmodern Philosophers' Abuse of Science. London, UK: Profile Books. Sokol, Joshua. 2019. “Fossils show large predator prowled Cambrian sediments.” Science 365 (6452): 417. doi:10.1126/science.365.6452.417. Southgate, Christopher. 2008. The Groaning of Creation: God, Evolution, and the Problem of Evil. Louisville, Kentucky, USA: Westminster John Knox Press. Splinter, Eric, H. Heath, J. Kooren, R.-J. Palstra, P. Klous, F. Grosveld, N. Galiart, W. de Laat. 2006. “CTCF mediates long-range chromatin looping and local histone modification in the ȕ-globin locus.” Genes & Development 20 (2): 2349-2354. doi:10.1101/gad.399506. Spufford, Francis. 2013. Unapologetic: Why, Despite Everything, Christianity Can Still Make Surprising Emotional Sense. London, UK: Faber & Faber. Srivastava, Mansi, O. Simakov, J. Chapman, B. Fahey, M.E.A. Gauthier, T. Mitros, G.S. Richards et al. 2010. “The Amphimedon queenslandica genome and the evolution of complexity.” Nature 466 (7307): 720-726. doi:10.1038/nature09201. Stadhouders, Ralph, G.J. Filion, T. Graf. 2019. “Transcription factors and 3D genome conformation in cell-fate decisions.” Nature 569 (7756): 345-354. doi:10.1038/s41586-019-118-7. Stannard, Russell. 2017. The Divine Imprint: Finding God in the Human Mind. London, UK: SPCK Publishing. Stark, Benjamin C., R. Kole, E.J. Bowman, S. Altman. 1978. “Ribonuclease P: an enzyme with an essential RNA component.” PNAS (USA) 75 (8): 3717-3721. doi:10.1073/pnas.75.8.3717. Steffen, Will, J. Rockström, K. Richardson, T.M. Lenton, C. Folkea, D. Liverman, C.P. Summerhayes et al. 2018. “Trajectories of the earth system in the Anthropocene.” PNAS (USA) 115 (33): 8252-8259. doi:10.1073/pnas.1810141115. Steinmair-Pösel, Petra. 2017. “Cooled down love and an overheated atmosphere; René Girard on ecology and apocalypticism in the Anthropocene.” In Religion in the Anthropocene, edited by Celia Deane-Drummond, S. Bergmann, M. Vogt: 202-217. Eugene, Oregon, USA: Cascade Books. Step, Edward. 1930. Woodland and Wayside Blossoms. London, UK: Frederick Warne. Stern, Nicholas. 2007. The Economics of Climate Change: The Stern Review. Cambridge, UK: Cambridge University Press.

Redundant God? Christian Faith in the Light of Evolution

405

Sulej, Tomasz, and Grzegorz 1LHGĨZLHG]VNL 2018. “An elephant-sized late Triassic synapsid with erect limbs”. Science 363 (6422): 78-80. doi:10.1126/science.aab4853. Sulston, John E., E. Schierenberg, J.G. White, J.N. Thomson. 1983. “The embryonic cell lineage of the nematode Caenorhabditis elegans.” Developmental Biology 100: 64-119. doi:1016/0012-1606(83)90201-4. Tarchini, Basile, and Denis Duboule. 2006. “Control of Hoxd genes' collinearity during early limb development.” Developmental Cell 10 (1): 93-103. doi:10.1016/j.devcel.2005.11.014. Taylor, Joan E. 2014. “Missing Magdala and the name of Mary 'Magdalene'.” Palestine Exploration Quarterly 146 (3): 205-223. doi:10.1179/0031032814Z.000000000110. Tedersoo, Leho, M. Bahram, M. Zobel. 2020. “'How mycorrhizal associations drive plant populations and community biology.” Science 367 (6480): eaba1223. doi:10.1126/science.aba1223. Teilhard de Chardin, Pierre. 1955/1959. The Phenomenon of Man, translated by Bernard Wall. London, UK: Collins. —. 1955/1999/2003. The Human Phenomenon, translated by Sarah AppletonWeber. Brighton, UK: Sussex Academic Press. —. 1957/1960. Le Milieu Divin: An Essay on the Interior Life, various translators, edited by Bernard Wall. London, UK: Collins. —. 1961/1965. Hymn of the Universe, translated by Gerald Vann. London, UK: Collins. —. 1965/1968. Writings in Time of War, translated by René Hague. New York, USA: Harper & Row. —. 1969/1971. Christianity and Evolution, translated by René Hague. London, UK: Collins. —. 1976/1978. The Heart of Matter, translated by René Hague. London, UK: Collins. Tenaillon, Olivier, J.E. Barrick, N. Ribeck, D.E. Deatherage, J.L. Blanchard, A. Dasgupta, G.C. Wu et al. 2016. “Tempo and mode of genome evolution in a 50,000 generation experiment.” Nature 536 (7615): 165-170. doi:10.1038/nature18959. Thackeray, J. Francis. 2012. “Deceiver, joker or innocent? Teilhard de Chardin and Piltdown Man.” Antiquity 86 (331): 228-234. doi:10.1017/S0003598X0006258X. Thiselton, Anthony C. 2009. Hermeneutics: An Introduction. Grand Rapids, Michigan, USA: Wm. B. Eerdmans Publishing Co. Thomas, Chris D. 2017. Inheritors of the Earth: How Nature is Thriving in an Age of Extinction. London, UK: Allen Lane . Thornton, Alex, and Katherine McAuliffe. 2006. “Teaching in wild Meerkats.” Science 313 (5784): 227-229. doi:10.1126/science.1128727. Throckmorton Jr., Burton H. 1992. Gospel Parallels: A Comparison of the Synoptic Gospels. 5th edition. Nashville, Tennessee, USA: Thomas Nelson, Inc.

406

Bibliography

Tian, Li, S.R. Rahman, B.D. Ezray, L. Franzini, J.P. Strange, P. Lhomme, H.M. Hines. 2019. "A homeotic shift late in development drives mimetic colour variation in a bumble bee." PNAS (USA) 116 (24): 11857-11865. doi: 10.1073/pnas.1900365116. Tipler, Frank J. 1994. The Physics of Immortality: Modern Cosmology, God and the Resurrection of the Dead. New York, USA: Doubleday. Tolkein, John R.R. 1977. The Silmarillion, edited by Christopher Tolkein. London, UK: George Allen & Unwin Ltd. Tollefsen, Torstein T. 2015. "Saint Maximus the Confessor on creation and incarnation". In Incarnation: On the Scope and Depth of Christology, edited by Niels H. Gregersen: 99-115. Minneapolis, Minnesota, USA: Fortress Press. Tollefson, Jeff. 2020. “How the coronavirus pandemic slashed carbon emissions— in five graphs.” Nature 582 (7811): 158-159. doi:10.1038/d41586-020-01497-0. Tomarev, Stanislav I., P. Callaerts, L. Kos, R. Zinovieva, G. Halder, W. Gehring, J. Piatigorsky. 1997. “Squid Pax-6 and H\HௗGHYHORSPHQW´ PNAS (USA) 94 (6): 2421-2426. doi:10.1073/pnas.94.6.2421. Tomás-Roca, Laura, R. Corral-San-Miguel, P. Aroca, L. Puelles, F. Marín. 2014. “Crypto-rhombomeres of the mouse medulla oblongata, defined by molecular and morphological features.” Brain Structure and Function 221 (2): 815-838. doi:10.1007/s00429-014-0938-y. Toner, Jonathan D., and David C. Catling. 2020. “A carbonate-rich lake solution to the phosphate problem of the origin of life.” PNAS (USA) 117 (2): 877-882. doi:10.1073/pnas.1916109117. Turner, Will R., B.A. Bradley, L.D. Estes, D.G. Hole, M. Oppenheimer, D.S. Wilcove. 2010. “Climate change: helping nature survive the human response.” Conservation Letters 3 (5): 304-312. doi:10.1111/j.1755-263X.2010.00128.x. Usinowicz, Jacob, C.H. Chang-Yang, Y.-Y. Chen, J.S. Clark, C. Fletcher, N. Garwood, Z. Hao et al. 2017. “Temporal coexistence mechanisms contribute to the latitudinal gradient in forest diversity.” Nature 550 (7974): 105-108. doi:10.1038/ nature24038. Ussher, James. 1650, republished 2003 in modern English. Annals of the World: James Ussher's Classic Survey of World History, edited by Larry Pierce and Marion Pierce. Green Forest, Arizona, USA: Master Books. Vais, Horia, S. Atkinson, N. Eldursi, A.L. Devonshire, M.S. Williamson, P.N.R. Usherwood. 2000. “A single amino acid change makes a rat neuronal sodium channel highly sensitive to pyrethroid insecticides.” FEBS Letters 470: 135138. doi:10.1016/S0014-5793(00)01305-3. van den Bergh, Gerrit D, Y. Kaifu, I. Kurniawan, R.T. Kono, A. Brumm, E. Setiyabudi, F. Aziz, M.J. Morwood. 2016. “Homo floresiensis-like fossils from the early Middle Pleistocene of Flores.” Nature 534 (7606): 245-248. doi:10.1038/nature17999. Van Wolde, Ellen. 2009. “Why the verb ʠʸy (bara) does not mean 'to create' in Genesis 1.1-2.4a.” Journal for the Study of the Old Testament 43 (3): 3-23. doi: 10.1177/ 0309089209348155.

Redundant God? Christian Faith in the Light of Evolution

407

Vanhoozer, Kevin J. 1998. “Effectual call or causal effect? Summons, sovreignty and supervenient grace.” Tyndale Bulletin 49 (2): 213-251. Vanstone, William H. 1977. Love's Endeavour, Love's Expense: The Response of Being to the Love of God. London, UK: Darton, Longman and Todd Ltd. —. 1982. The Stature of Waiting. London, UK: Darton, Longman and Todd Ltd. Vargha-Khadem, Faraneh, D.G. Gadian, A. Copp, M. Mishkin. 2005. “FOXP2 and the neuroanatomy of speech and language.” Nature Reviews Neuroscience 6 (2): 131-138. doi:10.1038/nrn1605. Varki, Ajit, and Tasha K. Altheide. 2005. “Comparing the human and chimpanzee genomes: Searching for needles in a haystack.” Genome Research 15: 17461758. doi:10.1101/gr.3737405. Vellutini, Bruno C., and Andreas Hejnol. 2016. “Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians.” Scientific Reports 6: 32387. doi:10.1038/srep32387. Venter, J. Craig, M.D. Adams, E.W. Myers, P.W. Li, R.J. Mural, G.G. Sutton, H.O. Smith et al. 2001. “The sequence of the human genome.” Science 291 (5507): 1304-1351. doi:10.1126/science.1058040. Verzijden, Machteld. 2019. “Frog mothers' powerful influence.” Nature 574 (7776): 38-39. doi:10.1038/d41586-019-02904-x. von Dittersdorf, Carl Ditters. 1781, score republished 1899. “Der Sturz Phaetons", 2nd Sinfonia in D after Ovid's Metamorphoses, Kr 74. Leipzig, Germany: Josef Liebeskind. von Rad, Gerhard. 1957, English translation 1975. Old Testament Theology: The Theology of Israel's Historical Traditions, translated by D.M.G. Stalker. Vol. I of 2 vols. London, UK: SCM Press. Wagner, Günter P., M. Pavlicev, J.M. Cheverud. 2007. “The road to modularity.” Nature Reviews Genetics 8: 921-931. doi:10.1038/nrg2267. Wallace-Wells, David. 2019. The Uninhabitable Earth: A Story of the Future. London, UK: Allen Lane. Wang, Guo-Dong, W. Zhai, H.-C. Yang, L. Wang, L. Zhong, Y.-H. Liu,, R.-X. Fan et al. 2015. “Out of southern East Asia: the natural history of domestic dogs across the world.” Cell Research 26: 21-33. doi:10.1038/cr.2015.147. Wang, Min, J.K. O'Connor, X. Xu, Z. Zhou. 2019. “A new Jurassic scansoriopterygid and the loss of membranous wings in theropod dinosaurs.” Nature 569 (7755): 256-259. doi:10.1038/s41586-019-1137-z. Watson, James D. and Francis Crick. 1953. “Molecular structure of nucleic acids: A structure for deoxyribose nucleic acid.” Nature 171 (4356): 737-738. doi. 10.1038/171737a0. Watts, Joseph, O. Sheehan, Q.D. Atkinson, J. Bulbulia, R. D. Gray. 2016. “Ritual human sacrifice promoted and sustained the evolution of stratified societies.” Nature 532 (7598): 228-231. doi:10.1038/nature17159. Weintraub, Abraham S., C.H. Li, A.V. Zamudio, A. A. Sigova, N.M. Hannett, D. S. Day, B.J. Abraham et al. 2017. “YY1 Is a structural regulator of enhancerpromoter loops.” Cell 171 (7): 1573-1588. doi:10.1016/j.cell.2017.11.008. Westermann, Claus. 1987. Genesis: A Practical Commentary. Grand Rapids, Michigan, USA: Eerdman's Publishing.

408

Bibliography

Wharton, Robin P., and Gary Struhl. 1991. “RNA regulatory elements mediate control of Drosophila body pattern by the posterior morphogen nanos.” Cell 67 (5): 955-967. doi:10.1016/0092-8674(91)90368-9. White, Lynn. 1967. “The historical roots of our ecologic crisis.” Science 155 (3767): 1203-1207. doi:10.1126/science.155.3767.1203. White, Rosalind V., and Andrew D. Saunders. 2005. “Volcanism, impact and mass extinctions: incredible or credible coincidences?” Lithos 79: 299-316. doi:10.1016/ j.lithos.2004.09.016. Whitehouse, Harvey, P. Francois, P.E. Savage, T.E. Currie, K.C. Feeney, E. Cionin, R. Purcell et al. 2019. “Complex societies precede moralizing gods throughout world history.” Nature 568 (7751): 226-229. doi:10.1038/s41586-019-1043-4. Williams, Rowan. 2014. Being a Christian. London, UK: SPCK. Williams, Thomas A., P.G. Foster, C.J. Cox, T.M. Embley. 2013. “An archaeal origin of eukaryotes supports only two primary domains of life.” Nature 504 (7479): 231-236. doi:10.1038/nature12779. Williams, A. Park, E.R. Cook, J.E. Smerdon, B.I. Cook, J.T. Abatzoglu, K. Bolles, S.H. Baek et al. 2020. “Large contribution from anthropogenic waming to an emerging North American superdrought.” Science 368 (6488): 314-318. doi:10.1126/science.aaz9600. Wilson, Edmund B. 1904a. “Experimental studies in germinal localization: I The germ-regions in the egg of Dentalium.” Journal of Experimental Zoology 1: 172. —. 1904b. “Experimental studies in germinal localization: II Experiments on the cleavage-mosaic in Patella and Dentalium.” Journal of Experimental Zoology 1: 197-268. Wilson, Edward O. 1984. Biophilia: The Human Bond with Other Species. Cambridge, Massachusetts, USA: Harvard University Press. —. 2016. Half-Earth: Our Planet's Fight for Life. New York, USA: Liveright Publishing Corporation (W.W. Norton & Company Ltd.). Woese, Carl R. and George E. Fox. 1977. “Phylogenetic structure of the prokaryotic domain: The primary kingdoms.” PNAS (USA) 74 (11): 50885090. doi:10.1073/pnas.74.11.5088. Wohlgemuth, Sandra, I. Adam, C. Scharff. 2014. “FoxP2 in songbirds.” Current Opinion in Neurobiology 28: 86-93. doi:10.1016/j.conb.2014.06.009. Woloschak, Gayle E. 2008. “Chance and necessity in Arthur Peacocke's scientific work.” Zygon: Journal of Religion and Science 43 (1): 75-87. doi:10.1111/j.1467-9744.2008.00900.x. Wolpert, Lewis. 1969. “Positional information and the spatial pattern of cellular differentiation.” Journal of Theoretical Biology 25: 1-47. Wolpert, Lewis, and Jonathan M.W. Slack. 1986. From Egg to Embryo: Determinative Events in Early Development. Cambridge, UK: Cambridge University Press. Wood, Rachel A. 2019. “The rise of animals.” Scientific American 320 (6): 19-25. Wood, Rachel A., A.G. Liu, F. Bowyer, P.R. Wilby, F.S. Dunn, C.G. Kenchington, J.F. Hoyal-Cuthill et al. 2019. “Integrated records of environmental change

