A Brief Natural History of Civilization: Why a Balance Between Cooperation & Competition Is Vital to Humanity 9780300252644

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a brief natural history of civilization

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A BRIEF NATURAL HISTORY OF CIVILIZATION Why a Balance Between Cooperation & Competition Is Vital to Humanity

M A R K B E RT N E S S

New Haven and London

Published with assistance from the foundation established in memory of Philip Hamilton McMillan of the Class of 1894, Yale College. Copyright © 2020 by Mark Bertness. All rights reserved. This book may not be reproduced, in whole or in part, including illustrations, in any form (beyond that copying permitted by Sections 107 and 108 of the U.S. Copyright Law and except by reviewers for the public press), without written permission from the publishers. Yale University Press books may be purchased in quantity for educational, business, or promotional use. For information, please e-mail [email protected] (U.S. office) or [email protected] (U.K. office). Set in Janson type by IDS Infotech, Ltd. Printed in the United States of America. Library of Congress Control Number: 2019949024 ISBN 978-0-300-24591-2 (hardcover : alk. paper) A catalogue record for this book is available from the British Library. This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). 10 9 8 7 6 5 4 3 2 1

For Janette and Sarah, the strong women who have made life matter to me

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Contents

Preface ix Acknowledgments

xiii

Introduction: Why Natural History?

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part i life: where we came from 1. Cooperative Life 15 2. Life in the Food Chain 35 3. Taming Nature 56

part ii civilization: who we are 4. 5. 6. 7.

The Triumph and Curse of Civilization Resource Exploitation 93 Famine and Disease 114 Domination versus Cooperation 135

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part iii fate: where we are going 8. Our Ethnocentric, Entheogenic Universe 157 9. Preserving Food and Improving Health 170

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Contents

10. Civilization on Fire 189 11. Unnatural Nature 209 Epilogue: The Natural History of Civilizations Notes 239 Bibliography 253 Illustration Credits 287 Index 289

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Much of my life has been about the seashore. Ever since my childhood spent exploring Puget Sound, I have been fascinated with the animals, plants, and interactions that occur where the water meets the land. This fascination took me into academia and a career focused on shoreline ecology, which led me to understand these landscapes as microcosms of larger forces—that is, as evolutionary theaters replete with the dramas of natural selection, competing species, and cooperative relationships. But studying the shoreline is not all snails and fiddler crabs: human activity has affected all of our world’s ecologies. We cannot think about the interlocking effects and partnerships and battles that occur in the natural world without thinking simultaneously about the humans who are now a part of these contact zones, whether clearly present (for example, in beachfront condominiums) or invisibly powerful (by causing the rising global temperatures or the spread of invasive species). We are, and always have been, just as much a part of the world as cordgrass and clams. Rather than splitting our conception of history between natural history and human history, then, I read the history of civilization as natural history, continuing the trajectory that writers such as Jared Diamond and Yuval Harari have begun. This means understanding how civilization and its products—from agriculture and medicines to political hierarchies and religious systems—have been derived from our evolutionary past within specific ecologies ix

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and environments. A natural history of civilization requires seeing each step of what we are tempted to call “human progress” as a response to a natural history problem. But there is more to this story, because to read human civilization through its natural history, we must know what natural history itself is, and this requires an accurate, holistic understanding of evolution. Half a century ago, evolution was largely seen as Darwinian battles of natural selection: the survival of the fittest, where change came about through competition between antagonists. This is certainly one component of evolution, but often overlooked (even within the scientific community) has been the integral and powerful role of cooperation. Cooperative interactions have been able time and time again to rise above competition and the selfcentered, competitive drives within all species that Richard Dawkins refers to as selfish genes. This cooperative framework of life on earth not only holds together the biological systems that humans depend on, but also has been responsible for the major innovative inflection points in evolutionary history—the origination of the cell, the transition into multicellular organisms, the ascent of humans, agricultural revolutions, and civilization itself. Telling this story is important, more so today than ever before. Without knowing just how tied we are to the world, in a time where we can and do affect the world as never before, our species will be prone to collapse. Unlike other organisms on the planet, we have been able to rise above the restrictions ecosystems naturally have, continuing to grow and fill the world, continuing to need more resources, and continuing to leave more and different kinds of waste. I wrote this book to communicate what scientists and academics have learned about the natural world, evolution, and ourselves in the past half-century. My hope is that understanding how connected and reliant we are on the organisms and intricate systems of the world will allow us to replace our ideas of evolution as purely competitive—ideas that, I believe, have been driving our furious and deleterious overgrowth as a species. In this book I will offer examples of the integral cooperation that has led to our species’ power and suggest that an intentional turn to cooperative processes and programs is the only path to our civilization’s continued survival. In doing so, I have sought to

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translate scientific research into everyday language. Although this approach means that I may at times omit the fine-grained distinctions that scientists make, I believe that conveying the more general findings of contemporary research is essential, as a way of enriching everything from our public policy debates to our lifestyle decisions. We need a common and communal understanding about our relationship to the world. This begins with knowing about the origins of our species and our civilization, and ends with clearly grasping the scope of how we affect the world that made us.

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Acknowledgments

Decades of working alongside open-minded students on the comfortingly predictable patterns in nature led to this book. Studying simple questions of what creates patterns on shorelines led to natural history lessons that I have applied to human culture and civilization. For this journey of discovery, I am indebted to legions of students I have worked with and learned from at Brown and elsewhere. Too numerous to mention individually by name, they have all had an impact on the thoughts and words in this book. Some students and colleagues encouraged me to write this book and then read and/or commented on rough, virtually unreadable early drafts. Among these colleagues, Darrell West, John Bruno, Leo Buss, Sam Lash, Keryn Gedan, Bruce Wheeler, Mark Thorson, and Q He were particularly valuable, each in his or her own way. I owe an equally great debt for the invaluable help and advice that I have received from the editors, reviewers, and artists with whom I have worked. Tim DeMay, a poet and gifted writer, helped make the prose accessible and engaging for general readers; Jean Thomson Black, Michael Deneen, and Julie Carlson supported and helped me negotiate the Yale University Press landscape; my Serbian daughter, Andjela Brasanac, and her crew of architects and artists, particularly Adrijan Karavdic´, helped get the visual imagery right; Deb Nicholls helped track down images and permissions to use them; Paul Ewald gave me the inspiration and confidence to finish this project when it was needed the most; and anonymous reviewers xiii

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gave me an instrumental perspective on the pros and cons of my writing and thoughts. This help and advice aside, I alone am responsible for any factual and judgment errors in this book. I am, after all, a natural historian by profession and an amateur historian by avocation. The opinions and omissions are my own. My early mentors Mike Tate, Gary Vermeij, and Bob Paine inspired me to study nature and not to stand on the sidelines. My wife and daughter, Janette and Sarah, as always, supported me unconditionally through good and bad days. I am extremely grateful to all.

a brief natural history of civilization

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Introduction Why Natural History?

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ho are we?” “where did we come from?” and “Where are we going?” are among humankind’s oldest questions, ingrained in our social groups, cultures, and civilizations. Our interest in these questions reflects our self-centered point of view: as we humans experience the world, we incorporate our surroundings and others into our perception of who we are. Our philosophies and sciences, too, began as entirely anthropocentric, or “human-centered,” where we were the focal point and purpose of the universe. Over the past hundred years, however, we have come to realize that not only are we far from the center; we also take up an infinitely small space and moment. Such a dramatic reorientation has rippled through our religions and philosophies, our sciences and societies, prompting a radical revision of our understanding of who we are as a species. In this book, I hope to inspire a similar revision in our understanding of ourselves by sharing what I know about the natural history of our species—that is, by explaining how humans too belong to the biological world of actions and reactions. In resisting the tradition of viewing human history as separate from and privileged over that of the natural world, I hope to bring to light essential insights about ourselves and our world, insights that can change how we handle the pressing challenges confronting us all. 1

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Introduction

While growing up in Washington State, I explored the Puget Sound and the Oregon shorelines and coastal forests, collecting snail shells and crab molts, learning exactly where and when to find them. Shoreline plants and animals are found at specific elevations and at predictable times, and I became fascinated by these patterns, at once conspicuous and soothing. What I didn’t understand then was that my curiosity and attraction came from a primal, ancestral source. The drive to understand, interpret, and follow patterns in our natural surroundings has made us who we are today. Natural history refers to the individual and interacting factors that control the resource needs, distribution, reproduction, and death of individuals, populations, and species. It is the study of how environments and those that live within them relate, but it can also refer to the intuitive understanding of our ancestors that led to their survival and successful reproduction. Homo sapiens, as well as our extinct close relative Homo erectus, have spent over 99 percent of their time on earth as hunter-gatherers. Our genetic baggage of millions of years of hunter-gathering experience eclipses our mere ten thousand years of civilization experience, so it is not surprising to find an attraction to the seashore, for example, echoing in us, as one of many genetic remnants of our familiar yet distant past. The rich food supply and relative safety from predators that coastal shorelines provided meant that these were crucial hunting and traveling thoroughfares. Expertise in navigating seashores was simply a necessity for human survival—like being able to avoid snakes, or to discern edible mushrooms and sponges from the brightly colored dangerous ones. The shoreline therefore has been imprinted on our souls and DNA. Natural and human histories are, just as they always have been, inexorably intertwined. As a species we have a long, intimate history with all life on earth. We know that self-replicating life evolved only once on our planet, because all organisms, from viruses and bacteria to humans, are designed according to the same genetic rulebook and feature the same DNA programming language. Our DNA is similar to that of clams, even more to that of dogs, and nearly identical to primate DNA. Although we have evolved into the most dominant organisms on earth and have escaped many of the constraints that limit other organisms, we still live within and are bounded by

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many of the basic rules of our natural history. We are the bigbrained products of the same ecological and evolutionary processes that shape the lives of all organisms, processes that have led to fundamental parallels in the spatial and social fabric of human civilization, animal communities, and plant assemblages. Although we have forgotten this ancestry and shared genealogy, examining human history as natural history can help remind us of our past and forecast our future. This approach is by no means novel. It underlies the influential work of Charles Darwin, Karl Marx, and E. O. Wilson, among others. But our understanding of human and natural history has accelerated at such a scorching pace over the past few decades that a new examination and synthesis for a general readership are needed. Because the topics covered here are more comprehensively examined in technical papers and books (cited for further reading), my focus is not on reporting details, but rather on synthesizing the broader important message that is emerging from a collection of disparate yet new information in the sciences. Bringing natural history to bear on how we see ourselves is a crucial and difficult task. Despite the vital role that natural history played in our ancestors’ survival, and the fine-tuning that our relationship with the environment underwent through millions of years of trial and error, today natural history is often disparaged as an antiquated study of observing plants and animals. In stark contrast to its lofty beginnings in ancient Greece, where natural history was the first science with a goal of understanding everything from the stars in the sky to the trees in the forest, it is today often set aside for large data sets built from second- or third-hand observations and communal data. But natural history is not democratic or library-dependent, and the frontiers of science are still driven by bold, creative, and unique observations. Louis Agassiz, the nineteenth-century geologist celebrated for proposing (based on decades of observations in the Swiss Alps) that geological formations are the product of ongoing processes rather than the creation of a supreme being, wisely taught his students to study nature, not books. This simple mantra is chiseled in granite over the entrance to the Marine Biological Laboratory at Woods Hole, one of the birthplaces of American science.

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Introduction

My own work as a scientist studying coastlines has bolstered Agassiz’s philosophy. It has also led me to believe that all life on earth, including civilization itself, developed from and is governed by the same physical and biological processes playing out through evolution: symbiogenesis and hierarchical self-organization. Many of the ideas related to these processes are relatively recent, or have recently become refined and appreciated. All reflect a growing concern with the collaborative components of shared life. One of the objectives of this book is to tell their story as integral players within an updated natural history of civilization, one that reflects what we have learned from the many scientific discoveries of the twentieth century. These processes are most noticeable in the dynamic relationships between the elements and participants of a given community. Like the mutual relationships developed between hunter-gatherers and coastline plants and animals, all communities—from coral reefs to cities—are connected by their positive and negative interactions, that is, by an ecosystem of cooperative and competitive forces that has evolved over time. Atoms attracting and repelling each other at the molecular level find a biological rhyme in the competition and collaboration of cells and microbes to create multicellular organisms. Plants and animals also compete and cooperate to form organized forests and salt marsh assemblages. From atoms to ecosystems, structure and organization are driven by conflict, compatibility, cooperation, and balance. Natural history has not always been viewed this way. Less than half a century ago, the overriding force shaping natural selection and ecosystems was thought to be competition among species for limited resources. Herbert Spencer’s “survival of the fittest” and Tennyson’s “nature, red in tooth and claw” still ruled the day, coalescing with a Cold War perspective that had little room for cooperation or group benefits. Positive cooperative relationships between or among individuals, species, and populations were underappreciated. Partnerships, symbiotic relationships, and mutualisms in nature—phenomena where all participants benefit—were thought to be interesting side plots, or exceptions to the rule, rather than organizing principles. This perspective cast a long shadow on human history, which had also largely been interpreted

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as a narrative of competition and conflicts. The discovery that the organelles in our cells led to multicellular life through cooperation among microbes began to change this narrative, and soon we were able to see similar effects of mutual causes and cooperation everywhere, until mutualism and positive feedback were understood to be essential processes in building the scaffolding of life and civilization on earth. These are crucial terms, so to be clear: mutualisms are the reciprocal positive interactions among unrelated species that benefit both species and are thus reinforced evolutionarily by natural selection and ecological positive feedback. The more technical term of symbiogenesis refers to the foundational, constructional role that symbiotic, cooperative interactions have played in overcoming obstacles during the history of life on earth. Since being tipped off to the powers of cooperation and the recursive relationships between species, scientists have seen and documented the vital role of cooperation time and time again. G. Evelyn Hutchinson, the father of American ecology, metaphorically envisioned the relationship between natural history and natural selection as “the ecological theater and the evolutionary play,” which became the title of his 1965 book.1 That is, the plot and unfolding of a play or drama depend on the makeup of the theater, and in turn the play itself can affect its setting. More recently, the British biologist Richard Dawkins reduced evolution to its lowest common denominator, envisioning the substrate for natural selection’s operations as composed of individual organisms acting as survival machines for “selfish genes.” These selfish genes are for Dawkins the true actors of evolution, with everything else simply the vehicles, resources, or obstacles for their action. Cooperation and group benefits, however, are consistent with a gene-based view of life. Moreover, Darwin’s evolutionary play initially represented natural selection as a slow, long process, which is certainly true. But more recently, natural selection has been shown to be capable as well of quick changes, such as conspicuous morphological and survival traits that meet new or fluctuating challenges. These phenomena are evident in our daily lives—for example, disease resistance leads to the short-term usefulness of antibiotics, quickly outmaneuvered by pathogens, forcing us in turn to redesign our antimicrobial

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Introduction

tactics. This faster version of evolution, however, isn’t restricted to rapidly reproducing microbes. One of the first demonstrations of rapid natural selection in the wild occurred at Brown University in 1898, near where my office now sits.2 Hermon Carey Bumpus, a young professor at Brown interested in the then-emerging field of statistics, found 136 incapacitated house sparrows that had been caught in an ice storm on College Hill. He collected them, attempting to nurse them back to health in his lab, but was only partially successful, and many of the sparrows died. When he measured the morphological traits of the sparrows that survived and those that didn’t, he found that he had captured one of the first natural selection events ever quantified in the field: simply put, the sparrows that survived were larger and stronger than those that died. Similar findings of rapid evolution are at the cutting edge of evolutionary biology a century later. Decades of meticulously patient research on Darwin’s Galápagos finches by Princeton University’s Peter and Rosemary Grant have shown that beak types, from heavy nut-cracking to skinny insect-probing beaks, as well as their parallel food preferences, can rapidly adjust to changing food resources.3 Evolution isn’t always the sluggish process we had assumed. Even slowly reproducing vertebrates can respond quickly to rapid changes if there is a pool of genetic variation from which to draw. Changes to our understanding of evolution have included the trend in the 1960s and 1970s to use uncritical evolutionary interpretations to explain the development of group behaviors and traits. Most notably, the British biologist Vero Wynne-Edwards was known for supporting group selection at the level of the species. He argued that traits evolved for the good of the species as a whole, an idea that was not supported by data or theory.4 Over the past couple of decades, however, evolutionary biologists have found that the explanatory power of natural selection and evolution can and does extend beyond models of simple survival of the fittest constrained within populations of a single species. This new model of evolution may better be thought of as one that spans interactive, cooperative networks of organisms rather than one composed entirely of selfish and independent organisms—the survival of the fittest group, rather than simply the survival of the fittest individual.5 Models of symbiogenesis thus describe how species evolve with

Introduction

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and among other species, and accordingly operate at higher levels of organization. This changes how we view natural selection, since group behavior at local, regional, and even global scales can be selected for if it increases genetic success. Eörs Szathmáry and John Maynard Smith argued that even the major transitions in the evolution of life on earth—from cells, to plants, to animals, to social organization—have all been driven not by competition among selfish-gene machines, but rather by cooperation. One of the goals of this book is to consolidate these understandings while suggesting that cooperation among groups can trump even competition, one of the driving forces of evolution. There are two ways to evaluate group selection in evolutionary theory: an uncontroversial one and a newer, more radical one. The first sees group selection occurring when an individual receives more benefits by living in a group or an association instead of alone. In other words, evolution working on the individual level leads to group living. This is readily accepted in the world, and we can see it in cases such as snails and barnacles living beneath seaweed canopies. The second, however, acknowledges cases when the group, rather than the individual, becomes the unit of natural selection. Such groups are often associated with shared genetic affinity or kin selection—for example, beehives and gopher colonies. This second kind of group selection widens the evolutionary possibilities for cooperation within an ecosystem. The continuum between individual selection and group selection is one we would be wise to acknowledge in our histories of evolution, especially because group selection more powerfully explains components within the evolution of human culture, such as cooperative technologies like speech and trade that counterbalance competitive forces. Group benefits can best individual gains and become the driver of human history and civilization itself. An expansive natural history—one that describes the transition from nucleated cells and multicellular organisms to cooperative hunting, trade, social organization, revolutions in civilization, and extreme population growth—is the story of escalating cooperation that has made us who we are today. If we allow it to prevail and inform our decision-making, it may change our futures. Life on this planet, then, requires positive and negative species interactions, coevolution, and symbiosis or mutualisms with

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Introduction

the organic surroundings. Rather than being interesting side plots, these processes, collectively referred to here as symbiogenesis, set up, build, and maintain the stage for ecological interactions in the evolutionary theater that shapes our history. Symbiogenesis generates patterns in nature, ranging from the relationships between nuclei, mitochondria, and plastids that control and power plant and animal cells and fuel ecosystems, to the process that took hundreds of millions of years to produce the oxygen that makes the planet livable. Our diets and medications, too, are derived almost exclusively from our trial and error discovery of coevolutionary relationships with plants and animals. Even spirituality and religion in humans may be rooted in our symbiotic relationship with the plants and mushrooms in our ecosystems. Alongside symbiogenesis, another powerfully simple idea that has structured all life on the planet is hierarchical organization, which describes an obligatory, sequential order to the development of repeated, predictable patterns. When counting to five, for example, one comes before two and five comes after four. Similarly, when building a house, the foundation is laid before the first floor, which in turn is added before the roof. Building from the roof down doesn’t happen. This is simple hierarchical organization. Self-organization and hierarchical assembly are why organisms are nonrandom associations— why plant and animal communities on rocky shores, coral reefs, mangrove forests, and forest gradients are not haphazardly arranged collections, but rather distinctly organized (and because of their organization, cooperative) systems, easily recognized by both natural historians and their hunter-gatherer ancestors. Even assemblages like tropical forests or groups of insects, which appear to be either organized nonhierarchically (or neutrally) or arranged randomly, bespeak high levels of self-organization when viewed from the appropriate spatial or temporal scale or perspective. For example, a sand dune on a low-wave-energy shoreline has conspicuous species segregation, whereas sand dunes on high-wave-energy shorelines superficially appear to have no spatial organization—until they are viewed from an airplane. Similarly, trees in tropical rainforests appear to be randomly distributed—until they are viewed across latitude, or biogeographically. At these latitudinal scales, plants and animals and their communities can be seen to

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have very predictable patterns of spatial organization, both ecologically and evolutionarily.6 Simple, elegant self-organization, driven by the rules of attraction, repulsion, compatibility, and incompatibility, is a basic law and common denominator in physics. It is also, therefore, essential to those physical and biological processes that generate repeated patterns in nature. Together, the fundamental evolutionary processes of symbiogenesis and hierarchical organization suggest that when viewed in terms of the large, broad strokes of time and space, human natural history and the evolutionary trajectory of intelligent life are relatively deterministic. Yet “relatively” means that randomness plays a just as large and equally influential role in evolution: Stephen J. Gould once famously proposed that if the play of life were rerun, it would produce different results each time. The complex and elegant traits and patterns that natural selection generates are accomplished only by random mutations that occur in response to the physical and biological environment. Moreover, teleological, or goal-oriented, thinking has no place in evolutionary thought. Evolution has no foresight or long game; it always plays for the success of single generations by acting in each generation on existing genetic variation; it cannot see into the future to anticipate needs or problems. Therefore, when we see magnificent products of natural selection, we must resist assigning causation or goals to their evolution. No trait, no matter how complex or elegant, is the product of a plan, but is instead the result of myopic, small, generation-by-generation steps. That said, randomness at all levels of organization—from physics and chemistry, to genetics, to biodiversity and organic community organization—is superseded by hierarchical self-organization, a process that in turn creates the illusion of intent and design.7 If nature were not bound by unifying rules and constraints, there would not be such distinctive and repetitive patterns in life and civilization. The same determinism that predictably leads to similar species-segregation patterns on seashores around the world, and leads to an orchid taking the shape of a winged insect to attract future pollinators, has shaped humans with respect to their environments and food sources. Such is the blurry line between the ecological theater and the evolutionary play. Humans evolved teeth and digestive enzymes to chew and process plants, and plants

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Introduction

responded defensively, by creating both heavy cellulose wood to limit digestive processing and metabolic chemical byproducts that poison consumers or impair their cognitive abilities and neurological perceptions. This process has been going on since before we were human. A group of Neanderthal fossils, for example, was recently found with abscessed teeth and the chemical residue that indicates consumption of natural plant aspirin. Even before Homo sapiens evolved, its hominid ancestors were learning by trial and error to self-medicate with forest plants and fungi. If the play of life were begun again, it would produce different details every time— but the major themes, structure, and plot would be similar and easily recognized, constrained by basic laws of physics, chemistry, evolution, and the rules of hierarchical self-organization. Three interrelated themes operate throughout this book. First, the oldest battle on earth is between competition and cooperation. Cooperation drives innovation, from the formation of cultural groups to industrial and information revolutions. Moreover, cooperation is the only solution to the current global environmental crisis. Historians, ecologists, and evolutionary biologists have traditionally focused on negatively competitive and predatory interactions, generally missing the important role that cooperation has played in human evolution and the development of civilization. Second, coevolution among organisms, such as between consumers and prey in their evolutionary arms races, is a pervasive force that regulates and contextualizes all life on earth, including humanity, in direct and indirect ways. The line between direct and indirect interactions is blurry, but, as a shorthand, direct coevolutionary interactions are those that occur between us and the organisms we live with, while indirect interactions are how we are influenced by the coevolutionary interactions between other organisms. For example, our complex mutualisms with microbes keep us healthy and alive while our mutualisms with plants and animals led to domestication, agricultural revolutions, and getting up in the morning to feed the dog. Meanwhile, the chemical defense products of evolutionary arms races between plants and their consumers have indirectly given us pharmaceuticals and spirituality. Third, self-organization and hierarchical control complement symbiogenesis and coevolution by imparting a large dose of deter-

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minism to ecological and evolutionary processes, patterns, and systems. This spatial and temporal determinism has provided a natural history roadmap, or template, for the evolution of humans and the emergence of civilization. The efficacy of these evolutionary processes does not stop at civilization, which we can operationally define as the organization of humans that leads to increasingly developed culture, science, industry, and governance. Or we can more simply define civilization as the opposite of barbarism, anarchy, or chaos—terms for the lack of societal organization. If humans, like all other life on earth, are the product of natural self-organization, selfish-gene selection, and cooperation, then civilization itself can be discussed through a natural history lens. In following the development of civilization from the extended family groups of hunter-gatherers that preceded it through the large-scale organization of human efforts made possible through agricultural and technological revolutions, we will discover that our species has now eclipsed much of nature’s control—in many areas, we now control nature, instead of the other way around. The organic link between natural and human history has thus led not only to the evolution of civilization, but also to the degradation of the very natural systems that created us. In a way, the more globally recent commencement of the Anthropocene era, the geological era of human impacts driving planetary patterns, has inverted the terms of natural history, and humans have become the most influential homegrown agent of disturbance that the earth has ever seen: whereas nature once determined the development of humanity, humans are now determining the future of nature and life on our planet.

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chapter one

Cooperative Life

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ow we define humanity has deep and lasting effects on how we define life, civilization, the world, the universe, and science itself. If humanity is defined as a particularly privileged species, for example, then the human lifespan becomes the measure by which the age of even the universe is decided, and the human body the ruler for its size. This standard of measurement has led to all sorts of confusing humancentric ideas: an earth created in six days; the earth, the universe, and everything in it being only some six thousand years old; the earth as a flat disk in the center of a universe that extends only as far as our sight; and human civilization as the apex of a special, creative, willed genius unlike anything else in existence. Natural history demotes humanity from this privileged throne above all life and matter. What happens to our understanding of the universe and life when humanity is not the chosen species or the middle ground between angels and animals, but rather a largebrained product of physical and biological processes that have been ongoing for billions of years? What does it mean to say that humans, quite literally, are simply vessels constructed from—and containing hosts of—cooperating and competing microbes? What is a natural history of civilization if civilization is simply the result of a process by which human society reaches an advanced stage of social 15

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development and organization, features shared by all species on the planet? To answer these questions requires first that we tell a different story of how we came to be—a story that happens to explain also how our pets came to be, and the insects that live on them, and the trees outside, and the bacteria everywhere, even the chemicals that make up the asphalt we drive on. The story of life on earth is simply one chapter of a story that started billions of years ago and will continue past us, for it is a story of the processes of self-organization that undergird existence, the physics and chemistry that write everything there is. These are grand sentences, and troubling ones for some of us to accept. It will take time to let them affect our philosophies. Before that, however, we will follow the story from the beginning to see how the development of the universe has led to the development of life, humanity, and even civilization.

The Universe Begins Fourteen billion years ago, our universe came into being from a cosmic event of unimaginable size. This event generated the atoms that, ever since, have self-organized through physical and biological processes to form galaxies and great apes, planets and plants, stars and starfish. We, too, are the products of this ongoing, ever-changing process. Until the eighteenth century, theologians used Old Testament genealogies to estimate that creation occurred approximately six thousand years ago. Then pioneering thinkers like James Hutton, Charles Lyell, and Lord Kelvin began looking at rocks, using geological inferences rather than the Bible. Hutton, the father of modern geology and deep geological time, analyzed Scottish rock formations to estimate that the earth was millions of years old. Hutton also inferred his theory of uniformitarianism from his observations, a theory that assumes that the same processes that shape the earth today shaped the earth in the past. Lyell then popularized Hutton’s views in his influential Principles of Geology, in which he estimated that the earth was 300 million to 400 million years old, while Lord Kelvin, analyzing the cooling rate of molten rock, put

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the earth’s age at 20 million to 40 million years. Radioactive dating by Arthur Holmes in 1913 changed the game yet again. By observing naturally occurring radioactive isotopes and their decay rates, Holmes and others were able to read the radioactive decay of matter as a molecular clock. Radioactive decay remains today the most accurate and consistent tool science has for calculating deep time. By using this technique, Holmes estimated that the earth is 1.6 billion years old, a number that increased as the methods of observation and analysis improved. Today, the consensus of the scientific community is that the earth is around 4.5 billion years old, and the universe itself, based on the age of extraterrestrial rocks that have impacted the earth and the distances and velocities of various galaxies from the earth, is 14 billion years old.1 As our age estimates changed, so too did our theories of the universe’s origins. In 1927, the Belgian priest and physics professor Georges Lemaître published a paper proposing that the universe was the result of an initial explosion from which it was still expanding. Initially referring to this hypothesis as the “cosmic egg,” Lemaître’s work did not receive attention until it was republished in English in 1931—two years after the American astronomer Edwin Hubble published a similar paper discussing the expansion of the universe. Though its name the “Big Bang” came along later, Hubble is generally given credit for the idea, despite Lemaître’s earlier work.2 That the universe and everything in it began in an extraordinarily dense point that it is still expanding from can be further confirmed from Einstein’s 1915 general theory of relativity— though this theory is unable to explain the actual physics of the Bang itself. New theories attempting to adjust Einstein’s equations and accommodate this problem suggest the universe may be infinite, with no beginning or end, but this highly interesting research is less important for our purposes than the organizing mechanisms set into motion by the Big Bang.3 After the Big Bang, astrophysicists believe the universe was populated by the simplest atoms and atomic particles. These particles and simple helium and hydrogen atoms collided over time to eventually combine and coalesce into increasingly complex elements, like carbon and oxygen. These in turn attracted and repelled each other due to their atomic charges to form molecules like

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water, transformations that took place over hundreds of millions, even billions, of years. Our planet was formed in a galaxy of billions of stars when a star ended its life in a massive explosion, sending shockwaves into the interstellar medium. The shockwaves impacted a cloud of dust, compressing the dust to a density that quickened its gravitational collapse. The original cloud was asymmetrical, so the dust began to spin. This spin caused the dust cloud to compress into a disk. At its center, gravitational collapse produced a protostar, which upon reaching sufficient mass triggered thermonuclear reactions to become a shining star. Debris remaining in the spinning disk collided, forming pebbles that became rocks that then fused to form planetesimals. The largest of these collected the remaining gas and dust and grew into planets that interacted gravitationally with each other and the new star, shifting their orbits until a quasistable configuration was ultimately reached. Such was the origin of the earth and sun. Later in the book I will pose the necessary question: with the vast number of solar systems and planets created by these same mechanical processes, is it reasonable to assume that life is a singular event?

The Ingredients for Life After the earth stabilized as a planet, it began to cool enough for a rocky crust to form and for water vapor, released by both volcanoes and impact events, to condense. Volcanic activity also produced gases with the basic ingredients of life—carbon, hydrogen, oxygen, and nitrogen—as well as toxic gases such as ammonia and methane. Early earth’s atmosphere consisted entirely of these gases, leaving no free oxygen. Within this primordial soup, organic molecules followed the same processes they did after the Big Bang: colliding, concentrating, and self-organizing to form more complex molecules. The earth was now full of the diverse elements essential to life on this planet, but what would spark the leap from organic and nonliving combinations to living communities? Until the midnineteenth century, this advance was explained by spontaneous generation: life generated independently. People pointed to the classic case of maggots and mold seeming to emerge spontaneously

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from rotted bread. Louis Pasteur’s demonstration of preventing such “spontaneous generation” simply by boiling water revealed the existence of microbes and the microscopic world and gave rise to the study of “abiogenesis,” the origin of life. Abiogenesis has been an active research field for over half a century, and has generated two general schools of thought. One supports the panspermia hypothesis: life, defined as self-replicating complex molecules, arrived on earth from space via asteroids or comets. The second is convinced that microscopic life was first generated from the earth’s own primordial physical and chemical conditions. While the panspermia hypothesis has its advocates, it is difficult to imagine how primordial life could have tolerated entry into the harsh atmosphere and extreme physical conditions of early earth.4 Moreover, if panspermia happened more than once, multiple genetic ancestries or origins would be present in the genetic signature of life on earth, but DNA sequencing data show instead that all life on earth has a common genetic ancestor, that is, we all follow the same genetic instruction manual. Finally, and frustratingly, the panspermia theory simply moves the goalposts on the question of how self-replicating, complex molecules came about in the first place. Evidence for the extraterrestrial origin hypothesis is largely theoretical, with no empirical or experimental support. By contrast, the second hypothesis, that life originated on the earth through chemical self-organization, has had increasingly strong experimental support. In the 1950s, Stanley Miller, while still a graduate student, sought to reproduce the conditions of early earth in a lab (Figure 1.1). Working under his adviser, Nobel Prize winner Harold Urey, Miller set up glassware containing water, ammonia, methane, and hydrogen—a mixture thought at the time to approximate the early atmosphere. A flame heated the liquid to simulate the conditions of a volcanically active planet, and electric sparks simulated lightning. In a few days, the water turned deep red: Miller had created a broth of amino acids, dubbed the “primordial soup,” necessary for life’s origination. Over the past two decades, various other experiments have mimicked early earth conditions, especially those surrounding deep-sea hydrothermal vents. As the earth cooled, it came to look much more like it does today, complete with a solid crust and mantle over its hot, liquid,

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1.1. Stanley Miller, father of origin-of-life chemistry. Miller’s simple experiments showed that key organic compounds can be synthesized from inorganic substances by simple chemical self-organization. Stanley Miller Papers, Special Collections & Archives, UC San Diego.

thermonuclear core. Similar in temperature to the sun, this core remains hot from radioactive decay, like the large mass of a thermonuclear reactor. Interactions between this core and the cooler surface of crust and water drive the movement of the continental plates that, when they collide, can result in mountain ranges, and when they separate, expose the mantle and core to the earth’s surface. This exposure and the movement of molten mantle material to the surface is what can lead to land formations like the Hawaiian islands or to hydrothermal vents, such as those that are tapped for energy in Iceland where the European and North American plates collide. Hydrothermal vents have attracted the attention of scientists since their discovery in 1949 and are responsible for some of the most important scientific breakthroughs in the past century. While all other ecosystems on earth are powered by solar energy, the eco-

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systems that have developed in and around hydrothermal vents are powered by the heat and chemical energy rising up from the earth’s core of nuclear reactions—which in turn are remnants of the universe’s Big Bang origins. The vents make possible new physical and chemical combinations, because the high pressure and higher heat can produce more sophisticated organic compounds, like sugars and amino acids.5 The present-day communities of unique, ventdependent organisms that exist near hydrothermal vents are founded on chemosynthetic, rather than photosynthetic, bacteria: the bacteria in vent ecosystems convert hydrogen gas, carbon dioxide, or methane into organic matter as a source of energy. Such “anoxic,” or oxygen-less, conditions are strikingly similar to those of the early earth, and thus both hydrothermal vents and experiments like Miller’s can act as telescopes through time for studying the origins of life. From these telescopes, we can hypothesize that life began in a chemically rich, high-temperature, anoxic environment, similar to that of hydrothermal vents where complex molecules commonly form. In fact, it is even possible that these hydrothermal vents are where life first began through this forming and self-organizing. To date, however, complex molecules are all that scientists have been able to synthesize under laboratory conditions—they have not yet been able to artificially recreate, from scratch, the self-replicating organic molecules that would mark the first moment of life and are the cornerstone of evolution. But how did complex molecules organize to form self-replicating proto-organisms, the raw material for natural selection? Or more simply, when did molecules self-organize to initiate life? After all, a definitional marker of “life” is the ability to propagate and reproduce. Two theories have been proposed. The first is that self-replicating molecules, or nucleic acids, were organized from the same amino acids that spawned in natural versions of the Miller-and-Urey-like experiments, and that these molecules were then subject to natural selection. This hypothesis, however, requires complex self-replicating molecules, like RNA (which controls development and metabolism), to form before there is a metabolism to harness and control or an energy source to fuel life. The second theory flips the scenario, proposing that energyharnessing metabolism self-organized first, then drove the production

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of self-replicating molecules. Thus, self-replicating molecules evolved to control this energy and made metabolism subject to natural selection, all the while fueled by the seeping energy stream from thermal vents. The “metabolism-first” idea, which Nick Lane of University College London has written elegantly about in Life Ascending, is currently the favored hypothesis.6 Figuring out a possible answer for the origin of life, however, does not solve the puzzle of life’s amazing diversity. How did the common genetic ancestry of such divergent species as sea urchins and condors and humans lead to such variety? How does difference arrive from similarity?