Redundant God? Christian Faith in the Light of Evolution

409

and evolution challenge the Cambrian Explosion.” Nature Ecology and Evolution 3: 528-538. doi:10.1038/s41559-019-0821-6. Wright, Nicholas T. 1986. “ਖȡʌĮȖȝȩȢ and the meaning of Philippians 2:5-11.” Journal of Theological Studies 37 (2): 321-352. Wright, Tom. 2012. How God Became King: Getting to the Heart of the Gospels. London, UK: SPCK. Wright, Tom. 2018. Paul: A Biography. London, UK: SPCK. Wroe, Stephen, U. Chamoli, W.C.H. Parr, P. Clausen, R. Ridgely, L. Witmer. 2013. “Comparative biomechanical modeling of metatherian and placental Saber-Tooths: A different kind of bite for an extreme pouched predator.” PLoS ONE 8: e66888. doi:10.1371/journal.pone.0066888. Xie, Kathleen T., G. Wang, A.C. Thompson, J.I. Wucherpfennig, T.E. Reimechen, A.D.C. MacColl, D. Schluter et al. 2019. “DNA fragility in the parallel evolution of pelvic reduction in stickleback fish.” Science 363 (6422): 81-84. doi:10.1126/science.aan1425. Xu, Yangyang, V. Ramanathan, D.G. Victor. 2018. “Global warming will happen faster than we think.” Nature 363 (7734): 30-32. doi:10.1038/d41586-018-07586-5. Xu, Jianfeng, V. Chmela, N.J. Green, D.A. Russell, M.J. Janicki, R.W. Góra, R. Szabla et al. 2020. “Selective prebiotic formation of RNA pyrimidine and DNA purine nucleosides.” Nature 582 (7810): 60-62. doi:10.1038/s41586-020-2330-9. Yancey, Philip D. 1997. What's So Amazing About Grace? Grand Rapids, Michigan, USA: Zondervan. Yang, Yusan, M.R. Servedio, C.L. Richards-Zawaki. 2019. “Imprinting sets the stage for speciation.” Nature 574 (7776): 99-103. doi:10.1038/s41586-019-1599-z. Yarus, Michael, J.J. Widmann, R. Knight. 2009. “RNA–amino acid binding: A stereochemical era for the genetic code.” Journal of Molecular Evolution 69: 406-429. doi:10.1007/s00239-009-9270-1. Youle, Richard J. 2019. “Mitochondria–striking a balance between host and endosymbiont.” Science 365 (6454): 655. doi:10.1126/science.aaw9855. Zakany, Jozsef, and Denis Duboule. 2007. “The role of HOX genes during vertebrate limb development.” Current Opinion in Genetics and Development 17 (4): 356-366. doi:10.1016/j.gde.2007.05.011. Zalasiewicz, Jan, M. Williams, A. Haywood,, M. Ellis. 2011. “Introduction: The Anthropocene: a new epoch of geological time?” Philosophical Transactions of the Royal Society, Series A (Mathematical, Physical and Engineering Sciences) 369: 835-841. doi:10.1098/rsta.2010.0339. Zaug, Arthur J., and Thomas R. Cech. 1986. “The intervening sequence RNA of Tetrahymena is an enzyme.” Science 231 (4737): 470-475. doi:10.1126/science. 3941911. Zhabotinsky, Anatol M. 2007. “Belousov-Zhabotinsky reaction.” Scholarpedia 2 (9): 1435. doi:10.4249/scholarpedia.1435. Zhang, Yinhua, and Scott W. Emmons. 1995. “Specification of sense-organ identity by a C. elegans Pax-6 homologue,.” Nature 377 (6544): 55-59.

410

Bibliography

doi:10.1038/377055a0 Zhao, Boxuan Simen, X. Wang, A.V. Beadell, Z. Lu, H. Shi, A. Kuuspalu, R.K. Ho, C. He. 2017. “m6A-dependent maternal mRNA clearance facilitates zebrafish maternal-to-zygotic transition.” Nature 542 (7574): 475-478. doi:10.1038/nature21355. Zhu, Fang, L. Lavine, S. O’Neal, M. Lavine, C. Foss, D. Walsh. 2016. “Insecticide resistance and management strategies in urban ecosystems.” Insects 7 (1): 2. doi:10.3390/insects7010002 . Zhu, Mao-yan, A.Y. Zhuravlev, R.A. Wood, S.S. Sukhov. 2017. “A deep root for the Cambrian explosion: implications of new bio- and chemistratigraphy from the Siberian Platform.” Geology 45 (5): 459-462. doi:10.1130/G38865.1. Zipkin, Elise F., G.V. DiRenzo, J.M. Ray, S. Rossman, K.R. Lips. 2020. “Tropical snake diversity collapses after widespread amphibian loss.” Science 367 (6479): 814-816. doi:10.1126/ science.aay5733. Zizioulas, John D. 1985. Being as Communion: Studies in Personhood and the Church. London, UK: Darton, Longman and Todd Ltd.

LIST OF BIBLICAL QUOTATIONS

Scripture quotations are from the New Revised Standard Version Bible, copyright © 1989 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.

Old Testament Proverbs 8:29-31

Genesis Genesis 1:26 Genesis 1:27 Genesis 1:28 Genesis 5:3 Genesis 9:2 Genesis 9:6b-11

220, 301 301 220 221 356 356

Exodus Exodus 20:5 Exodus 23:11

345 358

Leviticus Leviticus 26:33-35

358-359

Psalms Psalm 8:2 Psalm 22:1 Psalm 29:1-11 Psalm 34:8 Psalm 90:4 Psalm 139:11-12

323 279 187 166 264 333

Ecclesiastes Ecclesiastes 3:1-2

xvi

Isaiah Isaiah 22:12-14 Isaiah 45:6c-7 Isaiah 45:9 Isaiah 45:13 Isaiah 45:23 Isaiah 55:11

364 316 316 316 263 263

Ezekiel Ezekiel 34:16 Ezekiel 34:17 Ezekiel 34:20-22 Ezekiel 36:26

315 315 315 298

Daniel Daniel 5:26-27

362

Sirach (Ecclesiasticus)

Proverbs Proverbs 8:23

229

Sirach 24:3 229

212

412

List of Biblical Quotations

New Testament Matthew Matthew 5:3 Matthew 6:5 Matthew 6:12 Matthew 6:19 Matthew 6:24 Matthew 16:16 Matthew 19:26 Matthew 23:23 Matthew 26:52 Matthew 27:34 Matthew 28:19

276 314 277 320 346 195 170 331 193 266 286

Mark Mark 1:1 Mark 1:11 Mark 1:15 Mark 3:23 Mark 4:3-9 Mark 6:3 Mark 7:26-30 Mark 9:24 Mark 9:34-37 Mark 10:13-16 Mark 10:25 Mark 10:42-45 Mark 12;10-11 Mark 14:3b Mark 14:8-9 Mark 14:22-24 Mark 16:6-7 Mark 16:8

266 286 266, 320 192 321 222 322 281 322 322 350-351 324 326 327 327 328 330 330

John 1:1-5 John 1:12-13 John 3:16 John 6:68-69 John 8:32b John 8:41 John 8:44 John 10:10 John 10:30 John 11:16 John 11:35 John 13:13-14 John 13:34 John 14:5 John 14:6 John 14:9b John 14:11 John 15:9 John 15:12-13 John 18:36 John 18:37 John 19:15 John 19:22 John 20:25 John 20:29

229 222 281 328 303 222 192 xvi, 309, 323 273 194 344 277-278 281 194 194 273 273 281 281 278 278 279 279 194 194-195

Romans Romans 6:23 Romans 8:19 Romans 8:21

215 245 309

1 Corinthians

Luke Luke 4:21 Luke 6:24 Luke 9:58 Luke 11:5-8 Luke 12:6-7 Luke 12:27 Luke 12:27-28 Luke 17:19 Luke 23:34 Luke 24:32

John

275 314 361 362 318 Epigraph 319 363 231 254

1 Corinthians 1:3 272 1 Corinthians 1:25 276 1 Corinthians 13:4-8 282 1 Corinthians 13:13 286 1 Corinthians 15:17 202 1 Corinthians 15:19 202 1 Corinthians 15:22 215, 303 1 Corinthians 15:28 206, 300-301 1 Corinthians 15:44 270

Redundant God? Christian Faith in the Light of Evolution

2 Corinthians 2 Corinthians 1:2 2 Corinthians 13:14

1 Timothy 272 287

Galatians Galatians 1:3 Galatians 3:27-28 Galatians 3:28 Galatians 4:4 Galatians 4:5

272 290-291 197, 311 222 287

Ephesians Ephesians 1:9-10

303

Philippians Philippians 2:5-8

272

Colossians Colossians 1:19-20

413

303

1 Timothy 1:15 1 Timothy 2:3-4

256 303

Hebrews Hebrews 13:14 Hebrews 8:12

361 306

1 Peter 1 Peter 2:9

294

1 John 1 John 3:16 1 John 4:7-12 1 John 4:10

281 281-282 284

INDEX

Abba, 269, 287 abdomen, 40, 107, 116, 330 Abraham, 168, 217, 286, 300 activation domain, 18, 95 Adam, 201, 215-217, 221, 303, 320 Adam and Eve, 203, 215-216, 221, 319, 361 adaptability, 190, 317, 319 adaptation, 4, 37-38, 45-46, 49, 53, 56, 60, 75, 80, 86, 88, 91, 207, 305, 321, 325, 327, 363, 366 adaptive change, 50-51, 54, 61, 132, 339 adaptive radiation, 37-39, 46-47, 73, 75-77, 89, 293, 330, 367 adoptionism, 240, 268 adultery, 192, 277, 280 Advocate. See Holy Spirit aeon, 218, 298 affection, 194, 282, 296 affordance, 151, 161, 170 Africa, 46-47, 133-136, 142, 148, 156, 160, 201, 204, 216, 359 afterlife, 167, 251, 276 agency, 56, 155, 234, 305 aggression, 54, 152, 193 agriculture, 27, 56, 85, 155-157, 161, 167, 215, 226, 321, 335, 346, 347, 352-354, 359 agriculture, intensive, 29, 79, 359 algae, 7, 9, 41, 44, 60, 63, 80, 85, 129, 325 allegory, 255, 286, 311 allele, 23-24, 29, 49 dominant wild-type, 24, 98, 136 mutant, 23-24, 27, 161, 223 recessive mutant, 24, 98, 136 risk-factor, 137 variant, 135, 137, 161, 299 alternative splicing, 17, 95, 163, 207

altitude, 39, 60, 84, 353 altruism, 166, 193, 220, 259, 315, 325 amber, 73, 129, 328 America, 37, 51, 80, 156, 158, 359, 362 America, North, 52, 144, 165, 186, 202, 233 America, South, 77, 84-85, 276 amino acid, 10-12, 15, 23, 26-32, 150-151 ammonite, 73, 77, 88 amphibian, 41, 47, 71, 85, 222 anathema, 217, 287, 328 ancestor, 48, 58, 65-68, 70-71, 73, 75, 77, 89, 122-123, 130, 133, 156, 165-166, 170, 182, 203, 215-216, 300, 326, 354, 360-362 ancestry, 37, 44, 143-144, 170 androgen, 147, 223 angel, 222, 240, 257, 267-269, 286, 297, 320, 330, 339 Anglican, xiii, xx, 166, 202, 214, 244, 289, 294, 335, 355 animal development, 19, 33, 60, 9396, 308, 321, 338 animal, social, 54, 152, 155, 161, 194, 316, 324 annelid, 40, 65, 68, 70, 104, 108109, 117, 121-123, 125 anointed, 278, 280, 327 ant, 40, 85 Antarctica, 84, 294, 321, 347 antelope, 53, 84, 164, 259, 309 antenna, 115, 125, 147 Antennapedia complex (ANT-C), 115, 117 anterior-posterior axis, 96, 104, 106, 108-110, 116, 122, 124-125 Anthropocene, 235, 351

Redundant God? Christian Faith in the Light of Evolution anthropocentrism, xviii, 213-214, 231, 245, 255, 295-296, 307 anthropogenic (causation), xx, 79, 289, 292, 297, 346, 364 anthropomorphism, 153, 299, 333 apocalypse, 195, 254, 272, 296, 298, 344, 346 apocalyptic, 296, 345-346, 351, 353 apostle, 195, 198, 241, 269, 271, 273, 308 appendage, 63, 65, 67, 70, 125, 129 Aquinas, Thomas, 4, 195, 230, 232, 258, 260 Aramaic, 272, 279, 298 Archaea, 17, 30, 41, 44, 91, 326 Archaeopteryx, xiv, 73, 86 arms race, 53-54, 56, 67 arthropod, 40, 65, 67, 70, 73-74, 8182, 96, 105, 108, 114-117, 123125 artist, 134, 219, 257, 258, 337 ascension, 231, 261, 269, 273, 308 ascidean, 100-102, 119 Asia, 51, 156, 160 asymmetry, 99, 107, 119, 125 atheism, xv, xvii, 165, 191, 202, 245, 249, 252, 307, 312, 326, 337, 344, 364-365 atmosphere, 30, 60-61, 63, 66, 73, 78, 289, 350-352, 356, 366 atonement, 215, 222, 231, 281, 283 atrocity, 169, 191, 255 Attenborough, Sir David, 39, 61, 348 attractant, 147, 359 Augustine of Hippo, 201, 215-216, 222, 241, 247, 302 Australasia, 51-52, 362 Australia, 2, 53, 63-64, 83-84, 363 authority, 197, 204, 275, 360 authorship, 253, 254, 255 autonomy, 169, 227, 256, 367 autosome, 27, 150 Ayala, Francisco, 202, 249, 253 Ba’al, 188-189

415

Babylon, 159, 167, 189, 316, 327, 344, 354 Bach, Johann Sebastian, 172-173, 256, 338 bacteria, 6, 9, 15-19, 29, 41, 44, 56, 65, 84, 89, 91, 93, 162, 253, 289, 326, 339 banquet, 290-291, 298, 306 baptism, 290, 294 of Jesus, 266, 268, 277, 286, 320 barrier, geographical, 78 reproductive, 48-50, 59, 75 social, 197, 281, 291 basalt flood, 78, 327 base pair, 9, 17-19, 21, 23, 26, 95, 132 bat, 85-86, 91, 104, 333, 366 bee, 40, 116, 152, 194, 330 beetle, 28, 38, 40, 112, 323 behaviour, 32, 48, 137, 140, 146, 153, 155, 165, 167, 217, 220, 237, 277, 315-316 imitative, 151, 153-154 reproductive, 53-54 belief, 63, 163, 190, 195, 278, 357, 365 religious, xvii, 164-166, 189, 235, 252, 271, 284 believer, religious, xiv, 149, 164, 166, 200-201, 211, 213, 253, 257, 259-261, 277, 283, 285, 291, 300, 312, 361 beneficence, xiv, 45, 300 benefit, evolutionary, 154, 165, 325, 339 benevolence, 252, 259 benthic, 48, 50, 64 Berry, R.J. (Sam), xx, 177, 202, 214-224, 240, 248, 254-255, 264, 311, 317 betrayal, 177, 278, 329, 349 biblical account, 80, 183, 198, 200 biblical faith, 210, 287 biblical literalism, 183, 190, 200201, 215-218, 221, 224, 240, 248, 252, 255, 311, 345-348

416 biblical text, xix, xx, 187, 201, 214, 217, 248, 254-255, 301-302, 311-315, 332-333 big business, 295, 351 bilaterian, 65, 68, 70, 81, 83 91, 106, 112, 117, 122, 123-125, 127-129 binding affinity, 16, 84, 95 biodiversity, 36-39, 44-47, 52, 73 77, 129-130, 182, 200, 233, 247, 259, 294, 297, 304, 307, 317, 325, 343, 360, 363 biodiversity loss, 293, 344, 350, 359, 364 biomarker, 63, 65, 70 biosphere, 60, 79, 198, 200, 206, 212, 217, 221, 235, 245-247, 251, 289, 295, 297, 299, 304, 336, 342, 352, 355, 358 biota, 63, 65-67, 76, 227 biotechnology, 226, 227, 248, 292 bipedality, 86, 132-133 birdsong, 152, 232 bishop, 294, 302, 324 Bithorax complex (BX-C), 107, 115-117 blame, xvi, 169, 201, 258, 295, 297, 345-347, 351 blastocyst, 99, 102 blastoderm, 99, 102, 112 cellular, 109-110, 112 syncytial, 109-110, 112 blastodisc, 99, 102 blastomere, 99, 101 blastopore, 68, 103-104 blastula, 68, 99, 102-103 blessing, 221, 244, 263, 286, 295, 302, 322-323, 328, 346, 363 blindness, 27, 275, 276, 280, 297, 302, 326, 333 blood, 9, 73, 136, 328-329 blood of Christ, 244, 328, 329 BMP4, 97, 124 Body of Christ, 211, 213, 291 body plan, 40-41, 64, 67 70, 73, 104, 122 bolide impact, 77-78, 327

Index boundary, 18, 50, 123, 346, 354 expression, 116, 120, 124 geological, 66, 78 metamere, 108, 111, 120 brachiopod, 68, 70, 73, 104, 122 brain, 33, 60, 81-82, 84, 86, 104, 125, 140, 145-150, 152-153, 166, 168, 170-173, 177, 237, 239, 285 growth, 132 left, 147, 162, 312 right, 147, 162, 312 size, 132-133, 161 brain cortex, 132, 147, 168 brain development, 145, 150 brain lesion, 147-148 brain region, 82, 140, 146-148, 152, 168 brain volume. See brain, size bread, 58, 212-213, 244, 265, 269, 328, 362 Britain, xvi, 49, 51-52, 58, 142, 193, 197, 330 Broca’s area, 147, 150 Bronze Age, 158, 161 Buddhism, 191, 245, 312, 364 burial, 67, 157, 190, 327, 329 Burren, 157, 233-234 butterfly, 27, 40, 252, 320 Caenorhabditis nematode, 16, 42, 105, 114, 119, 123 Caesar. See Roman emperor calling, 169, 177, 290, 294, 296, 304, 319, 323-324, 361, 365 Calvin, John, 261, 284 Cambrian, 65-67, 70-73, 75-76, 79, 118, 123, 130, 201, 264 Cambrian explosion, 66-67, 255 camouflage, 55, 88, 152, 330 Canaan, 188-189, 313, 348, 354 cancer, 22, 137 capitalism, 186, 351 Cappadocian Fathers, 223, 287, 301 carbon dioxide, 9, 60, 63, 66, 78, 345, 350, 352, 366 carbon emissions, 294, 346, 349, 352, 363, 366

Redundant God? Christian Faith in the Light of Evolution carbon footprint, 295, 336, 350, 355, 364 Carboniferous, 71, 73, 352 care for creation, 255, 318-319, 355 carnivore, 53, 304 carpel, 9, 104, 127-128 catalysis, 10, 12, 31, 181 catalyst, 11, 230, 238 catastrophe, xvi, 27, 60, 73, 218, 293, 325, 343-347, 351-353, 361, 365 catastrophism, 44, 76, 80 Catholic, xx, 166, 189-190, 195, 197, 202-204, 210, 213, 216, 230, 247-248, 294, 300, 306, 311, 349, 355 cattle, 156, 189, 220, 233, 350 causal joint, 285, 286, 317 causation, bottom-up, 231, 242, 285 top-down, 232, 239, 242, 249, 285 cave art, 134, 156, 159 cell, xiii, 6, 31, 33, 96, 99, 145, 237, 290, 292 eukaryotic, 7-8, 21, 30, 44, 209, 326 germ-line, 8, 22, 103 movement, 101, 104 prokaryotic, 6, 8 somatic, 8, 22, 27 wall, 6-7, 109-110 cell culture, 44, 89-90, 123 cell division, 22, 29, 98-99, 105, 109 cell fate, 99, 338 cell type, 9, 90, 128 centipede, 40, 116 central nervous system, 124, 145 centurion, 266, 280-281 cephalopod, 41, 73, 77, 80-82, 152 Chalcedonian definition, 211, 274 Chalke, Steve, 266, 284-285, 297298, 300, 332 chance, 31, 60, 88, 91, 235, 299, 347, 365 change of heart, 298, 354

417

chaos, 179, 189, 238, 247, 249, 300 cheetah, 53, 305, 309 chelicerate, 40, 71, 105, 117 chemistry, 31, 178-181, 203, 235, 238, 285 chicken, 90, 95, 105, 121, 146, 156 children, 1, 156-157, 16396, 222, 268, 281, 299, 314, 322-323, 337 344-345, 362 children of God, 222, 245, 284, 309, 337 chimpanzee, 132, 151, 153 China, 67-68, 156, 158, 160, 195, 204, 215, 337, 350 chiton, 117, 123 chloroplast, 8, 9, 15, 325 chordate, 41, 68, 70, 73, 97, 117, 119, 123-125, 300 cephalochordate, 71, 119, 120, 123-126 urochordate, 70, 100, 119 Christian belief, xvii, 149, 169, 177, 183, 184, 190, 209, 213-221, 241-42, 248-249, 260, 266, 273, 337 Christian community, 282, 358 Christian faith, xiii, xix, 6, 166, 200, 210-212, 215, 222, 242-248, 251, 266, 271, 282, 291, 299-300, 336, 353 Christian tradition, xvii, 195, 200, 215-216, 219, 231, 236, 240-241, 244, 269, 270-274, 288, 298, 300, 302, 316, 355, 361, 364 Christianity, 149, 166, 168, 189192, 197, 210, 215-216, 243-245, 249-252, 266, 271, 274, 287, 289, 300, 311, 317, 337, 348, 357, 364 Christology, 208, 231-232, 272 chromatin, 19, 94, 98 chromatin architecture, 19, 21, 95 chromosome, 7-8, 19, 22, 26-27, 41, 58-59, 107, 115 W, 27, 54, 223 X, 27, 139, 142, 222-223 Y, 27, 133, 142-143, 222-223

418 chromosome duplication, 7, 22, 97 church, 52, 146, 160, 166, 190, 195197, 208, 211, 214, 216, 228, 244, 247, 251, 266, 271-272, 277, 288-294, 323, 336, 355-358, 361, 365-367 church council, 211, 273, 287 church, as Christ's body, 290-291 city, 52, 92, 155, 158, 165, 217, 298, 316, 335, 354, 358, 360-363 civilisation, 158, 162, 195, 223, 352 class (taxonomy), 40, 57, 70, 77 classification, 3, 35-36, 39- 40 cleavage, 97, 99-103, 109 cleavage, molecular, 12, 15, 21 clergy, 166, 182-183, 188, 222, 247, 294, 324, 355 climate change, 39, 60, 73, 133, 171, 220, 245, 289, 292-295, 325, 332, 335, 342-344, 346-357, 360-361, 363-368 climate change agreement, 293, 349 climate change denial, xix, 336, 351-352, 355, 362, 365 climate science, 336, 345, 351 clock and wavefront model, 114, 123 clone, 22, 94, 292 Cnidaria, 40, 42, 65, 70, 83, 102, 105, 117, 122, 124, 127, 129 coal, 73, 352 coding gene, 94-95, 163 codon, 11-13, 15, 23, 26, 32 coelacanth, 75, 120 co-evolution, 38, 54-56, 135, 161162, 234, 325-326 collapse, 178, 293, 312 collinearity, 17, 115, 118-119 collusion, 193, 270, 291, 348, 357 colonisation, 38, 51, 84-85, 143, 319, 325, 327, 330 colonising species, 37, 39, 46, 51-52 command, 148, 178, 191, 216, 263 commandment, 193, 271, 277, 281 commensalism, 52, 156, 259, 289, 325

Index commitment, 205, 243, 284, 285, 296, 357, 361 common ancestor, 18, 27, 30, 37, 41, 68, 83, 85, 91, 96, 112, 117, 123, 125, 127-129, 132, 142, 182, 308 communication, 32, 54, 148, 151153, 160, 162, 234, 263, 332, 336 communion, 288-292, 321, 329, 364 community, 146, 165, 167, 171, 198, 229, 231, 244, 251, 277, 284, 289, 291, 292-296, 347-350, 355, 357-361, 364-368 companion, 142, 179, 194, 198 companioning, 265, 295, 321, 364 compartment, 107, 109, 111, 120 compassion, 177, 243, 256, 280, 304, 323, 361, 364-367 competition, 29, 47, 163, 185, 193, 291, 321-322, 325 complexity, xix, 16, 27, 32, 35, 44, 76, 95, 110, 137, 141, 146, 149, 170, 179, 200, 206-209, 214, 232, 253, 258, 262, 308, 337338, 342, 352 irreducible, 4, 253 minimal, 337, 342 composer, 83, 170, 173, 178-179, 338-339, 343 computer, 89, 148, 170, 358 concern, xvi, 59, 146, 192, 215, 228, 239, 255, 276, 304-307, 318, 322, 362 concurrence, 265, 305, 333 condemnation, 189, 191, 195, 226, 252, 280-281, 300, 315, 331, 354-355 conflict, 141, 153, 191-193, 216, 292, 315, 353 of science and faith, xviii, 177, 183, 219, 224, 333 congregation, 166, 292, 313, 355 Conradie, Ernst, 306, 364 consciousness, xvii, xviii, 86, 140, 145-147, 153-155, 168, 171,

Redundant God? Christian Faith in the Light of Evolution 206-209, 214, 223, 239, 245-47, 255, 258, 264, 268 consecrated elements, 244, 328 consecration, 213, 294, 328 consensus, 3, 171, 189, 197, 205, 216, 227, 239, 247, 306 conservation, wildlife, 234, 249, 293, 296, 318, 347, 356, 360, 365, 366 conserved gene, 18, 115, 126, 130, 150 conserved sequence, 18, 96, 151152 consolation, 276, 279, 314 conspiracy, 192, 269, 346, 351 constraint, 26, 205, 232, 246, 256, 264 consumer, 227, 348, 350, 357 consumerism, 320, 336, 347-348, 351, 361 consumption, of food, 135, 161, 226, 329 of resources, 297, 343, 346, 358 contemplation, 295, 296 contemplation, Ignatian, 312 context, 118, 137, 181, 186, 196, 211, 220, 227-228, 232, 237, 244, 263, 271, 287, 311, 316, 332, 338 context, Christian, 214, 222, 251, 265, 272, 274, 291, 311, 328, 332 context, developmental, 96, 112, 114, 339 context, evolutionary, 91, 97, 171, 276, 299, 302, 315, 336, 339, 366 continental drift, 5, 39 contradiction, xiii, 6, 196, 199-201, 206, 242, 248-249, 253-254, 268-269, 272, 276, 284, 302, 311, 318, 324, 365 conundrum, xix, 210, 259, 284, 303 conversion, 166, 190, 252, 276, 296, 353, 365 Conway Morris, Simon, xvii, 60, 68, 76, 84-86, 236

419

co-operation, xvi, xix, 9, 156-157, 161, 163-167, 259, 276, 325, 344 co-option in evolution, See exaptation coral reef, 46, 155, 157, 293, 342 cosmic Christ, 210-212, 303, 317 cosmogenesis, 211, 214, 253, 256 cosmology, 200, 251, 262 costliness, of creation, 283, 285 of evolution, xv-xvi, 54, 246, 259 of God's love, 259, 282, 286 of grace, 283, 327 counter-cultural, 357, 366 counterpoint, 172, 256, 332 covenant, 217, 301, 328, 347, 356 creationism, 76, 80, 183-186, 190, 202, 217-218, 248, 252-253, 310 creativity, 45, 214, 232, 252, 262, 283, 360, 364, 365, 366 creed, 261, 274, 288-289 Cretaceous, 73, 77-80, 88 crop plants, 52, 58, 226-228, 352, 359 cross of Jesus, 231, 246, 272-275, 279, 282, 303-304 cross, genetic, 24, 26, 48 cross-regulation, 110-111 crucifixion, 192, 194, 232, 254, 259, 262, 266, 269, 272-275, 278-282, 290, 329 cruciform nature, 307, 329 crustacean, 40, 42, 73, 117 Ctenophora, 40, 65, 83, 105, 127129 cultural inheritance, 162-163, 171 cultural transmission, 22, 162 culture, xvii, xix, 88, 130, 135-137, 153, 156, 160-162, 164, 167, 189-193, 206, 209, 308, 326, 335-336, 352, 364 Cyanobacteria, 9, 41, 76, 85, 325 cytoplasm, 6, 17, 21, 23, 32, 96101, 109

420 Damascus road, 166, 240, 270 damnation, 252, 284, 298, 300-302 Darwin, Charles, xvi, xix, 23, 30, 33, 44-46, 52, 56-59, 65, 76, 182-186, 209, 308, 310, 330 Darwin’s “finches”, 38, 46-47, 53, 86, 97 Darwinian evolution, 74-75, 162, 186, 206, 248 Darwinism, xvi, 183-186, 206, 245248 daughter cell, 7-10, 19, 100 daughter species, 48 daughter strand, 10-11, 19 Davidson, Eric, 21, 338, 341 Dawkins, Richard, xiv, xvi-xvii, 29, 80, 83, 88, 155, 162-163, 166, 177, 191-192, 206, 208, 245, 364 DDT, 27, 29 deacon, 236, 294, 324 Deane-Drummond, Celia, xx, 177, 202, 224-227, 228-232, 241, 248, 258, 261, 279, 285, 292, 317, 323 decay, 41, 70, 149, 309 deception, 168-169, 201, 329-330 deep homology, xix, 60, 83, 91, 117, 126, 130 deep incarnation, 214, 307 defence, 140-141, 149, 184, 202, 240, 243, 246, 248, 251, 267, 293, 317, 330, 363 deforestation, 61, 233, 347, 350, 352, 356 deism, xvii, 200, 243, 245, 260 deity, 280, 287 dementia, 137, 145, 148 demon possession, 280, 321-322 dendrite, 145, 147, 151 Dennett, Daniel, xiv, xvi, 140-141, 148-149, 164, 168, 170, 177, 206 Dennett, skyhook versus crane, 4, 31-32 denomination, 197, 291, 337, 355 desert, 38, 212, 294, 357 desertification, 46, 347, 350, 353 design, xiv, 82, 91, 134, 170