Competition . . . and Cooperation First articulated by Charles Darwin, natural selection is the basis of the evolutionary process whereby any heritable characteristic of an individual that allows it to produce more successful offspring will be spread to its descendants and ultimately all individuals of a species. Traditionally, natural selection is linked with the concept of competition, for competition is the arena wherein such heritable characteristics are tried and tested, proved worth passing on or weeded out—a truly free-market theory of evolution, if you will. This traditional conception is attractive in its explanatory power and simplicity. Following our early history of life, for example, the initial self-replicating proto-organisms would reproduce into large populations that eventually stressed the chemical resources in their ecosystems, their inhabited spaces. As resources became limited, self-replication could continue only if certain members of the species adapted to give themselves a leg up on their competitors. Changes in environments would lead to different species, with competition as the primary catalyst. We know now that this model is incomplete and insufficient. Competition is an important driver for species differentiation and evolution, of course—but it is not the only one. Over the past half century, scientists have developed increasingly detailed theories, backed by ever more convincing evidence, regarding the extraordinary importance that cooperation has played in the evolution of life. As we will see time and time again, cooperation has existed at

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all critical points in the history of life on our planet, alongside and often spurred on by, or in response to, competitive standoffs. In fact, there are many examples of cooperation outweighing the benefits of competition at those major turning points—the very origination of eukaryotic cells and multicellular organization; the evolution of group behavior in schools of fish, herds of grazing mammals, or beds of mussels to beat predators and competitors; the ancient obligatory microbial associations between plants and animals (including humans); and the human cooperation for group benefits that maximized reproduction and population growth. These mutualisms have created the world as we know it. To explore further this necessary revision to Darwin’s theory of evolution, we can do no better than to meet the iconoclastic thinker Lynn Margulis, one of the most creative and controversial microbiologists of the twentieth century.7 In 1970, Margulis provided strong evidence for the symbiotic origin of plant and animal cells (“eukaryotic” cells, which feature organelles) from the ancient bacteria described earlier. This general idea had been around for nearly a century, but had not been supported by data. Margulis hypothesized that the cells of single-celled organisms and those of multicellular plants and animals are the evolutionary product of a symbiotic, mutualistic association between ancient cyano- and aerobic bacteria. She first noted that eukaryotic cells all have mitochondria, the organelles responsible for converting fuel to energy in a cell, and that these mitochondria are regulated not by the helical DNA that reproduces and regulates the cell itself, but rather by a circular DNA that resembles the DNA of bacteria. From this she proposed that eukaryotic cells are the product of two distinct ancestors, each contributing its own DNA (Figure 1.2). In other words, these different proto-organisms “worked together” and eventually became the cells of all plant and animal life.8 Reaction at the time to Margulis’s “heretical” hypothesis—that all cells evolved from microbial mutualism, or “endosymbiosis”— was swift and harsh. Her now classic paper on the hypothesis, written in 1967 when she was still a graduate student, was rejected fifteen times before it was finally published, and some still dismissed it as garbage. Despite the initial ridicule, however, her ideas are now accepted and taught in high-school and college curricula.

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1.2. The endosymbiosis theory of how eukaryotic (nucleated) cells originated from prokaryotic (without nuclei) organisms: two distinct ancestors contributed their DNA to make cells that, over time, led to all plant and animal life on earth. This theory was promoted and substantiated by the American microbiologist Lynn Margulis. Original drawing based on public domain sources.

Her work shattered the common extrapolation from Darwin that the evolutionary process was exclusively motivated by predation and competition for limited resources. Instead, the evolution of life was driven just as significantly by “symbiogenesis,” a term that not only refers to the evolution of eukaryotic cells from their ancestors, but also can be applied on larger scales, following its etymology of “living together.” The organisms we see today are symbiogenetic: their origins come from processes of cooperation just as much as competition, and they live in a balance between these forms of living together and living apart.9

Gaia and Autopoiesis James Hutton’s influential eighteenth-century geological work, mentioned earlier, was part of his larger theory of “uniformitarianism,” which described the earth as being shaped and regulated by natural processes. Hutton believed that the earth’s physical and biological characteristics were themselves self-regulating components of a larger, interactive whole. Two centuries later, this idea was expanded on and became the “Gaia hypothesis,” named for the Greek

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personification of the earth and mother of all other gods. First formulated by Margulis and a British atmospheric chemist James Lovelock (known for his invention of an electron capture device), the Gaia hypothesis proposes that living organisms interact with their inorganic surroundings, buffering extreme conditions and recycling chemical byproducts to form self-regulated, self-organized, and self-maintained complex systems on earth. Controversially, this hypothesis suggests that even essential attributes of the biosphere— like global temperature and an oxygenated atmosphere—were produced, maintained, and are still regulated by organisms that make the earth habitable. This means that the evolution of self-replicating organisms also led to the creation of homeostatic mechanisms that would generate and reproduce conditions for life on earth by creating positive feedback loops. For example, 3.4 billion years ago, cyanobacteria (blue-green algae) evolved from the first self-replicating proto-organisms. Cyanobacteria invented photosynthesis, which permitted it to convert sunlight energy into chemical energy, inorganic carbon, and nitrogen, with an oxygen byproduct. This allowed cyanobacteria to escape competition with other microbes over the ambient molecules that such microbes absorbed as food. After 2 billion years, oceans of cyanobacteria generated enough oxygen to oxygenate the entire atmosphere and oceans, which in turn created the environment for bacteria to develop oxidative metabolism—a form of energy transformation far more efficient than that of its anaerobic ancestors. This process, known as the Great Oxygenation Event, is an example of how the interrelation of the world’s organic and inorganic attributes leads to new conditions for life. In this basic positive feedback loop, photosynthesis creates oxygen as a byproduct, enabling energetically efficient oxidative metabolism that, in turn, creates a carbon dioxide waste product that fuels photosynthesis. The recycling of waste products is the critical linchpin of the Gaia hypothesis, one probably best illustrated by the homeostatic balance of our atmosphere. This balance, a byproduct of supporting oxygen-producing plants and oxygen-consuming animals, controls our global climate. This example also illustrates a key aspect of the Gaia hypothesis and other theories related to self-organization: “autopoiesis,” a

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process of self-creation through self-feedback first explained in 1971 by the Chilean biologists Humberto Maturana and Francisco Varela (Figure 1.3). Autopoiesis is not simply, however, selfcreation: it points as well to the reciprocal effects of what has been created. In other words, the (simplified) system “cyanobacteria + atmosphere” moved along a homeostatic path wherein cyanobacteria thrived in the anoxic world—but also gave off oxygen as a byproduct. Then the byproduct’s presence became part of the system and as the amount of oxygen grew, the system changed, becoming something like “cyanobacteria + oxygenated atmosphere + aerobic molecules,” and gradually, since oxygen is poisonous to cyanobacteria, “aerobic molecules + atmosphere + the nearly extinct, but still existing today, cyanobacteria.” An autopoietic system therefore moves along feedback loops that eventually shift the system’s conditions. It is self-replicating, but not perfectly so. The Gaia hypothesis suggests that autopoietic, self-regulating processes operated simultaneously to make the earth habitable and to create the diversity of living organisms present today. From temperature stabilization to oceanic salinity and atmospheric oxygen, the Gaia hypothesis proposes that evolution has influenced the global environment by leading to recycling of waste products and by promoting the stability and homeostasis that has allowed for biodiverse evolution. The Gaia hypothesis does not suggest that organisms evolve characteristics for the good of the biosphere—we must remember that these evolutionary processes are not teleological— but rather that organisms evolve reciprocal webs of interdependencies that are then associated with global stability. More generally, it suggests that processes of self-organization and mutual cooperation drive every level of the origin of life, because individuals and species are “always already” connected to other individuals and species and to the makeup and management of their ecosystems.10 The Gaia hypothesis is not perfect, and valuable criticisms continue to be levied against it. Most damningly, the hypothesis is testable only correlatively, in that scientists may study positive feedbacks experimentally only within and among smaller-scale ecosystems. To truly test the Gaia hypothesis and its global implications will require a comparative study of life and systems across planets, for at the moment the earth is the only data point for the

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1.3. M. C. Escher’s Drawing Hands, a powerful metaphorical illustration of autopoiesis—the ability of a system to reproduce and maintain itself. © Escher in het Paleis, Den Haag/Fine Art Images/age fotostock.

claims made by Gaia proponents. This may sound to many like a far-fetched notion, but it is one that scientists expect to be able to achieve within one or two generations. Without such a comparative study, the hypothesis can be, and is, critiqued as a nearly teleological attempt to describe natural processes in terms of their perceived function or purpose. That is, the Gaia hypothesis claims that things are as they are because of positive feedbacks through history, whereas a more classical explanation of natural selection would claim that inorganic materials simply are, and that organic life was shaped and promulgated based on the ability to survive. For the moment, what scientists can do is rigorously explore the mechanisms that may have created life on earth and continue to study smaller-scale examples of autopoietic systems, such as

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coral reefs and salt marshes. These organic systems demonstrate a dependency on the positive feedbacks that create and maintain their predictable structure, organization, and productivity—the same feedbacks that, on a larger scale, ultimately led to the evolution of the human condition. They are the best model systems available for testing the Gaia hypothesis and ultimately the predictability of the evolution of cognitive organisms, that is, until the hypothesis can be itself tested against life on other planets.

Salt Marshes: A Case Study in Mutualisms and Self-Organization Much of my career has been invested in looking into specific ecosystems and examining the strong but unrecognized forces of mutualism and the balance between competitive and cooperative processes at play within them. In the early 1980s I worked on the reciprocally positive interactions between New England salt marsh mussels and fiddler crabs, interactions that I feel provide an optimal, clear example of the power of positive feedback loops. Marsh cordgrass is the “foundation species” of Western Atlantic salt marshes, which means that it creates and maintains the spatial framework and heterogeneity of that ecosystem’s community assemblages.11 Foundation species are responsible for the physical structure that provides housing, refuge, and support for the organisms of an ecosystem. They compose nature’s biological infrastructure. Marsh cordgrass is periodically limited by ice and storms, and even on its best days is poor in nitrogen. But attached to it are marsh mussels, which make their living by filtering microscopic food from the seawater and depositing nitrogen-rich waste on the roots. The mussels live in dense clusters and are attached to the cordgrass roots by their wire-like byssal threads. The cordgrass responds to the nitrogen deposits by sending roots into the mussel aggregations, making the mussels into living nutrient pumps and seawall fortifications, while the mussels themselves are protected from predators and the high summer heat by the cordgrass shade. This symbiogenetic garden leads to hard, tightly packed marsh banks of mussel-fertilized cordgrass and shorelines buffered from erosion and ice damage. In the sediment-rich lower latitude marshes of Georgia, mussels play

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an even more critical self-organizing role in marshes by controlling sediment deposition and marsh growth through filter feeding. In these systems, mussels filter sediment out of the water for food and deposit on the marsh surface the mucus-coated sediment mortar that accretes, builds, and binds together entire marsh ecosystems.12 At higher elevations, however, cordgrass is stunted by low water movement through the dense marsh peat and the accumulation of dead plant material. This is where fiddler crabs enter the picture. Marsh fiddler crabs are dependent on the cordgrass roots to support their burrows and on the above-ground grass to protect them from predators. Like armies of tractors, fiddler crabs plow through and process the marsh sediment for food, thereby increasing the flow of tidal water through the higher elevation marsh regions and allowing the nutrients to cycle through. In addition to demonstrating active mutualisms that change the ecosystem that organisms simultaneously create and live within, cases like that of the North American saltwater marsh can explain another component of the world’s autopoietic self-organization: hierarchical organization (Figure 1.4). First discussed in reference to organism development thirty years ago by Leo Buss, hierarchical organization starts with the simple dependency of any organism’s initial colonization on secondary structures or processes. As that colony develops or evolves, it becomes more complex—but that complexity depends on the comparative simplicity of its predecessor.13 The foundational species—in our case, the cordgrass—pioneers life in a given ecosystem. When established on a new shoreline, for example, cordgrass increases sediment deposition by slowing water flow, and over time this leads to a stable, well-drained habitat that other marsh plants can move into. From cobble beach snails to fiddler crabs to great blue herons, the increased plant diversity leads to an increased diversity, and complexity, within the entire ecosystem. Hierarchical self-organization crafts a predictable spatial structuring of these elements, drawing order from former disorder. The computer scientist Herbert Simon provided a well-known explanatory parable of such organization—which is found in domains from economics to artificial intelligence—called the “Parable of the Watchmakers.” In the parable, two watchmakers, Hora and Tempus, are crafting fine, intricate watches featuring thousands of pieces.

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1.4. Wings Neck marsh on Cape Cod in Bourne, Massachusetts. The striking spatial structure and organization of salt marshes comes from a process of hierarchical self-organization, which is in turn driven by a balance between positive and negative interactions among local species. Photograph by author.

Hora is able to finish his watches more quickly, and therefore sell more of them, because of a simple change in how he constructs them. Whereas Tempus adds each piece individually—a risky process that means any error, like dropping a partly assembled watch, entails starting again from the beginning—Hora instead constructs modules of ten pieces each. Hora’s subassemblies allow for increasing complexity, in a form of “modular design” that the natural world has engaged in from the start: when self-replicating molecules, which coevolved symbiotic associations in the ancient microbial soup, developed into complex cells, plants, animals, ecosystems, and civilizations.14 Crafted slowly by inhabitants, marshes are some of the most productive native ecosystems on earth. They are the very ecosystems that, hundreds of millions of years ago, converted the sun’s energy into the fossilized plant biomass that fueled the eighteenth-

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century Industrial Revolution: coal. They are also the ecosystems that spawned the first civilizations in the frequently flooded land between the Euphrates and Tigris known as the Fertile Crescent and the Yellow River marshes of China. My early work suggested that positive feedbacks, or mutualisms, could be considered largely responsible for the success of marsh ecosystems that triggered these first civilizations. On a larger scale, work like this is an experimental testing ground for reciprocal habitat amelioration and species mutualisms, layered over the implicit processes of hierarchical organization, which in turn are ways to test the core components of symbiogenesis and the Gaia hypothesis. In the 1980s, studies of positive interactions were considered simply cute stories about nature, not glimpses into the motors of planetary self-organization. Whether reading about the termites that require microbes to digest wood cellulose, which the termites on their own cannot process, or Dan Janzen’s tropical ants that protect Acacia trees in exchange for a reward of sugar nectar, or the co-evolution of butterflies and plants studied by Paul Ehrlich and Peter Raven, few saw in these stories the general rules that would change ecological theory. They were exceptions to the rules of competition and predation that were most familiar to ecologists and evolutionists growing up in the Cold War climate.15 While the Gaia hypothesis remains correlative due to the experimental impracticality of having only one planet, foundation species–based ecosystems are replicated throughout the world. This has given scientists the ability to test if trees in tropical and temperate forests modify local climates toward greater ecosystem productivity and stability, for example, or how a mutualism between coral and algal partners can build and maintain diverse, selfsustaining coral reef systems. Such work can help us understand how the basic assumptions of the Gaia hypothesis—our deep, rich history of coevolved dependency—may be playing out today.16

Microbes and Humanity Everything, from eukaryotic cells and New England salt marshes to, so we theorize, the entire earth, is built from the composition and cooperation of otherwise distinct elements. We may be willing

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to accept this view of life and evolution without much struggle, for we have been increasingly primed to understand the dangers to an ecosystem when a species is forced into extinction through, for example, overharvesting. And yet, to properly study the natural history of civilization, we must go a step farther and acknowledge that the human species is itself a symbiogenetic collection. We, like ecosystems and earthworms, exist because of the cooperation of species that are not us: most importantly, we exist because of our symbiotic relationship with the microbial world. Only over the past decade have we begun to understand the fundamentally prominent role that microbes have played, and continue to play, in the sustainability of life on earth. Because of their short generation time (they reproduce quickly, creating frequent opportunities for evolutionary pressures to take effect), microbes are finely tuned to their habitats and form evolutionary defense systems to guard against threats from all multicellular plants and animals, including humans. Moreover, vertebrates are associated with trillions of microbes, most of which inhabit their digestive tract, that play invaluable roles in the development and performance of their hosts, particularly in digestion and defense. All multicellular organisms have coevolved symbiotic associations with their populations of microbes, collectively referred to as their microbiomes. Microbiomes influence the general health, resistance to disease, and metabolic efficiency of their hosts and are evolutionarily fine-tuned to species and among species populations. Thus, all multicellular organisms can and should be considered superorganisms that have coevolved symbiotic associations with their microbiomes.17 Microbes are simultaneously the cradles and sustainers of—and largest threats to—life, and human life is no exception.18 Since very early on, when microbes led to the first complex cells, they have been bound to the diversity of life in variously symbiotic and antagonistic relationships. In humans, microbes account for 90 percent of the cells in the large intestine, and the human gut microbiome controls many of the pathways critical for human metabolism. Recent evidence has even suggested that the human appendix, long thought to be a useless vestigial organ, actually serves as a safehouse or reservoir for important gut bacteria. After a digestive tract illness such as dysentery depletes us of needed mi-

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crobes, for example, the appendix can repopulate our digestive systems with these microbes. Severe dysentery must have been exceedingly common in our ancestors; as they expanded their geographical ranges and developed their diets, they would have encountered many new threats to their microbiomes.19 It has taken a long time for us to notice the positive effects of our microbial partners. Research into this mutualism first began a century ago when Ilya Ilyich Mechnikov and Paul Ehrlich won the 1908 Nobel Prize in Medicine or Physiology for their discovery of human-microbial codependence. Before their work, Pasteur’s discovery of microbial life had fit easily with the previous century’s germ theory of disease, in which microbes were universally demonized as threats and dangers to human health. This association, one that is still influential and expanding, limited for centuries any movement to elucidate the importance to human health of microbes. Until relatively recently, hairdressers were more familiar advocates of microbial benefits than family doctors. Today, this research has been stalled by the successes of modern medicine, successes that are simultaneously threats, because the omnipresence of antibiotics has poisoned our balance of good and bad microbes. Even so, the use of human microbes as tools for treatment is leading to a renaissance in modern medicine. Contemporary research, for example, shows that gut bacteria synthesize B7, B12, and K vitamins, which help our bodies protect against diseases ranging from diabetes to cancers to Alzheimer’s.20 Much of the power of microbes comes from their ability to reproduce through “vertical gene transfer,” which is a form of reproduction that is orders of magnitude faster than the way plant and animal cells reproduce. This gives them the ability to evolve rapidly relative to changing ecosystems. Moreover, microbes can transfer genes directly without sexual reproduction by fusion among individuals. This “horizontal” or “lateral” gene transfer allows microbes to function as networks of immunity and tolerance, making them our most important ally and first line of defense in battling diseases. It is this invisible world living within us that requires us to redefine humans not as distinct organisms, but rather as symbiogenetic superorganisms whose metabolism is intimately dependent on microbial processes. We are an orchestrated collection of cells

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that are themselves the product of biogenic, symbiotic relationships, living on a planet that has itself been biologically engineered by the habitats and organisms within it. We are not autonomous beings: we are instead the result of countless interrelations and cooperations. As Walt Whitman put it so eloquently: “I am large. I contain multitudes.”21

chapter two

Life in the Food Chain

I

n the timeline of the human species, civilization is a recent, young phenomenon. Early humans evolved 2 million to 2.5 million years ago and spread across the globe just 200,000 years ago. A mere 40,000 years ago, Homo sapiens stood alone as the last remaining human species on earth, and not until around 8,000 years ago did the settled, agriculturally dependent lives that we consider the first components of “civilization” occur. Civilization— whereby one species became the most dominant on the planet—is a blip in our earth’s genealogy, vibrantly powerful, staggeringly rapid in its development, and frighteningly adolescent. What happened in the pre-civilization history of Homo sapiens and our hominid ancestors? What occurred to create the world we know today? How did our symbiogenetic beginnings and our coevolution with other organisms on earth, small and large, generate the hierarchically structured, self-organized, predictable world we rule today? When I was a graduate student in 1978, I had the good fortune to join my mentor, the evolutionary biologist Geerat, or Gary, Vermeij on an expedition to circumnavigate Papua New Guinea and Irian Jaya on board Alpha Helix, the National Science Foundation’s research vessel. Our trip marked the end of an era, because the Alpha Helix was the last of the NSF’s fleet intended for ecological and evolutionary biology exploration, and this was its final voyage. 35

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Gary and I, joined by fish and crustacean curators from the Smithsonian and from Scripps Institution of Oceanography, were testing the idea that predation by shell-crushing crabs and fish had influenced the evolution of the architectural diversity of marine snail shells. Every evening, we would survey charts and maps and decide where to wake up in the morning to spend the day collecting and scoring New Guinea shells for predator injury and repair, repeating the process for almost two months. We used hermit crabs to collect our shells, since hermit crabs are dependent on empty snail shells for shelter, making them perfect employees. The eastern coast of New Guinea was largely unpopulated because of a thick, dangerous mangrove forest (called a “mangle”), and we didn’t see anyone for almost a week while traveling the hundreds of miles of its coastline. It was one of the last truly isolated places on earth, having drawn international attention in the 1960s because of the disappearance of Nelson Rockefeller’s son Michael. Though never proven, stories and rumors spread that Michael had been killed and cannibalized by native tribesmen from one of the more than seven hundred indigenous groups that lived in this area, which was not much larger than California. The rumors were not based on simple exoticism: lethal human contact among New Guinea tribes was so common that it had become ritualized into nonlethal daily events: warriors would confront enemy warriors at territorial borders, where they would leave their shields and go about their daily business, only to return and retrieve their shields at the end of the day, satisfied by having ceremoniously threatened their neighbors once again. From the Alpha Helix, we took small Boston whaler boats to the shore to collect shells inhabited by mollusks and hermit crabs, all the while keeping an eye out for crocodile slides that often marked the nest of a mother saltwater crocodile—one of the few large predators, like polar bears and great white sharks, that consider humans prey. One day, while collecting silently and near each other— for we had seen one such slide earlier that day—we saw movement in the distance, slowly nearing us. Finally we saw the source: a large, fifty-foot (15 m) outrigger with a native family on board. It was a timeless Indo-Pacific houseboat featuring three generations of a single family, from grandfather to the two kids and their dog, all covered with tattoos instead of clothes.

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Though we couldn’t understand their language—not even Gary, who grew up in Holland and could pun fluently across at least five languages—we somehow persuaded them to return with us to the ship, where our translator was. He also couldn’t communicate with the family, but by day two, Gary had unlocked their language. New Guinea had been a Dutch colony for centuries until 1975, only a few years before our visit, and Gary was able to find enough Dutch that had filtered into their language to use it to break the communication barrier. We learned that we were the first Westerners the family had ever seen, and that this family were hunter-gatherers, living the way humans had for millennia. They told us that they would spend the day in the mangrove fishing, but in the evening they cooked and slept offshore to avoid the saltwater crocodiles. They used stone and scavenged metal tools, and once a lunar month they would travel down the coast to visit, trade, and celebrate with their extended family. This family was still part of the food chain, their daily routine and distribution controlled by major predators. Such an experience taught me how precarious our dominance of the earth has been, how close our connection with the past is, and how recently the settled, civilized lives we now take for granted developed. How did hominids, a vulnerable, physically weak species embedded in the middle of the food chain, living at the mercy of predators and oppressive climatic conditions in refuge habitats, become the species that now controls, without competition from other species, the food chains that control all life? And most importantly, what does it mean when the natural historical lens we are using describes the development of civilization not as a choice or accident, but as an evolutionary destiny?

Making Humans The same processes that biologically created the diversity of life on the planet from microbes to slugs, crocodiles, and mangroves have led as well to the development of the technologies crucial to humans’ ascent up—and, as we will see, escape from—the food chain. These processes in humans selected for larger brains and the cognitive ability not just to survive, but to thrive. From a series of positive feedbacks, human lineages descended from Australopithecines,

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large-brained primates that abandoned the defensive, arboreal lifestyles of other apes for an entirely bipedal terra-firma existence. They also, more than two million years ago, developed stone tool technologies, such as hand axes and spear points with deliberately sharpened or napped edges, to use in hands newly freed from clutching branches or walking on all fours.1 Homo erectus, one of our most critical ancestors, was especially innovative, adding to its skill set the domestication of fire, which proved to be one of the most significant turning points in human and earth history. This step initiated our exit from the food chain menu and organized human sociality around the family hearth, propelling the development of civilization. While the timing is still uncertain, a consensus of genetic and fossil evidence shows that modern humans evolved in the African savanna from species like Homo erectus and others.2 This evolution occurred along the same pathways of positive feedback, cooperation, and autopoiesis, but whereas the evolution of life involved the transition of physical processes into biological ones, the creation of humankind introduced cultural processes as well. These are made possible, developed, and perfected in much the same way that ecosystems are. Some of the earliest factors in creating the human we recognize today, all of which interacted with each other in a system of growing complexity, include tool-making, fire, cooperative hunting, and trade, as well as the recursive effects these activities had on the human body and mind. Tool use for hunting and the acquisition of tool-quality stone were important initial factors in how our ancestors became the most dominant predators on earth, but their origins come from a biological change in primate motility. Living in trees had kept our pre-hominid ancestors safe from ground-based predators (and likely explains our universal fear of snakes), but a bipedal gait greatly changed our ancestral outlook. For one, a bipedal gait was more efficient than walking on all fours, a posture designed for climbing trees. Hominids such as Australopithecines, the first human species, took special advantage of their hands, freed by their bipedal existence, and developed communicative gestures and tool-making skills. Nearly universal human hand-gesture communication is evident to this day, as we can see on any crowded street. As for

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tools, humans first used simple rock slivers or rocks with sharp edges to crush and mine protein-rich marrow from the bones of abandoned prey, effectively learning to be skilled scavengers. Carcass scavenging was an intermediate step toward becoming the excellent hunters they soon were, as they began deliberately sharpening or napping the edges of locally found stone, improving their weapons and thus their chances of taking down prey on their own. With cooperative group-hunting skills guided by their growing brains, they were able to rely on more than the brute-strength approach taken by lions, bears, and crocodiles on their path to achieving top predator status.3 At the same time, becoming hunters changed human physiology in a tightly recursive feedback loop. As humans became hunters, their hind limbs enlarged, toes shortened, and respiration changed to increase running speed and long-distance endurance. The loss of fur and development of sweat glands increased the ability for the human body to cool itself, while increased shoulder, waist, and arm flexibility greatly improved human proficiency with projectile weapons like spears. This suite of hunting traits was the incremental and cumulative reward for successful hunting that had passed along the genes of our well-fed and reproductively successful ancestors.4 Yet hunting efficiency and the creation of tools—the “human the hunter” theory—do not alone explain the separation between Homo sapiens and their primate ancestors. Early hominids had large jaws and sharp teeth meant for crushing hard seeds and chewing food for days, which was what they had to do to digest raw vegetables and meat. Moreover, our primate ancestors had round potbellies to house the extensive digestive systems necessary for breaking down and digesting their diet. Becoming bipedal increased the efficiency of energy use by hominids on the ground, but it was the domestication of fire by Homo erectus that increased our energy intake and made possible the cognitive revolution that changed humanity and our planet (Figure 2.1). The domestication of fire is extraordinarily significant in human history, for it makes possible the ability to cook with heat, outsourcing the energetically costly predigestion of food to fire pits. As compellingly hypothesized by Harvard’s Richard

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2.1. Hominid morphology over time. Left to right: Arboreal hominids with long tree-climbing limbs; erect ground-dwelling hominids with shorter limbs, but large guts to process raw food; and after the invention of cooking, which outsourced digestion increasing the energy derived from food, modern hominids with slender builds, large brains, and limbs that could run and throw. Drawing based on public domain sources.

Wrangham, it is cooking that separated humans from primates.5 Drawing from archaeology, human physiology, natural history, and nutrition science, Wrangham argues that cooking began over two million years ago and is so important that rather than humbly calling ourselves “wise apes,” it would be more accurate to use the name “cooking apes.” Cooking with fire gave early humans innumerable benefits over their ancestors. Cooking softens meats and vegetables, thereby decreasing wear on teeth, and it breaks apart the chemical bonds and cellular walls that keep such foods intact, dramatically increasing a food’s energy value and making it easier to metabolize. The use of cooking favors brains rather than guts, and the cooked food that results in turn fuels and reinforces selection for cognition. Cooking also decreases disease and mortality by detoxifying and disarming food of its structural and chemical defenses and by killing parasites and pathogens, like tapeworms and toxic microbes. Even today, studies of raw food diets reveal more often than not that we have evolved an obligate dependency on cooked food, and on cooked meat in particular. Humans who choose, for health

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or ethical reasons, to eat exclusively raw food diets may literally be rendered sterile, as experimental and correlational studies from nutrition science demonstrate. Raw food diets, like lowcalorie diets practiced to increase longevity, cause dieters to suffer the symptoms of chronic energy deficiency. For raw foodies, this syndrome is brought on because cooking preprocesses foods, cutting the metabolic cost of digestion. For low-calorie dieters and anorexia nervosa patients, chronic energy deficiencies are simply the result of low energy intake. Chronic energy deficiency causes both men and women to lose their libido, or sex drive, and women on raw food diets risk losing their menstrual cycle, in time becoming infertile. Humans are as specifically evolved to eat a cooked diet as hummingbirds are evolved to sip flower nectar and cows to ruminate grass. Without it, many staple foods, from hard tubers like potatoes, to grasses like wheat, to fruit like breadfruit, would be impractical, and in some cases nearly impossible, to eat. Cooking changed who we are and expanded our global possibilities.6 Cooking motored humanity down a path toward civilization and eventual domination of the earth.7 More and better food made possible the continual maintenance of our growing brains, since brains are by far the costliest organs, in terms of energy, for vertebrates. Because hunting requires technique and tools, brains were more important than brawn for this small, bipedal ape’s survival. Hunting for and defending against larger, more powerful animals required imagination as well as coordinated behaviors like planning and communication. The fossil record supports this logic correlatively, revealing a strong positive feedback between access to energy-packed, cooked meat that fueled brain growth and technological innovations that increased hunting efficiency. Homo sapiens thus split from their hominid ancestors by doubling their brain size, and by fine-tuning their tools and weapons. Early humans began to flake their rock tools to sharpen them, and soon noticed that volcanic rock, heated by magma from the earth’s core, flaked easily and could be fashioned into uniquely razor-sharp blades. Chert, obsidian, and flint were highly valued for the sharp points that could be made from them. They were also relatively rare, typically found along the same tectonic plate borders that are theorized to have led to the origin of organic

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life itself. The ability to find these valuable minerals became a crucial skill for bettering early humans’ axes and spears, their awls and needles, their hooks for fishing, and their bows and arrows for hunting birds in flight.8 The first collaborative trade routes were born out of the positive feedback loops between cooperative hunting, growing brain size, and developing technologies, all spurred by the new diets that cooking made possible. Networks of exchange emerged to fulfill the need for workable volcanic and silica rock, connecting groups of early humans across regional and continental spatial scales. Rich sources of flint, obsidian, and chert in the Middle East, for example, made their way to mountainous regions of what are now Greece, Cyprus, and Italy. Engraved pieces of ochre—one of the first stones valued for its pigments—have been found in 75,000-year-old cave paintings in South African caves, such as the Blombos Cave. Around 40,000 years ago, the famous French Lascaux Cave, decorated with long extinct Pleistocene animals, was painted with local ochre and other mineral pigments to make different colors and shades. The first Stone Age miners were likely searching for these pigments, and the materials and technology were then spread via human communication. Contemporary chemical analysis suggests that these trade networks extended thousands of miles from their sources, operating through long, slow diffusion to nearby neighbors rather than via direct links to faraway trade partners.9 Over a decade ago, I experienced the scope of these trade routes firsthand while doing shoreline ecology fieldwork in the Chubut Province of Patagonia. I had been working at a stunning site on a remote rocky headland with a group of Argentinean students from the University of Central Patagonia. Above the shoreline covered with mussel beds where we were working was one of the largest Magellanic penguin colonies in the world: hundreds of penguins stood guard over their burrows in the sand, which were held up by the roots of plants that also shaded them from the Patagonian winds. The penguin colony supported a large sea lion breeding colony on an offshore island only a hundred meters away. During the winter, when the penguins vacated the colony for a sixmonth fishing trip and the sea lions followed suit, the abandoned shoreline looked like a gigantic termite mound. This penguin–sea

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lion linkage appeared to be many millennia old, judging from the nearly fossilized bones we found exploring the penguin colony during the winter, when the burrows were subterranean ghost towns. After working at the site for a couple of years, I asked Pablo, an Argentinean graduate student and jack-of-all-trades who was at once a sculptor, natural historian, and gaucho, if there was any evidence in the region of ancient hunting activity. “Of course,” Pablo replied, and took me up the embankment behind the beach to show me a series of shallow caves overlooking the panorama of the shoreline. It had recently rained heavily—a rare event in the Patagonian desert— which increased our chances of finding artifacts in the sand and cobble outside the caves. Sure enough, after an hour of searching, we had located some half-dozen skillfully flaked obsidian arrowheads, two flint butchering and scraping tools, and the fragments of broken lava bola balls (rounded rocks tied to the ends of leather straps that South Americans had used to hunt running prey like llamas and Darwin’s rheas, large ostrich-like indigenous flightless birds). Despite the years I had spent working the site’s shoreline, my view of it changed completely with this discovery. The large penguin colony had been there for thousands of years, supporting the local scavengers and predators like the South polar skua, the kelp gulls, and the sea lions just offshore. This created a perfect location for human hunter-gatherers to camp during the summer months: the flightless penguins were pinned by birds of prey and sea lions, making them easy to snag. To this day you can walk through the inhabited colony with ease. And against the windswept desert of fine sand, the volcanic glass bola balls were just as foreign as plastic bottles would be: the nearest volcanic source for these tool stones, carried to the spot by hunters at least a millennium ago, is in the Chilean Andes on the Pacific coast of South America, over four hundred miles (650 km) away. Thus, spurred by fire and cooking, Homo sapiens went through the “cognitive revolution,” dating at least 100,000 years ago, which led to the species’ unprecedented cognitive abilities. Cooperative group hunting, technology, and trade—the origin and dissemination of information, in other words—were the driving forces and first consequences of this growing brain size, but easily metabolized and detoxified food also freed humans from spending their days chewing

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raw food into a digestible mush. This in turn meant that another new component was added to a human’s daily regimen: free time. Humans began to use their cognitive abilities for more than answering pressing biological needs, instead creating shell jewelry, carved symbols, and cave paintings. The foundation for these first breaths of culture was the hearth, the think tank of innovation and Stone Age civilization. From the spark of fire, early humans began to walk down a path built from positive feedback loops toward the intelligent, cultural, and speaking animal we are today.10

Learning to Speak Along with the domestication of fire, language is one of the most critical attributes distinguishing humans from all other organisms. Language dramatically increased our ability to communicate, enabling the cooperation necessary for human social structure, creativity, and mythologies. Understanding the evolution of language has often been considered the most difficult problem in the science of early human development, because language leaves no fossil record. Indeed, in the nineteenth century, European scholarly societies banned the study of language’s origins to limit the proliferation of heretical thoughts around a problem then considered unsolvable. Thinking about the origins of language threatened our mythological cultural glue. Today, however, language is thought to have been one of the main driving forces in the evolution of our species and the development of civilization, because it facilitates cooperation. By ratcheting up our ability to communicate, language was a game changer. While speaking was initially selected for as a way to increase communication for group hunting and defense when we were embedded in the food chain, language would ultimately accelerate recursive positive evolutionary feedbacks related to brain size and cognitive ability. The result was civilization, cultural differentiation, even spirituality and nuclear physics. Recent phylogenetic methods have provided more insight into how human language developed. These statistical methods were originally designed to explore and quantify the significance of patterns in gene sequences as part of the effort to elucidate the origins of human health problems. The sheer size of gene sequences makes

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this a challenging problem. While bacterial genomes can be less than two million base pairs of amino acids long, the human genome is more than three billion base pairs long. Dealing with data sets this large has led to the development of computer technologies collectively called computational biology. Such methods are also ideal for examining languages and have shown that contemporary languages developed in the Fertile Crescent with agricultural technology (more on this in Chapter 3). Even so, although these phylogenic tools have helped to resolve fine-scale questions of where and when human cultural evolution occurred, how and when language first evolved are much less tractable questions.11 Whether or not our closest human relatives, who also domesticated fire and used tools, had basic speech is unclear: language that could coordinate group behavior may have given Homo sapiens a competitive advantage over our larger, stronger human relatives. Regardless, migration patterns, discussed more fully later, suggest that humans migrated out of Africa with basic oral communication some 200,000–300,000 years ago, and full languages date from 70,000 to 100,000 years ago.12 Many theories on the origins of language involve analyzing the physical machinery needed to speak, the genetic predisposition for learning language, and the selective pressure to evolve language. The use of tools may have minimized the value of hands for gesturing, for example, and pressured the development of speech for communication. Moreover, the hyoid bone that supports and controls the base of the tongue and is necessary for speech is found only in our closest human relatives, Homo heidelbergensis and Homo neanderthalensis, suggesting that these were the only other humans morphologically capable of speech. In fact, the discovery in Spain of intact hyoid bones over 500,000 years old suggests that language may be far older than previously thought (though these bones may have been used for the production of sound only, rather than speech, since brains at that time would have still been small). Erect posture, the physical capability for speech, and human competitors with formidable cognitive abilities may have all acted synergistically as selective pressures to evolve speech to facilitate communication and social organization, skills that were necessary for early Homo sapiens to compete with and outlast rival humans.13

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Also available for study are the as-yet poorly understood speech genes. For example, a study on an English family with a hereditary speech disorder uncovered the speech gene FOXP2. Considered the “language gene,” FOXP2 has been shown to play a role in acquiring grammar and syntax, developing language motor skills, and helping brain cells form new language connections. These genes have also been shown in comparative studies to be part of gene families responsible for integrating the morphological, cognitive, and cultural aspects of speech.14 Tracking human languages is a particularly vexing problem given that humans frequently change the use of familiar words, and often invent new words: each year, for example, eight hundred to a thousand words are added to the Oxford English Dictionary. But the most commonly used words are more strongly conserved, and these common words have revealed that rapid language change is most closely associated with cultural events such as migration. We can hypothesize about the migration of humans through the splitting of languages into the major language groups, basing an analysis on cognate and homologous words that derive from common ancestral roots. Though scientists have not yet developed a convincing, full account of the origin of language, tracking cognates and shared roots backward has led to a truly remarkable discovery: contemporary languages developed in the Fertile Crescent, the area bridging the continents of Africa, Europe, and Asia, then spread and radiated into the Anatolian peninsula (Asia Minor) along with agricultural technology. In other words, the results from our linguistic evolution analyses align with our archaeologically supported theories of general human migration.15

Filling the Planet The migration of Homo sapiens out of Africa began over two hundred thousand years ago (Figure 2.2). These early humans’ larger brains led to the development of fur clothing to overcome cold temperatures, as well as more cooperative hunting abilities and technologies, which in turn allowed them to track game on the savanna extending into Asia Minor. We know of the development of clothing because of the history of human lice, for whom the loss of human body hair and the ad-

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2.2. Human migration out of Africa. Scientists believe that after an initial migration from Africa to the Fertile Crescent, language developed and was dispersed, along with agricultural technologies, to other areas via trade routes. Original drawing based on public domain sources.

vent of clothing mark important crossroads in their evolutionary paths. Today’s head lice and pubic lice are different species, but they have evolved from a common ancestor, one that would have thrived in a human’s body hair. Phylogenetic analysis of human lice DNA reveals that, based on this genetic divergence between head and pubic lice species, our hominid ancestors lost their body hair 1.2 million years ago. (Hair loss on the hot African Savanna would have been an advantage to humans running long distances to catch large, exhausted prey, because it promoted evaporative cooling.) Then, to rewarm the body as humans moved into cooler environments, clothing developed around 170,000 years ago, which we can tell from the DNA divergence between head lice and clothing lice, which are dependent on clothing as an egg-laying substrate. Clothing allowed early humans to successfully migrate north from Africa onto the colder Anatolian peninsula that connects Europe with Asia, where—based on the appearance and dating of bone sewing needles in the fossil record 40,000 years ago—they developed sewn clothing. Thus our species reached Asia as early as 100,000 years ago, Europe 40,000 years ago, and Siberia 25,000 years ago. The Americas were reached some 12,000–15,000 years ago, facilitated by the

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Bering Sea land bridge and then prodded forward by the sea otters, seals, and other marine food resources that inhabited the “kelp highway” coasts of North and South America. The ease of travel, which included the use of primitive rafts, and the wealth of food and shelter, accelerated human migration along marine coastlines and river valleys.16 Current research is editing these dates and reevaluating some of these hypotheses. Genomic data, for example, suggest that Asian or Polynesian humans may have reached the Americas much earlier than would have been possible by the Bering Sea land bridge, and recent fossil finds in China suggest that modern humans arrived 100,000 years earlier than current models claim. We are refining our current understanding of the spread of humans across the globe as they emerged from Africa—the amateur anthropologist Thor Heyerdahl, for example, proposed that Native Americans traveled across the Pacific—just as we are refining, and even completely redefining, the relationships that early humans and human ancestors had with one another.17 In Europe and Eurasia, early humans overlapped in time and space with Neanderthals, who were larger, stronger, and more adapted to the cold than Homo sapiens. Neanderthals ultimately went extinct 40,000 years after prolonged contact with Homo sapiens, and while it may always be unclear exactly how much Homo sapiens and Neanderthals interacted, they definitely coexisted. Interbreeding, for example, is clear from Neanderthal genetic signatures in most modern humans. In fact, fossil and genetic evidence suggests that Homo sapiens coexisted with a number of other human species, races, or cultures during their ascent to global domination, all of whom used tools and were ground-dwelling, bipedal huntergatherers. These findings dramatically change the long-accepted, politically correct narrative of a slow, linear evolution of humans, one that assumed Homo sapiens simply climbed to the top of the heap of previous human species. A more realistic picture is likely one where early human species overlapped in time and space, in cooperation and competition, and Homo sapiens ended up as the only surviving species. What happened to winnow the field to just us?18 Comparative studies of modern and ancestral human DNA have suggested that Homo sapiens may have infected other human

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species they encountered in their migration out of Africa with novel, virulent tropical diseases. Simultaneously, their earlier exposure to these diseases would have inoculated modern humans against the less aggressive diseases they would then encounter in temperate climates across the globe. Moreover, history has proven time and again that humans do not treat unfamiliar humans well: the dominance and aggression of Homo sapiens likely led to the extinction of other Homo species. Steven Pinker has argued from the available fossil data that early humans had an intensely violent, murderous past that has mellowed through evolved cultural pacification, civilization, and cooperation—an idea we will return to in Chapter 4.19 The emphasis on competition between these differing human species aligns with evolutionary theory, even within the cooperative framework I am espousing. Ecological and evolutionary theory predicts that competition between species with overlapping needs and requirements is more intense than that between species with divergent needs, and can be broken into two types: exploitation competition and interference competition. Exploitation competition occurs when inferior competitors are displaced in their attempts to exploit limited resources, while interference competition occurs when species fight for these resources and stronger species displace weaker ones by force. Both kinds of competition were likely involved in the spread of Homo sapiens across the earth. If we look at more recent history, such as the European exploration of the Americas or Pacific Islands, the spread of disease, exploitation of resources, and direct conflict (through war and genocide) were all determinant factors in the displacement of one group at the hands of another. The violence implicit here should not be shocking: selfish genes morph quickly into selfish-gene-driven groups of warring, genocidal, and enslaving cultural groups. We will explore later the long, disturbingly consistent track record of humans using conflict and destruction to harm other humans.20 As humans continued their colonizing march across the globe, they had to contend with dramatic changes to the earth’s climate. In particular, two glacial maxima (times when vast sheets of ice extended over land masses) occurred, leading to colder weather and a sea level lowered by more than a hundred meters (meaning that

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early coastline settlements from the period are now hidden underwater and buried in sediment on the continental shelf). These events not only pushed the earth’s geography into the shape we recognize today—for example, by pushing sand together to create Cape Cod, and by leaving behind the large puddles of the Long Island Sound and the Great Lakes—but also severely challenged human populations, especially at temperate and boreal latitudes. The first glacial maximum coincided with the successful human movement out of Africa 70,000 years ago, while the second occurred only 12,000–25,000 years ago. These ice ages not only exposed bridges between continents and now remote islands, but also acted as powerful natural selection events. Recent examination of patterns in human fossil DNA and climatic variation has revealed that climate extremes have played a major role in shaping human populations and genetics, directly or indirectly, by affecting the survival of human competitors and predators. But despite these struggles—at one point, the density of humans on earth averaged only around one human per square mile—humans filled the planet, changing the lives of animal species they encountered along the way. Where humans settled, new relationships with the animals that shared the space developed—for better or worse.21

Partners and Prey We have already discussed how the cells that make up our bodies are a highly evolved mutualistic partnership of formerly independent microbes, and that we remain literally and metaphorically vessels of foreign microbial warfare and cooperation. Our relationships with the macroorganisms—the animals and plants—we associate with are also complicated and often enmeshed, ranging from passive commensalism, where there is no detectable impact on us, or us on them, to obligate reciprocal mutualisms, where we are as dependent on another species as it is on us. Most often these partnerships fall somewhere between these two extremes. Totally neutral associations (commensalisms) are truly rare, since careful analysis typically identifies some cost or benefit, however small, in any association: these costs and benefits make parasitism and mutualism more common labels.

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The classic human mutualism story began as early as 30,000– 36,000 years ago, though was not successful until 11,000–16,000 years ago: the domestication of dogs (or, as in my house, dogs’ domestication of humans). The domestication of dogs likely began passively, as a commensal relationship between nonaggressive members of wolf packs and Paleolithic hunting bands. It has also been suggested that early humans may have actively promoted domestication by raising abandoned wolves. Both passive and active processes likely contributed to the human domestication of wolves. Wolves may have taken advantage of carcasses left behind by early human hunters, assisted in the capture of prey, provided defense from competing predators at kill sites, and acted as campsite sentinels to warn of danger. Eventually, humans would have begun feeding the less aggressive wolves, leading initially to mutualism and then to the first known case of domestication (an obligate mutualism). From that point followed the coevolution of humans and dogs (which have descended from a now extinct gray-wolf ancestor).22 Once the relationship had evolved into a mutual codependence, the combination of a loyal pack animal with acute smell and vision and a human species equipped with creativity and tool technology enabled successful defense and the hunting of larger, more dangerous prey, such as mammoths, bears, and large cats. Thus, it has been hypothesized that domesticated dogs hunted with humans as they conquered new continents, creating a cross-species partnership that could achieve far more than either species could have accomplished on its own. The human-dog mutualism or collaboration has been argued to have led to the extinction of Neanderthals as this lethal partnership invaded Europe, and to the extinction of large mammal prey and threatening predators as humans and their dogs traversed North and South America.23 Recent studies in animal domestication have suggested that domestication led to the retention and selection of juvenile traits in domesticated species, a mechanism that is called neoteny. Forty years ago, the Russian geneticist Dmitry K. Belyaev led an important study on neoteny when he began domesticating foxes by selecting for tameness. Doing so created puppy-like adult foxes different in temperament, behavior, and morphology from their wild ancestors. Juvenile traits, like subordinate, passive dispositions,

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were retained. Neoteny is a common interaction between evolution and organism development. Baby humans are, in utero, hairless, and they are born with heads and brains proportionately larger than in adults. With neoteny, these traits already present in juveniles are selectively retained leading to proportionately large brains and the loss of hair and fur in human adults.24 Thus, with this new mutualistic partnership and their creative thinking to counter colder latitudes and adapt to new habitats, humans were able to move rapidly to new continents and islands. Humans were now free of biological and physical range restrictions, and by 10,000 BCE, we had invaded every continent except Antarctica, along with our dogs, our parasites, and our microbes. This led to one of the most drastic initial consequences of global human dispersal: encounters with larger animals that had no experience with humans. The consequences of our mutualism with dogs were dramatic. While microbial mutualisms led to nucleated cells and multicellular plants and animals, our mutualism with dogs has been suggested to have led to the extinction of most megafauna (big animals) in new lands. These large animals often had no fear of humans, because they did not have the experience and familiarity with humans that large animals in Africa had. In Africa, humans and dogs had coevolved alongside large predators and prey, so while humans advanced, the large African animals knew to be wary. Large, slowly reproducing prey on newly invaded landmasses had no such advantage, and this lack of familiarity is believed to have played an important role in the extinction of many of these species. To naïve megafauna, our ancestors were just small, skinny monkeys not to be feared, a misunderstanding that made them extremely vulnerable to the creative, group-hunting strategies of humans as they expanded their ranges across the globe. Though humans’ part in such largescale extinction events was complicated by the climate changes occurring simultaneously, and though Pleistocene large mammal extinctions in North America, for example, were caused by a cocktail of human invasion, climate change, and meteor impact, case studies from all over the world still demonstrate the incredible destructiveness of humans on newly met megafauna. The result is a striking pattern we can witness today: most landmasses have few

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large animal species, but on the African continent, where large animals evolved alongside humans, they continue to thrive.25 When humans arrived in Australia by rafting and island hopping during the Ice Age, for example, they found seven-foot kangaroos, grazing herbivores the size of large trucks, eight-foot flightless birds, and apex predators that could all be killed easily. Within a couple thousand years, 94 percent of the large animal species were extinct.26 Lack of familiarity with humans, as well as humans’ group-hunting tactics, tools, and even use of fire to clear habitats and drive animals from cover, led to the quick decimation of megafauna, just as it did in North America, where 73 percent of the large mammals were extinct within a couple millennia of meeting humans. Again, while the rapid climate change of an ice age certainly played its part, human activity cannot be set aside. In North America, for example, there are a number of kill sites dating to this period where we can see that human hunters simply herded large groups of prey off of high cliffs to their deaths. More recently, the colonization of oceanic islands put humans again into contact with unique large animals, particularly flightless birds that were quickly driven to extinction (Figure 2.3). On tropical Pacific islands, most land bird and nesting seabird species were pushed to extinction by human hunting or by the introduction, by humans, of rats to these islands. The loss of tropical island bird species is thought to exceed two thousand and represent a 20 percent global reduction in the number of bird species. On Madagascar, the arrival of humans two thousand years ago led to the extinction of some truly impressive animals: at least eight species of giant flightless elephant birds, seventeen species of monkey-like lemurs, a giant tortoise, a crocodile, three hippopotamus species, a giant predatory cat, and the giant crowned eagle. Because of small land areas and populations, low rates of immigration, and often a lack of any predators, species on oceanic islands are especially susceptible to extinction when humans arrive.27 By the dawn of the agricultural era, Homo sapiens had already impacted the earth more than any previous species. This first global wave of destruction had occurred through a particularly potent combination of a ruthless selfish-gene drive and the harnessing of coevolved mutualistic partners that greatly magnified their individual

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2.3. Animals that went extinct with the initial migration of humans out of Africa include the dodo (Raphus cucullatus), a flightless bird endemic to the island of Mauritius, east of Madagascar, and the woolly mammoth (Mammuthus primigenius), a species hunted by humans until its extinction 4000–10,000 years ago. Original drawing based on public domain sources.

and group selfishness. In less than 100,000 years, our species had not only destroyed all of its human species competitors, but had also become the most aggressive and destructive invasive species on earth. Equipped with tools, trade, language, and fire, with dogs at their side, humans were becoming the planet’s apex predator, able to move at will and creatively survive a host of struggles. Humans were developing and growing more complex due to the autopoietic processes un-

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derpinning their lives, whereby each change would change something else, and in turn change something else. The early history of our species is a telling parable for the powers of cooperation within an environment, such as our partnership with dogs, and for the destructiveness of competition, such as the extermination of other human species. It is also a reminder of what it means to be part of an ecosystem and to grow and evolve alongside the ecosystem’s participants: the extinction of large mammals across the globe, including today’s threats to the remaining megafauna in Africa, poignantly demonstrates the power and importance of cooperative, mutual life and how the introduction of new elements into a system can disrupt that system entirely. Yet as dominant as humans were, they were still trapped in the food chain. They still relied on what they could hunt or find. The environment still largely controlled them. This, however, was about to change, driven by further coevolution and cooperation. Moreover, this next change would unleash a second global seismic shift in life on earth, as Paleolithic humans developed mutual dependencies on a small group of plants and animals that would join us in conquering the globe with powerful, cooperative dependencies.

chapter three

Taming Nature

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each combing, like bird watching, clam digging, and deer hunting, has soul-soothing connections to our long apprenticeship on earth. As hunter-gatherers, our ancestors depended on natural history knowledge for their very survival. We have similar, but not as deep, ancestral connections to working the soil and caring for our crops. We decorate our houses with flowers, landscape our yards with greenery, and find comfort in tending gardens, acts that subliminally connect us to our evolutionary past with horticulture. I have an embarrassingly primeval urge to eradicate the particularly pervasive weeds that threaten my home garden, even when I don’t mind seeing them thrive in public parking lots. We even celebrate the bounty of the land on seasonal holidays that have become disconnected from their original purposes. Culturally and genetically, we reflect on our past because it has molded who we are and where we came from on our way to dominating the earth. Domesticating the relatively small, select number of plants and animals that we rely on, and that rely on us for their survival, is a coevolutionary mutualism, a symbiogenetic process, one as sharply shaped by reciprocal benefits as is the coevolved dependency between plant flowers and insect pollinators. The evolution of mutu-

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alisms between flowers and insect pollinators led to an explosion of diversity in flowering plants and their pollinators. Analogously, human domestication of a small, select group of plants and animals led to these species’ becoming some of the most abundant on earth as humans came to dominate the planet. Agricultural revolutions were some of the most dramatic turning points in human and earth history, commensurate with the domestication of fire and the invention of cooking that changed our brains and led us toward global dominance as a species. These revolutions—in plural, for the development of agriculture occurred independently at least a half-dozen times across the globe—were inspired and driven by the natural history partnerships among systems and organisms that led to the development of humans in the first place. Before agriculture and its concomitant sedentary lifestyle became the mode of life, humans were still controlled by their environment: climate, food supply, and predators still dictated human responses, and we were embedded in the food web as nomadic hunter-gatherers. To follow this transition between lifestyles requires understanding the hunter-gatherer life more intimately, specifically the mutualisms and feedbacks that were already occurring and developing in humanity’s pre-agricultural existence. From the land management techniques that were generated by living in low-productivity areas, to the domestication of grazing animals and grass seed, to the coevolution of plants, animals, and our digestive systems, agriculture was the end result of a web of largely unintentional or inadvertent cooperative relationships. As humans became fully aware of these mechanisms and mutualisms, they were able to grab the reins of agriculture and domestication and seize control of their environments. Agricultural revolutions resulted in humans procreating as never before in densely populated areas that changed the land, the plant and animal populations, and even the atmosphere of the entire planet. This development brought just as many negative consequences as positive. Leaving the restraints and structures of the food chain and of natural environments may have given us control of the planet, but it also set us on a dangerous course that threatens our heralded civilization.

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From Hunting Camps to Land Management Before there were farms, there were hunting camps. Because our hunter-gatherer ancestors from the late Stone Age were dependent on the natural ebb and flow of seasonal plant growth cycles and animal migrations, they established seasonal camps for fishing, hunting, and harvesting. Some heirloom caves, for example, were occupied by humans for more than two million years, predating Homo sapiens. Caves were natural short-term domiciles, but bands of early humans also built thatched-roof shelters of stone, sunbaked clay bricks, beams of wood, or rib bones of long-extinct mammoth species. At the same time, pre-agricultural proto-cities developed along productive, foodrich areas, such as the west coast of the Americas, the north coast of Africa, European river valleys, and along rivers in China. These were unique dwellings, especially because the most highly productive environments were not habitable for early humans due to dense, dangerous forests that were home to large predators. Dangerous forests dominated productive landscapes before humans developed the technologies of crop domestication and advanced tools that were necessary to clear the forests for agriculture.1 This inability to live in the most desirable and food-rich habitats speaks to a general community assembly rule in experimental ecology. Formally called “the competitive exclusion principle,” it states that two organisms with the same niche or requirements cannot coexist. This means that the most dominant predators and competitors monopolize the best habitats for growth and reproduction, displacing subordinate species to less favorable habitats. These pressures initially limited humans to low-productivity savanna and riverbank habitats, just as the dense mangrove forests in New Guinea limited the family I met during my 1970s research trip to spending their nights offshore for safety. Humans stuck to savanna and riverbank habitats, just as apes stuck to tree canopies, because of the natural history rules of ecological community assembly written by millennia of natural selection and understood over the past few decades by controlled field experiments.2 These low-productivity areas offered refuge not only to humans, but also to other organisms, such as rapidly growing weedy plants and passive, grazing herbivores that were restricted to such

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habitats for the same reasons and rules. The grasses and passive herbivores sharing such habitats were ideal for the formation of dependencies and mutualisms. This simple natural community assembly did not directly cause domestication; instead optimal actors were in the right place at the right time for coevolution, domestication, and civilization. As we will continue to see, domestication and agriculture resulted from cooperative relationships, not moments of radical ingenuity and creativity. Before domestication involved organisms other than dogs, humans had already begun managing the landscapes they inhabited in order to maximize food yields. This occurred most commonly and intensively near seasonal shelters, where generations upon generations of hunter-gatherer communities had amassed a wealth of knowledge of the local plants and animals.3 They selectively harvested and groomed plants with desirable features like large seed heads and weeded out those with small, stunted fruits. They also removed unwanted species and diseased individuals from the communities of their favored plants. While tending, gathering, and processing favored plants, they inadvertently became dispersal agents, spreading the seeds of these plants in hunter-gatherer seasonal camps, garbage dumps, latrines, and hearths, and along travel routes. These skills and unplanned associations were refined and harnessed by trial and error, so that over time, early humans became skilled horticulturists. They learned by practice what German monk Gregor Mendel would later prove in his nineteenth-century work on genetic variation in peas: when a certain trait is focused on and encouraged, natural selection will reward future generations of the plant with the same trait. Like bees and hummingbirds selecting the flowers with the best nectar, early humans became agents of natural selection—just as you are when you remove poorly growing or pestinfected plants from your garden. Another prominent and important pre-agricultural technique of land management was the use of fire to burn forest edges. Burning forests gave early humans an instant supply of cooked seeds, vegetables, and even cooked animals hidden in the forest underbrush—the Paleolithic equivalent of buying fast food. Controlled burning also maintained productive, less dangerous grass- and shrub-dominated landscapes while keeping at bay the threatening forests—complete

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with large, aggressive predators and competitively dominant and welldefended plants. Eventually, plants resistant to fire, or even dependent on burning for their persistence, dominance, seed release, and sexual reproduction, were selected for in these open spaces. This is less bizarre than it sounds, for fire-dependent plants and plant communities occur naturally in habitats exposed to frequent lightning strikes, such as the longleaf pine forests in Florida or the African savannas. In these habitats, where fire is a predictable hazard, many plants can’t reproduce without it. Humans may even have been schooled about the benefits of fire from those plant communities that depended on it in our ancestral homelands (in the Ethiopian savanna).4 The landscapes created by fire increased the abundance of rapidly growing, poorly defended weedy plants, which were in turn magnets for large, grazing, herding herbivores such as sheep, goats, and cattle. In other words, the mutualistic association between grazing herbivores and weedy grasses, where grazers benefited from an easy food source and the grass benefited from a forest expansion slowed by grazers, was one that humans tapped into and encouraged with their forest burning. That grazers maintain weedy borders has been rigorously tested on the rocky shore model ecosystem. In addition to stimulating positive feedbacks between herbivores, favored plants, and humans, burning forests may well have led humans to recognize how fire and cooking increased the breadth of their diets by softening and detoxifying inedible plants into foods full of energy. Forest burning also may have given humans insight into future technologies like hardening tools with heat, the advantages of charcoal, and even metallurgy and glass formation. Today, Australian Aborigines still use fire for land management, and slash-and-burn farming remains a method widely used by many indigenous cultures in Central and South America.5 Between the frequent returns to seasonal camps and the use of fire to manage plant populations—by preserving favored plants and limiting forest expansion—humans were part of a growing coevolution involving positive feedbacks between themselves and their herbivore and edible plant neighbors. This is why savannas and grasslands were our evolutionary origins: they are not the most food-productive places on earth, but they are where we could safely hunt and gather, and where we could learn the natural histories of

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the weedy world around us. It was only a matter of time before these elements combined into the mutualist relationships that immediately preceded animal and plant domestication.

Coevolution and Domestication Humans’ mutually beneficial partnerships with local flora and fauna were developed passively by natural selection, rather than cognitively with intent or purpose. “Coevolution” was initially coined and described by Paul Erlich and Peter Raven in their 1964 paper on butterflies and plants, but it is an idea that was implicit in Darwin’s observations on the interactions between flowers and insect pollinators.6 Coevolution aptly describes not only the feedback-based, passive relationships that grew from humans selectively weeding the areas around their campsites, incidentally dispersing beneficial plants to their campsites and latrines (thereby fertilizing them as well), and burning forest edges, but also by humans’ first gestures toward animal domestication. Domestication of grains by humans led to the loss of seed dispersal characteristics in plants: humans would preferentially select plants with seeds that remained attached to their seed heads for easy harvesting, then humans selected for the loss of various dispersal mechanisms like hairs, hooks, and barbs that complicated harvesting, transporting, and processing seeds. Ironically, it was these hairs and barbs that had first led to the domestication of these weedy plants, because their seeds had hitched rides with hairy mobile animals like large mammals or our hominoid ancestors. Now, however, humans were choosing seeds on the basis of the loss of these dispersal mechanisms, making further plant success dependent on human intervention, rather than on animals or the wind. Finally, seeds were selected for large size, favorable chemistry (such as the loss of germination cues), synchronous ripening, and compact growth morphology. All of this was done passively by huntergatherers unwittingly acting as powerful agents of natural selection, preferentially utilizing and inadvertently propagating plants with traits that humans liked.7 Animals, like sheep and cattle, also began as commensal organisms benefiting from living near humans: these passive herbivores

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could take advantage of the easily accessible grass outside of the more dangerous forests, and in the open grassland they could better develop their own defenses against predators. As herd animals, these species find safety in numbers and comfort in groups with leaders. W. D. Hamilton termed these groups “selfish herds,” proposing that physically and competitively subordinate individuals and vulnerable prey species evolved to live in groups, because the value of protection from predators outweighs the costs of living together. The benefits of group living can be seen in populations from cattle to starlings to shoreline mussels and oysters: living in aggregations is a common natural strategy for survival. Massive groups of oysters or oyster reefs on marine and estuarine shorelines attracted early human colonization, too: millennia later, the locations of these former oyster reefs, long overharvested, would mark in curious, geoarchaeological ways the cities that had developed to exploit them. In the boroughs of New York City, ancient shell-midden mounds led to the first cement-like tabby buildings, which were made by a yet-tobe-understood method of mixing oyster shells with sand and other readily available resources to make a durable building material.8 Unlike oysters (and starlings and most herd animals), however, the herding behaviors of herbivores like cattle could be easily managed by human behaviors that would become in time those of early shepherds. Herding herbivores grew close to humans until we developed an obligatory mutualism. This was easier with social, commensal animals, like the ancestors of sheep, who were passively tamed and eventually could have their traits actively managed and selected for. As demonstrated by Austrian biologist Konrad Lorenz half a century ago, such mutual relationships were strengthened by imprinting, whereby social, docile animals, when young, “imprint” on the humans they live near, seeing them as parent or leader figures. Coevolution and imprinting brought a number of plant and animal species to the point of domestication, and brought humans toward agrarian lifestyles. Over time, it also gave humans better nutrition, health, and greater reproductive success. Human creativity and cognitive ability then recognized domestication as a powerful new tool or technology and harnessed what was already occurring through generations of natural, reciprocally beneficial relationships.

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Active use of domestication technology led to two distinct, early human lifestyles: sedentary farmers who tended plant crops, and pastoral shepherds who nomadically herded grazers among productive grazing sources. This led to divergent cultures of, on one hand, sedentary agrarian farmers investing in plots of land that would in turn become cities, able to support their farming experiments and activities, and on the other, pastoral nomadic tribes with mobile lifestyles based on trading, tending livestock, and horsemanship. Cities drove the population growth of agrarian farming cultures, while horse domestication drove the growth of nomadic pastoral cultures and, in time, trade.9 As the Smithsonian’s Melinda Zeder reminds us, domestication is a sustained multigenerational, mutualistic relationship in which one organism assumes influence over the reproduction and care of another organism to secure a predictable supply of a resource of interest—with the partner organisms, both domesticator and target domesticate, gaining an advantage over individuals that remain outside this relationship.10 This precise definition points to the same play of benefits that leads organisms to coevolve in the first place, with domestication adding a conscious perpetuation of this relationship, one that also led to technologies designed to improve the productivity of domesticated animals. Escalating cognitive abilities in humans led to the coopting of plant and animal successes to benefit humankind, and the domestication that followed led not only to human dominance, but also to a handful of selected plants and animals collaterally becoming the most abundant plants and animals on earth. Coevolution doesn’t have to be a two-way street: some plants and animals have benefited from the growing success of humans without benefiting humans in return. These plants and animals can have one-way commensal relationships with humans, where humans aren’t helped or harmed, or parasitic relationships built on human success. Just as rats, dogs, lice, ticks, and other animal commensals passively followed humans and evolved with them, so too did plants that would become obligate commensals, requiring human dispersal, disturbance, and habitat creation. Plants like dandelions, goldenrod, plantain (called “white-man’s footprint” by Native Americans), poison ivy, and others popularly considered “weeds” are

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just as dependent on human dispersal and disturbance for their success as are rats, lice, ticks, cattle, and wheat. Inadvertent dispersal of opportunistic plants to human camps by hunter-gatherers played a large role in these plants’ reproductive success. These unchosen partners have natural histories that have maximized their success as hitchhikers of human lifestyles. For plants, important traits that aid in their ability to tie their evolutionary wagons to humanity’s rocket include high seed production, rapid population establishment, long-term seed dormancy, human-linked dispersal, vegetative (asexual) spread, and the ability to thrive in human disturbed sites. They are able to do this by sharing limited resources among their neighbors, so that the parts of a plant under stress can be supported and nurtured by its unstressed clone-mates. In the case of commensal animals like ticks, rats, bedbugs, lice, and fruit flies, what we call “pests” have evolutionarily followed the opportunistic food and shelter trails left by human trash and domiciles, becoming perfect hitchhikers for microbial pathogens. Cooperation, then, occurs at multiple levels and with multiple degrees of activity and passivity, intention and awareness. Cooperation of dandelions or rats with humans has helped their respective species, even if we are unwilling partners. In fact, domestication itself began as an unintentional process, a coevolutionary outcome rather than a brilliant idea. This has become apparent as biologists have learned more about the elegantly simple and powerful effects of natural selection in wild populations. The first evidence of plant domestication suggests that it occurred twelve thousand years ago, during a thousand-year period of rapid climate cooling called the Younger Dryas period. Early theories hypothesized that this cooling period was the primary driver of domestication because it restricted humans, plants, and herbivores to refuge areas. Though these theories have been largely discredited, climatic conditions surely played a crucial early role in the history of agriculture—its successes and its failures.11 Traditionally, explanations of the causes and consequences of domestication (other than of dogs) and agricultural revolutions have focused on the Fertile Crescent, the flood plain between the Tigris and Euphrates rivers in Mesopotamia (in what is now Iraq and Iran), and the Nile Valley on the north coast of Africa (today’s

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Egypt). The Fertile Crescent is commonly thought of as the cradle of civilization for this reason. Sheep were the first animals to be domesticated as a food source around 9000 BCE, and goats followed suit, with this pair becoming the standard animals of nomadic pastoralist shepherds’ flocks. Cows and pigs were domesticated soon after, and draft animals like oxen were domesticated around 4000 BCE for plowing fields and digging and irrigation systems. As described earlier, these animals were amenable to domestication because of their herding behaviors and instinct to follow or imprint on a leader. Horses, for example, have become one of the most important domestication successes in human history, while zebras, more cantankerous due to their differences in social behavior, can be trained in simple ways but not domesticated as a species. Domestication, after all, involves total control over an animal’s life cycle.12 Plant domestication similarly filled the planet with the same handful of species domesticated ten thousand years ago. At that time, barley, wheat, lentil, pea, flax, fig, and vetch were all domesticated in the Fertile Crescent following the usual passive and active domestication scenarios, and today these plants are some of the most abundant—and important—in the world. Wheat, for example, was just another weedy grass in the foothills of the Karaca Dağ mountains in Syria before it spread to such an extent that some have argued that wheat has in fact domesticated humans (Figure 3.1). As interesting as this “botanocentric” perspective is, however, it confounds cause and consequence: selection preferences in agriculture were intentional, discriminating choices by humans. For example, wild cabbage, a weedy mustard species native to the nutrient-deficient limestone cliffs of the English Channel, has been selectively bred by clever horticulturists into a diversity of common vegetables. Most generic gourmets would be surprised to learn that all cabbage varieties, and many popular vegetables, including broccoli, cauliflower, kale, brussel sprouts, and collard greens, are all domesticated and manipulated variants of the single mustard species Brassica oleracea, which is native to coastal Europe. By selecting differentially for leaf size, bud size, bud density, and flower and stem characteristics, horticulturists have harnessed selection to manipulate Brassica oleracea into such a wide variety of common vegetables that they no longer seem related. In the pro-

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3.1. Domestication of grasses. Ancestral and domesticated wheats from the Fertile Crescent (left), and ancestral and domesticated corn from Mesoamerica (right). Original drawing based on public domain sources.

cess, this inconspicuous, competitively subordinate plant that had been relegated to living in a physically marginal habitat became one of the more successful plants on earth.13 Similar domestication events happened nearly simultaneously in some half-dozen areas across the world, such as along the Indus River in Pakistan and along the Yellow and Yangtze rivers in China. Plant and animal domestication spread rapidly across the globe from these hubs, occurring with the exportation of seeds, animals, and domestication techniques.14

Bread, Beer, and Olives Carbohydrate-rich grasses and tree fruits like olives show the ingenuity of early humans and are fascinating case studies for illustrating the reasons and processes of initial domestication. Grass seed, for example, proved to be a flexible plant that not only directed humans to essential early technologies—namely, bread making and fermentation—but also brought us into relationship once again with the microbial world. And olive trees aptly represent the culti-

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vation, from inedible wild ancestors, of an edible fruit that became highly prized and traded for its many uses. As central as grass seed and grains have been in human history, scholars have suggested that the initial selective use of these carbohydrate-rich grasses was stimulated by fermentation and alcohol production. This is part of the “beer or bread” debate that is still being waged today. We now know that our primate ancestors had evolved the ability to metabolize alcohol, and even may have eaten fermenting fruit. University of California, Berkeley, biologist Robert Dudley has proposed that ripe fruit was such a high-value food for these ancestors that they would inevitably eat the occasional overripe fruit, which would sometimes have been attacked by microbes that fermented it to form alcohol. This would have not only exposed our ancestors to alcohol, but may also have exposed them to the value of alcohol as a disinfectant or antibacterial agent and mind-altering drug.15 Richard Wrangham, whom I introduced earlier, disagrees with this idea, claiming that in his four-decade study of primates, he has only ever seen primates avoid overripe fruit. Regardless, alcoholic beverages have long been a part of European diets, and may have been a component of our distant dietary heritage. Paleolithic people may have found that drinking fermented beverages limited disease, which in turn would have positioned alcohol as a prophylactic. Given the frequent contamination of early water supplies by farms and sewage, these drinks were often safer than local water sources. During the Middle Ages, alcohol was seen as a disinfectant, referred to as aqua vitae, or the “water of life,” and was used to counter the many sicknesses like cholera and dysentery that were related to a lack of sewage systems in increasingly large cities. The use of alcohol for health purposes is still widely promoted in indigenous cultures in Africa and Indonesia, even if Western cultures more often see it as a recreational beverage.16 Whether their goal was bread or alcohol (or both), the late Stone Age nomads of Western Asia or the Levant collectively referred to as Natufians developed grain-seed processing techniques at least fifteen thousand years before the domestication of grasses by hunter-gatherers, offering another example of the deep history of human-directed natural selection. Evidence for this is found on

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grinding stones, mortars, and pestles possibly as old as 30,000 BCE. Pre-agriculture grain-seed processing suggests that the Natufians recognized the food value of grains millennia before grains were domesticated, at which point grain, due to its food value and storage potential, became one of the main drivers of the civilization process. Chemical analysis of cooking artifacts from this period further suggests that intact or ground grain seeds were soaked in water to form a gruel that was a staple Natufian food, and likely the base of the original recipes used by Stone Age hearth chefs. Like all organic compounds, gruel was attacked by atmospheric microbes, including single-celled yeast fungi, which would produce a pasty broth that had much more nutrition and energy than grain itself, nearly the energy value of meat. The conversion of carbohydrates and sugars to carbon dioxide and alcohol is fermentation, a technology that early humans discovered and creatively used to make leavened bread, beer, and wine— staples that we find in today’s kitchens millennia later. Through the trial-and-error hearth chemistry of fermentation, early humans learned the additional ingredients and temperatures necessary to make gruel’s carbon-dioxide byproduct raise bread dough into leavened bread and make its alcohol create beer and wine. This places gruel firmly at the base of the human culinary tree.17 The same switch from passive coevolution to cognitively conscious domestication played out in the transformation of Mediterranean olive trees into one of the most important commodities of ancient Mediterranean and Near Eastern agriculture. Wild olives are virtually inedible by humans due to their toughness and bitter taste—though less discriminating wild and domesticated animals like cattle and goats will readily eat them. Yet olive trees were the first fruit trees to be domesticated, around 6000 BCE, just around the time of the first cities in Mesopotamia. Initially, olive trees were used as fire fuel, a source of charcoal, and building material: they were easy enough to domesticate because olive trees can be propagated asexually, without seeds, by cutting and rooting branches in a neat Neolithic trick. Olive pits and wood have been found in some of the earliest pre-agriculture sites along the Mediterranean, such as the 20,000-year-old Ohalo site on the Sea of Galilee. Evidence for olive oil production dated at 6000 BCE in

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Kfar Samir, Israel, supports the idea that olives were used as wild food or as fuel for lamps before being domesticated.18 Through a long trial-and-error attempt to make olives palatable and to maximize the value of these trees, ancient communities discovered how to process olives into brined olives and olive oil. Olives were gathered by laying mats under the trees so the ripe ones could be collected easily, and were then either crushed into a pulp that was pressed and decanted to oil (first used as lamp fuel or cooking oil), or soaked in salt brine or ash lye with various spices, thus removing the bitter taste and adding a distinctive flavor. These methods are still used today, and the sight of olive-collecting cloths under trees is a sign of autumn across the Mediterranean. By the time the Phoenicians had pioneered trade routes around the sea, olive oil was one of the ancient world’s most valuable trade commodities; by Greek and Roman times, it would be the first oil to drive commercial trading (Figure 3.2).