Index design solution, 84, 86, 88, 170 determinant, 101-102 determinism, 140-141, 205, 238 deuterostome, 42, 68, 102-103, 105, 117, 122, 130 development, mosaic, 101-102 musical, 339, 342 regulative, 101-103, 138 developmental abnormality, 23, 106 developmental fate, 59, 100, 102, 108 Devonian, 70-71, 73, 75-76, 352 dialogue, 177, 198 differential RNA splicing. See alternative splicing differentiation, 9, 90, 130 digestion, 53, 135-136, 161, 328329 digit, 86, 104-106, 119 dinosaur, 3, 73, 77-78, 80, 87-88, 105, 127, 255 diploid, 7-8, 24, 27, 58 directionality, 79-80, 208, 232, 235236 disciple, 192-196, 198, 241, 244, 267, 269-275, 277, 279, 286, 299, 321-325, 328-330 divergence, 26-27, 45, 47, 68, 86, 132 diversification, 37-39, 45, 48, 66, 70, 74-79, 83-84, 89, 95, 200, 263, 308, 342 diversity, 73, 79-80, 117, 262, 290, 293, See also biodiversity divine goodness, 247, 259, 261, 302 divinity, 165, 255, 272, 274, See God divinity of Christ, 195, 266-268, 271-272, 275 DNA, 7-9, 11, 15, 17, 23, 26, 30, 41, 74, 129, 133, 135, 163, 240 mitochondrial, 98, 133, 142-143 non-coding, 26 strand, 9, 10, 22 strand breakage, 23, 49, 235 structure, 10, 93

Redundant God? Christian Faith in the Light of Evolution DNA deletion, 26, 116, 132 DNA double helix, 9, 11 DNA insertion, 26, 132 DNA ligase, 14, 22 DNA looping, 18, 20 DNA methylation, 19, 139 DNA polymerase, 10, 14 DNA repair, 23 DNA replication, 9, 11, 14-15, 31, 93 DNA sequence, 26, 44, 68, 308 DNA sequencing, 3, 18, 35, 37-41, 47, 68, 89, 94, 101, 129, 132, 135, 143 DNA-binding domain, 18-19, 95, 107, 150 Dobzhansky, Theodosius, 3, 205, 249 doctrine, 177, 202, 204, 209, 217, 221-222, 229, 248, 263, 272-273, 284, 287, 294, 300, 302, 306, 312, 331 dog, 52, 57, 143, 156, 180, 298, 322 dolphin, 88, 152, 155 domain (taxonomy), 41, 44 domestication, 52, 57-58, 156, 158, 318, 356 dominance hierarchy, 55, 193, 316 domination, 185, 195, 220, 275, 325 dominion, 195, 220, 325, 356 dorso-ventral axis, 68, 100, 106, 124 double predestination, 261, 284 double-gradient hypothesis, 102103 doubt, xv, xx, 63, 80, 82, 168, 177, 195, 203, 216, 218, 222, 241, 269, 284-285, 304 Doubting Thomas, 194-195, 269, 313 Drosophila, fruit fly, 16, 18, 28, 59, 81-83, 107-110, 114-117, 120125, 130 drought, xvi, 46, 80, 239, 292, 322, 330, 347 dualism, xv, 149, 239, 300 dyadic formula, 272, 286-287

421

early church, 195, 197, 242, 267, 269, 287, 290, 308, 324 Easter, 194, 197, 204, 261, 269 Ecdysozoa, 42, 68, 117, 125, 130 echinoderm, 41, 68, 105, 117, 122, 125 ecological crisis, 195, 295-296, 365 ecology, 148, 195, 214, 233, 289, 318, 323, 329, 332, 336, 364 economic model, 349-350 economics, 346, 349, 352, 357, 366367 economy, 167, 346, 350 ecosystem, 32-33, 37, 46-47, 60, 67, 233-234, 237, 239, 249, 259, 289, 292-293, 304, 318, 325, 342, 364 ecosystem services, 297, 344, 349350, 363 ecotype, 48-50 57, 95 ectoderm, 101-104, 107, 122-123 ectopic, 26, 81, 121 Ediacaran, 63, 65-68, 70, 76, 264 education, 146, 153, 163, 169 Edwards, Denis, 258, 303, 305 egg, 21, 23, 27, 84-85, 98-101, 103, 109-110, 137, 142, 146, 222, 224, 246 egg, fertilised. See zygote Egypt, 156-158, 165, 195, 203, 215, 224, 254, 267, 268, 327 elect, 283-284, 303, 337, 365 elephant, 61, 88, 155, 306 embodiment, 178, 257, 266, 306, 319, 331 embrace, 211, 246, 256, 261, 265, 324, 329, 331, 363-364 embryo, xix, 19, 21, 50, 66, 81, 96, 98-102, 104-109, 112, 115-116, 120, 122-124, 138, 146, 187, 222, 323, 338 embryonic development, 94, 98-99, 109, 122 emergence, 28, 44, 48, 50, 68, 86, 130, 148, 165, 167, 171, 201, 206-207, 220, 251, 338 emergent order, 235-236

422 emergent property, 33, 149, 168, 209, 237, 239 emergentist, 237, 239, 243 emissions, 79, 344-345, 348-350 Emmaus road, 269-270 emotion, xvii, 145, 155, 165, 173, 179, 232, 241-242, 262, 285, 312, 339 empathy, 155, 245, 259 empty tomb, 197, 240, 269-270, 330 endemic species, 36-39 endoderm, 100-103, 122, 338 endomesoderm, 122, 338, 341 endorphin, 167, 285 endosymbiosis, 8, 44, 80 endtime, 296, 298, 345-346, 351, 356 energy, 8, 15, 41, 53, 55, 65-66, 207, 285, 325, 329, 336, 348349, 360 enhancer, 17-18, 20, 48, 57, 94-96, 110-111, 114, 120, 129 Enlightenment, 160, 162, 197, 285 entropy, xvi, 207, 309 environment, xvi, xviii, 6, 9, 41, 46, 53, 55, 64, 78, 80, 88, 95, 137, 151, 155, 171, 200, 205, 220221, 224, 227-228, 233-235, 238, 260, 289, 292, 296, 299, 321322, 326, 339, 342, 346, 348349, 352-354, 360-363, 366 environmental damage, 28, 226227, 233, 348, 350 environmental factor, 137, 139 environmental influence, 137, 139 environmental issues, 348, 355, 357 enzyme, 11-12, 19, 22-23, 29, 90, 135, 181, 292 kinase, 96, 112 urea cycle, 90, 326 epilepsy, 280-281, 322 epistle, 197, 221, 240, 254, 267, 270-272, 281, 291, 301, 332 equality, 196-197, 272-273, 288, 311 equilibrium, 235, 238-239, 249, 293, 342, 352

Index eschatology, 303-305, 314, 324 Escherichia coli, 15-18, 89 eternal life, 215, 281, 297, 328 eternity, 297-298, 300, 302, 305 ethics, 146, 168, 226-227, 230, 274, 325, 336 environmental, 307 utilitarian, 227, 262, 296 virtue, 227 ethnicity, 141, 143-144, 294, 357 eucharist, 213, 244, 284, 288, 290291, 294, 328, 329 eucharistic community, 291, 294 eugenics, 186-187 Eukarya. See eukaryote eukaryote, 7, 12, 16-19, 22, 41, 44, 76, 94-95, 129, 163 Europe, 36-37, 49, 51-52, 134-135, 143, 157-158, 160, 164, 179, 186, 191, 202, 226, 357, 359 evangelical, xiii, xix, 177, 182-183, 210, 214-218, 248, 251, 254, 260, 263, 295, 299-300, 311, 345-346, 351, 355-356 evidence, xiii, xvi-xviii, 3, 5, 31-32, 38, 41, 48, 53, 57, 59-60, 65, 73, 88, 91, 97, 117, 122, 124, 128, 130, 133-134, 142-144, 148, 151, 154, 156, 166, 177, 191-193, 198, 216, 220, 225, 243, 252253, 270, 307, 313, 345, 351, 365 evil, 140, 146, 169, 210, 231, 243, 247, 257, 259-260, 265, 277, 301-302, 317, 354 evil-doer, 277, 297, 302 evo-devo, 61, 91, 94, 112, 126, 171, 363 evolution, contingency of, 60, 67, 75-76, 87, 89, 232, 236, 261, 321 convergent, 4, 29, 33, 37, 49, 60, 80-91, 128, 130, 152, 209, 236, 326, 342 cultural, 33, 161 divergent, 90, 97 in the laboratory, 89, 339

Redundant God? Christian Faith in the Light of Evolution parallel, 29, 80-81, 83, 85, 91, 123, 130, 326 predictability of, 86, 88, 236 evolutionary advantage, 161, 165, 171 evolutionary change, 45, 57, 60-61, 74, 97, 339 evolutionary framework, 45, 75, 190, 209, 213, 247 evolutionary history, 39, 60, 171, 231-232, 293-296, 327, 343, 352 evolutionary perspective, xvii, 127, 164, 168, 201, 296, 320 evolutionary process, xiv, xvii, 38, 209, 259, 261, 264, 342 evolutionary progression, 76, 79 evolutionary science, xvii, 201, 205, 209-210, 213, 219, 247, 313, 325 evolutionary theory, xiii, 253, 311 evolutionary time, 57, 255-256, 279, 288 evolutionism, 183, 210, 311 example of Jesus, 353, 357-358, 365-366 exaptation (co-option), xiv, 89, 95, 116, 123, 125, 326-327 exclusivity, xvii, 271, 294, 307, 337, 365 exegesis, xx, 214, 218, 255, 286, 311, 332 exon, 17-20, 23, 26, 97, 151-152, 163 exoskeleton, 40, 123 experiment, 4-6, 51, 54, 70, 99, 140, 225, 237, 261, 264, 338 exploitation, xx, 195, 220, 296, 344, 347, 350, 354 expression domain, 111, 116, 119124, 128 expression level, 90, 120 Extended Evolutionary Synthesis, 172, 206 extinction, 37, 39, 47, 60, 65, 73, 133, 165, 292, 297, 343 extinction, background rate, 77, 79, 343 extrapolation, 171, 325, 345, 365

423

eye, 80-81, 89-90, 129, 153, 326, 333 arthropod, 81-82 camera, 80, 83 cephalopod, 81-84 compound, 67, 81-23 development, 66, 81-83, 93 lens, 81-83, 89, 327 photoreceptor, 81-82, 90 pigment cell, 81-82 retina, 81-83, 90 vertebrate, 81-82, 84 eye-spot, 80-81 fairness, 167, 234, 322 faith, xiii, xv, xviii-xix, 166, 168, 177-178, 190, 193, 195, 201, 209, 212-213, 220, 249-252, 255, 261, 267, 280-282, 284-287, 300, 311, 313, 319, 331, 335, 337, 343, 346, 357-359, 363-366 faithfulness, 260, 284-285, 300-301, 323 Fall, 169, 194, 201-203, 210, 215217, 221, 224, 231, 296, 312, 346, 352-356, 361 fallow year, 354, 358-359 falsifiability, 3, 5, 195, 270 family, 139, 141, 143, 150, 154, 163, 171, 191, 207, 268, 335, 362 family (taxonomy), 35, 37, 40, 7677, 80, 104 famine, 157, 347, 348 farming, 156, 167, 215, 228, 233, 347, 352, 359 feather(s), xiv, 54, 86, 309, 326 evolution of, xiv-xv, 86, 91, 127 feedback loop, 114, 244, 289 feeding, 53, 55, 64-66, 125, 269 fellowship, 285, 287 female line, 142-143 feminism, 229, 332 fern, 51, 71, 73 fertilisation, 8, 57, 97-100, 109, 142, 187, 222 fertility, 188, 190, 354

424 fiction, 88, 191, 313, 337, 346, 365 fidelity, of cultural transmission, 154, 161, 163 of DNA replication, 10, 22 field, embryonic, 102, 106 fin, 48, 58, 75, 120, 125 fingerprint, of God, 252-253, 255, 365 fire, 51, 156, 161, 187, 212, 285, 298, 330, 362, 363 fire, refining, 301, 302, 303 fish, 41, 47-48, 54-55, 70, 73, 75, 85, 90, 97, 118, 120, 125, 154, 156, 180, 201, 220, 222, 269, 320, 326, 333, 350, 356 fitness, 29, 48, 54, 59, 129, 153154, 161, 165 flexibility, 146, 148 flight, xiv, 86 flight feather, xiv-xv, 86, 91, 127 flight muscle, 73, 84 flightlessness, xiv, 53, 85 Flood, 44, 201, 217, 252, 347, 356 floral whorl, 9, 104, 127-128 flourishing, 259, 263, 293, 295, 306, 315, 322-324, 344 ecological, 234, 249, 292, 304, 307, 361 human, 169, 197, 225, 251, 292, 298, 350 flower, 9, 34-40, 51, 55, 58, 73, 104, 127, 309, 319, 330 follower of Jesus, 198, 278, 322, 324, 329, 331, 345 food resources, 53, 55, 65, 152, 154 foolishness, 276, 283 foot-washing, 194, 277-278, 325 foraging, 53, 154, 157 forelimb, 86, 91, 104-106, 120, 164 forest fire, 73, 347 forgiveness, 193, 277, 280, 284285, 300-301, 306, 364 forkhead domain, 18, 150 fossil, xiv, 44, 63-65, 67-68, 70, 7374, 86-87, 117, 204, 230, 252, 327, 352

Index fossil record, xix, 27, 33, 44, 68, 7376, 120, 130, 201, 218, 308, 327 fractal branching, 63-65 France, 134, 164, 179, 190, 202, 204 fraud in science, 5, 203 free choice, of God the Father, 288, 317 free will, xvii, 140-141, 146, 172, 243, 260-262, 281, 302 freedom, 140, 196, 243, 246, 258, 260, 262, 265, 275, 302, 305, 309, 324, 337, 354 free-market, 346, 349-350, 355, 357, 367 French, 141, 143, 149, 179, 181, 202, 204, 213, 279 French flag problem, 102 friend, xx, 194, 208, 215, 245, 280283, 321, 344, 362 friendship, 282, 362-363 frustration, 264, 309, 314 fulfilment, 206, 211, 234, 264, 271, 275, 279, 288, 290, 304-306, 309, 314-317, 320, 330, 337, 339, 344, 346, 357, 363 function, xiii-xiv, 9, 23, 26, 30-31, 33, 58-59, 89, 91, 95, 97, 112, 115-116, 122-125, 127, 130, 138-139, 145-150, 152, 163, 168, 237, 253, 290, 292 functions, multiple, xiii, 83, 97, 125 fundamentalism, xix, 183-185, 190, 249, 311-312 fungi, 6, 16, 41, 44, 47, 55, 63, 85, 127, 129, 325 future generations, 171, 323, 327, 336, 345, 350, 361, 366 Gaia, 212, 229, 289, 353, 362 Galilee, 197, 266, 269, 330 gamete, 7, 8, 19, 22, 98, 314 gap gene, 110-112, 115 Garden of Eden, 215-216, 221, 298, 362 gastrulation, 68, 101-104

Redundant God? Christian Faith in the Light of Evolution gender, 138, 196-197, 290-291, 301, 357 gene duplication, 90, 95, 132, 327 gene editing, 187, 227 gene expression, 21, 58-60, 97, 101, 120, 125, 139, 292 level of, 26, 97 striped pattern of, 111-113, 114, 122-122 zygotic, 99, 110, 123, 338 gene expression pattern, 58, 94-95, 108, 111-114, 116, 119-124, 128-130, 163, 226, 292 gene family, 83, 123 gene flow, 38-39, 50 gene regulation, 16-17, 19, 21, 32, 91-96, 125, 161, 207, 321 modular, 16, 18, 57, 94, 112, 115, 129 gene regulatory network, 338-339 gene therapy, 186, 227 genealogy, 266, 312 generalist, 51, 55, 60, 77 generation, 54, 59, 99, 144, 150, 181, 216, 285, 339, 345, 351, 362, 367 Genesis, 44, 156, 169, 183-184, 189, 192, 195, 200, 201, 214221, 224, 229, 248, 254-255, 263-264, 286, 300-301, 311, 319, 325, 332, 346-348, 352, 356, 361-362 genetic circuit, 96, 107, 151, 163, 338-339 genetic circuitry, 83, 110, 112, 124, 326 genetic code, 3, 11, 13, 30 genetic constitution. See genotype genetic determinism, 137, 140 genetic differences, 35-36, 38, 44, 143, 322 genetic disease, 136-137, 186, 223 genetic engineering. See GM genetic factor, 138-139 genetic identity, 98, 138, 321 genetic information, 8-10, 12, 30, 32

425

genetic material, 7, 9, 12, 22-23, 30, 41, 323 genetic modification. See GM genetic module, xix, 112, 117, 123, 127, 207, 321, 327 genetic pathway, 60, 91 genetic relatedness, 18, 35-37, 89, 138-139, 194, 314 genetic repertoire, 91, 127, 129, 321 genetic testing, 137, 187, 227 genetic tinkering, 91, 327 genetic toolkit, 80, 83, 91, 109, 112, 127, 130, 326 genetic variation, 22-23, 36, 48, 256, 308 genetics, 17, 33, 57-58, 107, 109, 132, 140, 150, 161, 205, 214, 226, 363 genius, 170, 172-173, 179 genocide, 133, 167, 191, 254, 357 genome, 3, 12, 15-19, 21, 31, 47, 90, 97, 99, 116-117, 125-129, 133, 139, 143, 224, 227, 290, 326, 339 genome duplication, 95, 97, 119 genome sequence, human, 132, 143, 226 genome sequencing, 3, 18, 101, 129, 132, 135 genomics, 6, 49, 129, 148 genotype, 24, 46, 98-99, 322 gentian, 40, 104, 233, 309 Gentile, 281, 301, 322, 324 genus, 35-36, 39, 47, 52, 70, 76-77, 133, 181, 330 geological epoch, xix, 36, 80, 327 geological time, 44, 57, 75, 80, 183, 200 geology, 203, 247, 251 germination, 55, 197, 330 Gilgamesh, Epic of, 44, 158-159, 201 gills, 48, 53, 67, 85, 117 Girard, René, 167, 191-194, 353, 354 glaciation, 63, 70, 293

426 global warming, 27, 60, 78, 327, 343-347, 349-353, 360-361, 366367, See also climate change glory, 187, 189, 211, 230, 232, 262, 270, 272, 275, 303, 319, 320 GM, 94, 225-228, 248, 308, 359 GM food, 225, 226, 359 GM technology, 225-227, 359 Gnosticism, 195-196, 212, 313 God, xiii, xv, 149, 169, 182, 189, 191-192, 200, 215, 217, 221, 224 as Creator, xiv, xvii, 86, 164, 199, 214, 217, 249, 251-252 as guarantor of natural law, 4, 232, 239, 258 as love, xiv, xvi-xvii, 215, 217, 239, 243, 246, 252, 256, 259261, 264-265, 274, 277, 279287, 293, 298, 302, 304, 306, 316-318, 329, 331, 364-365 as micromanager, 178, 243, 316 as non-coercive, xiv, xvii, 262, 264-265 as omnipotent, 45, 178, 259-260, 316 as self-limited, 239, 260-262, 264-265 as sustainer, 243, 249, 260 as uncontrolling love, 286, 302, 317 interventionist, 239, 317 non-interventionist, xiv, 86, 236, 316 God incarnate in Jesus, xv, 278, 282, 363 God of the gaps, 5, 243 Godhead, 223, 229, 240, 261-262, 273, 287-289, 293, 308 Godself, xv, 214, 240, 247, 260, 264, 273, 283, 329, 344 gold, 185, 301, 319 good news, xiii, 177, 266, 275, 281, 320, 327 Good Samaritan, 281, 296 gospel, xiii-xiv, xvii, 160, 177-178, 189, 192, 194-198, 210, 221-222, 229, 240-243, 254, 262, 265-270,

Index 273-281, 286, 290-291, 299, 307-308, 312-313, 320-321, 323, 327-331, 357 gospels, synoptic, 178, 254, 273, 278-280, 282, 328 Gould, Stephen Jay, xvii, 45, 59-60, 67, 74-76, 80, 89, 91, 127, 177, 184-186, 236 grace, 232, 245, 272, 283-285, 287, 293, 300 gradient, morphogen, 106, 109, 119, 124 signal, 102, 105-106, 119 transcription factor, 110 gradualism, 44, 57, 76, 80 grain, 156, 321, 330, 348 great apes, 88, 132-133, 149, 154155, 161, 182, 215 Great Commission, 269, 286 greed, xx, 245, 295, 297, 323, 331, 336, 346, 348, 352, 353, 355, 361 Greek, 149, 159, 165, 167, 195, 197, 201, 210, 248, 271-273, 276, 279, 284, 287, 291, 297298, 303, 306, 311, 318, 320321, 327, 354 green group, 226, 228, 355, 360 greenhouse climate, 63, 78 greenhouse gas, 60, 78-79, 344-346, 348-351, 358 Gregory Nazianzen, 223, 287 Gregory of Nyssa, 287, 300-303 growth, 49, 52, 58, 63, 112, 123, 125, 127, 209, 214, 233, 292, 367 guilt, 184, 297, 344 gut, 9, 41, 65, 68, 100-103, 122123, 125, 225, 289, 305 gymnosperm, 71, 73 habitat, 36-39, 47-54, 73, 75, 89, 234, 293, 319, 325, 330, 348, 351 habitat loss, 47, 52, 79, 343 habitat tracking, 60, 78 haemoglobin, 84, 136

Redundant God? Christian Faith in the Light of Evolution haltere, 107, 116 hand, 86, 132, 134 haploid, 8, 22, 27, 98, 224 hard-wired, 140, 147 harmony, 173, 178, 206, 257-258, 305, 336, 346, 360-361, 363 harvest, 212, 255, 305, 350, 354355 healing, 240, 260, 280, 281, 304, 322, 363 health, 136, 228, 289, 361, 363 public, 226, 228, 368 heart, 84, 124-125, 173, 254, 287, 298, 366 development, 130 hardness of, 280, 298 heat sensitivity, 293, 322, 333 heat-shock protein, 89, 292-293 heaven, xvi, 196, 251, 261, 267, 269, 274, 276-278, 284, 286, 291, 297, 300, 303, 308, 314, 320 Hebrew, 187-188, 195, 219, 248, 263, 279, 297, 318 hell, 284, 297, 300-301, 325 hellfire, 261, 297-298, 300, 303 hemichordate, 73, 125 herbivore, 53, 60, 289, 304 heresy, 195, 222-223, 287, 363 hermeneutics, xviii, 255, 313, 332 heterochromatin, 19 heterogametic, 27, 223 heterozygote, 24, 99, 136 heterozygote advantage, 136-137 hierarchy, 165, 237, 289, 294, 324 social, 153, 167, 217, 316, 325, 329 high priest, 278, 295, 351 hindbrain, 119-121, 123 hindlimb, 49, 87, 105, 107, 121 Hinduism, 211, 213, 312 histone, 7, 19, 93, 98 historicity, 177, 203, 254 history, Christian, 216, 287, 313 Deuteronomistic, 189, 191, 327

427

human, 134, 142, 162, 164, 210, 215, 232, 255, 260, 262, 265, 279, 327, 344 of Israel, 168, 254, 327, 332 of life, 3, 30, 44, 339 holiness, 280, 286, 292 holism, 32, 280 Holocaust, 144, 169, 191, 332 Holy Communion. See eucharist Holy Spirit, 200, 223-224, 229, 243, 251, 263, 266-268, 273, 275, 277, 279, 286-290, 304, 308 homeobox, 18, 107, 115-118, 125 homeodomain, 18, 59, 81, 83, 96, 107, 109, 111, 116, 127 homeostasis, 292, 293, 342 homeotic gene, 18, 107-108, 115, 127, See also Hox gene homeotic mutation, 59, 121, 127 hominid, 133, 149 hominin, 133-134, 149, 155, 164, 193, 255, 264 Homo sapiens, xviii, 16, 44, 88, 131-134, 148, 156, 161, 171, 200, 215, 255, 264, 295-296, 352-353, 356 homogametic, 27, 223 homozygote, 24 hope, xvi, 61, 171, 202, 207, 214, 231, 251, 261, 265, 267, 275, 279, 282, 286, 298, 302, 304307, 314, 331, 336, 360, 364-365 hopeful monster, 59-60 hormone, 53, 96, 223 hostility, 157, 167, 183, 204, 353 hotspot, 39, 49 Hox code, 119, 122, 128 Hox gene, 59, 96-97, 105-108, 115119, 121, 124, 126-128 Hox gene cluster, 115-117, 119-121, 127 Hox gene expression, 119-122, 124 hubris, xviii, 169, 252, 353 human ancestry, 60, 132-133, 149, 204 human brain, 148-149, 161, 308, 326 split, xvii, 138

428 human disease, 136-137 human evolution, 133 170, 184, 206, 216-217, 293 humanities, 132, 209 humanity, xviii-xix, 79, 132, 165, 171, 186, 192, 198, 200, 207, 209, 211-213, 215-217, 220, 222-224, 229, 231, 240, 245, 255, 259, 261-262, 265, 274, 281, 288, 290, 294, 299, 301, 304, 308, 316, 318, 324-325, 336, 343, 346-347, 352-353, 356, 360, 364-365 humility, 240, 272-273, 278, 294, 320, 324, 347 hunter/gatherer, 154, 156, 165-166, 215, 352, 354, 362 hunting, 52-53, 60, 133, 153-154, 156, 165-166, 259, 325, 350 hybridisation, 35, 49-50, 59, 93-94, 132 hydrothermal vent, 31, 41, 321 hymn, 159, 187-188, 230, 264, 283, 309 hypocrisy, 276, 314, 331, 358 hypostasis, 211, 274, 287, 293 hypothesis, 3-5, 8, 32, 75, 129, 180, 212, 264, 289, 311, 323 Ice Age, 36, 48-49, 52, 60, 78, 233 ice-cap, melting, 335, 345, 347 reflective, 78 ichneumon fly, 246, 252 icon, 244, 286 idealism, 358, 360 idolatry, 271, 316, 348, 354 image of God, 200, 214, 220-221, 301, 309, 333, 356 imaginal disc, 40, 115-116 imago dei. See image of God imitation, 152, 154, 161 imitative learning, 152-153 immanence, 213, 241, 243, 246, 249, 261, 306 immortality, 149, 212, 259

Index impassibility, 241, 259, 262, 264, 274, 344 imprinted gene, 19, 22 improvisation, 256-258, 261, 264, 321 incarnation, 214-215, 222-223, 231, 240, 242, 244, 256, 261, 265, 267-268, 271, 273-274, 279, 304, 306-307, 337 incomprehensibility of God, 261, 276, 288, 302 inculturation, 189-190 independence, 153, 177, 185, 243, 258, 306 indigenous people, 144, 165, 296, 350, 356, 362 individualism, 324, 331, 353 individuality, 148, 152, 171, 288290, 301, 305 indoctrination, 166, 193, 323 indulgences, 331, 349 Industrial Revolution, 162, 347, 352 industry, 60, 212, 226, 346, 349352, 366 infertility, 35, 49, 223, 314 information, 152, 160, 238, 239, 242, 333 inheritance, 23, 98-99, 162, 171, 308, 362 "Lamarckian", 22, 44, 162, 205 maternal, 98-99, 133 paternal, 133 inhibition, 21, 89, 110, 114, 145, 238 injustice, 302, 328-329, 354 inner cell mass, 99, 138 innocence, 191-193, 353 innovation, xix, 124, 157-158, 160, 162, 171, 227, 235, 261, 263264, 288, 292, 326-327, 358, 365 inscription, 158, 279, 306 inscrutability of God’s purposes, 259, 260, 284 insect, 29, 40, 55, 71-74, 81, 85, 9899, 108, 112-115, 124, 129-130, 147, 194, 299, 304, 330, 333, 359

Redundant God? Christian Faith in the Light of Evolution instinct, 146, 153-154, 169, 230, 242, 305 instrumental value, 318, 365 intelligence, 86, 88, 149, 152-153, 200, 246 Intelligent Design (ID), xiv, 4, 200, 253 intentionality, 153, 157, 165, 231 interbreeding, 35, 38, 46, 48, 57, 59, 75, 133, 142-143, 293 interconnectedness, 209, 212, 237, 364, 368 internet, 1610 192, 212 interpretation, xiii, xviii, xx, 5, 6, 63, 65, 67, 70, 82, 129, 149, 166, 177-178, 191, 193, 200-201, 209, 215-219, 231, 237, 241-242, 245, 248-249, 255, 270, 278, 283, 298, 301, 303, 311-313, 318, 332, 345, 348, 362 non-literal, 201, 224, 311 intervening sequences. See intron intervention, 224, 239, 245-246, 249, 252, 260, 263, 279, 317 intimacy, 269, 364 intrinsic nature, 305, 315 intrinsic value, 227-228, 255, 304, 307 intron, 15, 17, 20-21, 41, 94, 151 invasion, 71, 89, 157, 167, 190, 327 invasiveness, 51-52 inversion, 115, 124, 172-173 investment, 53, 61, 226, 322, 336, 344, 348 invitation, 141, 263-264, 267-268, 281, 284-285, 328 invocation, 263, 286 ionising radiation, 23, 26, 235 Irenaeus, 217, 247 Islam, 168, 190-191, 203, 312 island, 37-39, 46, 50, 54, 61, 75, 89, 97, 133, 144, 157, 6203, 214, 234, 330 laboratory for evolution, 38-39, 89 isolation, 30, 117, 151, 368 geographical, 36-39, 46, 56, 143

429

reproductive, 38, 47-48, 75 isotope decay rates, 80, 134, 252 Israel, 144, 167, 188-189, 275-276, 301, 315, 326-327, 345, 354 Jacob-Monod model, 15, 19, 93 Jerusalem, 167, 241, 269, 271-272, 297, 327-328, 344, 354 Jesus, xv-xvii, 169, 177-178, 192195, 196-198, 201, 215, 221-224, 230-231, 240-247, 251-256, 259, 264-282, 285-286, 290-291, 297298, 300, 304, 306-309, 315, 318-331, 337, 344-346, 351, 357, 360, 362-365 as second Adam, 274, 320 Jesus the Christ, xiii, 215, 223, 232, 266, 268, 271-274, 278-283, 287, 291, 308, 329, 357, 365 Jew, 144, 169, 186, 191, 197, 222, 271, 278-279, 290, 301, 311, 328, 363 Jewish exile, 167, 189, 316, 327, 344, 354 John the Baptist, 266-268 Johnson, Elizabeth, 258-259, 261, 296, 304-305, 307 Joseph (patriarch), 192, 348 Jubilee, 275, 354 Judaism, 165, 168, 189, 191-192, 266, 271-272, 282 Judas Iscariot, 196, 264, 278, 329 judgement, 167, 192, 204, 215, 248, 296-297, 302, 305, 315, 327, 345-346, 361 Jurassic, 73, 77, 80, 88 justice, 217, 227, 234, 267, 276, 296, 302, 305, 315, 331, 346-349 juvenile, xiv, 49, 151-154, 166, 323 kenosis, 240, 244, 246, 264, 268, 271-274, 283, 285, 293-294, 357 keratin, xiv, 91, 127, 132, 326 keystone species, 233-234 kin selection, 154, 166, 220 king, 165, 167, 275, 278, 354