3.2. Medieval processing of Mediterranean olives. © INTERFOTO/Alamy Stock Photo

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Becoming Agricultural Agriculture, once developed, spread to humans across the globe. Trade routes aided the early diffusion of farming technology, for example along the Nile River in Egypt and the Indus River in Pakistan. The diffusion into Europe was much slower due to climatic constraints and plant and soil conditions—humans also had to find safe ways through Western Europe’s dense primordial forest, which had developed since the retreat of the ice sheets ten millennia earlier. Due to this almost impenetrable forest, agriculture spread first along coastlines and riverbeds. Farming technology also spread more easily laterally across the globe than longitudinally, as Jared Diamond argues in Guns, Germs, and Steel. Diamond suggests that domesticated plants and animals, along with their microbial partners, were adapted to their climatic conditions, which meant that human culture could spread rapidly across continents, but not as easily from high latitudes to lowlatitude tropical habitats—even after long-distance travel and colonization became practical in the age of exploration. Higher temperatures and relatively constant climates without strong seasonality or harsh winter conditions failed to control insect vectors and disease populations. Thus, while human populations native to tropical latitudes acquired immunity to diseases like malaria, human populations from cooler, temperate seasonal climates were vulnerable to them. (The reverse was not a problem, since cooler temperatures and seasonality in temperate latitudes did not select as efficiently for highly pathogenic microbes.) Yet despite this acquired immunity, tropical cultures were still beset by disease and pathogenic microbial burdens, which limited their own development of technologies that would have enabled global exploration and access to agriculture from other lands. As symbiogenetic agricultural revolutions spread across the globe, they changed human social structures. Culture became a selective pressure on human physiology and on what we can and cannot eat, leading in turn to interactions between culture and genetics.19 As we will see, human genetics has been and continues to be shaped by our rapidly changing cultures, with genes and civilization coevolving to determine and shift dietary habits. Despite

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this, we still carry around heavy genetic baggage from our long legacy as hunter-gatherers. One of the clearest and most interesting genetic dietary shifts driven by human cultural change is the acquisition of adult lactose tolerance, which arose with the dawn of agriculture approximately ten thousand years ago. Adult lactose tolerance is particularly common in cold temperate environments where dairy farming prevails, but is also found among pastoralist farmers in low latitudes. The carbohydrate lactose is found exclusively in the milk of mammals whose infants can digest it, at least before the ability is lost after weaning. Adults, then, do not retain the capacity to produce the lactase enzymes necessary to metabolize lactose. Early in the agricultural revolution, during the development of dairy farming, this meant that humans had to let milk curdle to form yogurt and cheese, products that are digestible due to the metabolization of lactose by microbes. In this case, rather than natural selection changing human enzymes to allow us to digest milk and use it as an energy source, humans invented cheese and yogurt (just as we processed olives to become palatable). At the same time, in cultures where dairy farming developed, adults evolved to keep on producing lactase and so the ability to metabolize milk. Like the loss of our ape ancestors’ fur coats and the acquisition of large brains, the ability to metabolize lactose as adults evolved via the retention of infant traits in adults—in another example of neoteny. Reflecting the biogeography of dairy farming, lactase enzyme persistence in adults is high in northern Europeans (more than 90 percent of Scandinavians are lactose tolerant), comparatively low across southern Europe and the Middle East (50 percent of Spanish, French, and Arab peoples are lactose tolerant) and exceedingly low in Asia and Africa (only 1 percent of Chinese, and 5 to 20 percent of West African individuals, are lactose tolerant). The exception that proves the rule is that adult lactose tolerance is common (90 percent) in the dairy farming Tutsi culture in Africa.20 This story gets even more interesting when the global distribution of lactose tolerance and intolerance is considered. Lactose intolerance is correlated with the historical distribution of cattle diseases like anthrax, implying that dairy farming and its cultural consequences did not occur where the threat of cattle disease was

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high. This suggests that the ecology of disease influenced the chances that cattle herding and dairy farming were adopted in a particular area, which in turn generated a selective force for a digestive system enzyme. It also shows how agricultural revolutions dictated interactions among cultural traditions, genes, and ecology, crafting global patterns in human digestive metabolism and the human diet. For example, we can understand now why some modern cultures with goats and cows eat yogurt and cheese dairy products, but avoid milk, and why southern Italian sauces use bases of olive oil, rather than cream. Even regional, cultural, and biogeographic patterns in cholesterol metabolism, heart disease, digestive disorders like celiac disease, and nervous system disorders like Parkinson’s and Alzheimer’s disease may stem from this interplay of genetic and cultural effects. The ultimate cause of many chronic and often deadly contemporary maladies has been convincingly suggested to be rooted in modern diets that our hunter-gatherer metabolic machinery has not had sufficient time to evolve to handle. Thus, in the early days of agriculture, our ancestors were wholly, but unwittingly, reliant on microbes. They did not know how reliant they were, or why letting milk spoil made it more digestible and created the yogurts and cheeses we value today. They did not know that their gruel broths opened the carbohydrates and sugars in their grains to a transformation that would create the breads and beers we stock our cupboards with; they were unaware of their deep history as staple foods crucial to our survival. Similarly, we often remain unaware of how tuned our digestive systems are to the foods we evolved to eat, and how contemporary diets may fit awkwardly within this evolution.21 Agriculture, and the humans’ slowly changing diets and digestion, spread east from the Fertile Crescent to India where it encountered a different agricultural revolution based on the domestication of rice and spices. Further east, China experienced two agricultural revolutions, one in the north and one in the south. These revolutions occurred around the same time as the one in the Fertile Crescent, or earlier, but dates for Chinese domestication are not well established due to poor preservation and less research effort. The Yellow River Valley, where millet was domesticated, is often called the “cradle of Chinese civilization,” and a number of

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strains of rice were also domesticated in these valleys. From these regions the domestication of pigs, chicken, cattle, pears, lemons, and oranges diffused across Asia. The earliest known bird domestication occurred in northern China around 8000 BCE, which we know from archaeological studies of chicken bones.22 Over time, the connection between the great epicenters of the agricultural revolution—the eastern Mediterranean region, northern Africa, and western China—became the Silk Road. Nomadic pastoral tribes that controlled the steppes, deserts, and mountain ranges between the Mediterranean Sea and the Pacific Ocean were responsible for the roads and trade networks in these areas, which they created rather than building great cities. These tribes had built their culture not around agrarian life, but rather around the domestication of horses—eventually becoming the feared horse-warrior Mongols.23 Later agricultural revolutions occurred where human colonization was more recent, such as in Papua, New Guinea, where bananas, breadfruits, and sweet potatoes were domesticated as early as 7000 BCE. Colonization of Polynesia occurred later, around 1200 CE, after the development of seagoing vessels powered by wind and oar, and led to the domestication of many varieties of yams. Independent revolutions also occurred in the Americas: Paleo-precursors to the Aztecs and Maya domesticated corn, chili peppers, and papaya, while Incan ancestors domesticated potatoes and llamas in what is now Peru. Paleo–North Americans domesticated varieties of squash, beans, and pumpkins.24 Domestication and agricultural revolutions were never monolithic, singular events. Instead they resulted from acts of human ingenuity popping up within histories of coevolution across the globe at different times, in different ways, and related to different plants and animals. In each case, the early humans who realized they could control the lifespans and reproduction cycles of a given plant or animal had been primed by millennia of mutualist relationships to see the benefits of controlling another species. Histories of cooperation, combined with the big-brained creativity of humans, led to this new phenomenon—agriculture—on the planet. But was domestication the energy- and time-saver we assume it was? What were the benefits of an agrarian, pastoral, increasingly sedentary lifestyle versus our hunter-gatherer pasts?

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Why a Revolution Anyway? According to scientists in the early nineteenth century, the reason for the shift from the hunter-gatherer lifestyle that humans had lived for 150,000 years to a sedentary lifestyle relying on domesticated plants and animals was that staying put provided a more stable food supply with less famine and more leisure time. By becoming sedentary, humans would be freed to develop art, writing, deeper spirituality, and a richer cultural life. More recent empirical studies, however, have shown just the opposite: an agrarian lifestyle, which requires constantly tending to domesticated plants and animals, requires as much as twice the time and effort as mobile hunting and gathering. While early farmers could remain in permanent settlements and thus accumulate the pieces of a material culture, the tasks required of farmers and shepherds were extremely difficult—so much so that Diamond has called the agricultural revolution “a catastrophe from which we have never recovered . . . [one] that brought gross social and sexual inequality, disease, and despotism that curse our existence.”25 Agricultural revolutions were not human innovations; they were symbiogenetic evolutionary consequences. Of course, the transition from the hunter-gatherer lifestyle was not rapid, and hunter-gatherers persisted into the nineteenth and twentieth centuries in extremely harsh environments where farming was not possible, like the vast deserts of Central Australia and Africa and America’s subarctic habitats. Eventually, however, the passively motivated relationships between humans and the animals and plants in most ecosystems may have made farming an inevitable byproduct of the increasing mutualisms at play. This means that agriculture was an evolutionary consequence, rather than a choice or a natural progression; it was supported by shifts occurring independently among the world’s diverse groups of hunter-gatherers, from the Fertile Crescent where Africa, Europe, and Asia meet, to China, to the Americas. Diamond has referred to the spread of agriculture across the globe as “autocatalytic,” driven by millennia of positive feedbacks related to taming nature.26 Human control of animals and plants, this much-heralded domestication, is thus a natural extension of coevolution—a determined, nonrandom event that impelled its own feedback

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loops. Farming depended on cooperation and was labor intensive, but it produced greater food resources that translated into higher population growth, which then required more food and labor. Indeed, possibly one way to explain the transition from hunting and gathering to farming is simply that Paleolithic humans did not know the costs and long-term consequences of a farming economy, or what escaping the food chain and controlling nature would ultimately imply. Rather than a revolution, agriculture was a kind of evolutionary trap, a capitulation to the developing dependencies and mutualisms between humans, plants, and animals. It is of course impossible to rewind the calendar to the huntergatherer days, and describing the determined quality of our sedentary lifestyle is not a call for a “return to nature.” We simply can’t go backward: the agricultural revolutions that occurred in a halfdozen regions of the globe were evolutionary slippery slopes that ended in situations from which there is no recovering. They were wormholes to the future that required, and require, adaptation rather than counter-revolution. But now that we are outside of the natural food chain, have we escaped evolutionary forces or are we too entrapped by evolution to realize it? Can we change the paths that natural selection and self-organization have designed for us to follow? As the most powerful evolutionary force on earth, can we control our own fate?

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chapter four

The Triumph and Curse of Civilization

I

n 10,000 bce, earth’s human population is estimated to have been 4 million. By 1000 BCE, as domestication and agriculture spread and sedentary lifestyles became the norm, the global population had increased by two orders of magnitude, to 400 million. Over the next three thousand years, the population increased with the help of industrial revolutions to 1.6 billion by 1900, and in only the past century this number has skyrocketed to 7 billion human inhabitants on earth. Population growth is one of the most significant aftershocks of civilization. The agricultural revolutions that led to civilization simultaneously ignited exponential population growth, which then grew in tandem with civilizational forces of development and requirements for greater numbers. In other words, agricultural revolutions sparked an autopoietic process whereby development and population growth each influenced the other through positive feedbacks. Civilization became a selfperpetuating runaway train, one driven by the evolutionary forces of natural selection and reproductive success (rather than our impressive creative and cognitive abilities) and still operating on top of the mutualism and cooperative relationships between humans and other species on the planet.1 79

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In many respects, how this happened is conceptually and mechanistically analogous to the symbiogenetic evolution of eukaryotic cells discussed in Chapter 1: the mutualistic, cooperative partnership among primordial prokaryotic cell components eventually gave way to eukaryotic cells that could organize and control what had been individual independent parts. An increase in order, efficiency, and reproductive success—an increase driven by cooperative, rather than competitive, processes—simultaneously meant the loss of individual control.2 Cooperating eukaryotic cells then joined forces with mutualist microbes to form multicellular organisms. These multicellular plant and animal cooperative superorganisms were better suited to dominate their competitors and environments than simple nucleated cells, so they were, in turn, the answer to the problem that natural selection posed to organisms. Thus evolutionary history has shown time and time again that cooperating groups are stronger than individuals and that cooperation makes groups stronger than competitors. Whether this occurs within or between species, as long as it ultimately increases individual reproduction and fitness, groups will dominate. A swarm of bees can overtake a large mammal, a school of small fish can overtake the defended feeding territory of a coral reef fish, and a group of our ancestors armed with primitive weapons and domesticated wolves could dominate large, fierce predators or other groups of humans. Eukaryotic cells were the result of cooperation: to make these cells, prokaryotic cells had to give up their “independence” and selfishgene individual motivations to be a part of hierarchically structured, cooperatively organized complex organisms that are more suited to survive and thrive in a competitive world.3

The Evolution of Civilization As pre-agriculture family bands of hunter-gatherers continued managing their land and seeding crops, thereby investing time and effort into the future, their successes led to the establishment of permanent, year-round farms instead of seasonal campsites.4 In time, these genetically related extended family groups coalesced into villages while developing and becoming more specialized in their agrarian work: early farmers committed to these settlements

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by irrigating their crops, grazing their animals, and creating grasslands by burning forests. Permanent housing and infrastructure followed and created novel opportunities—and challenges—for this newly sedentary people. While farming for individual families was sustainable by the family itself, the population increase spurred by agriculture led to increased competition for resources, and escalated lethal violence for contested resources among extended family groups. Steven Pinker’s 2012 The Better Angels of Our Nature: Why Violence Has Declined recounts the carnage described graphically in sources like the Old Testament. This violence nullified the initial advantages of high population growth that had led to the early success of farming and agrarian life. We commonly think of the past in rosier terms, and believe we currently live in a uniquely violent world driven by economic and cultural divisions and disparities—a view articulated in Jacques Barzun’s 2001 From Dawn to Decadence: 1500 to the Present, 500 Years of Western Cultural Life. Pinker, however, has assembled an impressive body of empirical evidence and data that suggest that violence, war, genocide, and murder have all dramatically and consistently decreased over time and that we currently live in the least violent era of human history. Pinker’s work is worth a brief detour, because it highlights cooperation as an evolutionary and social process anchored within selfish-gene selection.5 Pinker’s focus on the murder, violence, and genocide in the earliest written human histories of the Old Testament and Homer’s Iliad is compelling, particularly given the contemporary ignorance of Western religion’s violent beginnings. He finds that a conservative estimate of documented violent death in the Old Testament is in the millions. The organization of rules and governments—the beginning, in other words, of civilization—created order from this disorder and limited the frequency, acceptance, and pervasiveness of violent deaths. Pinker calls this initial step toward humanity the “pacification process,” and it led to drops in human mortality rates by orders of magnitude. Later, in the late Middle Ages, human violence would deescalate again as centralized states, in what Pinker calls the “civilizing process,” consolidated to spread laws and legal codes across wider populations, protecting businesses, personal property, and civilians. Both the pacification and civilizing processes

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were likely driven at their core by selection pressures that favored successful individual reproduction through cooperation over human violence, and top-down decisions about who would survive and thrive. Since the civilization process began limiting violence, violence has continued to decline until the present day, driven by cultural rules that minimize violence and danger, including trade and commerce that require civil transactions.6 These data suggest that the high population densities that were necessary for agricultural revolutions led to so much violence and death that violent behavior was selected against. In other words, Pinker’s data offer strong support for our general hypothesis: cooperation has evolved from a violent, competitive past, and the development of civilization over time has been driven by this selective pressure of violence. This is analogous to how human communities, and their microbial mutualists, develop resistance to a deadly pathogen that causes an epidemic; the selective pressure of the fatal disease means that those who survive the outbreak will more likely be immune.7 The pacifying process, then, created the opportunity for cooperative agreements among early humans that maximized individual success. Farming became a communal, mutually beneficial activity, and increased regulation of water resources became essential, requiring management, organization, and coordination. Despite the rich, alluvial soils in Mesopotamia, for example, the hot, dry summer climate made irrigation necessary for year-round crop growth. Paleolithic farmers would flood their fields with river water, then drain them to prevent salt buildup. The labor of entire communities was needed to build and maintain irrigation channels large enough to service not only one family’s farm, but large clusters of farms. Scaled farming in proto-cities is but one of the early examples of how the group benefits of cooperation outweighed more individualist pressures. Such early civic projects required workers responsible for design, management, and accounting, and impelled a multitude of material innovations, such as pottery (to store seeds, grain, and fermented products), the wheel (first invented to throw clay pots and then used to move carts), and the plow (to dig furrows for seed planting). Sedentary life thus opened the possibility of material cul-

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ture, for humans could now invest in possessions like grain mills, storage containers, and farming implements. Food storage shows how competitive pressure for potentially limited resources shifted from individuals to cooperating groups, since the collaborating group was synergistically stronger and more efficient than the same number of individuals acting uncooperatively. Larger families were also possible, which played a role in the autocatalytic process of population growth. Early family farms, however, were susceptible to predators, rival humans, and food shortages if their personal crops grew poorly. This led to families clustering their farms, creating proto-cities easier to defend and feed with their domesticatedwolf hunting partners.8 Most significantly, farming and irrigation were the precursors to and reasons for civic organization and management, while leading to the population growth that such management would attempt to order and control. To manage, one needs managers, and to control, one needs controllers: stratified leadership soon became necessary for distributing food products and enforcing rules in these early proto-cities, the first of which appeared around 6000 BCE in Mesopotamia and along the Yangtze River in China. In Mesopotamia, Jericho is often referred to as the first documented city, consisting of eight to ten acres of mud-brick domiciles surrounded by walls, a stone tower for defense, and water tanks for irrigation, all to maintain its population of around 2,500 inhabitants. Organized control led directly to an autocratic class and a hierarchically organized society, and to the loss of the independent lifestyle of hunter-gathering. There was a strict division of labor as well as massive disparities in wealth, possessions, and way of life between the rich rulers and poor farmers. The ruling class gained and maintained their power through a number of means, including harsh punishment and intimidation of rule breakers. They also claimed unique communication with the gods (more on this in Chapter 8) and restricted other critical forms of knowledge, such as writing, to themselves. Cuneiform script was used in the Fertile Crescent for recordkeeping on clay tablets until it was replaced some five thousand years later, in 2000 BCE, by the Phoenician alphabet and language written on perishable organic sheets. Like other ancient writing systems, such as the ones developed in

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Northern Africa and China, cuneiform, another byproduct of the agricultural revolution, was initially a way to keep track of trade, so cuneiform literacy was highly guarded by those in charge. Knowledge, and access to it, has always been used to subjugate the weak to the powerful.9 In the first cities, positive feedbacks reinforced both population growth and hierarchical organization: larger populations required greater food production, which in turn required greater organization and management (Figure 4.1). A class of increasingly empowered, entitled autocrats took power, and their influence spread from farm management and resource control to early trade, religion, and relations between other city-states. These rulers then made membership to the new aristocracy hereditary, locking everyone both inside and outside of these families into their social roles. At the core, the rulers’ selfish genes were the victors, which as we will see later, made the structure of early civilization similar to that of social insects like bees. Again, the reproductive success of the group outweighed that of the individual, which stimulated this shift in organization. Such shifts in scale appear to be associated with major transitions in the organization of life—whether from bacteria to eukaryotic cells, eukaryotic cells to multicellular plants and animals, or individually driven organisms to cooperating groups of organisms. Prokaryotic genes gave way to cells, which gave way to multicellular plants and animals, which gave way to groups of organisms as the critical operational units of selection. This expanded view of evolution adds organizational change to the story of species to species change, and is the basis for the hierarchical order of life on earth.10 As city-states sprang up, specialties emerged based on local resources, which in turn compelled trade networks that simultaneously disseminated agricultural technologies. Rare commodities like obsidian, clay pots, salt, copper for jewelry, tin and lead for alloying with copper in order to form bronze, and wood for buildings made their way between cities and became essential to city growth. The Fertile Crescent, for example, had become deforested due to farm activities, and thus depended on trade (Figure 4.2). Local trade via donkey caravans morphed by the dawn of the Bronze Age, around 3100 BCE, into extensive networks along the Mediterranean, into

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4.1. The Sumerian walled city-state of Ur, in ancient Mesopotamia, showing early organizational structures used for defense, agriculture, and religion—and for maintaining the distinction between farmers and the ruling class. Original drawing based on public domain sources.

Africa via camel caravans, and beyond. Salt, gold, and ivory were moved along far-reaching camel caravan routes controlled by African trading centers such as Timbuktu. Ultimately, the legendary Silk Road would become a vast trade network with lasting cultural and technological effects on the societies it linked, allowing accelerated innovation in both the East and the West and making possible Mongol control of Central Asia through piracy on its trade routes. In this way, humans established forms of life that were a far cry from the small, nomadic clans that had been characterized by limited population growth and hierarchical organization. In only a few

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4.2. The Fertile Crescent, the first discovered and most heavily studied agricultural revolution site in the world. Original drawing based on public domain sources.

millennia, the formerly cooperative, egalitarian lifestyle of familyunit hunter-gatherers that had survived a hundred thousand millennia was overturned. Group organization meant that competition for resources would now occur largely between populations and states, rather than families.

Religion and Göbekli Tepe The explanation that agriculture birthed civilization is only one theory: other views also exist, some informed by recent findings of ancient, large-scale ceremonial ruins that predate agriculture and cities. Did agriculture give birth to cities that then spawned spiritual mythologies and religions in the civilizing process, or did spiritual mythologies that grew from experiences with psychotropic plants lead to sedentary living and cities? These are not wholly incompatible theories, and both may have occurred as agriculture drove the global spread of urbaniza-

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tion via increased population growth and stronger, fitter humans. There will likely be many refinements to our understanding of the development and spread of human civilization, but one fascinating theory comes from the late German archaeologist Klaus Schmidt’s twenty years of work excavating the Göbekli Tepe site on a mountain in Turkey, near the Syrian border and overlooking the Fertile Crescent. A massive site featuring large stone pillars arranged in concentric rings, Göbekli Tepe is not associated with any cities and is thought to have been used for religious ceremonies. What makes Göbekli Tepe unusual, however, is its age: it was active before 10,000 BCE, which means that it predated pottery, the wheel, and cities built in response to the agricultural revolution. Yet the massive size of the pillars and the site in general required the organization and sustained labor of hundreds of people.11 This suggests that sedentary life and civilization developed from ritual centers and the desire to live near sacred ritual sites. According to this theory, mythology first organized populations in single places, and these communities then turned to agriculture to sustain themselves. The natural history patterns discussed here, however, are not consistent with this hypothesis. From the natural history point of view, domestication appears to be the product of coevolutionary mutualisms, like that between flowers and their pollinators, rather than the invention of a community that has already assembled. Though there appear to be other pre-agricultural sites like Göbekli Tepe, taking a hardline stance that mythology led to civilization conflicts with what we know about the central role of cooperation among organisms. Agriculture was an evolutionary fact, not a creative response. So what to make of Göbekli Tepe? It may have been the result of an early shamanic culture that emerged due to experiences with psychotropic plants, which would make it the mark of some of the first manifestations of religious mythology. If so, this would mean that mythology developed concurrently with the domestication of plants, psychotropic plants in particular, and so fits within a deterministic, evolutionary framework. Further, ceremonial centers, primitive religion, and experimentation with certain plants may have played a far larger role in early civilization than currently recognized. The combination of psychotropic experimentation and

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civilization’s hierarchical order may be the soil from which grew the highly stratified religions that long controlled civilizations through ruling families of kings and priests.12

At What Cost? Natural selection is an effective tool, but a shortsighted one. It operates generation by generation without long-term planning or future goals. It answers problems posed by environments, and over enough time changes organisms and ecosystems, but this does not mean that what is selected will always work for general long-term stability and sustainability. The short-term reproductive advantages stemming from agricultural revolutions generated explosive population growth and ultimately led to human domination of the planet. This happened rapidly in geological time: less than 1 percent of the time that humans have been on the earth, and less than .001 percent of the time that plants and animals have covered the planet. We have not yet fully grasped how significantly the fast-track trajectory of civilization has affected human evolution and the planet as a whole. What we do know is that civilization brought with it art, technology, religion, and science—but also a multitude of costs we are today still paying for, and adding to, all within the span of an evolutionary heartbeat of geological time. I have already gestured toward one of the costs of hierarchical, stratified civilization—namely the establishment of a ruling elite and mythologies that would dominate the masses. This came at the expense of a lifestyle where everyone was needed and important for group success and survival. The transition to the more stratified arrangement made sense, for early farming needed entire communities at varying levels of importance and disposability: this system then only became more entrenched and elaborate over time. The first farmers surely had no idea that a stratified structure of cities, which separated managers from the managed, would give rise to an economic and social disparity that would escalate class conflict within and among emerging cities. Once a sedentary lifestyle was adopted, however, city-states, with their large and growing populations made possible by agricultural revolutions, and with their com-

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munity decision-making controlled by an elite class of religious leaders and educated managers, battled with one another over the accompanying declines in available resources (Figure 4.3).13 In this sense, city-states acted like internally cooperative superorganisms, competing with other superorganisms over the same lands, the same materials, and the same water. Aggressive warring cultures arose and gave birth to walled cities, like Jericho, and the first standing armies in global history. The human fossil record backs up this rise of aggressive, hostile human relations by showing an increase in violent injuries during this era. The legacy of these early wars continues into the present day. It is a cruel historical irony that the countries that now exist in what we have called the Cradle of Civilization remain continually war-torn some eight thousand years later.14 Other regions were also subject to these pressures. Mortal conflicts for resources and wars among competing cities and mythologies

4.3. Assyrian stone relief of a war chariot, circa 2000 BCE. As local resources dwindled, and as decision-making became concentrated in the ruling class, the lower classes were often sent to war to acquire what the growing population needed. Original drawing based on public domain sources.

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were in fact the rule among developing civilizations, as discussed in Francis Fukuyama’s 2011 book The Origins of Political Order. These growing pains of civilization were most severe in China, where a culture of never-ending war lasted for nearly five centuries. Farmers also could not have anticipated the conflicts with nature that would quickly follow the establishment of cities. With no understanding of the germ theory of disease, early city dwellers had no way of knowing that greater population density would create breeding grounds for diseases (human population density, from the increased supply of food, grew five-fold in the Fertile Crescent in only a few millennia). Similarly, in the twentieth century, we had no idea that insecticides would weaken the eggshells of birds of prey, nearly leading to the extinction of hawks, eagles, and other raptors, nor did we know that large-scale farming in arid habitats would exhaust the land and lead to salt accumulation and desertification. More on this later.15 An agrarian lifestyle also greatly affected human health. Relying on a small number of food sources meant consuming a less diverse diet, one that often relied heavily on grains and carbohydrates. This resulted in dental problems, low birth rates, reduced adult stature, and shorter lifespans. An increasingly sedentary life also indirectly led to more health problems for women, who were more frequently pregnant. Our metabolism, honed by millions of years of evolution for hunter-gatherer diets, is thought to be at the root of many contemporary health problems such as obesity, diabetes, and gluten intolerance. The reliance on less diversified food sources during the first agricultural revolutions made early human populations vulnerable to problems like food shortages, famines, and animal and plant diseases.16 Finally, early farmers could not have known the devastating environmental costs that would be incurred by farming and civilization (Figure 4.4). Habitat destruction, desertification, and other forms of environmental degradation all followed from the citystates’ ballooning populations and their ever-growing need for food. This was a larger problem for early farmers than we might think, because early humans had not settled in the most productive habitats available: as mentioned earlier, they did not have the technology to safely clear the massive forests that hid predators and

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4.4. The Mesopotamian city of Jerusalem, one of the oldest cities in the world, whose origins date back more than eleven thousand years. Original drawing based on public domain sources.

prevented crop growth. Instead they clung to the overused edges of the forests where they could more easily farm and watch over grazing animals, in the process making these habitats vulnerable to resource depletion, erosion, and, with the harvesting of trees, desertification. All of these problems are painfully evident in the Fertile Crescent today. Moreover, the machine of escalating population growth and accompanying demands for ever more resources has, we know now, influenced more than the planet’s ecosystems. In the past few decades we have finally come to see how deeply civilization has affected the planet, changing even its geology.17 Civilization is generally considered the triumph of humans over nature, the point when humans hijacked their own natural history and became masters of their own futures. And yet, rather than leading to general human welfare, this “triumph”—which has existed for only 2 percent of the time that Homo sapiens have been on earth—has led to stark and very serious outcomes. These include

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economic disparities across populations with a small class of elite leaders profiting most, habitat (and planet) degradation, famine, disease, and the perennial threat of war driven by a frightening cocktail of population growth, competing mythologies, and resource depletion. Violence has subsided, but not inequality. We still live in a world shaped by the basic conflict between competitive and cooperative pressures. But cooperative domestication and civilization are the results of evolutionary processes, not the choices of individuals. How then should we evaluate the benefits and costs of civilization? Are these consequences the inescapable products of hierarchical selforganization? Will these processes lead our species only to further resource exhaustion, the erosion of human life support systems, and global conflict? In the course of our evolutionary history, selfish and competitive behaviors have been repeatedly overcome by the group benefits of cooperation; whether facing disease, violence, or limited resources, working together has been the answer. But these cooperative advantages, which have been non-teleological and short-sighted, have also set us on a dire course. Are there intentional and cooperative solutions to our now unsustainably high human population densities, contemporary food resource limitations, opposing mythologies, and the collapse of the symbiogenetic world we have evolved in? These are the questions that animate the rest of this book.

chapter five

Resource Exploitation

R

esource limitation and exploitation are central problems for all self-replicating organisms, and, as we saw, they are among the costs and drivers of civilization. From bacteria to plants, to animals without backbones to vertebrates, including humans, resource availability limits populations. Resource limitation, however, is species-specific and habitatdependent. Liebig’s eighteenth-century “Law of the Minimum,” initially developed for agriculture, explains some of this process and has stood the test of time to inform contemporary ecological theory.1 Liebig’s Law states that population growth is controlled not by general resource supply but by the single most limiting resource. In other words, populations are limited by their weakest resource link. When we were nomadic hunter-gatherers, we did not face this problem at the same scale that we did once we became sedentary: we were not committed to single lands nor did we have large numbers to feed, and we were mobile and clever. As cities developed, however, limited resources drove innovations—better materials for tools and weapons, cooperative trade networks, ways to tap more energy for exploration—that we recognize even today. A perfect case study for exploring the causes and effects of limited resources and creative attempts to manage these resources is early Phoenician civilization. In fact, the Phoenicians’ rise to power 93

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was due to the very creature that fascinated me on Puget Sound as a boy and eventually led to this book: the snail, which is something of the star of this chapter. The cultural dynamic between the Phoenicians and the snail would set off one of the most important early trade networks in the Mediterranean Sea, a development that also involved new technologies and exploration. How did these two organisms—snails and people—come to be so intertwined?

Arms Races As human populations expanded and supply needs increased, communities had to store and defend their resources from others. Limited resources lead to human conflict, just as they do in the plant and animal world, and these conflicts are resolved in one of two ways: cooperation or evolutionary escalation. Cooperation handles limited resources by relying on group advantages, such as defensive strength in numbers and benefits in associations. We see these associational advantages in everything from mussel beds to bird flocks, from the walled cities of Paleolithic humans to the organisms that depend for their survival on the chemical and structural protection of coral reefs. Cooperative feedback and strength in numbers allowed consumers— such as ants, bees, schooling fish, wolf packs, and human hunting groups with their dog partners—to maximize their foraging success. Conversely, safety in numbers or selfish herd behavior developed as a primary prey strategy in a variety of organisms ranging from spineless invertebrates (including sea anemones, ants, oysters, and snails) to vertebrates (such as flocking birds, herding ungulates, and cooperative primates). In many species, including humans, group living was at the same time a leading offensive and a leading defensive weapon, a foundation of their basic behavior and natural history. Escalation, however, led to arms races. As resource supplies dwindled, interacting species responded by reciprocally upping their games. The snail and its predator, the crab, are useful examples here. Geerat Vermeij has had an influential career dissecting the evolutionary dynamics of predator-prey coevolutionary combat using snail shell architecture and crab and fish predators as a model system. Because of their hard, calcium carbonate shells, snails have a long, well-studied fossil history, and they were of intense interest

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to affluent eighteenth- and nineteenth-century naturalists during the era of exploration, when new species were collected by and for the educated elite. Vermeij himself often relies on Victorian shell collections and fossil shells now at museums around the world to reconstruct the history of Molluscan arms races. The story this research reveals is simple, robust, and generalizable. Snails and snail predators have long coexisted in shallow saline seas. To avoid being eaten before passing on heritable shell defensive architecture to their offspring, a variety of interconnected advancements were selected for, such as thick shells, structurally reinforcing shell ribs, shell spines that limited the ability of predators to hold and attack the shells, and occluded shell apertures that limited predator access to snail soft tissue. In turn, evolution selected an armory of responses for crabs hoping to crush the snails, such as harder calcified claws, powerful muscles with maximum mechanical advantage, and claw teeth that chipped shell aperture lips to access the snail’s soft tissue or to hold shells firmly in place to be crushed. Incremental shell defensive developments by the snails selected for stronger, more specialized shell crushing claws by the crabs, in an escalating evolutionary arms race that led over time to today’s architectural diversity of snail shells and crab claws (Figure 5.1).2 While the evolutionary arms race led overtly to architectural diversity, it also led less conspicuously (but more consequentially) to chemical warfare. Defensive chemicals, evolved primarily in sessile plants, fungi, and marine invertebrates to limit their losses to predators, would have deep, profound impacts that reverberate throughout all life on earth to this day. Humans borrowed other organisms’ chemical defenses as protection from their own predators and diseases, ultimately leading to the pharmaceutical industry. But humans were also targets of evolutionary chemical warfare. This led not only to addictions that have crippled humans, but also hallucinations that led humans to imagine other worlds and helped to create mythologies. It is one of the great ironies of humanity that organic chemical warfare between sessile organisms and their consumers has been the path to both addiction and belief in religious mythologies, two of the most consequential behaviors influencing human culture. Escalation also drove the development of tools. During the Bronze Age, which began around 3000 BCE, humans began alloying

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5.1. A coevolutionary arms race between the snail and its primary predator, the crab. Snails respond by natural selection to shell-crushing predation by thickening their shells and by adding architectural features like spines, ribs, and occluded apertures. Crabs respond by natural selection to these shell architectural defenses by developing larger, more specialized crushing claws. Original drawing based on public domain sources.

tin and lead with copper, creating a metal more durable than copper alone. These metals, like the volcanic rock before them, became the preferred material for acquiring and defending subsistence resources, such as the food that laborers needed to tend fields and to harvest and process crops, and for storing food reserves through harsh weather. The advent of bronze meant more rugged farming implements as well, and in what has become something of a universal principle for humankind when there is a technological leap, weapons.3 In a classic example of the positive, deterministic feedback between resource exploitation and population growth, the introduction of bronze increased farming abilities and supplies, which led to greater populations, which required even greater supplies. And with new bronze weapons that far outmatched stone-tipped spears and arrows, conflicts between competing city-states for access to food and metal resources intensified. Such was the ongoing battle between cooperative trade and competitive control over the newest limited resources.

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Bronze alloying was followed by iron smelting, kicking off the Iron Age. Though the earliest manufacturing of iron occurred on the Anatolian peninsula in 1700 BCE, iron forging did not become commonplace until 1200 BCE. Initially, the most limited resource was the smelting technology itself, which diffused along cooperative trade routes. The development of cast iron, which was brittle, and wrought iron, which was malleable, depended on not only the distribution of iron deposits, but also the know-how to use pure carbon charcoal in an enclosed furnace to increase the temperature of fire enough to melt, smelt, and alloy iron ore with carbon. Because iron is a far harder and more durable material than bronze, city-states with this technology had an edge in the resource wars. Iron production and the Iron Age accelerated the development of metal technologies for both farming and warfare, leading by the thirteenth century to stronger swords and knives as well as crossbows, guns, and cannons. Iron was the structural material of choice for tools and weapons for over three thousand years. It wasn’t until the nineteenth century that high-quality, carbonized steel, or “crucible steel,” which requires extremely high temperatures to remove impurities from the iron, became commonplace. (Viking weapons of crucible steel from much earlier, 800–1000 CE, have been discovered. These advanced weapons allowed the Vikings to bend or break their opponents’ swords. But how the Vikings developed this technology so early is not entirely understood to this day.)4 This human arms race is an example of simple, old-school natural history. Competing consumers and their prey have been interactively upgrading their weapons and defenses for hundreds of millions of years: the difference with humans is simply greater cognitive ability. Much like when humans evolved long-distance running, cooperative hunting, and mutualistic partnerships with dogs in order to master their prey, they used their enlarging brains to develop tools and metallurgy that would help them defend and acquire necessary resources. This human arms race was in many ways no different from the ancient evolutionary kind that leads to shell-crushing claws, increasingly elaborate snail-shell defenses, or poisonous sea slugs.5 From this perspective, the ocean floor is a weapons testing ground hundreds of millions of years old, one where the hard

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calcium carbonate armor developed by sea slugs to ward off or dissolve the teeth of predators is akin to the walls of Jericho—and the massive undersea coral communities, created by interconnected calcium carbonate exoskeletons of sea anemones, are much like fortresses and fences. The predators of these calcified seaweeds, corals, and heavily defended snails responded with their own enhanced weaponry: iron-capped or razor-sharp teeth to challenge calcified seaweeds, and dentition and crushing digestive systems that, like food processors, could pulverize and process coral skeletons (most sea stars spew digestive enzymes directly on live coral soft tissue by extending their stomach and the associated digestive enzymes from their mouths, liquefying the soft tissue, and slurping it up). Crabs and lobsters, too, have strong claws or mouthparts able to rupture shells and subdue well-armored prey. This ancient evolutionary arms race among common marine organisms is directly analogous to that of humans, who used their creativity during the early days of civilization to improve their weapons and tools by using rock, then bronze and iron. Rather than modifying our teeth, hands, or skin, we turned to creative tool technologies to keep pace with, and outmatch, our competition in the evolutionary game of survival.