430 King David, 167, 187, 189, 316, 354 King Josiah, 298, 354 King Solomon, 167, 189, 319 kingdom (taxonomy), 41, 44, 57, 85, 88, 126, 151, 154, 326 kingdom of God, xiv, 177, 196, 266, 273, 275-281, 283, 285, 290-291, 295, 299, 302-306, 314-315, 318-323, 329-331, 351, 361, 363, 365 kingdom teaching of Jesus, xiii, 197, 298, 336 kingship, 275, 278, 354 kinship, 156, 166-167 lactose, 15-16, 135-136 lactose tolerance, 135-136 lagerstätten, 67-68 laity, 294, 324, 355 Laland, Kevin, 135-136, 151-154, 161, 171, 206, 325, 336 Lamarck, Jean-Baptiste, 22, 44-45, 162, 205-206 land crab, 39, 85 land use, 158, 354, 359 landform, 80, 251, 335 landscape, 61, 294 language, xiv, xvii, 33, 130, 147154, 161-162, 188, 193, 288, 299, 312, 328 larva, 40, 48, 53, 66, 101, 105, 108, 116, 121-122, 246, 252, 323 Last Judgement, 232, 897, 300, 315, 355 Last Supper, 244, 290, 327-328 Latin, 35, 166, 181, 279, 284, 302 Law of Moses, 189, 276-277, 301, 331, 344, 346, 354 leaf, 9, 73, 104, 127, 151 learning, 54, 146, 148, 151-154 lens. See eye, lens lens crystallin, 81, 89-90, 95, 327 lens fibre, 81, 89-90 leprosy, 280, 363 letting be, 253, 263, 286 Lewis, Ed, 107, 109, 116, 121

Index liberal, xiii, xx, 177, 183, 202, 217, 222, 248, 300, 302, 311, 357, 365 liberation, 242, 276, 316, 332 lichen, 63, 85, 325 life-history strategy, 52, 55, 57 lifespan, 88, 153, 339 lifestyle, 54, 325, 361, 366 lifestyle choice, 137, 297, 336, 358, 361, 364 ligand, 95-97, 114, 120 light sensitivity, 80-81, 90-91, 333 lily, 35, 40, 319, 320 limb, 50, 65, 85, 124-125, 130, 305 limb autopod, 105, 119 limb bud, 48, 105-106, 119 limnetic, 48, 50 lineage, cell, 101, 105, 129, 338 evolutionary, 85, 88, 119, 132, 308, 326 human, 132-133, 151 Linnaeus, Carl, 35, 52, 201 lipid, 6-7, 30-32, 96 liturgy, 218, 244, 284, 297, 355 livestock, 156, 234, 315, 352 lizard, 41, 50, 85, 89 logos, 211, 229, 241, 265, 312 Lophotrochozoa, 42, 68, 117, 122, 125 Lord’s prayer, 277-278 losers, 210, 292, 299, 307, 315 love, as an ideal, 281-282 human, 207, 220, 255, 262, 358, 360, 365-366 personified in Jesus, 240, 281, 290, 337, 353 love for creation, 256, 264, 265, 283, 295 love for enemies, 277, 358 lung, 53, 85 lure, 93, 262, 330, 361 lust, 216, 277 Luther, Martin, 160, 191, 284, 332 macrofossil, 63, 71, 76

Redundant God? Christian Faith in the Light of Evolution macromutation, 59, 75 Mahler, Gustav, 232, 337, 338, 343, 363 Maitland, Sara, 246, 256, 331 malaria, 28, 136 male line, 143 mammal, xv, 17-18, 27, 39, 41, 73, 77, 80, 83, 86, 88, 98-99, 103104, 150-151, 180, 222, 305, 326, 329, 333 eutherian, 83-84, 88 marine, 85, 88 marsupial, 84, 88 monotreme, 84-85, 88 manipulation, 132, 243, 262, 338, 354 manufactured goods, 352, 358 Mary Magdalene, 197-198, 269270, 313 mass extinction, xvi, xix-xx, 44, 57, 60-61, 73, 75-80, 86-87, 171, 231, 264, 295, 327, 330, 338, 343-344, 367 mass extinction, sixth, xx, 60, 79, 292-293, 319, 325, 331, 335, 342-345, 364 materialism, xiii, 141, 149, 177, 191 maternal factor, 110, 338 maternal mRNA. See mRNA, maternal maternal mRNA, inactivation, 21, 99 mathematical modelling, 53-54, 154, 161, 237-238, 325 Maximus the Confessor, 241, 288 medical genetics, 136, 186 Mediterranean, 35, 38, 188, 195, 201, 233, 330 medulla oblongata, 120-121 meiosis, 7, 18-19, 22-23, 26 melody, 173, 339, 342 membrane, cell, 6-7, 109 lipid bilayer, 6-7, 32, 96 meme, 162-163, 166, 168-173, 193, 312, 351, 366

431

memory, 145, 154, 170, 201, 254, 305-306, 312 Mendel, Gregor, 24, 57, 164, 205 Mendelian segregation ratios, 24, 26, 99, 136 mental health, 197, 363 mental illness, 197, 268, 277, 299 mercy, 280, 298, 302, 306, 331, 346, 364 mesoderm, 100-101, 103-104, 109, 120-121, 123, 338 Mesopotamia, 156-158, 201, 215 messenger RNA. See mRNA Messiah, 195, 266-267, 278 metamere, 107-109, 115-117, 119, 123-124 metamorphosis, 40, 53 metaphor, xvii, 81, 162, 193, 200, 241, 256, 261, 299, 347, 360 metaphysics, 60, 207, 208 metazoan, 63, 68 methane, 41, 78 microbe, 35, 44, 63, 65, 80, 136, 265, 307, 318, 323, 324 microRNA, 20 microvariation. See variation, smallscale midbrain, 120-121, 123 migration, 54, 133-134, 142-144, 293, 350, 353, 365 mimetic rivalry, 191-193, 351 ministry, 178, 197, 231, 265-266, 268, 273-276, 282, 295, 299, 315, 331, 335, 357 miracle, 195, 221, 224, 240, 260, 313, 317 mirror, 155, 291, 331 image, 31, 106 neuron, 155 mission, 268, 279, 331, 355, 357 mitigation, of climate change, 293, 344345, 348-349 mitochondrial Eve, 142-143, 216 mitochondrion, 8, 15, 98, 142, 325 mitosis, 7-8, 18-19, 22

432 model, 3-6, 9, 15-16, 26, 53, 57, 5960, 79, 116, 127-128, 163, 188, 193, 197, 205, 216, 242, 249, 285, 287, 293, 313, 323, 331, 348, 359 modification, 5, 84-85, 104, 107, 127, 235, 321 molecular biology, xix, 6, 31-32, 92, 94, 237, 364 mollusc, 41, 49, 65, 68, 70, 73, 77, 80, 84, 98, 100, 117, 123, 152 Moltmann, Jürgen, 210-211, 232, 241, 244, 262, 267-268, 270, 273-276, 279, 299, 303, 314, 331, 356, 358 monism, 149, 237, 239 Monod, Jacques, 15, 171, 208, 235, 241, 258, 365 monophyletic group, 41, 104 monotheism, 165, 168, 189, 271 moral responsibility, 140, 253, 259, 295, 297, 304, 317, 344-347, 351, 355, 360, 364-365 morality, 146, 160, 167, 185, 187, 191, 217, 234, 255, 274, 357, 360, 367 morph, 49-50, See also ecotype morphogen, 106, 110, 124 morphology, 35, 38, 48-50, 97, 121 mortality, 136, 155, 169, 259, 302, 320 motility, 65-66, 125 motivation, xx, 165, 169, 359, 361, 364 mountain, 36, 39, 84, 141, 234, 269, 294, 298, 304, 318, 335, 336 mourning, 155, 276, 364 mouse, 56, 81, 118-119, 121, 150151, 222 Mozart, Wolfgang Amadeus, 169, 171-172, 179 MRI scanning, 146, 168 mRNA, 12, 15, 17, 21, 48, 93, 95, 98, 109 maternal, 21, 98-99, 109-110, 124 zygotic, 21

Index multicellularity, 7, 9, 63, 76, 80, 95, 97, 105, 129, 209, 264, 326 multinational corporation, 226, 228, 346, 349, 351, 359 multiverse, xviii, 198, 211, 331, 337 murder, 186, 191-192, 194, 217, 277 Murphy, Nancey, 149, 239 muscle, 9, 17, 65, 70, 100-104, 128, 145, 161 music, xix, 146, 159-160, 167, 170, 173, 178-179, 236, 244, 256-258, 338-339, 342-343 musical form, 339, 342, 343 musical notation, 159, 338 mutation, 17, 22-23, 29, 46, 57-58, 89, 95, 97, 112, 125, 129, 150, 205, 223, 231, 258, 271 beneficial, 30, 91, 151, 258, 299 frameshift, 24, 26 gain-of-function, 26, 121 homeotic, 107, 115 lethal, 59, 116 loss-of-function, 24, 111, 115, 121 neutral, 23, 91, 143 point, 23, 26, 28-29, 84, 136, 299 random, 171, 200, 235, 236, 342 regulatory, 57, 59, 107, 115, 137 mutation rate, 27, 29 mycorrhizal fungi, xvi, 55 myriapod, 40, 105 mysticism, 208, 210, 212-213, 247, 255, 311 myth, xvii, xviii, 38, 133, 165, 180183, 188, 191, 201, 221, 254, 312 mythology, 167, 257, 337 narrative, xvii, 195, 201, 232, 313, 343 biblical, 201, 240, 255, 312 gospel, 221, 242, 266, 269, 312 popular, 177-178 National Park, 233, 234, 347 natural environment, 164, 262, 325, 347, 360, 363

Redundant God? Christian Faith in the Light of Evolution natural resource, 47, 53, 133, 220, 344-347, 350, 352, 360 natural selection, xiii-xiv, xix, 23, 44-47, 53, 57, 59, 66, 74-75, 91, 97, 162-163, 170-171, 185, 200, 205, 232, 235, 247, 256-257, 314, 317, 323-325, 339, 342, 363 natural world, xviii, 32, 165, 187, 230-231, 234, 245, 265, 295-297, 307, 318-321, 325, 329-332, 347-350, 356, 365 naturalism, 224, 236, 239-242, 244, 246, 249, 255, 260, 262, 267, 317 Nature-Nurture debate, 137, 139 Nazi, 169, 185-186, 191, 332 Neanderthal, 132-134, 143, 151 necessity, xvii, xviii, 126, 288, 293, 358, 365 neighbour, 90, 95, 116, 145, 157, 193, 220, 290, 296, 327, 354 nematode, 40, 56, 68, 83, 98, 105, 117, 119, 125, 228, 237 neo-Darwinian synthesis, 171, 205206, 209, 363 Neolithic, 135, 156, 159, 190, 216, 233 Neolithic Revolution, 156, 161, 165, 167, 215, 217, 255, 352, 356 neoteny, 53, 97 nerve, 28, 104, 120 nerve cell, 81, 125, 128-129, 145, See also neuron nerve cord, 122, 124 nerve net, 83, 102, 153 nervous system, 9, 60, 103, 125, 129, 140, 145, 153 neural circuit, 140, 145-146, 148150, 152 neural tube, 104, 109 neurobiology, xv, 33 neuroimaging, 147 neuron, 28, 33, 129, 132, 145, 148, 237, See also nerve cell neurotransmitter, 145, 152

433

New Testament, 149, 177, 196, 201, 220, 221, 267, 273, 286, 287, 303, 308, 318, 345 niche, 37, 155, 322, 326, 330, 342 ecological, 37, 39, 46-47, 49, 75, 77, 84, 292 specialised, 46-47, 75 niche construction, 155, 157, 171, 233-234, 249, 343, 352 nightmare, 296, 298, 345 nitrogen, 55, 90, 180, 326 Noah, 44, 217, 347, 348, 356 Nobel Prize, 10, 15, 31, 94, 145146, 206, 208 non-believer. See atheism non-human creation, 245, 265, 295, 302, 305, 308, 318, 319, 329 non-reductive physicalism, 149, 239 noogenesis, 206, 208-209, 215 noosphere, 206, 212-213, 299 Northcott, Michael, 146, 193, 295, 346-354, 360 notochord, 70, 101, 104 novelty, 23, 49, 127, 339 nucleosome, 19, 94 nucleus, 7, 8, 15, 17, 21, 41, 96, 98, 109, 114, 325 nurse cell, 109-110 nurture, xv, 138-139, 143, 146, 282, 311 nutrient, xvi, 6, 32, 55, 65, 85, 98, 136, 307, 323 nutrition, 53, 98, 156, 225, 321-322, 329 obedience, 209, 240, 244, 272, 274, 301 oblivion, 282, 300, 301, 305, 315, 318, 320 observation, 3, 4, 6, 165, 230, 242, 318, 330 observer, 154, 246, 304 ocean, 39, 64-66, 76-77, 90, 201, 294 ocelloid, 80, 91 octopus, 80, 82, 84, 153 oestrogen, 98, 147

434 offspring, xv, 21-24, 48, 53-54, 58, 98, 136, 143, 314, See also progeny Old Testament, 167-168, 188-192, 217, 220, 229, 256, 262, 268, 273, 275-276, 280, 282, 286, 315, 318, 332, 344-345, 354 Omega Point, 206, 208-209, 211213, 288, 299, 317 ommatidium, 67, 81-82 omnipotence, 243, 247, 259 omniscience, 243, 259, 261 ontogeny, 60, 205 oocyte, 22-23, 109 oogenesis, 98, 109 ooplasm, 99, 101 Oord, Thomas Jay, xiv, 260, 286 openness, 261, 274, 294, 323 operon, lac, 15-17 opportunist, 39, 51-52, 60 oppression, 268, 276, 312, 327, 332 oral tradition, 156, 159, 270, 312 orchid, 35-36, 40, 55-56, 104, 233234, 330 order (taxonomy), 40, 57, 77 ordination, 294, 324 Ordovician, 70-71, 73, 76 organelle, 8, 80 organic compound, 30, 63-64, 180181 origin of life, 30, 206, 209, 299 original sin, 203, 215-217, 221-222, 274, 288, 290 Orthodox, 197, 222, 229, 241, 251, 274, 288-291, 294, 300, 303, 311, 355 orthodoxy of belief, 149, 183, 189, 213, 229, 241, 248, 287, 363 orthologous genes, 83, 108, 112, 115, 117, 121-125, 129, 158 oscillator. See periodicity ostrich, 85, 306 outer darkness, 297, 303 outgroup (phylogeny), 27, 37 ovary, 98, 109 overpopulation, xx, 79, 245, 343 ovum. See egg

Index oxygen, 3, 9, 65-66, 73, 76, 84, 136 paganism, 185, 188 Page, Ruth, 245, 265, 295, 305-306, 315, 320-321, 333 painting, 134, 164, 170, 221, 257, 337 paired domain, 18, 81, 83 pair-rule gene, 110-112, 114, 116, 122, 130 palaeontology, 202-205, 308, 363 Paleogene, 77-78 Paley, William, xiv, 45 panentheism, 241, 243, 261-263, 308 panpsychism, 207-209 pantheism, 241, 307-308 pantheon, 165, 189, 271 parable, 196, 240-241, 255, 275, 280-281, 284, 306, 318, 322, 330 paradigm, xiii, 3, 5-6, 163, 171, 195, 253 paradigm shift, 3, 6, 324 paradise, 231, 303 paradox, 54, 81, 140, 192, 207, 254, 267, 274-275, 279, 284, 288, 321, 353, 363 paralogous genes, 119-120, 125 parapodia, 65, 125 parasegment, 107-109, 111-112, 115 parasite, 6, 51, 55-56, 136, 161, 166-167, 228, 231, 353, 359 passion of Jesus, 244, 259, 262-265, 282, 285 pastoralist, 135-136, 161, 233 pathogen, 56, 133-136 patriarchy, 197, 222 pattern, xix, 19, 27, 48, 53-55, 60, 63-64, 74-75, 84-85, 94, 99, 103107, 110-116, 119-122, 127, 134, 137, 142-143, 147-148, 152, 168, 172, 188, 191, 238-239, 257, 264, 272, 289, 324, 329-330, 339, 343 Paul, 149, 197, 211, 215, 221, 240, 245, 254, 264-267, 269-275,