Snails, Sailing, and Slaves War and conflict among cooperating human groups or cultures was one result of resource exploitation, but as cities cleared trees for building boats and homes; drove game to local, regional, or global extinction; and discovered and developed luxury resources— as well as learned of other resources spread across the globe— another result was set into overdrive: trade. Trade has always been an important factor in the early days of civilization and is accomplished via cooperative agreements. Some of the most notable early traders were the Phoenicians from the Levant region of the Fertile Crescent. Rather than becoming empire builders of great cities, like the Greeks and Romans, the Phoenicians built the first commercial trade network based on their knowledge of natural history, ability to exploit resources, and sailing fleet. They dominated trade in the Mediterranean for three millennia (Figure 5.2).

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5.2. Phoenician trading network. Rather than building trophy cities, the Phoenicians gained dominance over the Mediterranean Sea and its resources by creating an extensive, cooperative trading network. Original drawing based on public domain sources.

The Phoenicians came from humble beginnings, collecting Murex snails on the rocky outcrops of the Levant shoreline by mastering their natural history. Murex snails are shallow-water predators that live on temperate rocky shores across the globe. They prey on barnacles and mussels by boring precise, drill-like holes in their victim’s protective calcium-carbonate armor or shells, alternately secreting a mild acid to dissolve the shells and then rasping and boring away at the softened shell with their toothed tongue. Once the hole penetrates the shell, a purple liquid poison sac is injected, liquefying the soft tissue, which is then sipped out by the snail’s proboscis like a milkshake through a straw. In other words, Murex snails fit neatly into our story of highly developed predators that have advanced weaponry honed to break through otherwise impenetrable defenses. Murex snails are easily harvested because they annually migrate to the same locations in massive breeding aggregations, where hundreds to thousands of snails deposit egg cases in dense clusters.

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Growing up exploring Puget Sound rocky shores, I knew my snails, including where and when to find their breeding aggregations and their nurseries of translucent egg capsules that contained developing snail embryos. I discovered which boulders served as their annual nurseries and learned not to collect them in my pockets, since they could leave a purple stain on my pants that my mother complained was difficult to remove. Phoenicians had learned these same things about their Murex snail communities by 3000 BCE, enabling them to efficiently exploit large numbers of snails and kickstart the first trading empire with a snail startup company (Figure 5.3). To build their network, the Phoenicians discovered how to use the purple liquid in the snails’ poison sacs to produce a deep purple clothing dye (even the name Phoenician comes from the ancient Greek phíonios, meaning “purple”). Until the nineteenth century, when the German chemical company BASF became an innovator in the production of synthetic dyes from coal tar, thus turning chemistry from a solely academic pursuit into an industrial engine, all cloth dyes were produced from plant and animal mixtures. The resources that made up these dyes were rare, expensive, easily exhausted, and highly sought after. Due to its rarity, Phoenician purple was especially valuable, and was coveted by the elite in Greece, Rome, and elsewhere as a symbol of power and wealth. Caesar, for example, codified purple as a symbol of power by passing sumptuary laws prohibiting all but senators from wearing purple-edged togas. Elsewhere, wearing purple was restricted to a select few and only on certain days of the year. To create purple, the Phoenicians would harvest Murex snails, crush their shells open, then remove and sun-dry their poison sacs before grinding them into a fine powder. It took 250,000 snails to make one pound of dried dye for export, a quantity that rapidly depleted local snail populations. Today, if it were even possible, it would take months to collect that many snails in the Mediterranean due to millennia of overexploitation and habitat degradation. Recently, during nearly six months of research every day on the shorelines in Sardinia, I didn’t see a single Murex snail. But still today, at the sites of ancient Phoenician settlements like Tyre and Sidon, built on rocky shorelines to exploit these snails, one can find large mounds of crushed snail shells, thousands of years after these snails were harvested to make dye.6

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5.3. The Murex snail ( family Muricidae), source of the dye Tyrian or Phoenician purple, which was made by crushing thousands of snails and drying and pulverizing their poison glands. “Royal purple” was as valuable as gold in the ancient Mediterranean and was the foundation of the Phoenician trading empire. Original drawing based on public domain art.

In addition to scouring beaches for Murex nurseries, catching these snails would have involved baited traps similar to lobster traps. Shallow-water Murex snails typically live to be six to seven years old, so they were extirpated to local extinction quickly, forcing the Phoenicians to collect in deeper water. As each rich snail resource spot was depleted, the Phoenicians would move on throughout the Mediterranean and along the North African coast. Following this trail of snail breadcrumbs, the Phoenicians became maritime resource explorers. Their sea trade demanded strong, reliable ships that they built with sturdy Lebanese cedar. As they overharvested snail populations and cedar forests, the Phoenicians developed skills for navigation and oceangoing, which allowed them to take to the sea and develop new resource supplies while reaching new trading partners. They imported cedar and pine from the North African coast to make up for the Lebanese cedar, which today is restricted to a limited number of refuge habitats and is endangered by climate change. This success led them to operate a Mediterranean-wide cooperative trading network run by a large fleet of hundreds of merchant ships, along with warships to protect their routes from pirates.7

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The Phoenicians established trading bases as distant as Africa, Spain, Cyprus, and Sardinia. In addition to purple dye, ivory tusks, exotic animal hides, and even slaves flowed through the networks. And to transport goods, the traders needed new storage containers, which led to developments like glass for vessels to transport wine, olive oil, and grains. Glass was likely an inadvertent discovery when hot fire combined potash and sand, and it was dyed blue by the Phoenicians to create the blue containers emblematic of their trade prowess. Slavery, too, changed due to trade: formerly a consequence of war, slavery became a byproduct of increased labor needs in an era of rapidly growing populations. The Phoenicians appear to have been the first commercial slave traders, trading slaves that had been the spoils of tribal warfare in Africa for other commodities and selling them across the Mediterranean. They also used a motor of 120 slave rowers to power their famous double-decked galleys (Figure 5.4).

5.4. The bireme was the innovative seagoing vessel that allowed Phoenicians to establish a network of cooperative Mediterranean trade and travel routes along the western coast of Africa. Original drawing based on public domain art.

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Slaves could be used as laborers, servants, and soldiers. At its peak, the Roman Empire required nearly half a million slaves to function.8 If the Phoenicians commercialized slavery, the Vikings industrialized it, raiding European coastal and riverside towns for their wares and for people to violently capture and sell into slavery across the world. Early medieval Viking raiders looted eastern European towns along rivers as a summer enterprise while their own fields were maturing, but the slave trade became a more lucrative focus of their energies. Slaves were traded for labor, lumber, and salt to preserve perishable supplies. Vikings raided the vulnerable, poorly defended, rural regions of southern Russia, trading “Slavs,” an entire ethnic and language group connected etymologically to its past as a target for slavery, to Eastern Europe and to Persian kings. Though slavery legally ended in the middle of the nineteenth century after moral questioning that began in the eighteenth century, its value in a world of limited resources has meant that even today it is a commodity on the black market.9

Overland Trade While the Phoenicians were developing seafaring trade routes across the Mediterranean, land-based cooperative trade networks struggled because of the difficulty of moving goods and traders over land. This logistical issue was ultimately solved by cooperation: that is, by the domestication of horses and camels, a codependent mutualism still not entirely understood despite these animals’ vital importance in the development of civilization. The domestication of horses by nomadic tribes on the steppes of the Anatolian peninsula spurred a pastoral economy based on herding and the exploitation of meat, milk products, leather, and wool, rather than agriculture. Horse domestication occurred around 5000 BCE and rapidly spread across Eurasia, changing transportation, trading, culture, and warfare. Camel domestication happened around the same time in the Fertile Crescent, though camels originally evolved in the Americas and made their way across the Bering Land Bridge to Asia from North America.10 Camels were at first used for meat, milk, and leather products, but their value as transportation and as pack animals was quickly

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appreciated in the desert landscapes near the Mediterranean and into Africa. Highly adapted for life in harsh, desert environments, camels are the ideal beasts of burden for stretches like the Sahara in northern Africa or the Gobi Desert, which covers half a million square miles in the shadow of the Himalayas, mountains so high that rain clouds cannot pass over them without releasing their precipitation. Camels have closable nostrils, a double row of long eyelashes, and dense hair in their ears to keep out sand; large, twotoed feet with fleshy pads to distribute their weight like snowshoes; and kneepads to allow them to rest on hot dunes. They have special metabolic processes to conserve water, as well as concentrated urine, long nostril cavities that condense and recycle water vapor from respiration, and the capacity to drink and store large quantities of water. They also have their signature humps for fat storage, making them able to withstand long periods without eating, and leathery lips so that they can eat hard, spiny, well-defended desert plants. It is no wonder that they were used in trade caravans until recently, that is, until the advent of trains and other motorized transport about 150 years ago (Figure 5.5). Camels were perfect mutualistic partners for helping our ancestors to conquer desert environments.11 As for horses, it has long been debated whether horses were domesticated once or a few times, or whether the knowledge of horse domestication itself was shared and spread throughout Eurasia, leading to frequent domestication events. Genetic and archaeological evidence has recently revealed that horses were first domesticated for meat—early nomadic tribes in present-day Kazakhstan and Turkey needed horses as a valuable winter source of protein to survive a harsh environment, and horses, unlike sheep and goats, could dig through snow themselves to find food. Over time, horses became beasts of burden; some horse skeletons from this time, around 3500 BCE, have tooth wear patterns that suggest bridling. As domesticated horses spread through Eurasia, they bred with wild horses, leading to vigorous hybrids that were even more appealing for domestication. Like the taming of camels, the cooperative mutualism or domestication of horses led to human domination of the vast unproductive land of the Eurasian steppes, while facilitating trade across land on a continental scale.12

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5.5. Camel caravans were used from ancient times until the early twentieth century to move resources like salt and other minerals into and out of the African continent as well as for warfare. Photograph: World War I in Palestine and the Sinai, by John D. Whiting, Lewis Larsson, and G. Eric Matson (ca. 1914–1917), Papers of John D. Whiting, Library of Congress, Prints and Photographs Division.

At that point, the use of horses to pull carts and chariots and to move quickly across distances spread rapidly, from Turkey to Rome and China in less than five hundred years. This rapid cultural diffusion was facilitated by the next great trading network: the Silk Road that connected Europe and China economically and culturally, at least until the global Spanish trade empire of the sixteenth to eighteenth centuries opened the Atlantic for further resource exploitation. Historians often point to a visit made to Central Asia in the second century BCE by a Chinese ambassador searching for new resources as the opening of the Silk Road trade network: before this, ancient Chinese civilizations had been isolated (and protected) from the Mediterranean by the Himalayas. The Chinese were particularly interested in domesticated horses, which they acquired by trading silk.13

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The many trade routes of the Silk Road were immensely important for developing human civilization, maximizing the exploitation of resources, and mixing cultures and technologies that had evolved independently. Starting modestly as cooperative exchange routes for spices and tea that diffused across the land much like tool-making rocks did in prehistoric times, they eventually became a powerful means of exchanging goods, ideas, and diseases that would transform both the European and Asian worlds (Figure 5.6). Camels and horses carried goods along the robust overland trade routes for millennia, and the need to protect trade from nomadic pirates led to fortifications and way stations that developed over time into the Great Wall of China. The balance between cooperative trade advantages and competitive defensive disadvantages was omnipresent in the development of civilization. The four thousand or so miles of Silk Road trade routes were named after the domestication of silkworms and production of silk cloth by the Chinese around 3000 BCE. Like the Phoenicians who monetized harvested Murex snails, the Chinese marketed the value and use of silkworms. But while the Phoenicians overfarmed their resource, the Chinese wisely domesticated, propagated, and indus-

5.6. The Silk Road connected the European and Asian worlds via trade in goods, technology, cultural influences—and pathogens. Original drawing based on public domain sources.

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trialized silkworms and the production of silk cloth. Silkworms are no longer found in nature because thousands of years of domestication have made them entirely dependent on human intervention. They have lost their wings, so they can no longer fly or find their mulberry-leaf food on their own. They have been deliberately selected to produce large amounts of silk, are no longer restricted to Asian mulberry trees, and have a nearly global distribution. Without human assistance, however, they would die and the species would go extinct. Silkworms, then, are an example of obligate domestication or mutualism, a species whose survival has become entirely dependent on humans. They are dandelions, rats, or ticks on steroids. To the people of the Mediterranean, silk was so unique and magical that bizarre myths sprang up about its origins, such as that it grew on trees or was bark. The truth of silk was a closely guarded technological secret in the ancient world until industrial espionage revealed the source of the material. Also like the purple dye of the Phoenicians, silk became a cloth for the aristocracy and a symbol of wealth. During the peak of the Roman Empire, silk became such a valued luxury that laws dictated where and how it could be worn, since it revealed so much of the body.14 It became the first X-rated trading product. China added to its silk exportation with tea, spices, and technological innovations like medicine, rugs, gold, and glass. As pirating and taxation increased, alternate roads were built, along which grew way stations for rest. By the time the Roman Empire was overseeing the network, even high-speed mail services were in place. Trade along the Silk Road, however, carried heavy collateral costs: namely, the spreading of disease. The new trading routes exposed human populations to foreign microbes and commensals that they had not evolved with, causing pandemics that killed so many people that the entire social fabric across Eurasian cultures was reset. Outbreaks of plague in the fifth and fifteenth centuries CE were facilitated by Roman and Silk Road commerce and by growing, increasingly dense populations. The disease, called the Black Death, devastated human populations, killing nearly a third of the people in the old world, wiping out entire cities and hitting other large population centers especially hard. Recent molecular evidence has shown that the Black Death originated in China and spread specifically along the Silk Road routes.15

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Roman Roads Despite the costs that we see accurately only in hindsight, the benefits of a more connected and easily traversable world were clear. Consider the importance of trade to the Roman Empire, which emerged from a combination of cooperation and successful warring campaigns to create a large, centralized city and a vast trading network. The Roman Empire dominated the Mediterranean basin and Europe for more than seven centuries. Trade fueled the prosperity of its capital and allowed it to expand its influence by both land and sea. In an empire stretching from northern Africa to the British Isles, from the Iberian peninsula to Alexandria and Antioch, Roman rulers used a combination of diplomatic strategy and military intimidation to form a web of roads and government infrastructure across the West. This allowed Rome to control the most distant lands of its empire, exchanging trade and communication for taxation. And all of this control, expansion, and taxation were for the benefit of Rome, a city that by 200 CE had become a metropolis of over a million people that had severely outgrown its local and regionally available supplies. To maintain the privileged life of those in the world’s most prestigious city, then, required an entire empire, replete with trade networks leading back to the center.16 (After all, Rome was one of the most extreme early examples of a few massively wealthy elite being supported by agrarian masses of peasants and slaves— economic disparity at its finest.) The first roads of this trade network, those built to complement the empire’s sea trade and those roadways the Romans had inherited in wars with the Persian Empire, were constructed in 300 BCE from Rome to the port city of Brindisi on the Adriatic Sea. These roadways, 350 miles (560 km) long, connected Rome to the Phoenician sea trade routes that Rome had taken over in the Punic wars for Phoenician assets. With the empire’s expansion came a growing desire for the resources and goods, often luxury goods, not found near Rome itself. Rome’s highways were the answer to fulfilling these desires, and the consequences of these roads far outlasted the empire itself. At twenty-seven-mile (44 km) intervals, travelers would find way stations for rest and food, and a courier service moved messages along

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5.7. The Roman Empire at its peak of power and influence. Original drawing based on public domain sources.

at a rate of approximately fifty miles (80 km) per day. In especially important commercial centers, grid designs for neighborhoods, government buildings, and bathhouses sprang up. All of this spread civilization, including law, order, and central governance, to areas that had been far from developments in the progressive city of Rome (Figure 5.7). The Roman highway system grew to include nearly 50,000 miles (80,000 km) of stone-paved, drained roads at least fifteen feet (5 m) wide. Like the internet today, or cable television over the past few decades, these roads increased the spread of culture (and the recognition of economic equality and inequality) across the empire. The effects of resource exploitation in this case included the understanding of its cultural and social consequences, and the recognition of who benefited from such work. Pulitzer Prize–winning author Thomas Friedman has argued that global communication

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has made both rich and poor aware of massive disparities in income and quality of life; the Roman highways were an early example of this “flattening” of society that we see burgeoning in today’s smartphone information era.17 It is arguable that this flattening led to the fall of the empire itself, when ruler greed and an expansion too distant from its governing center combined to sow growing resentment among its conquered peoples. After the collapse of the Roman Empire in the fifth century, the Byzantine Empire grew from the eastern portion of the Roman Empire and controlled trade along the Silk Road network—at least until the Mongol Empire. The Mongols, descendants of the very nomadic steppe people who had domesticated horses, then dominated the Silk Roads of Eurasia as feared, horse-backed warriors. Initially led by Genghis Khan, the Mongols ruled the trade network of the largest contiguous land empire in human history, from the Fertile Crescent to the Chinese Empire, for two centuries.18 This may very well have had to do with the Mongols’ ability to play to the strengths of their ecosystem, and to harness the power of the group, even if membership in that group was coerced. For as other civilizations became trapped in their sedentary agrarian lifestyles, the Mongols acquired an intimate understanding of horses, geography, and the harsh steppe environment. Like the Phoenicians millennia earlier, the Mongols focused on trade rather than building monumental trophy cities. They preferred to dominate other cultures through fear, and they carried most of their tents and valuable possessions with them, reflecting their cultural roots as nomadic tribes. By the late Middle Ages, though, exploratory sea voyages, launched in order to find new routes to Asian markets, were in full swing—and would break this early trade monopoly.

The Age of Exploration As sea exploration began to open the world yet wider, the most sought-after Asian commodity was spices, since Europeans had by this time acquired the silkworm domestication technology needed to make their own silk. Spices had become increasingly popular, and many were worth their weight in gold. They were used for preserving and cooking food and for their medicinal and health-

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care properties. From pepper to cinnamon to garlic, these plants all had developed their own ways of protecting themselves from the herbivores and diseases with which they had coevolved. These compounds also conferred benefits to humans and became essential symbiotic elements of human diets (more on this later).19 Stimulated by a hope both to dominate the spice trade and to discover new spices, the age of exploration began. In these efforts, some smaller countries like Holland, Spain, and Portugal gained unlikely power because they had nautical expertise, were in a geographical position amenable to Atlantic expeditions, and were populated with skilled, cooperative traders and aggressors. Just as the Phoenicians earlier had tracked the abundance and distribution of snails and cedars across the Mediterranean, trading their way and leaving a changed human civilization in their wake, European spice explorers found resources in a discovery that would shift the center of global civilization to the Atlantic: the New World. Discovering the New World not only changed commerce, but also global biodiversity and biogeography. As European countries claimed and colonized parts of the New World, they wiped out native human populations by introducing new diseases and by waging violence against cultural and religious differences. Native cultures of the New World, while as advanced as European cultures, were seen as savage because they had different gods, languages, and cultural traditions. I experienced this distasteful ethnocentric behavior while exploring the coast of Papua New Guinea forty years ago. The crew on our research vessel assumed that the indigenous people we encountered, many of whom had never seen Westerners before, were stupid because they didn’t speak English. Natives of the New World, meanwhile, saw European explorers and invaders as dirty, liceinfested people with incompatible cultural values and lethal weapons. European explorers and New World natives had independently developed their divergent cultures over nearly ten millennia, so communication and cooperation between them was extremely difficult. Europeans, whose human arms race was older and more developed than that of North Americans, introduced their “superior” cultures and agrarian lifestyles to America—and in the process, intentionally and unintentionally spread intercultural violence and disease to native cultures. Competition trumped cooperation due to the

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asymmetry of the two civilizations’ weapons and the massive cultural gap: this was not an interaction between familiar neighbors, but between humans separated by vast distances and differences. In short order, conflict led to the large-scale loss of many native cultures. Time and time again, European explorers naively brought novel and lethal microbial diseases to indigenous people in North America, South America, and the Pacific Islands who had not evolved immunities to them. Just as predictably, European explorers and colonists also brought their ethnocentric cultural identities and spiritual beliefs and forced them on the cultures they encountered, even though these cultures had their own long-established civilizations and spiritual mythologies. Europeans aggressively and intentionally destroyed the spiritual history of these peoples by targeting and eliminating all written and oral records of their spiritual traditions.20 Consequently, the independently developed spiritual traditions, beliefs, and mythologies of the Aztec and Maya, as well as those of other Pacific Island cultures, were largely lost forever, becoming yet another sad historical casualty to cultural dominance and pathology. Another collateral, naïve consequence of the global exploration era was the inadvertent and intentional introduction and transport of exotic species around the globe. So began the ongoing, haphazard mixing of plants and animals with others they had not evolved alongside, a species roulette that continues to this day. Weedy plants and opportunistic animals and diseases overtook the earth at the expense of native plant and animal diversity. Stowaway rats with insect commensals and parasites that in turn gave a ride to pathogens on intercontinental voyages are one clear example, but ships from the sixteenth to eighteenth centuries also inadvertently trafficked marine organisms from port to port. These ships carried in their hulls heavy ballast, like beach rock cobbles, to keep them stable across the high seas. Often this material was covered with the tiny native organisms that then invaded new territories when the ballast was dumped overboard to lighten the load. Worse, the wood of these ships was constantly under attack by fouling and boring organisms like barnacles, seaweeds, and shipworms, which made the ship itself a floating island of foreign biota.21 In this way, weedy marine species have for centuries crossed the world along paths virtually identical to well-traveled shipping lanes.

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Just as influential were the intentional introductions of new species across the world, as commercial ships carried agricultural supplies, food, and livestock—along with their associated organisms—to new destinations. European settlers often attempted to “naturalize” their new locations by introducing familiar home species, leading to some of the most infamous natural history disasters. Starlings, for example, were introduced to New York City’s Central Park in a misguided attempt to introduce all species named by Shakespeare to America. After a decade of attempts, the starlings made a home for themselves, and today they are a serious avian pest species and vector of disease in North America. Similarly, Australians introduced rabbits for hunting in order to make settlers feel more at home, but with no natural predators, rabbits became major pests that defoliated plants not evolutionarily equipped to deal with this new neighbor.22 Human-driven species mixing continues to this day, and has led to a world dominated by a homogenized assemblage of weedy plants, the biological equivalent of the global spread of strip malls. This was the second great global impact of human colonization of the globe, the first being the extirpation of many predators and large animals when early humans migrated out of their African homeland to all large landmasses except Antarctica (discussed in Chapter 2). The acquisition of new resources has been important throughout human history, leading to science and exploration, culture and creativity. What is not clear in this picture, however, are the costs of war and ecological abuse that follow our sea routes and overland commerce, or the negative effects on human, animal, and plant populations as the extent and strength of human influence outpaces the ability of these populations to evolve together. The vaunted control over nature that cooperative agriculture gave us did not change the basic rules of natural history that lead to increased population growth, accelerated resource utilization and depletion, the spread of disease, habitat degradation, and competition. The cultural divides that remain the largest challenges facing modern civilization have their seeds, we might say, in our discovery of how to use seeds.

chapter six

Famine and Disease

C

ommonly referred to as “child dumping,” the abandonment of children in the Middle Ages and earlier occurred during times of low food supplies. The Christian elite denied these practices at the time by claiming they were done by nonbelievers, but the truth is that the value of life was considerably downgraded during famines, and child dumping was present across all kinds and classes of people. While famine triggered violence and conflict, devaluing all lives, children were far and away the most dispensable, and a peasant’s family-planning decisions affected female and physically disabled children most of all. It is not easy to find evidence for these events, nor are they easy to accept, but literature of the time describes the cries of abandoned children in rivers and latrines across medieval Europe. It also appears as if consequences for infanticide were relaxed during famines and economic hard times. These stories are told most clearly by demographics: throughout Europe in the Middle Ages, wealthy families averaged 5.1 children, middle-income families 2.9, and poor families 1.8, which suggests that poor families dumped or disposed of more than half of their children. Historical literature reveals that infanticide and child dumping happened whenever children were unwanted or could not be cared for throughout all human cultures, from the Greeks to the Romans, Persians, and Chinese, until the modern age.1 114

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6.1. In the well-known Grimm brothers’ fairy tale, Hansel and Gretel are a German brother and sister who are abandoned in the woods during a famine, then heroically escape from their captor—an evil witch with a house made of sweets. Redrawn based on a public domain illustration from the nineteenth century.

The omnipresence of child dumping, also referred to as “exposure,” is supported as well by its common occurrences in legends and folklore, which often reframed the scenario of child dumping as one where the abandoned children somehow find a better life. Moses, Oedipus, Hansel and Gretel, and Snow White were all abandoned children (Figure 6.1). Tom Thumb and Snow White’s dwarves were handicapped children (like Oedipus) left in the woods by their parents, specifically during a famine.2 Despite adversity, these children were granted treasures or high rank, giving hope to parents who may have dumped their child in the real world. Churches played a complex role in this practice, for religious leaders considered deformed newborns to be divine punishments, castigated unmarried mothers, and set sexual standards of celibacy— all of which made infant exposure more tolerated and a more welcome option than raising a child one didn’t have the food to feed, or who would stigmatize his or her parents. Yet at the same time,

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churches and other religious institutions frequently received abandoned children from parents. Churches would take unwanted children to orphanages, while nunneries and monasteries would sometimes take in abandoned children from higher-class families. Often, laws in Europe gave the person taking in the abandoned child the child’s services, effectively granting the person a slave.3 Horrific as these practices are, they are not exclusively human (as genocide is): infanticide is the rule in natural history for all animals and plants, so they can maximize the prospects for success of their more robust offspring in response to the available resources and any competition. After a plant’s flowering and fertilization, for example, the number of viable seeds produced is adjusted by spontaneous ovule abortion typically in response to resource supply: plant baby dumping is the rule rather than the exception. And among the same Murex snails that attracted my interest to shorelines and enriched the Phoenicians, the first juvenile snail to hatch in an egg capsule will eat unhatched eggs for nourishment before emerging from its protective capsule, then proceed to feed on embryos in other egg capsules. This filicide, or sibling eating, is an insurance policy against bad years of food resources: it maximizes Murex snails’ reproductive successes and, by rewarding the first juvenile to emerge, the snails’ genetic fitness, the currency of evolution. Similar evolved family-planning decisions are found in species from single-celled protozoans to our primate ancestors. Yet this gives little consolation to those distressed by the idea of human child dumping. What made exposure and infanticide so necessary for a species that had managed, through invention and mastery of various technologies, to increase the community’s food resources enough to have more children in the first place?4 In this chapter, we look at two of the most basic of all natural history problems, problems that plague populations of all species regardless of their position on the food chain or cognitive ability: famine and disease.

Too Little Food We have seen how accelerated population growth rates and increasing population sizes accompanied the boom-and-bust bounty and labor needs of cooperative agricultural revolutions. This led to

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frequent, destructive famines, for humans became reliant on the success of a small number of crops and domesticated animals, sacrificing variety for production while not understanding the genetic and disease risks of putting, as it were, all of their eggs in a single basket. Extreme weather, low rainfall, and crop or livestock disease could quickly lead to famines that were difficult to escape. The low genetic diversity of the first domesticated plants and animals made diseases especially dangerous, because they could spread quickly and easily across broad geographic regions. Limited food storage and spoilage exacerbated the effects of early famines: early preservation methods for grains and meats were often insufficient (a problem that would take centuries to finally solve). Frequent food shortages and famines also occurred as humans struggled to adapt to new farming conditions after expanding past the riverbanks that had been the home of early agrarian life. Neolithic farmers had to experiment with plant irrigation and soil fertility techniques to make up for not having the annual floods that would flush away accumulated salts and re-nourish soil depleted from the previous year’s crop. Selecting disease-resistant crop plants was surely also a problem that early humans had to solve, as was how to store food to survive harsh winters, years with poor crop yields, and exploration trips meant to scout new resource locations. Eventually, these experiments would lead to agricultural enterprises far from riverbanks, but even this would not stave off increasing famines, which data from pre- and postagriculture societies show rose after the agricultural revolution.5 The first well-documented famine happened in ancient Rome in 441 BCE. At the time, pioneering Neolithic humans were learning how to farm while still hunting and gathering on land that was increasingly overharvested and resource-depleted by sedentary life. In the formative years of the Roman Empire, famines were frequent due to erratic climate conditions, food spoilage, and food distribution problems. In 426 BCE, thousands of starving Romans drowned themselves in the Tiber River because their rulers were withholding grain as a form of punishment and forced compliance. Also around this time, Chinese peasants were enduring famine due to government controls, an increasing population, and infrastructure and technologies too limited to preserve and distribute food

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adequately. In Bronze Age China, people greeted each other not with “Hello,” or “Good day,” but rather “Have you eaten?” This greeting is still common in China as a vestigial cultural remnant of the early days of agriculture.6 Famine has continued into modern times with similarly catastrophic consequences. In the nineteenth century, the fungus Phytophthora infestans appeared first in Mexico and the United States before mutating into a deadly genotype that was transported around the world. In the 1840s this virulent strain reached Europe and Ireland, where it devastated the Irish economy because of the lack of genetic diversity among the few crop species. This event, better known as the Irish Potato Famine, brings into sharp focus how commerce and trade continually challenged homogenous, domesticated crops and farm animals with new diseases and microbes.7 Famines may be having evolutionary legacy effects on human health to this day. Frequent famine conditions during and following the development of agriculture may underlie current epidemics of diabetes and obesity in contemporary Western culture. Frequent famines during Neolithic times selected for overeating high-energy foods when they were available and storing them as fat to survive the next famine. Now that high-calorie foods are readily available twenty-four hours a day in developed countries, our evolutionary response of overindulging and binge eating, once a valuable adaptation, can lead to health problems such as obesity, heart disease, and diabetes.8 Simply put, the magnitude of fatalities caused by famines through human history is daunting by any standard.9 Drought and famine between 800 and 1000 CE killed millions—nearly twentyfive million in eighteenth-century India, one hundred million in nineteenth-century China, and ten million alone during the 1932– 1933 famine in the USSR. Famine has also long been a tool of war, used in siege tactics designed to starve troops out of heavily fortified cities. Leaders of walled cities protecting the elite and their valuable food resources would leave the peasant workers outside of the walls, vulnerable to violence. In times of famine or population growth, cities would be attacked by killing the peasant men and children, taking the peasant women, and starving out the elite and their resources. Siege warfare was common from the dawn of

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civilization through the Middle Ages, a consequence of competition for resources among the ambitious elite and their subjects. Famine remains a threat today. Calamitous natural events can spur it, such as the 1815 “Year without Summer,” when a volcano in Indonesia caused cold weather and crop failure as far away as Europe, eastern Canada, and the northeastern United States. War can also leave famine in its wake, as in the Congo where 3.8 million people have starved as a result of collateral damage from a political conflict that surged more than ten years ago. In Africa more generally, unrestrained population growth, the vagaries of climate change, and the political use of food to compel the compliance of the masses persist to make famine a frequently severe problem. Globally, 10 million people a year die from poverty-driven hunger, with children and women suffering the most, according to World Health Organization statistics.10 And as witnessed in Ireland, famine has been not only one of the primary effects of sedentary life and urbanization, but also one of the consequences of another unanticipated result from the agricultural revolution: disease.

Life against Life The growth of ever larger populations to meet the labor needs of cooperative agriculture and trade meant that people lived closer together, which in turn attracted commensal organisms from rats to ticks and fleas, all of which share evolutionary histories alongside mammals as disease vectors. Poor sanitary conditions provided ample habitats for diseases to flourish, and the dramatically increased human contact with animals was one of the largest causes of human diseases. Anthrax, the plague, influenza, yellow fever, Lyme disease, malaria, and tuberculosis are just a few of the “zoonotic” (originally evolving in animals) diseases that have torn through humanity, and disease microbes have proven to be perhaps our greatest evolutionary foe, evolving to weaponize the human body itself—and its cough, vomit, and diarrhea—to spread pathogens from host to host. The spread and evolution of disease between humans and commensal and parasitic organisms remains a powerful and threatening unintended consequence of urbanization.

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Today, we know that diseases are caused by parasites and pathogens, self-replicating organisms that coevolved with their hosts and use the same genetic language that we do. Whether bacterial, parasitic, or viral, human diseases have evolved over human history (and earlier) alongside vectors such as lice, mosquitoes, fleas, and rats in order to move from host to host more efficiently. It is thus no accident that, for example, diseases in biting insects infect their hosts’ blood systems, or that among a disease’s symptoms are those, like coughing or sneezing, that simultaneously spread the disease. This knowledge was not always available, though ancient Egyptians and Greeks suspected links between diseases, urbanization, and sanitation: their rulers slept beneath insect netting to avoid bites, and stayed away from the “bad air” of wetlands, where many disease vectors reproduced. These early medical and public health efforts were wholly based on trial and error, and on taking note of associations. Cooperative trade increased the risk from highly coevolved diseases, for microbes could be passed to populations not yet biologically prepared to defend against them. This made travel itself a hazard. Microbes moreover reproduce at rates many orders of magnitude faster than humans, giving them an enormous advantage over more slowly reproducing humans in adapting to new conditions. If an average human generation is around twenty-five years, then modern humans have been around for only eight thousand generations, while if a typical microbe has, extremely conservatively, a generation time of a week (for some, generations can be measured in hours), then microbes associated with humans have been around 10.5 million generations. In other words, diseasecausing microbes respond and adapt to local populations far more quickly than humans can—which is why, for example, last year’s flu shot is obsolete in less than a year. Recently, more and more diseases previously thought to have genetic and environmental causes—cancers, heart disease, Alzheimer’s, mental illnesses like schizophrenia, and other chronic maladies—have been found to be linked to our ancient war with microbes. Our long-lost relatives from our forgotten beginnings in the primordial soup, microbes are still fighting the ancient battle for the control of life. This expansion of our understanding of

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human diseases to include microbial and human natural history was predicted by the evolutionary biologist Paul Ewald in his 2000 book Plague Time. While humans would seem to be greatly overmatched in their battle against nefarious microbes, we must remember that humans have their own beneficial microbial relationships. As discussed in Chapter 1, some of our best defenses against disease are the symbiotic microbes that have evolved with us and can respond to new threats more rapidly than can human evolution.11 The one hundred trillion microbial cells of hundreds of species in the human colon cooperate and interact with our own cells to protect us from microbial attack—if not for them, human life may have ended within the first years of early city life. Microbes thus demonstrate the influential and non-teleological character of cooperation in evolution, for it is the cooperation of some microbes with commensal organisms that threatens humans, but also the cooperation of other microbes with humans that protects them. The point here is that no organism evolves in a vacuum, but rather responds to and influences the organisms and environments around it. What has civilization done to this process? Have the new organizations and environments we have created, which are themselves the result of cooperative relationships, thrown the otherwise self-regulating system of life on earth into a self-destructive tailspin?

Elegantly Evolved Problems While it is natural to think of pathogens as really bad relatives that you don’t want to admit are on your family tree, disease pathogens are amazing products of coevolution. Unfortunate as it is that they consider us their meals, they are in their own way as elegant a product of selfish genes and cooperation as we are. Many of them are living fossils, dating back to the dawn of life when competing, self-replicating microbes dominated the oceans, before life had colonized land or microbial competition was buffered by microbial cooperation. At about the same time that multicellular plants and animals evolved with the help of mutualistic microbes, other microbes went to the dark side. Confronted by the same struggle to replicate, these microbes cooperated maliciously, parasitizing

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others like bad roommates. When plants and animals evolved, these microbes found their niche as commensals catching free rides and meals. They became sophisticated freeloaders on their multicellular hosts, evolving elegantly synchronized and orchestrated lifecycles that allowed them to shadow their transportation and food source. Lice and bedbugs are visible and relatable examples of how these embarrassing relatives long ago wrestled their way into our family dinners and, until recently, were common pests of humans (Figure 6.2). Lice and bedbugs both benefited from the parasite bonanza of cooperative agricultural revolutions and the concomitant cities with their high densities of potential human hosts. This remains true today: contemporary bedbug outbreaks occur in densely populated apartment buildings in large cities like New York City, not rural areas where possibilities for transmission are limited.12 The omnipresence of these creatures in densely settled human communities means that nitpickers, small combs used to pick nits (lice eggs) out of human hair, are one of the most common implements found at archaeological sites. Nitpicking grooming behavior

6.2. Head, pubic, and body lice have been itchy problems and disease vectors for humans since we inherited them from our hominid ancestors. They attach their eggs or “nits” on the base of hair follicles and as adults tenaciously cling to the body with hook-like appendages. Redrawn based on data from Jon Stafford, The Lice Capades, Daily Kos, November 10, 2011.

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has long been a tedious process: calling a co-worker a “nitpicker” today hearkens back to the Middle Ages. Back then, body lice were an acute problem associated with poor health and disease because beyond causing hygiene problems, human lice can carry and transmit the potentially lethal diseases of typhus, relapsing fever, and trench fever.13 Humans are host to three lice species: head, pubic, and body. DNA sequencing of these species has revealed that they trace back to our ape ancestors, with head lice originating from chimpanzees 5.5 million years ago and pubic lice from gorillas 3 million years ago. As mentioned earlier, the DNA sequencing of human body lice, which lay their eggs and live in clothing, has revealed that humans started wearing clothes forty thousand years ago.14 Bedbugs are another human ectoparasite that has thrived due to the density of human settlements. Originating in caves inhabited by bats and ancestral humans, they are blood-sucking insects that are pests, but not major disease vectors. Bedbugs were first described by the Greeks in the first century BCE and are closely related to similar microscopic ectoparasites that specialize on other warm-blooded hosts. Bedbugs evolved 145–165 million years ago, transitioning from bat to human hosts when humans began sleeping in caves during the Pleistocene. During the Middle Ages, they were extremely common in crowded cities; to counter them, people fumigated their sleeping areas by burning peat fires and laid leaves to trap bedbugs on their floors, changing the leaves daily to eradicate them. “Good night, sleep tight, don’t let the bedbugs bite,” is a still common phrase from the eighteenth and nineteenth centuries, when most people slept on rope beds that needed routine tightening for a comfortable sleep and bedbugs were a pervasive problem.15 Bedbugs are lie-and-wait, blood-sucking parasites that inhabit beds so that their meals will come to them. They are common in cities, hotels, college dorms, and communal sleeping places with high transmission opportunities. They also don’t hang around hosts long—they hide elsewhere to digest their blood meals, making them hard to detect after they bite. Victims react idiosyncratically to bedbug bites: some notice immediately, while some don’t react until days or weeks later, making bedbugs difficult, innocuous bedfellows to detect and exterminate. Like leeches, they inject an

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anesthetic to numb the pain and an anti-coagulant to make the blood flow more freely from the host. Bedbugs disappeared as a major pest problem in the early twentieth century when extensive DDT use curtailed human insect pests, but they have returned to large cities over the past few decades since the damaging effects of DDT on birds of prey was recognized and its use banned in most developed countries. They themselves are friendly hosts to the obligate mutualist bacteria Wolbachia. This cooperative microbe provides bedbugs with B vitamins for their metabolism and reproduction, while bedbugs provide Wolbachia endosymbionts with a host and metabolic byproducts.16 While we can easily observe the coevolution of lice and bedbugs with human populations, they have, despite lice’s ability to act as disease vectors, acted truly as pests more than as threats to the survival of entire populations. To account for more dangerous, historyshaping organisms, we must magnify our focus to include some of the smallest creatures on the planet, our old microbial friends—and in this case, foes. The first of these is the malaria-causing protozoan Plasmodium. Malaria was first described in ancient Egypt in the third millennium BCE and is one of the deadliest diseases in human history. Every forty seconds, a child dies of malaria, resulting in a daily worldwide loss of more than two thousand young lives, and one million to three million lives a year. Malaria remains a severe human health problem despite major efforts since ancient times to eradicate it. It is particularly virulent in regions where warm temperatures allow for rapid generation time, magnifying its impact. Throughout history, many tropical civilizations were crippled by malaria until preventative measures became available.17 The relationship between malaria and humans predates recorded history; Plasmodium evolved alongside mammals and birds. The lifecycle of this parasite occurs in two stages, one in mosquitoes and the second in vertebrates, and in each host the Plasmodium asexually multiplies, creating tens of thousands of infective cells that are passed from mosquito to the bitten vertebrate, or vice versa. In mosquitoes, the protozoa migrate to the saliva glands for dispersal during blood meals, and in the vertebrate, they multiply in the host’s liver, entering the bloodstream after an incubation pe-

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riod. This cycle of reproduction is what causes fevers in human patients, and as the density of Plasmodia increases in the blood, they slow and eventually shut down circulation. Of the more than one hundred species of Plasmodium parasites, four prefer human hosts, and two of these are extremely virulent. These human-centric parasites diverged from a chimpanzeeinfecting malaria (Plasmodium falciparum) 10,000 to 20,000 years ago, and even earlier Plasmodium vivax, another variety, likely spread from infected macaques to our Homo erectus ancestors.18 By 2000 BCE, humans had evolved defenses, such as sickle cells—red blood cells that have a sickle shape and produce an enzyme protecting host cells from malaria. These cells evolved independently in Sardinia, Africa, and China, attesting to the mortal threat of malaria in these regions. We do not yet know for certain how sickle cells protect from malaria, but the cells’ smaller size and shape may reduce the intensity of malarial infections.19 After evolving in Africa, epidemic human malaria appears to have begun during the agricultural revolution, when large groups of human farmers settled near freshwater irrigation sources that doubled as mosquito breeding grounds. We have been living with the consequences ever since, according to the earliest written records about it, from the third and fourth millennia BCE in Egypt and China. The Greek historian Herodotus wrote that the workers responsible for the Egyptian pyramids were fed large amounts of garlic thought to prevent malaria, and pharaohs, from Snefru in the third millennium BCE to Cleopatra VII in the first century BCE, slept beneath mosquito nets. Malaria spread along the famous Roman roads and aqueducts, and “marsh fever,” as it was known in the Middle Ages, devastated southern England and coastal Italy. The French were famously prevented from building the Panama Canal because of yellow fever and malaria epidemics; the Americans succeeded only after mosquitoes were clearly understood as disease vectors and action was taken to control the spread and infection rate of both diseases. Solving malaria was the key to building the Panama Canal, not dynamite or human labor.20 Malaria continues to be one of the most widespread diseases influencing human civilization, but understanding the natural history of the mosquito-Plasmodium-vertebrate lifecycle has minimized its

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impact. Despite ancient Egyptian correlations between malarial swamps and insect pests, it wasn’t until 1880 that the French physician Charles Laveran identified the protozoan parasites that cause malaria and other tropical diseases. In 1897, the use of mosquitoes as intermediaries between protozoa and humans was shown by Ronald Ross, and both Laveran and Ross received Nobel Prizes for this work. Today, malaria is controlled by limiting mosquitoes’ breeding grounds of standing water, the same control measures used during the construction of the Panama Canal.21 Despite these measures, humans are far from winning the evolutionary war against pernicious microbes, as demonstrated by recent AIDS and Spanish flu epidemics, and by battles that microbiologists are waging against diseases that are evolving to resist treatment. While the AIDS epidemic that kills over one million people a year, mostly in Africa, is well-known today, the global Spanish flu epidemic that occurred only a century ago killed tens of millions of people during its three-year spread and has been largely forgotten. In fact, the Spanish flu pandemic, which began in 1918, is likely the deadliest epidemic in recorded history, erupting just as the First World War was ending and killing more people than the war itself. Spain was not hit any harder than any other country, but due to a combination of underreporting—to avoid eroding the morale of a world celebrating the end of the Great War—and the death of the Spanish king from the flu, the name stuck. Overshadowed by the end of the war, the Spanish flu may have killed more people than the considerably more famous Black Plague and was unusual both in how quickly it killed and in its high mortality rates among otherwise healthy adults in their twenties and thirties. Its societal impact has wholly slipped from our collective consciousness: we remember the economic hardships of the Great Depression, but not the strict quarantining and other movement restrictions due to the flu a decade earlier.22 While the Spanish flu may have killed more people, the Black Death—or bubonic plague, or pestilence, or simply the Plague—was the most dramatic, influential disease outbreak in human history. The Plague, which ravaged Europe in the mid-fourteenth century, reshaped Eurasian civilization and history by indiscriminately killing

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nearly a third of the global human population. Plagues have recently been shown to have occurred in the Bronze Age as well, between 2500 and 700 BCE, and likely earlier. But they seem to have never been as virulent or deadly as the Black Death of the Middle Ages, which was triggered by a deadly synergism of increasing population growth, filthy cities, and exposure to new disease strains along the Silk Road trade network (Figure 6.3). Cities like London, Paris, Venice, Genoa, and Milan, which had between 25,000 to 100,000 human residents, lacked adequate sanitation systems.23 The narrow streets were unpaved, with waste simply dumped on them. New diseases were being trafficked with goods, adding to the problem of familiar diseases finding new ways to spread farther and wider. Trading vessels also introduced large numbers of rats from distant lands into human populations. These rats were the most direct cause of the Plague’s first transmission, since the Plague is caused by the bacteria Yersinia pestis, a zoonotic bacteria endemic to rodents that uses ticks and fleas to transfer the disease to humans. Infected rats are asymptomatic

6.3. Depiction of the Dance of Death (1493) by Michael Wolgemut, illustrating the futility of life during the Black Plague. From Hartmann Schedel, Nuremberg Chronicle (1493), Wikimedia Commons.

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until near death, when they swell up from rapid bacterial growth blocking their bile ducts. The fleas on the rat then leave their dying or dead hosts to seek out the nearest warm-blooded animal host. One to six days after a human is bitten, the armpit and groin lymph nodes become tender and swell into painful areas, or buboes, that break open, discharging a putrid pus. Infected humans are typically mentally confused, delirious, and nauseated with aching extremities and backs, and high fevers. If the fever breaks, there is usually a remission signifying that the immune system has gained the upper hand over the pathogen and can now destroy and expel it. If remission never comes, however, the infection spreads to the blood, causing septicemia and death. Septicemic Plague causes blood vessels to break under the skin, forming a dark rash of dried blood, which is the reason for its appellation of Black Death. Death occurs three to seven days after infection from internal bleeding and multiple system failure: the death rate for untreated bubonic Plague is 50 to 70 percent, and 100 percent for septicemic Plague.24 Plague can also morph into an even more virulent pneumatic form, causing patients to cough up a bloody mucus froth and spread the disease by aerosol droplets. Pneumonic Plague also has a 100 percent death rate, and death can occur in hours. Spreading through the Mediterranean and Europe, the Plague is estimated to have killed 30 to 60 percent of Europe’s population, reducing the world’s population from 450 million to 350–375 million. The severe religious, social, and economic upheavals in the disease’s aftermath had cataclysmic effects on the course of European and Eurasian civilization and it took Europe’s economy nearly a century to recover and its population more than 150 years (nearly twice that long in Scandinavia). The Plague led to the scapegoating of European lepers, gypsies, and Jews; a loss of authority among religious and political leaders; and the further detachment of the aristocracy as many moved into country homes away from the disease centers. A slow rebuilding was necessary after the Plague had passed, for medieval cities, gutted by the massive loss of life, had lost not only institutions and parts of their culture, but also their social order.25 After the Plague, and before epidemics like the Spanish flu, disease began to travel even greater distances due to the extensive voy-

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aging and exploring done by European peoples. In the sixteenth century, European attempts to colonize North America were failing due to conflicts with and lack of cooperation from the indigenous people. But when the pilgrims arrived in New England in 1620, they found an indigenous people ravaged by human disease: Native American settlements were deserted and fresh graves littered coastal Massachusetts. Native Americans had been infected with diseases they had had no previous exposure to or evolutionary experience with, but to which their European carriers had developed immunity. This led to the death of an estimated 50–80 percent of Native American populations from smallpox, influenza, and other diseases as novel pathogens spread across the New World. But while not symmetrical, the transmission of disease between Europeans and Native Americans was not entirely one way: the rape and pillage mentality of fifteenth-century Europeans was about to receive a measure of microbial revenge from the New World.26 In 1495, only three years after the return of Columbus’s first voyage to America, there was an outbreak of the sexually transmitted disease syphilis in Naples, seemingly spread by Columbus’s infected crew members.27 Syphilis then spread rapidly through Europe, killing as many as five million people over the next decade. A new European disease, syphilis was particularly virulent, causing pustule sores that covered the body, flesh loss, disfigurement, and death in as little as three months. It also carried a strong social stigma due to its sexual nature and obvious disfigurement. The Dutch called it the French disease in Italy, Poland, and Germany, whereas the French called it the Italian or Spanish disease, Turks called it the Christian disease, and Tahitians, the British disease. It was clearly the disease of your enemy, and Native Americans had developed an immunity to it. Syphilis remained an epidemic in Europe through the Renaissance and up until the twentieth century, when a cure was discovered. Before then, syphilis was treated with toxic compounds like mercury and arsenic (not unlike contemporary cancer treatments), and its side effects of disfigurement were managed with prosthetic noses and eventually the first cosmetic plastic surgery.28 This disease was finally effectively combatted with antibiotics, specifically penicillin, which arose out of a growing understanding of the natural history of microbial life.

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Playing Defense I have mentioned already the defensive work that our own symbiotic gut microbes perform for us, keeping us safer against foreign microbes and showing why the water in certain places adversely affects certain human populations (until those members develop the microbial environment to properly adapt to this water, for example). But treating disease involved a more conscious assessment of bacterial and viral life cycles. Before humans understood the germ theory of disease, cures for bacterial diseases were elusive, often based on trial and error and relying on then-unknown antibiotic effects. Greeks and Indians, for example, used molds, Russians used warm soil, Sumerian doctors gave patients a beer soup mixed with turtle shells and snake skins, and Babylonians treated eye infections with sour milk. All of these treatments involved natural sources of antibiotics—evolved defenses by molds and other rapidly reproducing organisms to combat pathogenic microbes—and were thus somewhat effective. Early medics also knew to cauterize a wound or amputated limb, or sterilize it with alcohol, in order to prevent infection.29 When penicillin was discovered in the early twentieth century, it changed the landscape of human diseases, ending bacterial epidemics like syphilis. The discovery of penicillin started as a simple natural history observation in the late 1920s by Alexander Fleming while doing research on bacterial cultures in the then new field of bacteriology. Fleming noticed that in some of his cultures, mold had colonized, likely from mold spores that were known to be common in the air. But what caught his attention was that when the molds grew on his culture plates and came into contact with the bacteria, the bacteria died. He then made a slurry of the mold and found that the mixture killed many bacteria that were thought to cause human disease. Soon, penicillin was identified as the antibacterial agent and synthesized in the laboratory. Penicillin and most other antibiotics specifically affect bacteria without adversely affecting other cell types, tapping into the evolutionary history of microbes to fight our own microbial wars. In other words, the beauty of antibiotics is that they are weapons fashioned from the evolutionary arms race between mold and bacterial

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enemies. They are secondary metabolites, molecules not necessary for metabolism, that emerged through natural selection to defend molds from bacteria—a feature that we can borrow and artificially synthesize. It is impossible to know how many lives have been saved by penicillin, but one estimate claims as many as two hundred million.30 At the same time, humans face a new challenge in the war against pernicious bacteria: the overuse of antibiotics has led to growing bacterial resistance, as bacteria make their next evolutionary moves to circumvent the effectiveness of antibiotics. Over the last three decades, more than a hundred new antibiotics have been discovered, synthesized, and overused, often for protection from infection, rather than as a cure. Moreover, the large amount of antibiotics used in industrial agriculture has reached humans through food and water supplies. The consequence is that antibiotics have lost their efficacy over time due to the selection for and evolution of antibacterial-resistant pathogens. To date, this evolutionary race between pathogenic bacteria and human-designed, novel antibiotics is still being won by humans, but the battle is continuing in laboratories across the world.31 Viral and parasitic diseases required wholly different solutions. Viruses have been difficult to treat because of their extremely small size—they are little more than strands of DNA or RNA instructions that reproduce within other cells. They use human biochemical machinery to replicate rather than having their own machinery, which means there are fewer treatment targets for the immune system or antimicrobial compounds. Even though viruses are the most common life form on earth, they were not discovered for two hundred years after bacteria could be seen under Antony Leeuwenhoek’s first microscopes in the seventeenth century.32 Viruses are thus not only invisible, but show up literally everywhere, in the air, soil, and water, making them an especially tricky problem. The first successful treatment to prevent nonbacterial disease occurred in tenth-century China, when an understanding of natural history was deployed against the smallpox virus. Similar to early medicine acknowledging the effectiveness of molds against bacterial infections, initial treatments against viral infections reveal a direct influence of natural history observations. After the survival of

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some smallpox victims, physicians inoculated healthy patients with the dried smallpox scabs from patients with mild cases. These scabs were pulverized and blown up the noses of healthy individuals, who would then develop similarly mild cases of the disease and recover. The use of “nasal insufflation” spread into Africa and the Middle East, and was practiced until the late seventeenth century (it was not used in Europe or North America, where it was considered folklore). Inoculation against smallpox did not occur in England and North America until the early eighteenth century. Its success led to the use of cowpox as a vaccine for smallpox, based on observations that milkmaids seemed to be immune to smallpox during epidemics. The first smallpox vaccine from cowpox-infected cows was pioneered by the British physician Edward Jenner, leading to its widespread use and the eventual eradication of smallpox, as well as the development of additional vaccinations to prevent against other viral diseases.33 The efficacy of vaccinations led to a greater understanding of the human immune system and how it deals with pathogens, for vaccines work by stimulating the immune system to produce antibodies to fight against a certain disease without actually producing that disease. Vaccinations have been successful at preventing anthrax, measles, cholera, influenza, diphtheria, mumps, tetanus, hepatitis A and B, tuberculosis, typhoid fever, polio, rabies, smallpox, shingles, yellow fever, and cervical, rectal, penile and oropharyngeal cancers. If made widely available to developing countries, existing vaccines could prevent the deaths of more than 6.4 million children over the next decade alone and save trillions of dollars.34 One of the most overlooked, but pervasive, defensive strategies to counteract the constant threat of viral and bacterial disease may be sex. This idea, the “Red Queen Hypothesis,” suggests that sex evolved to increase the genetic variability of offspring, thus maximizing the production of offspring more likely to escape infection by disease. (The hypothesis is named after Lewis Carroll’s Through the Looking Glass, where the Red Queen says to Alice, “Now, here, you see, it takes all the running you can do, to keep in the same place.”) The Red Queen Hypothesis reflects the need for host populations to evolve continuously just to avoid being overwhelmed by pathogens, since obligate pathogens are under selective pressure at

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all times to infect more hosts (Figure 6.4). J. B. S. Haldane, one of the founders of the field of genetics and modern synthesis of evolutionary biology, pointed out in 1949 that infectious disease has been one of the main agents of natural selection of humans since the agricultural revolutions. While populations initially exposed to a new disease can be devastated and nearly wiped out, over time their genetic composition, independent of specific immune responses, adapts to diseases. This is the general rule for most diseases, including smallpox, influenza, plague, and sexually transmitted diseases. Thus, sex and its genetic consequences are likely responsible for much of the unexplained genetic variation in humans and other plants and animals. The human genome consists of six billion DNA base pairs with human individuals differing from each other by less than 0.1 percent and humans differing from chimpanzees by only 4 percent. With few exceptions, such as malaria, the actual genetic basis of this immunity is unknown. Ultimately, we may even discover that the vast majority of the human genome is historical

6.4. The Red Queen and Alice running “to keep in the same place” from Lewis Carroll’s Through the Looking Glass. In evolutionary biology, the Red Queen Hypothesis proposes that sexual reproduction evolved to stay ahead in coevolutionary races, particularly those with ubiquitous, rapidly evolving pathogens. Redrawn from public domain art.

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genetic garbage, left over from a history of evolution to defend us from pathogens.35 It is also possible that human monogamy evolved due to disease. Our primate ancestors were hunter-gatherers and generally polygamous. With the agricultural revolution’s population explosion, humans began living in high densities in cities that relied on cooperative group benefits—a perfect storm for the transmission of sexually transmitted diseases like syphilis and gonorrhea, which evolved to maximize their success in this new environment. Monogamy became a way of limiting the spread of venereal disease by restricting transmission to a single partner. Monogamy is also found in other species that live in dense groups, but is rare in more solitary species. While the jury is still out on this idea, venereal diseases may have led to an emotion, an institution, and an industry, in, respectively, guilt, marriage, and condoms.36 The current battles between diseases and their cures are part of the same evolutionary war that has been waged since the beginning of life, but at a larger scale, escalated by the consequences of cooperation, crowded cities, and resource trade networks that we now need to survive. We may have escaped the food chain, but we have not escaped our primordial battle with microbial and invisible organisms. In addition to our symbiotic microbial partners, however, humans are equipped with a unique tool to fight disease and the consequences of civilization writ large: our ability to cognitively understand and untangle the natural history around us. We may be the vessels or arenas where three-billion-year-old primordial conflicts still occur, but we are continuously learning how to respond to and mobilize environments and manipulate our own evolution. Our story, however, is not yet one of success. Civilization has led to other kinds of selfish-gene behaviors that have curtailed the ability of human individuals and communities to thrive.

chapter seven

Domination versus Cooperation

B

efore becoming the powerful, stratified, hierarchical civilization that we are today, humans lived as huntergatherers in small, cooperative, extended-family bands.1 As for our primate ancestors, conflict, violence, and dominance were the rule between these genetically related bands, but less so within them, since they shared common selfish genes that could potentially pass to the next generation. Every member of these bands played an indispensable egalitarian role in the day-to-day life of pre-agricultural human culture. But the results of agriculture— the population explosion, food surpluses, possessions, property, and control over resources—changed this lifestyle dramatically to one threaded through by conflict among familial, cultural, and ethnic groups. (In resource-poor areas that did not experience agricultural population booms, such as the Canadian subarctic, the Australian outback, and African savannas, these extended family-band cultures persisted until the modern age turned them into tourist attractions.) This conflict was matched by the cooperation inherent in the new urban organization of life and increasingly stratified societies. How dominance evolves within and among species follows unchangeable processes that affect a range of species as well as the environment itself. At its basal level, dominance is selected to preserve and maximize gene transfer to the next generation. Over 135

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generations this makes the selection for dominance the primal life process. For species that live communally, from apes to ants, groups can dominate individuals, leading to selection for group behavior to achieve the maximum genetic success of individuals. Returning to an idea first mentioned in the Introduction, the principles of self-organization that lead to evolutionary success result from two distinctively different types of group organization. Some communal species are organized vertically, like bees and humans, among close genetic lines of related individuals so that the group can become an operational unit of selection and dominance. Others are organized among unrelated individuals, or horizontally, like mussels, oysters, and forest trees. In these more loosely related assemblages, individuals living in cooperative groups are more likely to live longer and reproduce successfully, independent of kinship with others in that group. Here the individual remains the unit of selection, but group behavior that protects individuals from enemies, competitors, and physical stress trumps the dominance of individuals. In both of these cases, the advantages of cooperation for individuals outweigh those for going it alone.2 For humans, processes that led to dominance over the food chain and natural selection have had additional consequences that have shaped the situation we have today: a world of vast inequalities that have created and support many of our most pressing problems. As we will see, this story is not simply one of powerful leaders gaining control over society, but rather one of holistic, organizational means of cooperation being pushed into overdrive by civilization— it is a system problem, not an individual problem. Yet the story is also still being written. Changes in the modern age have opened possible cracks in humanity’s hierarchies of dominance.

The Rules of Social Dominance As has been the running thesis of this book, the dominance of some humans over other species and other humans is a result of the same processes that have created hierarchies within the nonhuman plant and animal world. These processes are explained by “social dominance theory,” through which we can understand the development and maintenance of dominance hierarchies in animal, plant, and

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human populations. Developed by Harvard sociologists James Sidanius and Felicia Pratto to explain human social organization, social dominance theory can be generalized to explain the ubiquity of analogous hierarchical organization in plant and animal populations. According to the theory, group or individual inequalities are maintained by three intergroup or inter-individual behaviors: (1) institutional discrimination, or “dominance rules,” (2) consistent discrimination following dominance rules, and (3) pervasive asymmetrical behaviors that reinforce established discrimination and dominance rules. Behavioral asymmetries, or asymmetries in general, occur when members of a dominant group treat peers more favorably than they do members of subordinate groups. Asymmetries also occur when members of subordinate groups show aggression toward others or perform poorly because of low expectations—“self-fulfilling prophecy” behaviors. Members of dominant groups reinforce hierarchies when they have roles or behaviors that maintain the myths that community hierarchies are built on. These authority figures that help maintain hierarchies are, in human civilizations, ruling families and members of occupations like the police, while in animal populations they are often the alpha males—which in shoreline communities can simply mean those individuals with large bodies or fast growth rates such as mussels, barnacles, and seaweeds.3 Social dominance theory has led to the hypothesis that widely shared cultural values or dominance rules (including traits like size, kinship, or age) provide the justification for intergroup behavior that forms and maintains social dominance and leads to hierarchical organization. The similar patterns found in plants and animals suggest that similar assembly rules can be applied across phylogenetic groups, from plants to primates. Sociologists and ecologists can thus be interested in explaining the same problem—inequalities within and among communities—and even use similar principles to understand these problems.4 Dominance rules literally shape the environment, determining the placement and spacing of organisms and communities of organisms ranging from African termite colonies to shoreline barnacle and mussel assemblages to human housing developments. Termites, for example, are colonial organisms, and each colony is produced and organized around a dominant queen whose offspring

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are her genetic clones. As a result of this genetic affinity, all individual termites in a colony cooperate like the cells in a multicellular organism. Since termite colonies compete for resources, the balance between cooperation and competition leads to termite colonies that are conspicuously self-organized spatially across African savannas (Figure 7.1). Similar spatial patterns reflecting dominance hierarchies and a balance between dominant and cooperative forces can also occur within and among organisms that are not close genetic relatives. This is particularly easy to observe in sessile, or immobile, organisms. Sessile organisms, including plant monocultures, mussel beds, and barnacle-covered shorelines that develop on homogeneous surfaces, naturally form regularly spaced, symmetrical, self-organized mounds or hummocks of competitively dominant individuals surrounded by competitively subordinate individuals. These spatial patterns are as organized and symmetrical as planned housing developments, but are simply the byproduct of asymmetries in dominance magnified over time as neighbors grow (Figure 7.2). Individual

7.1. Termite mound fairy rings on the African savannah. The regular spacing of the mounds reflects a balance of aggression and cooperation among the colonies, which compete for food and other resources. © Huang Jenhung/Shutterstock.

7.2. Parallels between barnacle and human group spatial structures: barnacle hummocks of the common shoreline acorn barnacle Semibalanus balanoides and the housing development of Levittown, New York. In the barnacle community, regular spacing of the hummock mounds reflects the benefits to the group of sharing walls for structural support and of sharing stored water, balanced against competition for space and food. The aerial photo of Levittown shows a regular spacing of houses, which in turn demonstrates the group benefit of individual home ownership as well as individual competition within the neighborhood for space. Barnacle photo: By author. Levittown photo: © Ewing Galloway/Alamy Stock Photo.

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barnacles or plants, for example, can secure initial competitive advantages by settling or germinating earlier, or by selecting a habitat that may be nearly indiscernibly better. Such an advantage will depress the growth of neighbors and lead to regularly spaced dominant and subordinate individuals. Early Neolithic cities, city-states, and crowded medieval feudal landscapes across Europe, Anatolia, and China featured similar self-organized arrangements of human settlements that reflected dominant and subordinate neighbor relations. From space, aliens would see both crowded self-organized barnacle hummocks and classic Levittown housing developments as identical and definitive signs of the balance between competitive dominance and cooperation. The striking spatial patterning of city landscapes and of marine organisms along shorelines around the globe is eerily similar (Figure 7.3).5 Moreover, community ecology and sociology overlap in ways that allow us to test in one arena, ecology, ideas that may well lead to insights about human behavior. This connection was explicitly drawn in 1975 in Edward O. Wilson’s seminal Sociobiology, a book that revolutionized thinking about human behavior by applying natural history and evolutionary reasoning to all—including human—animal behavior. Groundbreaking at the time, Wilson’s extrapolation of evolutionary logic to social behaviors, from cooperation to aggression, dramatically influenced the fields of evolutionary ecology and animal behavior. Is our common fear of snakes really an ancestral trait from our arboreal past living in trees? Is male promiscuity the product of maximizing fitness? Is sexual division of labor an ancestral primitive trait? We are not accustomed to or comfortable thinking about our own basic behaviors as having been crafted by the same natural selection processes that affect ants, birds, and other primates, and Wilson’s book was hotly debated, even within the scientific elite.6

The Human Age Once Homo sapiens were smart enough to understand the simple and powerful rules of natural selection that controlled their surroundings, they were able to turn natural selection into their own tool, manipulating it to their advantage. Humans inaugurated “artificial selection,” complicating and changing the rules that had governed

7.3. Similar distribution patterns in human and marine organism shoreline communities. Note how the contemporary waterfront of the Lower East Side of Manhattan displays obvious competition for space and cooperation among humans, just as the New England rocky shore shows the effects of these same forces on marine organisms. Photo of New York City: Melpomenem/Dreamstime.com. Photo of New England shoreline: Courtesy of Catherine Matassa.

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the evolution of life for more than three billion years. We have seen already the early uses of artificial selection in how humans selectively bred domesticated plants and animals, including wild cabbage, wheat, and dogs, disregarding reproductive success in the wild in favor of coat color, temperament, size, meat, milk production, nutritional value, and other qualities. What we can learn from maladaptive, manipulated plants is that for some organisms, coevolutionary mutualism with humans has led to evolutionary success not due to natural selection, but rather to the hands-on engineering that humans have used to reshape them for their own benefit. In the natural world, the mutualisms between, for example, flowers and their pollinators created global diversity and the dominance of both flowering plants and the insects pollinating them; similarly, humans have “brought along” the fauna, flora, and microbes that have naturally and artificially evolved with humans on the path to worldwide dominance. The relationship between these organisms and humans can be symbiotic or more parasitic, for just as grasses were transformed into wheat and wild cabbage became common vegetables, hitchhikers or commensals like rats, cockroaches, dandelions, and crabgrass have also come to dominate the planet courtesy of human dominance. The positive reciprocal feedback loops between domestication and population growth made humans a more dominant species, able to control—with the important exceptions discussed in Chapter 6—the food chain and spread over new lands, while cooperative communal living protected them from predators and competitors. Successful sedentary life required new levels of human cooperation on one hand, but on the other it led to the loss of a culture of individual freedom and its replacement with a heavily stratified human hierarchy. Greater resources, after all, required greater management, and a growing class of laborers and farmers required protection: together this meant that a small group of leaders became increasingly powerful, and the hierarchical organization of the city-state became the standard for urban organization. Spatially, the city-state model also standardized the self-organization of the peasantry around a centralized or nucleated ruling elite.7 The dominance of the ruling elite was such that from the earliest civilizations onward a small ruling class was enough to oppress,

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through strict social dominance mechanisms including violent punishment for disobedience, a peasantry and slave population that comprised more than 90 percent of the total population. We can see this from the immense public works, such as the pyramids, which were built to honor or even deify the ancient rulers of Egypt, the Fertile Crescent, and Asia, and which required the work, and often the lives, of thousands of workers. These early hierarchies reigned throughout Africa, Europe, and Asia for millennia, often resembling the social organization of an ant colony or beehive where the members of the community are controlled in order to operate like a single organism. A peasant’s station in life was permanently fixed, not unlike the situation for the working poor in today’s world. And like the situations for termite colonies and bands of chimpanzees, violent conflict was the rule between neighboring city-states or species, while social organization and cooperation were more common within human citystates, beehives, mussel beds, and kelp forests.8 Violence, as well as threats of public castigation, were how the ruling class enforced, reinforced, and strengthened their strict dominance and control of the masses from early agrarian Fertile Crescent cultures through the Middle Ages. Regular public executions featuring physical torture were a common way to keep the ruling class in control of the fearful masses. Steven Pinker summarizes the great lengths that rulers would take to publicly humiliate, dehumanize, and inflict excruciating pain on peasants who stole, disobeyed rulers, or failed to follow even the simplest rules.9 Publicly amputating body parts like hands, arms, and noses was a popular punishment for petty crimes, such as children stealing food or trespassing, while brutal sadistic executions featuring slow scenes of torture, like being torn apart on a rack or hung on a stake or cross, displayed to large audiences what would happen if one committed a more serious offense. Serious crimes could involve any affront to rulers—looking them in the eye, consorting with their slaves, or cutting down trees on public land for firewood. The elevated cages at the Tower of London where offenders were left to die slow painful deaths from starvation and exposure for all to see and learn from are artifacts of these brutal methods of execution. Public torture and execution became so severe through the Middle Ages that the introduction of the guillotine for beheading was seen as more

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humane. But death by guillotine still took place in public, because the spectacle of the punishment was just as important for controlling the masses and maintaining elite rulers’ dominance as was the punishment itself. The very lowest rung on this social-dominance ladder was the slave. Human slavery has been a part of hierarchical organization from at least the start of post-agricultural civilization. Beginning as spoils of war or as debtors enslaved until their loans or bills were paid off, slavery filled the needs of dominant aristocratic families who needed many workers to run their large parcels of land. In classical Greek and Roman civilizations, a third of the population was enslaved. Slavery went out of style in Western Europe, however, for it was a less profitable and easily maintained model of labor than simply giving a peasant a small plot of land on which to work and pay tribute.10 One of the great ironies of human history is that the ruling families that tortured and tormented their minions into thinking they were gods are the same royal lineages that still actually or symbolically rule countries around the globe today. They are often revered by their subjects even though they are the same families that terrorized, dehumanized, and killed their people to achieve absolute subjugation of their subjects. Though there have been many mutinies and revolutions against ruling families—such as the brutal revolution in Russia, which killed off entire ruling bloodlines—respected royal families with bloody pasts are still common across the globe. To control slaves and reinforce social dominance, one tactic humans turned to was castration. Enemies of war—dead or alive— were castrated to demonstrate the victor’s dominance, and in many cultures, male scribes and the brightest advisers were castrated to render them less ambitious, threatening, and aggressive to rulers, as well as more focused. Castration of male threats was practiced from ancient Greece to the Byzantine Empire, and in Persia male slaves from Slavic countries and Africa were castrated to make them more docile. Not surprisingly, castration was also commonly used by humans in animal domestication to control overly aggressive, dominant male farm animals.11 Something as symbolic as castration might strike us as exclusively human, but in fact, castration has a rich evolutionary history

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that humans were simply following. For example, many types of parasites castrate their hosts, turning them into large females that produce the clever parasite’s offspring rather than their own. Similarly, males of social insects are kept hormonally neutered so that they are docile, dedicated workers in the hive or colony. Castration has the same evolutionary motive, whether in humans, plants, or animals: to increase the reproductive output or fitness of the castrator by manipulating the hormones of the castrated.12 The most extreme example of social control through sex manipulation in vertebrates is in harem-forming coral reef parrotfish and their relatives, which are called labroids. Labroids have evolved social control over sex change: a parrotfish harem consists of one dominant male surrounded by females, with the other, smaller males cast out of the harem. When the alpha male dies (or a biologist removes it from the group), the next largest fish, a female, undergoes a hormonally mediated sex change and becomes the alpha male in a matter of days. This allows for the most competitively dominant, largest fish to pass along its genes to the next generation.13 But the animal world is not exclusively masculine: there are also examples of female dominance and socially controlled sex change in other animals. One example familiar to New England beachcombers is the slipper limpet, playfully named Crepidula fornicata by Linnaeus. Crepidula is found on wave-protected shorelines, in stacks of individual snails neatly arranged from the largest at the bottom topped by smaller and smaller snails. The largest individual is the only female in the stack, and all of the smaller individuals are male. Like the parrotfish in reverse, removing the female spurs the largest male to change sex. The reason for this difference in socially controlled sex change is that large female size translates in Crepidula into larger reproductive output, while in parrotfish and other labroids, large males control harems of smaller females. Thus, in both snails and parrotfish the genes of the most successful largest individual are selected for. Castration was once a common practice of control and dominance in humans, but it has been replaced by other mechanisms that support and extend the power of the ruling class. Perhaps the most surprising consequences of human dominance are the trends toward pacification and civilization, which have reduced human aggression

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and violence.14 This has, as we have seen, reduced homicide rates by many orders of magnitude from the Bronze Age to the present day, increased pressures for cooperation, and encouraged cultural and social forces like those that resulted from developing mutually beneficial trading networks. These processes have even led to a softening of crude public social behavior and language, which helps to limit the asymmetrical interactions that drive hierarchical dominance. The most essential mechanisms for dominance and control, however, are spiritual power and passing rulership down through familial lines. Together with pacification and civilization, these mechanisms increased individual survivorship and reproductive success while controlling human thought and lives.