Redundant God? Christian Faith in the Light of Evolution 281-282, 284, 287, 290-291, 296-300, 302, 324, 328, 332, 337 peace, 187, 193-194, 269, 272, 290, 298, 304 Peacocke, Arthur, xx, 177, 202, 222, 224, 232, 235-246, 249, 255-256, 260-262, 267-268, 274, 285, 295, 304, 313, 317, 338 peer review, 5, 225 Pentecost, 270, 273, 287, 308 peptide bond, 10, 12, 15 periodicity, 111, 114, 238 Permian, 70, 73, 76, 78, 343 persecution, 144, 241, 270-271 personality, 137-138, 148, 168 of Jesus, 267, 290 personhood, 149, 288 Persons of the Trinity, 200, 210, 229, 266, 273, 286-289, 293 perspective, human, 141, 178, 277, 307 scientific, xix, 208 theological, 193, 226, 248, 249, 288 pest, 28-30, 51, 57, 226-227, 319, 359 pesticide, 27-29, 359 PET scanning, 146-147 petal, 9, 35, 40, 58, 104, 127-128 Peter, 192, 195-196, 198, 269, 324, 328-330 Pharisee, 268, 277, 280, 314, 331, 346, 357 phenotype, 24, 46, 58, 75, 97, 130, 136, 155, 223 phenotypic plasticity, 36, 51, 61, 171 pheromone, 147, 330 philosophy, xvii, 149, 216, 219, 236-237, 245, 252, 255, 265, 271, 287, 325, 337 Phoenicia, 159, 188, 280, 322 phosphate, 9, 21, 31-32, 96 phosphorylation, 95-96 photosynthesis, 8, 41, 60, 63-64, 76, 218, 325

435

phyletic group, 65, 77, 112, 117, 122-123, 342 phylogeny, 3, 27, 60, 205 phylum, 40, 57, 63, 67-68, 70, 73, 75, 77, 112, 117, 119, 123, 130 physiology, 84, 181, 224 pilgrimage, 190, 306 pioneer, 51, 93, 292, 347 placenta, 83, 85, 100 placental mammal. See mammal, eutherian planning, 153, 170-171, 256 plant, xvi, xx, 6-9, 16, 18, 34-41, 44-45, 51-55, 57-60, 63, 71, 77, 80, 95, 104-105, 127, 129, 156, 180-181, 200-201, 218-219, 226, 230, 234, 264-265, 289, 304, 318, 325, 330, 335-336, 343, 347 plant breeding, 56, 58, 228 plasmid, 7, 94, 162 plastic, 336, 348, 357 poetry, xvii, 158-159, 208, 229-230, 254, 295, 305 politics, xvii, 169, 192, 255, 275, 329, 336, 349, 351-352, 354 Polkinghorne, John, 177, 242-243, 249 pollen, 7, 9, 55, 57, 98, 330 pollination, 55, 330 pollution, 79, 237, 292, 319, 343, 347, 350, 357 polypeptide, 11-12, 15, 18, 23, 26, 28 polyphyletic group, 41, 85, 325 polyploidy, 58-59 polytheism, 165, 167, 282 Pope Francis, 204, 324, 355, 366 Popper, Karl, 3, 5, 195, 270 population, xx, 4, 22, 24, 29-30, 36, 46-51, 57, 61, 133, 135-136, 142-143, 161, 167, 215, 239, 259, 321 isolated, 36-39, 46, 91, 293 local, 49, 54, 56, 142-143, 153 population growth, 47, 156 populism, 185-186, 352 positional identity, 102, 111

436 possibility, as God's gift, 265, 274, 286, 301, 305-306, 309, 317, 333 post-translational modification, 21, 95 potato, 58, 225-228 potential, 88, 153, 209, 263, 264, 276, 309, 359 potter(y), 156, 158, 219, 316 power, of the Spirit, 268, 304 symbolic, 222, 240-242, 267 worldly, 276-278, 291 powers of darkness, 279, 300 praise, 189, 243, 268, 286, 295, 319, 363 prayer, 260, 276 preaching, xiii, xviii, 177, 214, 254, 311, 313, 333, 336, 365 Precambrian, 3, 62-65, 83 predation, 39, 48-50, 54, 154, 201 predator, xvi, 48, 51-55, 67, 84, 154, 259, 289, 305, 318, 320, 325, 329, 359 predictability, 60, 149, 237-238 prediction, 3-5, 33, 48, 54-55, 165, 237-238, 330, 344-345, 348, 351, 356, 367 prehistory, 161, 170 prejudice, 197, 254, 323, 331 pre-lapsarian, 231, 288 pre-mRNA, 17-18, 20-21, 95 prey, 53-54, 61, 67, 84, 153, 259, 289, 305, 318, 333 priest, xiii, 160, 167, 177, 203, 212213, 236, 243-244, 249, 265, 268, 279, 294-296, 304, 324, 326, 329 priest of creation, 245, 294-296 priesthood, 290, 294-296 primary cause, 232, 258-260, 317 primary mesenchyme, 101-103, 338 primate, 39, 86, 130, 133, 151-152, 193, 220 primordial soup, 30-31, 308 Principle of Divergence, 45, 47 process theology, 232, 261-262

Index proclamation, 195, 222, 266, 275, 290, 320, 327-330 Prodigal Son, 178, 280, 306 profligacy, 320, 346-347, 352, 367 progeny, 24, 47, 288, 322-323, 339 progress, xviii, 45, 79, 160, 188, 205, 210, 222, 283, 351 prokaryote, 7, 9, 15-17, 41, 76, 80, 209 proliferation, 22, 31, 46, 66-67, 70, 132, 206, 342 promise, 126, 227, 244, 251, 271, 273, 275-276, 280, 287, 290, 298, 301, 309, 315-316, 324, 330, 331, 344, 365 promoter, 15-18, 20, 95 propaganda, 169, 191, 332 prophecy, 221, 254, 298, 344, 346 prophet, 191, 210, 255, 262, 268, 276, 296, 319, 344-345, 354 protection, 50, 53, 157, 167, 228, 278, 316, 333, 368 protein, xiii, 6-7, 10-13, 15, 17-24, 26, 28-33, 48, 57-59, 81, 84, 8990, 94-98, 101, 105-106, 109112, 114, 116, 119, 124, 136, 145, 150, 163, 181, 253, 293, 326-327 protein domain, 18-19, 97, 163 protein structure, 11-12, 23, 31, 163, 293 protein subunits, 11-12, 84 protein synthesis, 12, 98 Protestant, 183, 197, 210, 355 Protista/protist, 41, 63, 80 protostome, 68, 102-103, 117, 130 providence, 230, 277, 295 proximo-distal axis, 107, 125 prudence, 227, 230 Psalm, 187-189, 198, 229-230, 279, 313, 323, 333 Psalm 29, 187-189, 230, 313 pseudogene, 97, 132 psychism, 207 psychology, 132, 140, 186, 201, 219, 268, 329

Redundant God? Christian Faith in the Light of Evolution publication, 5, 45, 203, 206, 225226 punctuated equilibria, 60, 74-75 punishment, 167, 259, 297, 298, 302, 316, 345 purgatory, 298, 300, 306 purine bases, 9, 31 pyrethroid insecticides, 28-30, 299 pyrethroid-resistant mutations, 2830, 299 pyrimidine bases, 9, 31 quantum phenomena, 3, 31, 242243, 246, 285 rabbit, 3, 52, 56 racism, 179, 186, 197, 311 rainforest, 46-47, 294, 342, 350 rangeomorph, 63-65, 70 rat, 153, 225 rationale, 169, 200, 206, 357 rationality, xvii, 3, 5, 112, 155, 160, 166, 169, 195, 220, 245, 267, 285, 312 rebuilding, 298, 354 receptor, ligand, 96, 111-112, 114, 120 neurotransmitter, 145 recognition sequence, 95-96 recombination, 8, 19, 22-23, 26 reconciliation, 193, 198, 236, 256 reconstruction, 218, 338 recovery, 275, 292, 330 recycling, 307, 323, 336, 358 redemption, 211, 223, 240, 253, 265, 298, 301, 303-304, 307-308, 317-319, 344, 365 reductionism, 32-33, 177, 230, 237, 242 redundancy, xvii, 11, 180, 199, 326327 refinement, 4, 114, 170, 207, 302 Reformation, 160-162, 191, 284, 331 refuge, 154, 198, 235, 302 regulatory gene, 83, 94, 96 regulatory inputs, 95, 127

437

regulatory sequences, 17-18, 23, 26, 85, 94-95, 111, 119, 163 regulatory switch, 57, 129, 338 rejection, 274, 313, 331 rejection, of God, 165, 266, 302 of worldliness, 277, 357 relationship, 207, 220, 243-245, 265, 268, 276, 287-288, 291, 295, 305, 312, 345, 360 evolutionary, 35, 41, 63, 68, 101, 120 relativity, 3, 246 religion, xvii, xix, 33, 132, 134, 144, 146, 157, 164-169, 177, 189, 191, 193, 209, 217, 221, 226, 235, 244-245, 252-253, 257, 271, 275-276, 279, 311, 312, 328-329, 336, 348, 351, 361 religious leaders, Jewish, 268, 275, 281, 314, 326, 329, 331 remembrance, 212, 244, 306, 327, 328 renewal, 212, 307, 329-330, 355356, 363 renunciation, 305-336, 357 repeatability, 6, 242 repentance, 215, 297, 299, 303, 314, 320, 347-348, 354 repetition, 104, 170, 256, 329 repressor, 15-16, 18, 114 reproduction, 53-52, 247, 292, 315, See also sexual reproduction reproductive failure, 299, 314 reproductive success, 53-55, 97, 153, 166, 307, 316, 322-323 reptile, 27, 39, 41, 71, 73, 85-86, 90, 99-100, 180, 222, 326 resilience, 293, 319, 330 resistance, 7, 28-29, 57, 80, 135136, 359 resonance, 214, 245, 313, 333, 338 resource(s), 156, 191, 327, 355 non-renewable, xix-xx, 297, 358. See also natural resource responsibility, xix-xx, 149, 185, 201, 324, 347, 356

438 environmental, 224, 294-295, 325, 360. See also moral responsibility restoration, 8, 188, 270, 301, 321, 344, 347, 356 restraint, 22, 171, 230, 265, 353, 357-361, 365 resurrection, 149, 192, 194, 197198, 201, 221, 231, 232, 240242, 254, 260-261, 265-271, 274, 279, 290, 299, 304-306, 317, 329, 330-331, 364 resurrection appearance, 194, 269270, 308, 331 retribution, 192, 298, 326 revelation, 218, 273 Revelation (Book of), 254, 296, 298, 306, 346, 351 reverence, 294, 304 rhetoric, 76, 191, 256, 258, 272, 275-276, 302, 333, 345 rhombomere, 120-121 rib, 104, 120-121, 221 ribosomal genes, 12, 15, 18, 26, 93 ribosomal RNA. See rRNA ribosome, 12, 15, 17, 21, 26-27, 98 ribozyme, 12, 15, 31 righteous people, 259, 277, 296, 300 righteousness, 191, 215, 248, 263, 316, 358 risk, xviii, 2, 137, 154, 161, 170, 212, 222, 232, 240, 246, 253, 263-264, 283, 297, 305, 308, 322, 332, 336 ritual, 159, 164-168, 191-193, 282, 290, 312, 328, 348, 362 rivalry, 160, 167, 193, 196 RNA, 31, 366, See also mRNA, rRNA, tRNA non-coding, 21 self-replicating, 31 world, 31-32 RNA polymerase, 12, 14-16, 18 RNA retrovirus, 12, 31 RNA splicing, 15, 17, 21, 94 Rolston III, Holmes, 305-308, 315, 329

Index Roman emperor, 177, 271, 279 Roman empire, 178, 271, 272, 278, 282, 357 root(s), xvi, 9, 55, 156, 228, 289, 321-322 biblical, 229, 284, 300 rotation, 253, 359 rRNA, 12, 15, 26, 31-32 Russell, Robert J. (Bob), 177, 242, 249, 285 Sabbath, 280, 359 Sabbath rest, 217, 354, 358, 363 sacrament, 213, 244-245, 288, 328 sacred text, 167, 254, 312 sacredness, 191, 193, 228, 244, 291 sacrifice, 193, 243-244, 282, 294295 sacrifice of Christ, 192, 220, 222, 274, 281, 283 sacrifice, human, 167, 191, 217, 297, 328 personal, 336, 348 saint, 177, 190, 195, 277, 301 Saint Francis, 195, 337, 355 saltation, 59, 75 salvation, 192, 212, 214, 231, 251, 256, 261, 267, 281, 284, 296, 299-308, 314, 318, 324, 331, 337, 363 Samaritan, 268, 280-281, 296, 357, 363 sample, 2, 4, 139 sample size, 4, 139 Satan, 192, 277, 279, 291, 300-301, 320 Saviour, 266, 303 sayings of Jesus, 194-196, 266, 277, 297-300, 318-320, 327, 351 scandal, 268, 328 scapegoat, 191-194, 283, 297, 353 scepticism, 222, 249, 254, 351, 355 schism, 289, 292 scholarship, biblical, xviii, 189, 218, 254 science, xiv, xvi-xvix, xxi, 3, 5-6, 32-33, 130, 160, 163-164, 170,

Redundant God? Christian Faith in the Light of Evolution 177, 180, 183, 195, 204, 207210, 219, 225, 230, 235, 239, 242, 246, 248, 253, 265, 296, 307, 317, 332, 336, 346, 351 applied, 6, 351 science and religion, 177, 202, 214, 236, 245, 335 scientific journal, 5, 204 scientific paper, xxi, 5-6, 10, 21, 57, 74, 107, 127, 164, 170, 204, 225 Scopes trial, 184-185 Scottish Episcopal Church, 284, 289, 335 scripture, xviii, 168, 183, 190, 202, 215, 219-220, 224, 242, 251, 254-256, 275, 287, 295, 311-315, 346, 356, 364-365 sea anemone, 122, 128 sea levels, falling, 78 rising, 335, 350, 352-353, 363 sea squirt, see ascidean sea urchin, 16, 41, 93, 101-103, 122, 233, 338, 341 macromere, 101-103, 338 mesomere, 101, 103 micromere, 101-103, 338 secondary cause, 232, 258-260, 285, 317 secondary loss, 117, 129 secularism, xvii, 249, 312 sediment, 41, 63-67, 78, 153 seed, 46, 55, 59, 77, 197, 292, 321322 segment, 40, 59, 96, 108-109, 111, 114-116 abdominal, 107, 112, 116 posterior budding off, 109, 112, 114-115, 123-122 thoracic, 105, 107 segment identity, 59, 107, 109, 116, 122 segment polarity gene, 111-114, 122-123 segmentation, 65, 67-68, 108-110, 115-117, 122-123, 129