Family and God The aristocracy generally passed on their dominance over land, resources, and people along family lines—most often to the eldest son, a practice called primogeniture that was first mentioned in the book of Genesis. While primogeniture often led to bloody infighting and fierce family rivalries, it also often confined rule to a small, genetically related, tightly controlled few. Younger sons (who were unwilling to kill their brothers) eventually had the options of knighthood or priesthood, because only the landed gentry were educated to read and write and to train for knighthood or priesthood. These “second options” successfully brought both information and military control into the fold of family rule. Families were able to spread their influence through religion as well as through the knights’ ability to conquer new land and resources and to subjugate others in established estates. Ruling families dominated the masses with a good cop–bad cop strategy. Rulers’ orders and rules were reinforced by harsh punishments for any who disobeyed. Conversely, ruling families offered comfort, hope, and a happy ending for the masses by creating and propagating religious mythologies that promised future rewards for suffering gladly and accepting one’s position in life. It was a perfect one-two punch that guarded the status quo for the powerful.15 Women were largely treated as commodities or genetic bargaining assets in most early cultures, and from the Bronze Age through

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the Middle Ages, they were often captured as part of the spoils of war. In feudal Europe and elsewhere, they were married off to create genetic family alliances with powerful families as political pawns, or became part of the religious fabric of cultures that also cemented and extended the power of dominant ruling families. Across Europe, the Middle East, and Asia, human communities became organized into regularly spaced, semi-autonomously ruled family estates, or, in larger kingdoms, farms around heavily defended castles. At a fundamental ecological level, this setup resembles the deterministic pattern formation of plant and immobile marine animal assemblages on coral reefs, rocky shores, and marshes. Even as humans dominated the planet, they could not escape certain processes and patterns that are fundamental to life itself, such as the self-organization of subordinate organisms around competitively dominant ones—whether those organisms are barnacles on the shore or humans in medieval Europe.16 Social dominance in humans, however, is different than that in barnacles, for human dominance can be established not only by size and ability, but also by cultural myth. Human vulnerability to cultural myths explains why in virtually all civilizations with abundant resources, a small, elite ruling class eventually controls the masses passively through social dominance myths—giving extra resonance to the saying, “the winners write the history books.” Today, religion’s diminished role means that it has relinquished its power to create the myths that maintain social dominance: wealth has largely replaced religious mythology as the currency or language for controlling human behavior.17 Before this change, religious leaders and the aristocracy together subjugated the great majority of the planet’s humans. In Europe, the ideology that buttressed this subjugation is referred to as the Great Chain of Being, which claimed not only that God had imbued everyone and everything with purpose, but also that one’s purpose was the social and economic role one was born into (Figure 7.4). In other words, if you were born a barnacle, a partridge, a slave, a serf, a cleric, or a ruler, you were to remain one: there was no possibility of social mobility. This ideology cemented the hierarchical structures of medieval Europe, and its basic components were replicated across the world to create the caste systems that

7.4. Medieval illustration of the Great Chain of Being, the notion that life forms are born into their proper place with no possibility of vertical mobility. It was of course a doctrine promoted by the nobility and church to maintain their power. Public domain image from Rhetorica christiana by Fray Diego de Valadés (1579).

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stratified society. Analogous spiritual social structures secured hierarchical control in the cultural fabric of African and eastern cultures of India and China, with mythologies and rulers playing the roles of good and bad cops, respectively. The church and institutions like it were active participants in placating and controlling the masses through mythologies. They kept populations illiterate and fearful, teaching that famine, disease, and war were divine punishments. They codified what one could eat, what one could wear, and how and when one could have sex. In Europe, religious institutions developed economic ties, originally allied with pagans, to a fishing industry that supported them, and in turn they helped the fishing industry by establishing fish-fasting—holy days where believers could eat only fish despite this ritual’s absence in Christianity’s sacred texts. The church was also instrumental in supporting religious wars that extended the ruling class’s power and moved ideological motives into economic or political actions—a tool sadly still present in today’s world.18 As discussed earlier, the disease pandemics and famines of the fourteenth and fifteenth centuries went a long way toward breaking the stranglehold that religion and aristocracy had on the masses. Disease mortality did not recognize human dominance hierarchies: mass mortality struck randomly across social strata. And as long eras of domination unraveled, nations flung out like a disturbed beehive, throwing their energy behind exploration as smaller kingdoms— Spain, Portugal, Holland, and England—dominated sea trade and built colonial empires. While we refer to this period of human history as the Renaissance and the Enlightenment, it was also the spreading out from an overexploited resource base, a common natural history response to overcrowding and limited resources—in other words, the causes and effects of events like disease and famine. Religion and mythology still played a vital role in this period, providing colonists with the authority to dominate, enslave, and destroy newly met civilizations, such as the Maya and the indigenous cultures of North and South America and the Pacific Islands.19 During these final throes of religious domination, in 1215, the aristocracy in Europe received its most devastating blow: the signing of the Magna Carta, a document that overturned the divine rights of kings, and so cracked the European collusion of aristocracy

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and religious authority.20 The spirit of the document was broadly interpreted and began to infect in the peasantry a distrust of the Great Chain of Being. This development in turn planted the seeds for the more serious threats to society’s hierarchical structures that would become the eighteenth century’s Age of Enlightenment, with revolutions in France and America that spread like an intellectual social disease across the globe. But as these classical forms of hierarchy began to disintegrate, society was still not in charge of its own development: instead the societal and organizational changes that occurred were spurred along by natural history constraints and gave way to new powers and new dominances. One of these new powers was science.

The Power of Information Science itself is as old as humans, for even our earliest ancestors needed to have a complex understanding of the natural histories around them (something that would be nearly impossible for us today). Natural history was the first defined science that included biology, geology, and physics under its umbrella, and many civilizations from early on understood the benefits of strong centers of learning. The oldest continually operating university, for example, is the Karaouine in Fez, Morocco, founded in 859 CE, and older universities like the Academy of Gondishapur existed in fifth-century CE Iran. China, too, had a strong history of science and technology—but rulers of both the Chinese and Persian empires banned science and philosophy when they came under strict theocratic control, closing some of these earliest of universities.21 Science has always been beholden to more powerful social actors, and marginalizing science is as old as civilization itself. Skipping ahead, during the Industrial Revolution of the eighteenth and nineteenth centuries, power was not only reinvested in science and technology, but also led to the rise of a wealthy merchant class that utilized new technologies to expand business ventures. Like the agricultural revolution before it, the Industrial Revolution harnessed the group benefits of the masses to achieve goals that were impossible without cooperation. Reinforced by accelerated population growth and positive feedback, industrial revo-

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lutions around the globe again showed the power of cooperation as a more empowered population reshaped the world and reorganized hierarchies, challenging aristocracies and churches by making new opportunities available to the public. In the Industrial Revolution, the merchant class challenge showed the limits of the Great Chain of Being: laborers were able to work their way up to management and leadership roles within a business, and societal position was no longer a fixed component of one’s life. Moreover, science and technology were able to make good on promises that religion couldn’t keep, such as providing a better life. From disease cures to industrial developments, science improved the lives of the living in ways that religion—especially during the Black Plague—could not. Human cultures began the process of secularization and the church worked to defend its status quo by casting science as its enemy, a tactic it had used since Galileo was sentenced to house arrest for teaching that the sun, rather than the earth, was the center of the universe. In 1987, I was able to see one of the consequences of this defensive position when I visited a small, local natural history museum in Plymouth, England. The museum had an impressive collection of dinosaur bones that had been discovered in the 1800s by local farmers. Back then finding large, buried bones of unknown animals was a mystery, more so because the church taught that the earth was only 6,800 years old, so the local church had stashed the bones in its basement until there were so many that they could not hide them anymore. Around the same time, Mary Anning (1799–1847), a selftrained natural historian, began finding and studying fossils in the eroding marine outcroppings of her hometown of Dorset, England (Figure 7.5). She became one of the first paleontologists to provide evidence for the concept of deep time, because the fossils she found dated to the Jurassic geological period some 145–200 million years ago. The dinosaur fossils she found in eroding sandstone cliffs along the shoreline were thought by locals to be dragons. Though she wasn’t able to publish her findings due to her gender, lack of formal training, and social status, she remains one of the most influential paleontologists in the field.22 In the middle of the twentieth century, the next great transformation in human civilization began: the Information Age. The

7.5. Mary Anning (1799–1847), the pioneering “amateur” English fossil collector and paleontologist, was famous for finding fossil remains of the Ichthyosaur “sea dragon,” a large, extinct sea monster. Her discovery challenged early nineteenth-century paleontology and fascinated the general public. Photo of Mary Anning: © The History Collection/Alamy Stock Photo. Drawing of fossil: Based on Ichthyosaurus skull discovered by Joseph Anning, published in Philosophical Transactions of the Royal Society of London 104 (1814).

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transition from industry to information has dramatically accelerated and unleashed cultural change—though we will be wise to remember that since the beginning of civilization, information has controlled the masses and consolidated power. Information has routinely been kept from the hands of common humans and siphoned off to the educated elite, from the Mesopotamian rulers who claimed to be representatives of the gods on earth; to the Egyptian ruling families who used hieroglyphs, readable only to themselves and their scribes, to track commerce; to the Chinese who often castrated their scribes so that their knowledge could not be used as power. Religions too prevented information from reaching average parishioners, who like women and slaves were kept illiterate, a practice that still exists in parts of the world today. Until very recently, for example, Catholic liturgies were usually given in Latin, hiding the words of God from ordinary people. As a teenager, I remember attending a Catholic mass with a friend and being properly humbled and impressed.23 The Information Age has flattened these hierarchies in ways we still don’t entirely understand, exposing cultural differences and inequalities across the globe while opening other possibilities. In 1990, I was diving with a group of scientists off an island near Bali in a place where the native cultures were still engaged in the traditional economies of seaweed harvesting and basket weaving. We traveled by donkey carts and witnessed women sifting seaweed on the shore, wearing cloth skirts over their sun-beaten skin. The scene was such that I thought we had traveled back in time until, on the way back to the boat, we drove over a hill behind the beach. There we saw a thatched roof covering a dirt floor packed with seated children. As we approached, we saw they were watching attentively a small television showing cartoons. This was no primitive, idealistic, uncontaminated space, but a location just as much a part of the global world as your home or mine. If history is our guide, the recent developments in information and technology signal that rapid changes are on the horizon for civilization. Previous permanent changes in the history of civilization have all been brought about by information or cooperative breakthroughs. They shrink the effective size of the globe by increasing the spread of knowledge, flattening roadblocks among cultures—a

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process that initially creates cultural chaos—and disturbing dominance hierarchies. Fire, cooperative hunting, agriculture, land and sea trade, global exploration, and the Industrial Revolution all were game changers. All caused some chaos at first, including dramatic increases in violence and other dominance-asserting behaviors, but over time these effects were ameliorated by order and cooperation, which were mediated by the spread of knowledge and information. Knowledge equals power, and as rulers and spiritual leaders used knowledge to subjugate humans in new lands, they initially dominated the masses, but as that knowledge diffused to the masses over larger and larger areas, order and cooperation developed. These are examples of a willed and teleological cooperation, however, rather than the cooperative acts within our natural history that led to the developments in the first place. That is to say that the flattened world of increasingly empowered citizens finds ways to choose to cooperate that challenge the blind, forward push of evolution. Examples include the Silk Road, the development of railroads, and the internet: while operating at different times and over different time scales, each at first involved intense competition and initially increased hierarchical control, but over time led to the widespread dispersal of information, which ultimately increased willed cooperation through trade and mythology. What will happen now, as the global spread of information increases and coincides with the largest global disparity in opportunity and resource distribution the world has ever seen, as well as with unsustainable population growth, diminishing resources, and the poisoning of our global resource base? In the past, major transitions in life on earth have been met with holistic, cooperative solutions in which the whole is recognized as greater than the sum of its parts. Similarly, the ecosystems on earth and the services they provide have been buoyed by the cooperative mutualisms that I have discussed here. But what are the solutions for our civilization if we have reached a point where our population growth is outpacing our resource supply globally? What happens when cooperatively driven human population growth intersects with coevolving arms races for survival? What do we do when we have poisoned the cooperative elements of our ecosystems and prevented them from healing our shared surroundings?

chapter eight

Our Ethnocentric, Entheogenic Universe

W

hen the seventeenth-century French philosopher René Descartes famously declared, “Cogito, ergo sum” (I think, therefore I am), he was expressing the widely believed perspective that we humans are superior to other forms of life. We love our dogs, cats, and other pets, but few of us consider them to be deep thinkers who wonder where they came from, who they are, or where they go when they die. Even ardent animal lovers don’t advocate dog mythologies or think about pet heaven. For humans, then, the high peaks of culture that religion often represents might be seen as the culmination of what truly separates us from the rest of the natural world. The mythologies, religions, and beliefs that came from cooking meat in fire pits—which led to greater energy from our food, which led to brain growth, which led to communication, cooperation, language, and problem-solving, which in turn selected even higher-level brain development—are as human as human can be, aren’t they? After all, though the brain biochemistry that gives humans consciousness is not yet fully understood, the consequences of our high-functioning cognitive abilities are clear: they have led to our 157

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questioning the meaning of life, what we are doing now, and what we will do later.1 They have produced psychology, sociology, the sciences, and religion. They created J. S. Bach, Bob Dylan, the Beatles, and civilization. They are what make us able to do other things with our days than plan for food. They are what make us able to read this book. In other words, we might be tempted to believe that religion, philosophy, and art, these arenas wherein we search for (humancentric) meaning, represent the essential break between our species and every other species—and indeed, the ability to think, to become Aristotle’s “rational animal,” has been used for precisely these categories. There are animals, and there are humans. Natural history says otherwise. While it may indeed be true that we are the only species capable of mythology, such a power did not arise in a vacuum, but rather from the same symbiogenetic processes of cooperation that have led to human dominance over the planet. The story of mythologies that grew into religions that became integral to the wielding of social power over others is one that involves some of the strangest and most creative theories and hypotheses of cooperative evolution in natural history. Namely, it is the story of our continual fascination with and understanding of plant chemistry—not simply for medicinal purposes, as I will explain later, but also for various plants’ hallucinogenic and mindaltering properties. While some of these hypotheses are more speculative than others, all of them point to an intimate relationship between human cooperative social structures and the chemistry of plant defenses.

Soma and the Meaning of Life Hinduism is the oldest extant religion with written records of religious practices—the oldest of the Hindu religious texts, or vedas, is the Rig Veda, which may be as many as six thousand years old and was written in Sanskrit, the oldest Indo-Iranian written language. In this text is described the preparation and use of a beverage, Soma, which is intended to allow priests to communicate with the gods and act as the conduit between the gods and their worshippers. Soma would reappear millennia later as a psychotropic drug

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in Aldous Huxley’s dystopian novel Brave New World, where it is administered by the government to control populations. In the novel, it is described as the ideal pleasure drug, giving its users “all the advantages of Christianity and alcohol; none of their defects.”2 Soma did not lead to religious wars and did not require moral guilt, but it still provided the comfort and relief from angst that religion would give with its dogma of being existentially meaningful. But the connections do not end there: some twenty years after Brave New World, Huxley would write the provocative The Doors of Perception, where he explored the role of psychogenic plant compounds as gateways to higher levels of consciousness.3 This thesis was already present, however, in the very word “Soma,” the source of which was long unknown until it was identified as the processed liquid form of the Amanita muscaria mushroom, commonly known as the fly agaric. Recent attempts at preparing Soma as described in the Rig Veda show that the preparation detoxified the deadly secondary products of the Amanita muscaria mushroom and increased its psychological effects in ways that would give the user non-ordinary states of consciousness. These non-ordinary states of consciousness may very likely be what we refer to when we talk about “spiritual experiences.” Substances that stimulate these kinds of consciousness, like Amanita muscaria mushrooms, are called “entheogenic,” and by now it will not come as a surprise that humans have a long evolutionary history with entheogens. Is it possible that the mythologies and religions that have comforted individuals, controlled masses, spurred wars, and affected at all points our cultural lives have themselves a natural history? When we dig beneath our religions, might we find that the roots of our belief systems and mythologies are exactly that—roots?

Myths in Parallel and in Conflict Before turning to the possible physical substrates of religion, however, it is worth discussing the symbolic or ideological level on which myths across the world share a degree of parallelism. Parallel myths already point to common sources: indeed, scholars of myth have long been fascinated by the resonances and repetitions

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in various cultures’ foundational stories. Virgin births, for example, are common in the stories of many religious traditions, including Jesus in Christianity, Quetzalcoatl for the Aztecs, and Houji, the Chinese god of agriculture.4 Christianity specifically borrows from a number of preceding sources, such as ancient Egyptian mythology, which predates Christianity by three thousand years yet still features a Garden of Eden, original sin, a god of creation, and an afterlife with heaven and hell. Kersey Graves, an early nineteenth-century Quaker abolitionist, wrote extensively about these connections and inconsistencies, believing that religion exaggerates the truth and that Jesus was a fictional figure who came from ancient mythological oral history. In 1875, Graves outlined these arguments in The World’s Sixteen Crucified Saviors: Christianity before Christ, a book simultaneously criticized by clerics and considered creative by academics. In it, Graves noted the other cases of immaculate conception, births announced by star formations, and even the attendance of wise men or kings at the birth. Again, Egyptian mythology compares uncannily with Christianity through its figure of Horus, a god with twelve disciples who was born of a virgin after stars announced his birth. Like Christ, he was baptized at thirty years old, and he performed miracles like raising people from the dead and walking on water. He was also crucified, buried in a tomb, and later resurrected to rise to heaven. Buddha and Hinduism’s Krishna also bear a striking resemblance to Christ, a story that seems too attractive to ever give up.5 Incorporating, assimilating, and transforming ancient myths into contemporary forms of belief had a practical, political motivation beyond nurturing an unspoken form of group management and cohesion. History is replete with cases of successful conquerors—such as Alexander the Great and Genghis Khan—choosing to adopt local customs and beliefs to maintain the peace over recently conquered lands. During the early Middle Ages, Christianity changed from a banned heresy to the state religion after the wives of emperors like Charlemagne converted. To make the conversion of an entire population palatable, religions like Christianity adapted to previously held customs, like the festival days that celebrated the winter solstice in December and the spring equinox in March. In ancient times, these dates were the most important milestones of the year. Today,

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Christmas is timed to the winter solstice, and Easter to the spring equinox, when pagans would celebrate the renewal of life. Similar borrowing occurred in Christian symbolism, such as the use of the pagan cross instead of the customary stake that would have been used for crucifixion. For pagans the cross was an important symbol for the mother goddess, and the fish symbol, still seen ubiquitously today as Christian, originally evoked a pagan god of birth and fertility. Even Christian churches were often built over ancient holy sites, literally overlaying one tradition on top of another.6 Despite the work of socialization and community building that religions often did for political leaders and conquerors, the use of religion to further these rulers’ ends inevitably led to conflict. Doctrines proclaiming the authoritative and divine transmission of God’s word tilled the ground for conflicting and incompatible religions to rise up across the globe, leading to a pandemic of holy wars that remain with us. Samuel Huntington’s The Clash of Civilizations and the Remaking of World Order, an influential and controversial book, predicts the increase of religious and cultural clashes between civilizations as global populations continue to increase.7 Common mythologies, traditions, and belief systems united cultures. They were the social glue that gave meaning to bigbrained humans. Throughout history, competing, or simply novel, mythologies threatened the identity of early cultures, and so caused tighter cooperation within specific cultures and against others. Mythologies and different belief systems drew battle lines between groups already competing for resources. Thus groups became connected and disconnected in competitive and cooperative relations along religious lines, adding a spiritual register to an ongoing biological and sociological process. Moreover, religion was yet another tool for rulers and leaders to exploit to control the populations under them as these populations grew exponentially. The battles and bindings of cultural mythology are superficially analogous—if not mechanistically similar—to the battles between dominance and cooperation that have, through the coevolution of humans and microbes, shaped human civilizations. The cultural assembly rules that govern the organization, interactions, and dominance of cultural mythologies are a perfect example of how social constructs are dictated and reinforced by social dominance theory:

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cultural and mythological identity and beliefs, even when they have been beaten into subjects of kingdoms or followers of mythologies, create strong cooperative identities that have led to cultural conflicts. The Crusades of the late Middle Ages and the ancient and ongoing conflicts in the Fertile Crescent are examples of wars of mythological difference, while the two world wars were fought over cultural dominance.

Medicines and Divine Mushrooms While the flexibility of religion and myth to move, transform, and incorporate or be incorporated is fascinating in its own right, how did the first myths arrive? What accounts for the initial seeds that would grow and flower into the wildly active cultural forms of religion today? One of the most creative theories for the development of religious thinking suggests that humans have been self-medicating for millennia, perhaps even before agriculture and civilization, with plant compounds that increase cognitive abilities and stimulate human creativity. Indeed, new evidence from the Göbekli Tepe site in Turkey has suggested an origin for religious thinking predating agriculture, and Paleolithic burial sites have been found that have included poppies, suggesting the importance of these opioid sources and their relation to the afterlife. Is the natural historical origin of religious thinking bound to the discovery and use of entheogens, or psychotropic compounds? Is it a coincidence that opioid poppies may simultaneously be at the origin of both human spirituality and substance abuse and addiction?8 An increasing amount of diverse research suggests that this may very well be the case. Studies of primate diets in the wild over the past thirty years have shown that some diets include plants with medicinal, rather than nutritional, value.9 This means that our primate ancestors had evolved certain self-medication behaviors, often to protect themselves from or rid themselves of parasites and microbes. This occurred through simple natural selection: primates that ate medicinal plants or fermenting fruit had fewer infections and produced more offspring. During the cognitive revolution, humans developed strong relationships with foods and plants that affected both their physical and

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cognitive abilities. This led to coevolution between humans and plant sources of compounds like caffeine, alcohol, yerba mate, nicotine, and coca, as well as other plant derivatives for medicines, such as antibiotics, anti-fungals, and insect repellents. As Northwestern University pharmacologist Richard Miller argues in Drugged—The Science and Culture behind Psychotropic Drugs, these links have long been a part of humans and other species. Caffeine, for example, has been shown to prevent herbivory and disease in plants and acts as a memory stimulant for bee pollinators. In humans, this relationship eventually became the pharmaceutical industry that picked up where evolution left off. (More on this in Chapter 9.)10 A less frequently told story of human-plant coevolution centers on plants that are sources of mind-altering chemicals. These chemicals may have been the origin of humanity’s spiritual experiences, making the concepts of deities and other worlds or realities the result of natural history experiments that altered our sense of reality. Trying to consume plants and fungi that caused psychotropic effects was a dangerous business, but this trial-and-error process is likely what created the shaman culture characteristic of early human civilization.11 This is admittedly a controversial idea, but it is less implausible than it might seem at first: there is a wealth of evidence connecting humans, mind-altering chemicals, and spirituality. It is also undeniable that some of the first plants associated with spirituality are today the source of some of our largest societal drug problems. Consider the work of evolutionary biologist Robert Dudley, who, as I mentioned in Chapter 3, suggested that our use and abuse of alcohol may date all the way back to our primate ancestors who were attracted to the showy flowers and sweet smells of ripe, calorie-rich fruits. The high sugar concentration of ripe fruit, however, also attracts colonies of microbes, which lead to fermentation. Dudley argues that foraging for these ripe, sugar- (and energy-) rich fruits was selected for, and so exposed primates to alcohol, the natural end product of sugar fermentation. This led to the evolution of enzymes to metabolize alcohol, selective foraging for and consumption of ripe fruit, and exposure to mind-altering natural chemistry. While finding ripe fruit was rewarded with reproductive success in these primates—such fruits, after all, were relatively rare prizes—in

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contemporary human culture where sugar and alcohol are readily available, overindulgence in high-sugar ripe fruit and their alcohol fermentation product has led to epidemic obesity, diabetes, and alcohol addiction and alcoholism. The mind-altering euphoria associated with alcohol consumption has also long been associated with religious rituals, and evidence of alcohol beverages is commonly found in Paleolithic burial sites. Dudley hypothesizes that this behavior has also been selected for, laying the underpinnings of both religious rituals and addictive behavior. Others dismiss these evolutionary connections, arguing that primates and humans are attracted to consuming anything with mind-altering properties. Nonetheless, the association between alcohol, spiritual events, and spirituality is well documented as being at least five thousand years old, and became a common bridge across cultural boundaries.12 Similarly, the natural stimulant ephedra, selected for and produced in plants to affect the nervous systems of herbivores, has also been found in Neanderthal graves dating to sixty thousand years ago, in present-day Iraq. This stimulant is especially present in opium poppies, which were among the first domesticated and cultivated psychogenic plants eight thousand years ago. We know from graves dating back to that era that its cultivation spread from the Fertile Crescent to northwestern Europe during the sixth millennium BCE. Cannabis too has a long history dating back to the prehistoric and Paleolithic eras, when it was associated with spiritual ceremonies, rituals, and burial sites. These plants all have natural products with two things in common: first, they originated by natural selection as chemical defenses against being eaten, and second, if taken by humans in proper dosages, they interact with the chemistry of the brain to produce altered states of consciousness, ranging from mental and physical stimulation to euphoria and hallucinations. While it is not entirely clear if early humans were using these plants’ chemistries for their own benefits or if these plants were manipulating human behavior to act as agents of dispersal—or both—today’s widespread addiction problems are strong evidence that the masters in this plant-human symbiosis are often plants.13 But perhaps the star of this natural history of religion and plants is the Amanita muscaria mushroom.

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More Mushrooms and Myths We first met the Amanita muscaria, or fly agaric, in our discussion of the Rig Veda. Amanita muscaria is a common, widely distributed, large, red-capped mushroom with white polka dots, the one that has become famous in cartoons and popular culture—from the Mario videogame universe to the hookah-smoking caterpillar in Lewis Carroll’s Alice in Wonderland, which perches on an Amanita. Lethal if eaten raw, it can be processed, as explained in the Rig Veda, to retain its psychotropic effects while being rendered nonlethal. Potions made from the Amanita muscaria were also used beyond Hinduism; in indigenous Siberian cultures, for example, it was used to communicate with higher spirits, and the traditional winter solstice celebration featured a shaman dressed in a red costume to mimic the mushroom caps’ color, passing out the mushroom potion to others (some believe this red-clothed figure who gives gifts was the inspiration for Santa Claus).14 One of the most creative and fascinating theories involving the Amanita muscaria was presented by John Marco Allegro in his 1970 book The Sacred Mushroom and the Cross.15 In this much-maligned work that only now has begun to be reevaluated, Allegro, an Oxford trained and credentialed scholar, argues that Christianity is rooted in mythology deeply tied to visions produced by the mushroom. Hypothesizing that Christianity was originally an entheogenic mushroom cult, he argues for a reinterpretation of the Christian Bible’s New Testament as a mythology of the mushroom, rather than of Christ, based on early Christian art and word origins. Allegro points to early medieval Christian art frescos and mosaics that clearly depict Amanita muscaria, such as images of the tree of life and the tree of knowledge in the Garden of Eden as a tree of mushrooms, or of Eve offering Adam a mushroom (Figure 8.1). Even if Allegro is not entirely correct, the connections are hard to deny, backed as they are by similar cases across the world, like primitive cave drawings in Africa and Europe (made between 7000 and 10,000 BCE) that show a shaman dancing with and around mushrooms (Figure 8.2). Meanwhile, in North America, Psilocybe mushrooms have historically been used in religious rituals by indigenous peoples from

8.1. This twelfth-century fresco from St. Mary’s Cathedral in St. Michael’s Church in Hildesheim, Germany, depicts Adam and Eve in the garden of Eden, where they are picking mushrooms from the Tree of Life—against an Amanita muscaria mushroom background. © Azoor Photo/Alamy Stock Photo.

8.2. African cave drawing (circa 7000 BCE) of a mushroom-capped shaman administering mushrooms to dancing celebrants. Redrawn based on an ancient public domain image.

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the Maya and Aztecs to the Meso-Americans. When the Spanish Christians arrived, not only did they ban these rituals; they also destroyed most of the texts and written history of the rich, advanced Maya culture. Maya innovations included an accurate calendar; knowledge of the stars and planets advanced enough to predict eclipses; domesticated corn, beans, and squash; vulcanized (hardened) rubber three thousand years before its discovery by Western cultures; and a sophisticated language and writing system. It took scholars more than three centuries to decipher the ancient Mayan written language and begin reconstructing Maya culture from the few texts that hadn’t been destroyed and the stone monuments that recorded the achievements of Maya rulers. What were the Spanish conquistadors afraid of? Why had they eradicated an entire culture? Given the use of mushrooms in Maya spirituality—Maya statues shaped like mushrooms have been found in caves—could this be another instance of the church suppressing, rather than explaining, a past that could threaten its own foundations?16 During the early twentieth century, an unlikely iconoclast traveled and wrote extensively about the history and role of Psilocybe mushrooms and other natural psychotropics used for spiritual purposes (Figure 8.3). A successful American businessman and amateur anthropologist, Gordon Wasson wrote about species such as Lophophora williamsii, the peyote cactus of North American southwest deserts, which has been used by local people for over four thousand years.17 Wasson’s work attracted considerable public and academic attention, but, like Graves’s compelling work in the nineteenth century, it was considered heretical and was largely forgotten. A more recent, but still extreme, interpretation of the role played by entheogens in human evolution is articulated by the ethnobotanist Terence McKenna in his 1992 Food of the Gods. McKenna interprets the relationship between hominids and the plants and mushrooms they eat as a coevolved symbiosis that began with experimental diets and led to altered states of consciousness. According to this theory, it was the discovery and use of psychotropics that increased the reproductive fitness of hominids by accelerating and enabling the development of creativity, art, speech, and religion. Reciprocally, the plant sources of the mind-altering compounds were valued and protected from other consumers while being simultaneously spread by humans.

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8.3. Mayan mushroom-head statues. These artifacts, along with other documentation of Maya spiritual beliefs, were almost entirely eradicated from history by Roman Catholic Spanish conquerors. Original drawing based on a public domain photograph by Richard Rose.

As humans developed, they lost the conscious connection between religious mythologies and plants. When chemistry emerged as a discipline and when humans began to understand the pervasive power of natural selection, they were able to slowly rectify this hidden connection. Alongside returning to the otherwise ignored work of the occasional eccentrics, science has begun to take more seriously the idea that religion has its foundations in entheogens and to rethink the “coincidences” that place such plants alongside so many ancient religion origins. Religion and spirituality are thus the latest arenas opened to the explanatory power of cooperative evolution: we saw how religion became a tool of power and domination, but here, we see how our religious experiences may have themselves been created by our intimate relationship with mind-altering plants, a theory that has been subject to its share of scientific studies.

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One such study is the Marsh Chapel experiment performed by Walter Pahnke in 1962. Pahnke, then a graduate student at Harvard, wrote his dissertation on the link between entheogenic drugs and spirituality. In his experiment, he divided a Harvard Divinity School class randomly into control and experimental groups. He then blindly administered psilocybin, a compound derived from the Psilocybe mushroom, to ten students and a placebo to the other ten. After waiting to let the drug and placebo have their effects, all of the students listened to a sermon in the Marsh Chapel at Boston University. The results were dramatic: all of the students who were given psilocybin described intense religious experiences, while only a couple of the students who were given the placebo expressed noteworthy experiences. These feelings remained strong during a reexamination fourteen months later. Moreover, when the experiment was replicated by other research groups, similar and even stronger results were found. As science enters more deeply into this realm, it seems more and more likely that psychotropic drugs enhance, intensify, and perhaps even create spiritual or religious experiences.18 We still have more to answer, and science continues to chip away at areas and realms that some have argued are beyond its purview. To answer a question like “Where did we come from?” or “What is life?” we can now offer explanations that take into account the age of the planet and everything in it. We are more able to realize today that we are a minuscule speck in the universe rather than its center, and that humans share 96 percent of their DNA with apes—and 80 percent with rats—rather than simply strutting about believing we are a unique and separate creation. Science continues to reveal and explain both our present and our past with data, while religious mythology is based not on data and evidence, but on beliefs. As science solves more and more human problems and explains more about human lives than religious mythology can, our society is becoming more secular and less dependent on belief systems that haven’t come up with the goods. As we learn more about who we are, we may need to confront certain truths that we may at first find uncomfortable. And one of those may very well be that God does not exist—or if he or she does, it is as a plant that, starting very long ago, diffused its psychotropic chemicals into the human brain in a cooperative, coevolved dance that benefited both organisms.

chapter nine

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he role of mushrooms and entheogens in human spirituality, cooperation, and cognition is only one example of how humans have evolved alongside plants and animals in ways that in turn affected human evolution and civilization. The feedback loops between our environments and our evolution have fed us, grown our cities, and founded our religions, while at the same time making us more vulnerable to disease and famine: in particular, microbes have attacked our common resources, and they have assaulted our bodies. Humans have eradicated and controlled our macroscopic enemies—the lions and tigers and bears—yet every day we are still battling our invisible, microscopic, microbial enemies. We have fought these enemies by recognizing, first through trial and error, the defensive solutions that other organisms have developed against microbes. Evolution is, as we have seen, an arms race: for every new threat, a defense is mounted, whether within an organism or through its cooperative partners, or by the organism exerting control over its attacker. One of the unique aspects of human natural history has been the evolved ability to seize, control, and harness our environments consciously. For instance, inadvertent 170

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discoveries and mutualisms marched us toward the development of agriculture, but also toward food preservation and medicines. Salts and spices preserved food, allowing us to survive harsh winters and drought years and enabling global exploration, while the chemical wars between plants, fungi, and their enemies led to the innovation of new, life-saving drugs. In this chapter, I explain more fully the positive and beneficial aspects of conscious cooperation by taking note of the ways in which humans have made use of their relationships with the world around them. While humans, like other species, benefited from cooperative relationships within our environment through the non-teleological motor of evolution, even in the case of medicinal plants, civilization brought about and continues to make necessary a mindful return to the world in which we are, while a dominant species, still simply one among many. The story of how humans preserved food in order to survive harsh winters and poor crop years, as well as to facilitate the exploration of the unknown, is one that shows a species learning to equip itself more creatively by making use of nearby organisms and materials. Both ethnobotany and pharmacology emerged from the various discoveries surrounding the preservative benefits of spices, discoveries that utilized hundreds of millions of years of coevolved plant defensive chemistry for human well-being. (Similarly, technologies like refrigeration dramatically changed how we store and transport food.) Few of us recognize trips to the drugstore as vestigial byproducts of humans’ exploitation of plant defenses for human health. We have short memories when it comes to our own natural history. At the same time, our natural history of food-preservation technologies included both failure and success: even the earliest forms of keeping and storing perishable food had their risks. To properly preserve food, humans had to battle the many microbes that competed with us for harvested plant and animal resources. Just as they have in the history of disease, microbes have had their share of victories and countermeasures, as we will soon see. In seventeenth-century New England and Europe, many people in agrarian communities were accused of witchcraft, tried, convicted, and executed. The most famous were the twenty “witches” in Salem, Massachusetts (Figure 9.1) who were accused of “bewitching” young women and girls, causing them to have fits and other

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9.1. Trials of people accused of witchcraft by young women and girls in colonial Salem, Massachusetts, during the late seventeenth century. Nineteen of the defendants were found guilty and hanged; one was crushed to death. Unusual behaviors leading to these trials and similar events in Europe may have been caused by exposure to a hallucinogenic fungus in the grains tended by the young women. Photograph published in William A. Crafts, Pioneers in the Settlement of America: From Florida in 1510 to California in 1849 (Boston: Samuel Walker, 1876), Wikimedia Commons.

erratic behavior. Traditionally, these horrific events were explained as a consequence of the stifling religious culture of the era colliding with rebellious teenage behavior in a social context rich with gender and ethnic prejudice. In 1976, however, Rensselaer Polytechnic Institute professor Linnda Caporael, then a graduate student, complicated this view by proposing a biological reason for the erratic behavior of the accusers in the Salem witch trials: fungal infection. Caporael had noted that these witchcraft trials occurred in areas of Europe and America with damp temperate climates that hosted ergot fungal infections, which appeared as black spots on individual grain seeds or solid black spikes protruding from grain seed pods. In the Middle Ages, the consumption of ergot-contaminated rye bread

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caused epidemics of St. Anthony’s Fire, so named because of the burning sensation it caused, that killed thousands. Ergot fungus produces alkaloids and lysergic acid—the precursor to the hallucinogenic recreational drug of the 1970s, LSD—ostensibly as chemical defenses against microbes and herbivores.1 Caporael showed that the young women who were accused of witchcraft were also charged with caring for the stored grains. The job of the young women who tended grain stores was to keep the grain dry to prevent rotting, which they did by raking and shoveling the grains to root out dampness. If they were successful, this meant hours of exposure every week to the inhalation of dried aerosol grains and ergot fungus. Fungal and microbial infections of grains were later controlled and limited by soaking grain in salt brine before drying for storage, a technological advance that effectively ended the witchcraft crisis. Ergot’s potency was already known in other contexts. In the Middle Ages some of its pharmaceutical properties had been recognized and used by midwives to induce labor during difficult pregnancies, as well as to cause spontaneous abortions of unwanted pregnancies. In the early twentieth century, ergot was studied in an effort to identify and isolate useful biologically active chemicals for medical treatments, making it one of the first natural chemical products mined by pharmaceutical companies. In other words, the very chemicals that produced “witch-like” behaviors in the young women were eventually seen as possible therapies. LSD was isolated and synthesized in Basil, Switzerland, in 1938 by Albert Hofmann while he was making isomer variants of lysergic acid from ergotamine for use as a medicinal respiratory and circulatory aid. The strong psychotropic effects of the LSD 25 variant (one of the three-dimensional isomers of lysergic acid diethylamide or LSD) were discovered five years later when Hofmann inadvertently touched some LSD 25 in the laboratory and had vivid hallucinations. The witches and witchcraft trials of the Middle Ages and the seventeenth century were thus episodes in our exposure to, experimentation with, and exploitation of plants and fungi, rather than examples of mystical visits by evil spirits.2 As with ergot and LSD 25, coopting the defenses of evolutionary partners has presented humans with incalculable benefits, including

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our first pharmacies and refrigerators. They have allowed us to improve our own immune systems by adding defenses against pernicious microbes and fungi. From spices to salt to ice, the natural world has been turned by humans into an evolutionary tool chest to combat the threats around us. This coopting, however, has had its share of reciprocal effects. These may not be as theatrical as witchcraft, but they are just as dangerous.