439

long germ-band, 109, 114, 116, 123 short germ-band, 109, 112, 114116, 122 selection, xiii, xvii, xix-xx, 56, 58, 86, 141, 163, 170, 255, 339 positive, 132, 135-136, 161. See also natural selection selection pressure, 29-30, 45, 56, 171, 299, 342 selective advantage, 30, 32, 46, 136, 161, 299 selective breeding, 56, 156, 186, 228, 352 selective memory, 254, 312 self-emptying, 177, 220, 240, 244, 272, 274, 283, See also kenosis self-giving, 220, 239, 243, 283 selfing, 24, 98 selfish gene, 162, 193 selfishness, 171, 290, 305, 315, 323 self-righteousness, 192, 331 self-sacrifice, 192, 222, 255, 295, 347, 352 sense of self, 147-148, 154-155 sensory input, 148, 152, 171-172 sentience, 246, 304 sepal, 9, 104, 127-128 servant, 255, 280, 306, 322, 324325, 347, 354 service, 325, 329, 347, 358-359, 365 service to others, 240, 290, 353, 358 setback, 3, 79, 232, 264, 284, 301, 338 settlement, human, 142, 154, 156157, 165, 167, 233, 352 sex cell. See gamete sex chromosome, 27, 54, 223 sexism, 197, 311 sexual reproduction, 7, 22, 50, 53, 97, 139, 288, 307 sexual selection, 54, 56, 315 sexuality, 139, 147, 186, 294 shadow Sophia, 230-231, 248 Shakespeare, William, 162-163, 173 shalom, 234, 288, 290, 298, 363

440 sheep, xvi, 156, 269, 297, 315-316, 323, 364 sheep and goats, 297, 315, 364 shell, 49, 53, 67, 98-100, 123 shell coiling, 98-99 shepherd, 267-268, 316, 323 short-termism, 172, 344, 350, 361 Sibelius, Jean, 339, 342-343, 363 sickle-cell anaemia, 136-137 signal, inductive, 81, 101 intercellular. See also ligand, or hormone neural, 145, 168, 171 pheromone, 147, 330 protein, 101, 105, 111-112, 119, 125 signalling pathway, 83, 96, 114, 123, 338 signalling, intercellular, 81, 95, 101-102, 111-112, 292 intracellular, 95-96, 112, 114, 292 neural, 152, 168 silencer, 17-18, 57, 94-96, 123, 129 Silurian, 65-66, 71, 76, 201 sin, 201, 210, 215, 217, 222, 240, 248, 256, 259-260, 274, 277, 280-283, 296, 301, 303, 306, 320, 344, 346 sinfulness, 170, 296-297, 320, 327, 337 sinner, 232, 268, 277, 281, 299, 357 six-day creation, 183, 217-218, 252, 264 skin, 9, 81, 101-103, 293, 326 slaughter, 231, 329, 364 slave, 167, 179, 197, 272, 278, 291, 311, 324-325, 327, 354 slavery, 179, 197, 285, 311 snail, 41, 89, 98 snake, 41, 47, 85, 104, 121, 152, 333 social group, 151, 153, 191, 325 social stratification, 154, 167, 217, 291

Index society, human, 6, 155-156, 165, 167, 186, 194, 222, 244, 285, 292-293, 311, 324, 354, 359 soil, 9, 63, 136, 197, 215, 228, 237, 289, 321, 323, 344, 347, 350, 356, 359 solidarity, xv, 216, 232, 276, 277, 307, 314, 328, 329 somite, 109, 120-121, 123 Son of God, 223, 240, 266-267, 278 Son of Man, 240, 324, 361 Sophia. See Wisdom soul, xv, 149, 169, 212, 220, 237, 239, 300-303, 355, 365 Southgate, Christopher, 273, 294, 304-305, 307 sower, 321, 330 sparrow, 318-319 special creation, 182, 246 specialist, 55, 60, 75, 77, 154 speciation, 33, 38, 47-49, 59, 75, 129 allopatric, 37, 46 ecological, 48-49, 75 sympatric, 38, 46 species, xvi-xx, 7, 24, 28-29, 32-39, 44-60, 66, 74-80, 84, 88-89, 95, 101, 105, 117, 122, 132-134, 153-156, 169, 171, 200, 204, 216, 234, 237, 239, 252, 256259, 292-293, 296, 305, 307, 318-319, 324, 329-331, 336, 342, 344, 352, 359, 361, 365, 403 species loss, xvi, xx, 39, 61, 289, 297, 332, 356 speech, 148, 150-151 sperm, 7, 23, 98, 103, 137, 142, 222 spider, 40, 73, 117 spinal cord, 104, 120-121, 124 spirit, xv, 149, 164-165, 213, 237, 239, 298, 328 spirituality, xvii, xx, 164-165, 195196, 206-209, 212-216, 221, 246, 248, 299, 312, 337, 361, 363 spliceosome, 17, 20 sponge (Porifera), 40, 63, 68, 70, 83, 102, 127-129

Redundant God? Christian Faith in the Light of Evolution "sport", 57-58 squid, 80-81, 90 stamen, 9, 104, 127-128 standard of living, 345, 348, 349, 350 standards, moral, 217, 277 stasis, 74-75 statistics, 4, 141, 225 steroid, 65, 96 stewardship, 195, 220, 265, 325, 354, 356, 360 Stickleback, Nine-Spine, 154 Three-Spine, 48-49, 58, 95, 154 stone tools, 155-156, 330 stop codon, 12, 24, 26 story-telling, xvii, 156 strategy, 53, 56, 61, 96, 127, 305, 322, 325 stress-response, 90, 237, 292 structures, serially repeated, 70, 96, 104-105, 124 struggle for survival, xv, 47, 185, 264, 315 sub-species, 36, 39, 58, 133 substance (ousia), 287, 288, 293 success, 148, 156, 163, 166, 169170, 179, 204, 299, 336, 344 suffering, xv, xvi, 282, 304, 317 Suffering Servant, 276, 306 suffering, animal, xvi, 315 human, xvi, 187, 259-260, 276, 301, 307 of Christ, 240, 273-274, 282-283 of creation, 231, 243, 246-247, 252, 257, 261, 298, 304, 307, 317, 329 summary, 75, 189, 198, 236, 261, 269, 277, 282, 343 superiority, 167, 189, 302, 331 supervenience, 237, 239 survival, 9, 53, 97, 156, 166, 171, 185, 210, 233, 321-322, 325, 330, 342, 344, 352 survival of the fittest, 47, 186, 353

441

sustainability, xx, 234, 244, 249, 295-296, 336, 349-350, 354-361 symbiosis, 8, 55, 60, 65, 85, 209, 259, 325-326 symbol, 134, 158 symbolism, 216, 240, 242, 278, 296, 328, 339, 354 symmetry, bilateral, 104-105, 122, 125, 128 radial, 104-105, 122 symphony, 83, 164, 172, 178-179, 232, 338-339, 342-343, 363 synagogue, 280, 291, 314, 328 synapse, 145, 151-152 syncretism, 190, 271 target gene, 21, 96, 114, 151, 338, 341 TATA-binding protein, 18, 20, 95 tax-collector, 268, 277, 280-281 taxon, 35, 44, 57, 60, 77, 79, 130, See also taxonomy taxonomy, 3, 36, 39, 105 teachers of the law, 280 teaching, 93, 154, 161, 166, 184, 195, 203, 204, 266, 291, 302 teaching of Jesus, xvii, 196-197, 244, 274-278, 296, 328 technology, 6, 88, 157-158, 225, 336, 348, 349-353, 358, 365-366 Teilhard de Chardin, Pierre, xix, 202-215, 230-232, 247, 249, 251, 288, 299, 317 teleology, 171, 205-206, 208, 210, 213, 231, 235, 317 teleonomy, 171, 235, 241, 258, 265, 288, 315, 365 temple, 157, 167, 187, 327, 354 temptation, 194, 266, 277, 320, 350, 361 terminology, 89, 306, 356 terrorism, 169, 354 testimony, 67, 210, 252, 270, 327 tetraploid, 7, 8, 58-59 thanksgiving, 280, 328, 363 theism, 241, 246, 252, 262, 263

442 theme, musical, 172-173, 232, 256257, 342 theodicy, 247, 260, 305 theo-drama, 231-234, 248, 261, 279, 317 theologian, xviii, 161, 182-183, 211, 216, 239-242, 249, 251, 254, 285, 300, 302-303, 306, 336, 355 theology, xiii, xv, xvii, xx, 149, 177, 182-183, 193, 198, 202-203, 208, 214-216, 219, 222-226, 229, 231, 235-236, 242-243, 248, 249, 251, 255, 260, 262-267, 272, 274, 276, 283-287, 300-301, 306, 308, 310, 325, 332, 338, 355 political, 308, 352 process, See process theology Theory of Mind, 155, 165 theropod dinosaur, xiv, 73, 86, 326 Thomas. See Doubting Thomas thorns, 278, 321 time-frame, 201, 215, 342 Tolkien, J.R.R., 256, 337 tool use, 133, 153 tool-making, 133, 153-154, 161 Torah. See Law of Moses toxicity, 41, 53, 65, 76, 78, 137, 226, 292, 329, 356 trade, 60, 1587-158, 269, 362 tradition, 40, 80, 160, 163-166, 179, 189, 195-196, 202, 214, 222, 229-233, 288, 291, 294, 296, 311-312, 347, 359 trait, 7-10, 22, 24, 53-54, 84, 98, 129-130, 137, 139, 152-153, 161, 193, 206, 265, 314, 344 transcendence, 239, 241, 243, 261, 279 transcription, 12-13, 15-17, 22, 3031, 93, 95 transcription factor, 17-21, 59, 81, 83, 94, 101, 107, 109-114, 116, 120, 127, 129, 150, 338 transfer RNA. See tRNA transformation, 59, 115, 121, 149, 164, 180-181, 189, 207-208, 213, 240, 282, 309

Index transience, 55, 111, 120, 189, 292, 303, 320, 361, 365 translation, 12-13, 15, 17, 21, 22, 26, 30-31, 93, 98, 109 inhibition of, 21, 110 translation (linguistic), 187-188, 195-198, 208, 210, 213, 218-219, 266, 272-273, 278, 284, 297, 298, 302-303, 311, 318, 320, 321 transmembrane protein, 32, 90, 145 transmembrane receptor, 91, 96, 120 transport, 61, 155, 157, 346, 348, 351 transubstantiation, 213, 244 tree, 32, 51, 61, 71, 73, 151, 164, 233, 286, 309, 325, 352 trial of Jesus, 192, 278, 329, 351 Triassic, 73, 76-78, 343, 352 trilobite, 70, 73, 76, 82, 88 Trinity, 192, 200, 210, 229, 244, 251, 261, 266-267, 272-274, 282, 285, 286-290, 292-294, 299, 337, 364 triumphalism, 288, 299 tRNA, 12, 15 tropics, 39, 47, 63, 294, 342, 347, 353 trunk, 104, 111, 117, 121 truth, 2, 6, 177-178, 194, 201, 221, 252, 261, 269, 273, 275, 282, 286, 296, 303, 312-313, 333, 348 twin studies, 137, 139 twins, dizygotic (non-identical), 137, 139 monozygotic (identical), 137-139 uncertainty, 168, 242, 330 unconditional love, 280, 284, 290 understanding, xvii-xviii, 3, 6, 49, 107, 114, 149, 186, 191, 210, 213-214, 220, 231, 245, 251, 284, 288-292, 294--296, 299, 332, 364 uniqueness, evolutionary, 89 326

Redundant God? Christian Faith in the Light of Evolution genetic, 98, 288-289 human, xvii, xix, 88, 149, 151152, 155, 161, 193-194, 206, 220-221, 310 unity, 209, 211, 288, 290, 293, 337 unity of the Godhead, 287-288, 292 universalism, 299-303, 306-308, 324, 331, 337, 364 universality, 193, 284, 290 unsustainability, 344-345 upstream DNA sequences, 17, 94 urea, 90, 180-181, 326 urochordate. See ascidean user-illusion, 168 value, in God’s eyes, 305, 317, 319 to humans, 262, 318-319, 344, 346, 348, 361, 365 Vanstone, W.H., 244, 246, 262, 264, 282-283, 285 variant, extreme, 45-46, 57 sequences, 23, 135, 142-143, 151, 299 specialist, 46-47 variation, isotropic, 57, 74 morphological, 36, 64, 74, 105 natural, 56-57, 289 small-scale, 23, 57-59, 74, 339, 342 thematic, 172, 339, 342 vegetable, 56, 156 vegetation, 50, 219, 233, 336 veneration, 190, 271-272, 287 vertebra, 28, 96, 104, 120-121 cervical, 104-105 thoracic, 104, 120-121 vertebrate, xvi, 9, 41, 70, 74, 80-85, 89, 96-98, 101-106, 108-111, 118-125, 130, 150, 152, 222 VGSC, 28-29, 299 victim, 133, 143, 191-193, 210, 282, 297, 314, 353 victory, 184, 188, 275, 279, 300, 303, 329

443

vineyard, 255, 358 violence, 170, 191, 193, 312, 353 Virgin Birth, 221-224, 240, 266-267 Virgin Mary, 190, 221-223, 230, 267-268 virtue, 230, 282, 361, 365 virus, 6, 9, 12, 52, 56, 166, 366-368 vision, 90, 182, 206, 208-214, 232, 240, 247-248, 270, 296, 298, 300, 304, 306, 314, 345, 360, 366 visual communication, 88, 152 vital force, 180-181, 206, 209, 232 vitalism, 180-181, 232, 243 viviparity, 85, 98 vocalisation, 151-152 vocation, 245, 273, 295-296, 324 volcanic eruption, 62, 345, 347 von Balthasar, Hans Urs, 231-232, 248, 261, 273, 302 vulnerability, 240, 262, 267, 274, 366, 368 warm-blooded, xiv, 333 warning, xvi, 79, 204, 314, 329, 336, 344-347, 351, 364 wastage, 225, 231, 243, 253, 329 wastefulness, human, 327, 348, 361 of evolution, xv-xvi, 257 wavelength, 90, 333 weed, 51, 58-59, 319 welfare, animal, xvi, 234 well-being, 160, 167, 171, 227, 234, 244, 289, 292, 361, 363 whale, 61, 77, 88 wheat, 58, 244, 330 wheel, 91, 158, 327 wilderness, 187-188, 266, 277, 320 wine, 212, 244, 328, 364 wing, xiv, 40, 59, 73, 86, 91, 107, 116, 320, 326 wisdom, xviii, 214, 231, 262, 268, 319, 358 creaturely, 230-231 human, 276, 346, 361 received, 178, 182, 275, 323

444 Wisdom, divine, 230-231 literature, 229-230, 248, 318 Wisdom, Lady, 212, 229, 230 witness, 184, 197-198, 270, 285, 312 wolf, 57, 84, 156, 194 women, as resurrection witnesses, 197-198, 269-270, 330 wonder, 229, 230, 242, 248, 295, 323 Word, 211, 229, 241, 263, 288, 304 world-view, xiii, xv, xix, 6, 162, 164, 236, 243, 296, 320, 332, 365 worship, xv, 167, 178, 187, 189, 218, 256, 260, 267-268, 271-272, 282, 287, 291-292, 316, 348 wrath of God, 241, 266, 283, 296297, 344, 347 Wright, Tom, 197, 240, 270-275, 278, 284-285

Index writing, 130, 153, 156, 158, 162, 332, 362 writing system, 158, 160 wrong-doer, 167, 277, 282, 296 Xenopus, toad, 93, 124 X-linked gene, 27, 139 Yahweh, 167, 187, 189, 276, 280, 286-287, 298, 345 Y-chromosome Adam, 142, 216 yeast, 16, 94, 285, 359, 365 Y-linked gene, 27, 142-143, 223 yolk, 6, 98-102, 109 zeal, xiii, 241, 270, 295, 357, 361 zebrafish, 21, 120 zinc-finger domain, 18, 120, 130 Zizioulas, John, 287, 289-291, 294 zone of polarising activity, 105-106 zygote, 97-101, 109-110, 138