Pirating Plants The compounds we are familiar with as spices evolved in plants as defenses to protect them from being consumed or being infected by microbial pathogens.3 Because plants can’t run away and lack immune systems, natural selection found another way to help them cope with enemies or disease: turning metabolic byproducts into defensive compounds. These byproducts are generically known as secondary compounds since they are not directly involved in the primary job of metabolism. The sophistication of these secondary compounds is stunning. They range from simple natural products that prevent disease, to very specific hormone copycats that kill or halt the development of animals that consume the plant, to highly lethal neurotoxins and poisons. A classic discovery of plant defenses came about inadvertently in the 1960s. Forest ecologists were trying to understand the life cycle of gypsy moths that, in their larval stage, can cause massive defoliation in hardwood forests like those in New England and so need to be controlled. These scientists were using standard European protocols to raise gypsy moths in their laboratories in New England, but could not understand why their larvae were failing to grow and develop normally in North American laboratories. They studied every component of the protocol, which involved growing the larvae in petri dishes on wet paper towels and feeding them their favorite leaves until they underwent their metamorphosis into moths. Surprisingly, the paper towels proved to be the problem: the initial paper towels were made from Balsam fir pulp, which produces a plant compound that mimics hormones in juvenile insects that prevent growth and development. That is, Balsam firs had developed a fake insect hormone to prevent gypsy moths from developing into

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defoliating herbivores, whereas the European trees used to make paper towels didn’t produce these defensive insect hormones. This serendipitous discovery tipped off scientists to the existence of a variety of similar compounds in other plants, such as growth and molting hormones and hormone disrupters. Mimicking critical insect hormones has proven to be a sophisticated, but common, plant defense strategy.4 Human addiction to secondary defense compounds, ranging from caffeine, alcohol, and nicotine to opioids, are rarely recognized for what they are. They are not simply human social problems, though that is what they have become. They are in fact a manifestation of the evolutionary arms race on human civilization, revealing how plants and fungi control their consumers through the use of chemical weaponry. The chemical products of evolutionary arms races can also be borrowed and shared among species. A widely recognized example comes from the indigenous people of the Amazon Basin, who use naturally produced, rapidly acting lethal defense toxins from the skin of poison dart frogs to weaponize their arrowheads. Many other mobile organisms have capitalized on plants’ chemical defenses. Monarch butterflies, for example, collect and concentrate cardiac glycosides from the milkweeds they feed on: these glycosides cause immediate heart problems for vertebrate predators while purging parasites from the butterflies.5 Like the brightly colored mushrooms or plants they eat, these mobile organisms also evolved warning colorations to advertise their dangers as they sequestered the toxins of their prey. When cognitive ability was added to the equation, our primate and human ancestors learned by trial and error that these same plants could be repurposed for their own uses. In the wild, primates like gorillas and chimpanzees regularly eat the whole leaves of toxic plants, which pass undigested through their systems but simultaneously eradicate gut parasites. Some even partially ingest the stem and leaves before pulling it back out of their mouths, as if taking medicine. These self-medication behaviors suggest that primates developed an ability to recognize the value of plants for this purpose, and ever since we have been pirating plant defenses to do things like preserve food and treat infections. In an especially bizarre case, humans and other large mammals will occasionally even ingest

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dirt. Called “geophagy,” this occurs when the individuals are experiencing low-nutrient conditions, but a recent review of dirt eating suggests that it is a response to parasitic and bacterial infections rather than nutrient limitation. Geophagy is yet another example of self-medication and inoculation, an attempt to prevent and cure infections.6 Such pirating has been happening since before civilization, and the basics were inherited, so we are born hardwired to coopt the defenses of organisms around us for our own protection. Some of these defense compounds became the spices in our kitchen cabinets and have been valuable since as early as 5000 BCE, when Egyptians used thyme as an antibacterial agent. In 3000 BCE, Mesopotamian farmers were growing garlic as a health food that warded off disease and mosquito disease vectors. Egyptians at the time coveted garlic, too, feeding their slaves onions and garlic to keep them healthy. Ancient Sumerians valued spices for food preservation— more on that later—and early Chinese medicine was almost exclusively based on herbal and spice remedies. In 408 CE, Attila the Hun demanded as ransom during his siege of Rome three thousand pounds of peppercorn, a key ingredient in medieval herbal cures for maladies as diverse as constipation and cancers. Cinnamon was more precious than gold in ancient Egypt and, alongside cumin, anise, and other spices, was used to mummify the dead by limiting flesh’s microbial decay. In the Middle Ages, spices were valued as exotic commodities from faraway lands, eventually stimulating the globalization of trade and exploration—as well as wars for control of distant spiceproducing lands and, eventually, European empires. The spice trade dates to 4500 BCE, involving routes in countries like Ethiopia, India, and the Mediterranean. The driver of the global spice trade in medieval Europe was the desire to add flavor to bland foods. These new additives became popular with European and Persian nobility; demand for these luxury items then grew quickly and led to new exploration, trade networks, merchants, taxes, and wars. In time, spices were found across all sectors of society as peasants used them to preserve meats and nobility used them to show off their wealth. But alongside their food benefits, spices were providing medical benefits that were only partially understood.

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By the mid-thirteenth century, Venice had gained control of the spice trade in Europe and had become enormously wealthy, charging large spice tariffs that eventually became so high that spices were a luxury even the nobility could barely afford. These exorbitant prices triggered the European age of exploration and discovery as nations sought alternate sea routes to avoid the Silk Road highways and their Venetian and Mongol taxation gauntlets. By the Renaissance, the spice trade was the internet boom of the era, the world’s largest industry, and collateral discoveries like the New World were opening paths to globalization as well as new technologies. By the fifteenth and sixteenth centuries, the spice trade had transformed the globe geopolitically, economically, and culturally. The age of spices, however, had an expiration date: as humans learned how to transplant them, spices became commonplace. Once-luxurious spices like pepper and cinnamon, which had been as expensive as precious metals and stones, dropped precipitously in value to become the daily flavorings we know today. But the impact of the spice trade on history remains. No longer was the Mediterranean Sea the dominant trade center of the world now that oceans had been conquered, and the great cities of antiquity—Venice, Rome, Carthage, Alexandria, and Istanbul—faded into history as tourist destinations.

The First Pharmacies Spices were our earliest medicines, and their use in this way led to some of the first empirical sciences, particularly Egyptian and Indian medicine. Human use of plants for medical purposes, though, stretches back through the millennia, predating even the evolution of the human species itself. We, like other animals, evolved alongside plants, incorporating their compounds into our diets. For example, Paleolithic hunter-gatherers used plants to purge their systems of parasites, just as modern primates do. Moreover, a group of Neanderthal fossils was recently discovered that included an individual with a badly abscessed tooth. Paleontologists were able to reconstruct the diets of these human ancestors from chemical residues on their teeth, and they discovered that the individual with the abscessed tooth had a different diet from that of the others: it was

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eating plants that contained natural aspirin and antibiotics, that is, it was already self-medicating. As humans evolved, our diets diversified to include a variety of local plants, studying and developing a conscious natural history with our surroundings as proto-drugstores.7 This was especially true in tropical habitats, where primates and humans have a more vital need for the defenses that plants offer. Microbial growth rates are temperature-dependent and enhanced by high humidity, so their threats are more pronounced and common in moist, warm, tropical environments. Jennifer Billing and Paul Sherman at Cornell University examined the differing kinds, uses, and quantities of spices among cultures by collecting 4,570 recipes from ninety-three cookbooks representing the traditional meat-based cuisines of thirty-six countries around the world. They hypothesized that if spices were used to improve human health, they would be found in higher quantities in the recipes from warmer climates, where unrefrigerated foods would spoil more quickly. They also hypothesized that meats would be spiced more heavily than vegetables, and that the cooking process used would not destroy the potency of the added spices. Their data supported all of their hypotheses and they found that virtually all widely used spices have strong to medium antibacterial or antifungal effects, with allspice, garlic, onions, and oregano being the most effective. In India, recipes include an average of 9.3 spices per recipe from 25 available spices, while Norwegian recipes feature an average of 1.6 spices from a possible 10. Similarly, in Hungary’s temperate climate, recipes used an average of 3 spices from a possible 21. The study also found that spice application was recommended during or after cooking, which maximized the spices’ medicinal efficacy, and that vegetables received less attention than meat (vegetables are less prone to infections that can be passed along when eaten). While we consciously apply spices to enhance the taste and palatability of our food, studies like Billing and Sherman’s show a coevolved effect: spices help keep food free of dangerous microbes, and can have medicinal properties, all of which increase the health, longevity, and reproductive success of those who find the flavors enjoyable (Figure 9.2).8 Spice application is in many ways a perfect example of not only the ongoing evolutionary arms races that predate humanity, but

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9.2. Most spices are potent inhibitors of bacterial growth. They are used more in meat-based recipes than vegetable-based dishes and are applied more heavily in tropical than temperate latitudes, which is consistent with their role in inhibiting food-borne bacterial infections. Original drawing based on Sherman and Billing, “Darwinian Gastronomy,” fig. 4.

also how we have used human creativity to improve our standing in the busy ecological landscape we share with other organisms. Our evolutionary inheritance of big brains and complex thought has enabled us to utilize the chemicals already around us, such as the cinnamon, cloves, and mustard that all have extremely strong antibacterial properties, or the similar antibiotic defenses of allspice, bay leaves, caraway, coriander, cumin, oregano, rosemary, sage, and others. Microbes such as salmonella, E. coli, staphylococcus, and others that attack and rot meat can be serious public health problems, but spices in high enough concentrations protect humans from these dangerous and deadly microbes—an insight we learned first through evolution and practice, and then through creative, conscious thought. Even spices like black pepper and cayenne pepper have a role, for while they are not antibacterial on their own, they increase the effectiveness of other antibiotic

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compounds and are themselves antioxidants, inhibiting the oxidative decay of meats.9 The booming spice trade in our recent history, then, one that happened alongside pandemics and famines that devastated the global human population, can be considered humans’ first global public health project. Over time, spices and the knowledge we gained from using them led to the beginnings of today’s pharmaceutical industry, as evolutionary biologists and natural product chemists zeroed in on plants from tropical habitats, like rainforests and coral reefs, that could offer new chemical treatments for disease. Just as the 1850s California gold rush led miners to dig for gold, chemists have been prospecting tropical systems for the next drugs that can improve human well-being (and can line their pockets). Chemists today are focusing increasingly on endophytes, which are somewhat mysterious compounds in plants that appear to help them cope with infectious disease, pathogen problems, and tumors. We have also located in our own microbial fauna possibly important medical applications: by studying and further developing probiotics, we are learning ever more about natural selection and the rapid evolutionary response of our own mutualistic microbes to fight the diseases our immune systems have not been able to overcome, even with the help of vaccines.10 The stakes for contemporary research into new medicines are high, because, as mentioned earlier, antibiotic medicines have become dramatically overused and have spawned drug-resistant strains of bacterial infections that could have catastrophic consequences. According to the Centers for Disease Control and Prevention, each year in the United States at least two million people become infected with bacteria that are resistant to antibiotics and at least twenty-three thousand people die as a direct result of these infections. New discoveries related to plant compounds can aid in this battle—and in others, since there is some hope that plants may have evolved cures for the recent epidemic of cancers.11 Overtreatment also works against current evolutionary biology, which suggests that good health lies not in disease prevention—the usual aim of hygiene, antibiotics, and vaccines—but in disease control, which could encourage a decrease in the virulence of pathogens. In practical terms this might mean isolating severely infected

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patients to keep them from passing the most virulent genes to new victims. This approach could potentially eradicate lethal diseases by evolutionarily favoring the reproduction and success of less virulent pathogens. The strategy would be inexpensive relative to antibiotic and vaccine production and distribution and thus especially practical for low-income countries. It involves evolutionarily outsmarting pathogens rather than playing along with their escalating arms race game.12 This is, admittedly, a counterintuitive approach to treating human health and disease, termed “Darwinian medicine,” and in spite of its promise, it is not taught in most medical schools because it contradicts millennia of medical dogma. (It may not surprise the reader to learn that science, like religion, has its own dogmas and institutions that deserve to be challenged.) Outside of Darwinian medicine, however, the possibilities for creating new medicines are further limited by the destruction of our tropical resources, whose biodiversity is under siege. We will explore the human-caused effects on the environment more in Chapter 11, but tropical deforestation has accelerated by nearly 10 percent since the twenty-first century began and is estimated to be destroying eighty thousand acres of rainforest a day, with a collateral loss of 135 plant, animal, and insect species a day, some fifty thousand species every year. Coral reefs, too, are being lost at an alarming rate because of development, global warming, ocean acidification, eutrophication, and disease. Indo-Pacific coral reefs are shrinking 1 percent each year, a loss equivalent to nearly six hundred square miles annually, which makes the rate of reef loss about double that for tropical rainforests. We are destroying some of the most diverse habitats and environments on the planet, and with them some of the most valuable resources we have for improving human health—a treasure trove of hundreds of millions of years of evolved chemical defenses.13

The First Refrigerators While spices have been crucial for protecting our immune systems against harmful fungi and microbes, and for leading to effective medicines, they have been just as important in making possible our ability to store and preserve food. As early humans settled into farming and populations grew, they faced the same bottlenecks that

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threaten all rapidly growing populations: resource limitations that increase the chances of famine and disease. This was a new problem facing our ancestors and it inspired them to look for new ways to store food through winters and through years of low production. Drying, smoking, freezing, pickling, curing, and spicing became vital skills, and these food preservation technologies worked in conjunction with early medicinal practices, promoting human health while also further catalyzing the feedback loop of population growth. Food preservation was additionally a prerequisite for long-distance exploration across land and sea. Without provisions, long expeditions were impractical and too dangerous. Preservation technologies made possible the Silk Road, the expansive, nomadic Mongol Empire, and the Roman Empire and its offshoots, as well as trade and colonization across the Atlantic and Pacific. Humans in the Middle East first preserved meats and grains through sun-drying, a method that predated agricultural revolutions. Paleolithic hunter-gatherers also smoked meat and fish, a tactic still used by native Inuit in the Canadian Arctic and Alaska. Lye was an effective preservation technique, too, but the meat and fish stored in it acquired a specific taste that some—like my Norwegian relatives who eat lutefisk, lye cured sardines, and anchovies on holidays— might call “foul.” Garum is another example: a similar traditional Roman and Greek concoction made from fish blood and intestines, garum was a nutritious sauce made by sun-curing the salted fish guts and letting the results sit for a month, fermenting and liquefying. All of these preservatives were important in their own right, and all left their marks on human development. These technologies were the first that humans devised to keep food from spoiling across days or even months. Yet the most successful food preservation technique, and one of the most influential resources on the planet, sits in a little shaker on our tables.

The Story of Salt Since life originated in the sea, all animals have been dependent on the properties of seawater as a proxy for the primordial soup that gave birth to and nurtured life on earth. Land animals effectively internalized this dependency, bathing cells and organs in a saline

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solution. Sodium is vital for cellular functioning and regulating cellular metabolism, a physiological need that we see play out in the natural world: when an herbivore’s plant diet is too low in salt, it seeks out a salt lick to make up for the deficiency.14 Despite the current human obsession with low-salt diets, our species is no different.15 Salt today, however, is so overused that we have forgotten its natural history and how essential it is and has been for our survival. We can still see vestiges of its importance in recipes from around the world: the salted cod used in Portuguese dishes recalls the oceanic exploration and control of the seas that augmented a tiny country’s growth into a world power, and holiday ham is reminiscent of earlier days, when the invention of salted pork enabled one of the first domesticated animals to be consumed long after butchering. The history of salt reveals a running human obsession with this now most humble of minerals: wealthy towns developed where salt was abundant, access to salt drove innovations (like the inadvertent discovery of fossil fuels, as we will see later), and salt was a powerful resource taxed and controlled by governments. Natural salt deposits occurred in seasonally evaporated bodies of saltwater and could be produced locally by creating saltwater evaporation pools. Salt can also be found in geological formations as rock salt, the remnants of ancient seas or subterranean salt brine pools. Throughout Eurasia, Africa, and the Americas, human civilization developed around these rich salt resources, with ancient human salt mining starting before 5000 BCE. The first large-scale salt production facilities developed in China around 1000 BCE. The Chinese aristocracy controlled the price of salt through a monopoly and used the profits from sales of salt to both support their army against civil war and protect export routes in the north from their aggressive Mongol neighbors. This importance is reflected in the traditional Chinese symbol for salt, which was used as a tax stamp. But despite the rich natural resources in the Szechuan region, there were no surface salt deposits. Instead, the Chinese discovered subterranean brine pools and began digging wells to extract the brine and evaporate it away, leaving the salt in shallow brine pans. These wells were first dug by hand, but workers became sick and died from the flammable fumes

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emanating from them, which would also occasionally ignite and blow up the wells, burning for weeks afterward. The mysterious fumes turned out to be natural gas, and this inadvertent discovery led to some of the most amazing technological innovations of the ancient world. Nearly three thousand years ago, the Chinese began percussion drilling for salt brine and for natural gas that could be used in households, and commercially, as a source of portable fire. These natural gas wells, called “fire wells,” were connected by networks of bamboo pipelines. The techniques used to harness this resource were developed a full thousand years before they were used anywhere else in the world, and ever since, natural gas has been used in China (Figure 9.3).16 In the second millennium BCE, Egyptians exported salt and saltdried fish across the Mediterranean through the established trade networks that were first developed by dye-trading Phoenicians. Egypt and North Africa kept secret their heavily protected Saharan salt routes, because salt was at the time said to be worth its weight in gold, and was often sold by the ounce.17 Salt had additional importance in

9.3. Chinese brine works in the second century BCE were percussion drilled to reach brine pools for salt extraction, leading to the discovery of natural gas in the same areas. Brine was then pumped to the surface and evaporated using natural gas fires. Redrawn based on a public domain illustration from Annals of Salt Law of Sichuan Province.

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Egypt, since it was one of the critical ingredients used to properly preserve a body for the afterlife. After a body’s internal organs were removed, salts, resins, and spices were used to mummify the body— and lower-status Egyptians would often use only salt for this purpose. The use of both spices and salt in this process may have led to the first use of spices to preserve food, as Egyptians noticed that spices delayed spoilage much as salt did. Salt production was additionally important for the Roman Empire. Ostia, the long-lived port of Rome on the Tyrrhenian Sea that dates to the fourth century BCE, was near local salt marshes already used for salt production and proved to be essential for trafficking salt across the empire. The Roman Empire controlled the price of salt, an early example of the European salt tax where salt taxes and overcharges were used to raise money for wars and civic projects. Caravans with as many as forty thousand camels would travel hundreds of miles into the Sahara to harvest and transport salt from ancient evaporated seas to inland European markets. Many of the first towns in Europe sprang up precisely because of their proximity to salt resources. The early Celts dominated the European continent in the late Bronze and early Iron ages, growing wealthy by trading salt to the Greeks. The town of Hallstatt—literally, “piece of salt”—owes its name to this cultural power. The Celts developed salt mines between the eighth and sixth centuries BCE, digging mineshafts down into salt springs that had been frequented by Paleolithic hunter-gatherers. Mines were initially dug by hand, then with tools from new iron technologies, and although they were initially 2.8 miles (4.5 km) long and 919 feet (280 m) deep, in the Middle Ages they stretched to nearly 50 miles (80 km) long.18 In the sixteenth century, wet salt mining was innovated in the Hallstatt mines: water was diverted into the wells, dissolving salt to brine that was then pumped out and evaporated in pans. This technique revolutionized salt mining and increased the region’s wealth. Across Europe we see the remnants of this salt wealth in towns like Salzburg (salt city) and Hallein (salt work), both of which lie on the Salzach, or Saltwater, River. In Britain, several towns are suffixed with “wich,” also denoting salt production. Not surprisingly, such a valuable resource caused numerous wars over its access, such as when Venice fought with Genoa to dominate the salt trade in ancient Rome. In the fourteenth century,

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the French enacted a hated salt tax called the gabelle that was in effect until 1790 and was one of the major motivations for the French Revolution. Salt taxes also played a role in the American Revolution, as British Loyalists intercepted American salt shipments to interfere with America’s ability to preserve food over the winter. And protests against English salt taxes stimulated India’s independence movement: in the 1920s, increasing salt taxes on already impoverished Indian subjects led to Mahatma Gandhi’s peaceful protests, especially the March to the Arabian Sea in 1930. This march and the continuing peaceful protests against the salt tax led to the establishment of Gandhi as an international symbol of peaceful protest, justice, and the twentieth century’s equal rights movement.19 Salt’s prominence in human history cannot be overstated, and until recently it was considered a symbol of power and wealth. Salt has been a currency in many ancient cultures, from China to Rome, and its value as a preservative is threaded through the history of human civilization. It has been a monetary unit, a resource of state power, and a tool of war—all because of our evolutionary needs for stronger defenses against pernicious microbes and fungi. After civilization increased our populations and condensed our living arrangements, we had to defend not only our bodies against these threats, but also our stored food. Spices, and salt in particular, were the result of years of natural history knowledge and coevolution with the plants and other organic material around us.

Frozen While salt’s replacement, the icebox, was not invented until the nineteenth century, the use of ice for food storage has a longer history. Ice was shipped and stored across warm climates to preserve food and other perishables from as early as the seventeenth century BCE in Mesopotamia. Ancient icehouses in the Fertile Crescent were thick walled, dome-shaped clay structures partially buried underground and insulated with straw. Ice was harvested in the mountains and transported by boats in the winter (Figure 9.4). In the tenth century BCE, underground pits were used as ice cellars to keep ice and store perishables until the spring and summer.

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9.4. An ancient Iran icehouse or yakhchaˉl, thought to be more than two thousand years old. These structures stored ice that had been transported from mountains during the winter, with the goal of preserving perishable food during the warm summer months. © Artography/Shutterstock.

These icehouses were only for the rich even well into the seventeenth century—for example, George Washington and Thomas Jefferson both had insulated icehouses in their basements.20 In the United States, the commercial ice business began in the late eighteenth century in New England, with the goal of shipping ice to rich Caribbean plantation owners. Home icebox use and home delivery of ice began in Boston shortly thereafter. Ice was harvested during the winter in the northern lakes and transported and stored in insulated icehouses in large cities across the United States.21 At first it was harvested by hand, with blocks of ice cut with saws; then horse-drawn ice cutters were used. Home delivery was made by horse-drawn carriages and perishable products were transported south to warmer climates in insulated ships and railroad cars. By the 1850s, nearly 100,000 tons of ice a year were being delivered to home iceboxes.

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In the nineteenth century, an attempt to refresh oyster beds in the overharvested Puget Sound led to Atlantic coast oysters being sent across the country in iced boxcars.22 This effort failed, but it paved the way for the introduction of the electric refrigerator in the early twentieth century, and the concomitant rapid decline in the everyday use of ice and salt. It was the oyster industry that developed electric refrigeration, in order to successfully transplant Japanese oysters to the U.S. Pacific coast. This dramatic technological advance came, as has happened so frequently in human history, with unintended consequences, among which has been the spread of invasive species and the global homogenization of species. Oyster introductions became a major conduit for the introduction of other, hitchhiking Asian marine species to the North American Pacific coast and then across the world. As a result, rapidly growing and reproducing species from around the globe have spread to dominate heavily trafficked habitats. Shallow waters in San Francisco Bay, Tokyo, and Boston, to take just a few examples, share many of these organisms, as a longterm signature of this “species roulette.” We do not understand all of the consequences of these introductions, and the human cost of replacing coevolved native communities with anthropogenic communities of weeds is largely unknown—but we know this process is one we may only slow, not stop. The unintended consequences of our innovations, all of which come from the extreme population growth of civilization and the maneuvers and techniques we have needed to keep pace with our expansion as a species, are not small, localized issues. They are true problems that threaten the survival of our species alongside many others.23

chapter ten

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hroughout the history of life on the planet— evolution and its adaptations; cooperation and competition; the varied and intricate plots of survival, dominance, and extinction across species and habitats—one simple truth has remained: all self-replicating organisms seek enough energy to grow and successfully reproduce so they can pass along their genes to the next generation. The evolution of this currency and economy based on energy was an unimaginably long process that showcases the battle between conflict and cooperation. Life began when replicating molecules captured the metabolic processes that had developed over millennia in the primordial soup. This was followed by the tapping of solar energy and the evolution of microbial symbiogenesis to form eukaryotic cells and organisms that, through self-organization and cooperation, formed trophic groups, food webs, recursive elemental and energy cycles, and complex multicellular plants and animals. Over the billions of years that these changes occurred, the earth accumulated vast quantities of living and fossil solar-energy reserves that have almost exclusively powered the engines of life on earth ever since. Like nearly all other organisms on earth, humans depend on solar power, transmitted through food chains, to run their metabolic processes. Unlike other organisms, however, humans have 189

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also developed energy-dependent technologies, from hardening spear points to splitting atoms. Our species first harnessed energy through the control of fire, which turned medium-sized primates who were the prey of large carnivores into top predators and top energy consumers. Fire expanded human dispersal into colder climates; protected early humans from predators, insects, and disease; and improved tool making. Control of fire is one of the most powerful human dependencies, and humans’ reliance on fire has led to boom and bust cycles of innovation, resource exploitation, and resource depletion as we discovered new and increasingly efficient resources for fire production. The evolution of civilization, then, both led to and depended on an evolving connection with energy resources, which, through our overuse, has strained the cooperative relationships between humans and the rest of the world. Energy sources have shaped not only human history, but also the geological landscape of the entire planet, privileging our species over others, and even certain subsets of our species over the rest. How we produce, treat, and use these energy resources are among the most important questions facing humans today.

Burning the Forests Wood was the first resource tapped for heat and light by our newly ground-bound hominid ancestors around two million years ago. But wood has limitations. Because fresh wood is more than 60 percent water, it won’t burn easily unless dried first, so early hunter-gatherers collected dried wood for fires and learned to dry or season wood that was not yet ready. And wood fires burn at relatively low temperatures and give off smoke, due to their water content. Among other things, this means that wood fires do not burn hot enough to melt metals from ore or melt sand into glass. The likely inadvertent discovery of these technologies, however, when extra-dry wood on the edges of hearth fires became hot enough to melt ores or sand, led to the development of charcoal. Evidence of initial charcoal use can be seen in 30,000-year-old charcoal cave drawings, and its widespread use as fuel for copper smelting began around five thousand years ago. Charcoal production

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is an ancient industry, arguably the first human industry, and it required precision burning pits with carefully controlled, slowburning, oxygen-starved fires to dehydrate and evaporate volatile compounds from wood without burning it. Early charcoal production pits were large, about three yards (2.7 m) square, and about two yards (1.8 m) deep. Chopped wood was stacked densely in the pit and lit with burning embers before it was covered with sod to limit burning. After a number of days or weeks, this left nearly pure carbon, a material that could burn hot enough to be used for such early technologies as metallurgy and glass production. Charcoal fires ushered in the Bronze and Iron ages that dramatically changed civilization through innovative metal farming plows, tool technologies, and weapon building. Charcoal was thus crucial both to the early growth of civilization and to the increasing complexity of weaponry.1 Because of its importance and accessibility, wood was an easily overharvested resource. The low-productivity forest edges that humans were initially attracted to and successful in were quickly deforested, leading to some of our earliest habitat modifications. Plant roots and canopies limit soil evaporation and erosion, and their fallen leaves enrich the soil and lead to positive fungi and microbial interactions.2 Deforestation removed these benefits, leading to dire habitat changes like desertification and a host of other unanticipated social and environmental consequences. There is a reason that many ancient ruins are discovered in otherwise uninhabitable regions: deforestation was a natural consequence of early cities, and the removal of trees and forests made it easier for the wind to dry and remove a region’s topsoil. Deforestation increased alongside technological advances, as humans developed new powers through innovative tools like handled axes. This clearing of forests, to obtain fuel and construction materials, and to create croplands and pastures, was the most important geological event to affect natural, terrestrial ecosystems since the end of the last Ice Age fifteen thousand years ago. Beginning around 3000 BCE, increasing population pressures and urbanization brought dramatic changes in forest vegetation, as well as organisms dependent on forested landscapes. Archaeological and paleoecological records document this history of human deforestation. Paleoecological research—which is research based on reading long-lived

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pollen in anoxic lake sediments—reveals significant deforestation by 1000 BCE, which is long before the date many had predicted. As civilization spread over the next five hundred years, its focus on development accelerated deforestation and desertification throughout vulnerable areas of Europe and particularly in the Middle East.3 In Europe, the Roman Empire’s expansion drove continued deforestation due to its high energy demands—the same demands, it has been argued, that precipitated the cultural, social, political, and economic instabilities that eventually led to the empire’s collapse. Though the history of such changes is not well known in China, the presence of only 14 percent of China’s original forests remaining today suggests a similarly destructive past. The major exceptions are the dense urban centers that developed in China around iron and metallurgy facilities between 910 and 1126 CE, which substituted coal for charcoal earlier than in other parts of the world. This occurred during the Sung dynasty and in 1078 CE steel production in China was approximately that of eighteenth-century western Europe, five centuries later. The more advanced Chinese technology was surely paralleled by greater deforestation and desertification.4 Wood harvesting has also had a variety of social effects and consequences. Fears of overharvesting led, for example, to a thirteenth-century ban by England’s King Edward I on cutting down trees for firewood. Poaching trees was a capital offense, punishable by death. A healthy forest was an important security concern: without it and its resources, which were particularly critical for boat building, trade and defense were compromised. Consequently forests were owned by the aristocracy and the church. Peasants were permitted to gather only fallen branches—an allowance that may have given birth to the phrase “by hook or by crook,” because they could gather any dead branch, in a tree or on the ground, as long as they did not harm live trees. This may have been one of the earliest conservation laws, and it was followed in the sixteenth and seventeenth centuries by regulations on harvesting seaweed, which was used as potash in glass making. The practice of deforestation rippled across the globe, depleting Lebanese cedars and turning isolated Pacific Islands from tropical habitats into unvegetated wastelands. Even today the effects of deforestation are noticeable

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and tragic: in contemporary deforested sub-Saharan Africa, women searching for firewood have to forage farther and farther from their tribal borders. This has exposed them to the dangers of rape, a form of domination by neighboring tribes that has become a problem of epidemic proportions.5

The First Fossil Fuel While wood and charcoal remained important through history, wood scarcity led to the discovery and use of the first fossil fuel: peat. Peat is a carbon fuel formed from the underground accumulation of wetland roots, rhizomes, and debris. In wetlands, where oxygen is depleted by microbes, the acidic chemical byproducts of plant decay buildup. Continued plant growth presses down and compacts the peat, which is also stitched together by dead plant roots. Because of its high carbon density, peat burns at a higher temperature than wood. Peat forms slowly, however, at a rate of approximately one millimeter a year, and only in cooler climates, where plant decomposition is slow enough for plant root debris to accumulate and peat to form. In European wetlands peat can be up to sixteen feet (5 m) thick, representing centuries to millennia of wetland production of this resource (a process that is also the initial stage of the kind of carbon fixation that fossilizes into coal).6 Peat was also historically used as a building material, because it is readily harvested and cut into easily handled compact blocks, and makes for good thermal insulation. Its first widespread use as fuel occurred during the Roman Empire after deforestation limited fuel supplies along the Roman road network. Peat was cut into blocks and then stacked loosely to air dry, creating a combustible, highcarbon fuel. Peat was long used as an easily harvested and produced home fuel before the Dutch began harvesting the extensive wetlands of the Wadden Sea, leading to its widespread use as fuel for industrial purposes as well.7 Through their peat-mining ventures, the Dutch became leading water management and flooding engineers. Since the Middle Ages, Holland has “reclaimed” land by constructing seawalls and groins on sedimentary shorelines to trap sediment. This created seven thousand acres of new land—Amsterdam itself is built on reclaimed

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land—and influenced similar civic projects to expand Copenhagen in Denmark and Saint Petersburg in Russia. Because of Holland’s lack of natural forests and its flooding expertise, discovering and utilizing peat resources was inevitable. By the fourteenth century, Holland had become a world commercial power, and the Dutch made use of windmill technology to add to their peat resources. But much of Holland exists at sea level, and to retain economic dominance through the sixteenth century, it overmined peat to the tune of over half a million acres. This ultimately left nearly a quarter of Holland below sea level, requiring both windmill-powered flood control systems and elaborate dikes to prevent permanent flooding and land loss. Holland’s long history of reclaiming land compounded the problem and led to development of a highly complex network of dikes and drainage systems to control flooding.8 Even into the seventeenth century, Holland maintained its dominance over parts of Europe because of its peat resources. For example, it exported peat to England, which had banned the use of industrial coal out of air pollution concerns. But consistent problems with flooding reversed this trade, causing Holland to slow its peat mining and begin importing coal. Economics trumped environment once again as both England and Holland turned to coal use, which led to London’s rise as the commercial epicenter of the world, as well as Holland’s diminished influence. Peat continued to be used in less developed countries for centuries: peat was used for heating in the colonial United States and Canada, industrial peat farming continued in Scandinavian countries and Russia into the mid-twentieth century, and peat is still in use for home heating in Iceland and Finland to this day.9 But while coal largely replaced peat during this time, it was whaling that created the first international oil business that lit the nascent Industrial Revolution in the early eighteenth century.

The Oceanic Energy Cartel Whaling dates to ancient Greece, and possibly earlier, as evidenced by primitive harpoons and art in the Middle East. Whales are mentioned in the Old Testament, and Aristotle understood that because of their lack of gills whales were mammals rather than fish

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(Figure 10.1). The first uses of whales as resources—oil for lamp fuel, baleen and ivory teeth for jewelry, and blubber for food—involved beached or stranded whales. Although these events are still not understood, we do know that they occur more frequently in certain parts of the world, and that the human populations in these parts, such as Holland, Cape Cod, and New Zealand, were the first to turn to hunting whales. By studying the coastlines, and learning from the whales that ended up on their shores, humans developed an industry. Basque fishermen hunted whales around 1000 CE in the English Channel and the Basque North Sea coast, innovating the practice of rendering whale oil and butchering whales at sea, rather than dragging them to shore for processing. These practices, and the innovation of tracking migration routes, turned whaling into a vast global enterprise.10

10.1. This engraving by Jan Saenredam from the year 1602 shows a beached whale near Beverwik, Netherlands, on the North Sea Canal. Whaling during this era was a significant driver of the economies of coastal areas. As technologies were developed to cull more whales, and whaling became a global enterprise, whale oil and other whale products helped fuel the Industrial Revolution. Rijksmuseum, Amsterdam.

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At roughly the same time, whaling commenced in the Pacific Northwest, becoming central to the indigenous Haida and Makah cultures. Historians learned much about the whaling history of these cultures when, more than fifty years ago, two seasonal Makah longhouses were discovered eroding from a seaside cliff near Lake Ozette at the northwestern tip of the continental United States. More than a thousand years earlier, a mudslide had swept over the houses without warning in the middle of the night, burying the structures, and their sleeping occupants, where they lay.11 Archaeologists from Washington State University, led by Richard Daugherty, had to develop new techniques to analyze and conserve the material at the site, because it would decay and crumble to nothing just hours after being washed from the mud. They used hoses to gently wash material from the cliff and moved the material to an ethylene glycol (or “antifreeze”) bath that would prevent oxidation. Only then were they able to study one of the most important West Coast native archaeology sites, complete with leather, cloth, and other organic relics. As a student in the 1970s, I became interested in the Ozette site, meeting and learning from some of the archaeology graduate students who were studying basket weaving, contemporary Makah culture and language, and the mud burial site. I was able to contribute my natural history understanding to their cultural puzzle solving, and I was fascinated by their ability to piece together thousandyear-old artifacts for teasing out the history of the Makah. A highlight was meeting Harold, the oldest living Makah at the time who had been on the last traditional Makah whaling trip as a young teenager around 1900. He told us about the weeklong spiritual and physical preparations, the ten-yard-long Douglas fir outrigger canoe, and the two weeks at sea that they returned from emptyhanded. Driving out to meet with Harold and visit Ozette in a maroon, split-windshield VW bus was my first experience with archaeology, and it directly influenced my life and interests. While whaling continued, and even expanded in the seventeenth and eighteenth centuries as Dutch and French fishermen chased whales to Greenland, the whaling industry did not truly begin until the early eighteenth century in New England. Towns on Cape Cod, Nantucket, and Long Island were all sites of whale and dolphin

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strandings (even in 2010, when I was working with students on a large salt marsh in the Cape Cod National Seashore on Lieutenant’s Island, we found six large, eight-foot-long dolphins who had been recently stranded during a high spring tide). For the struggling colonists in seventeenth- and eighteenth-century New England, a stranding was a godsend, especially since farming was unproductive in the area’s soils, which were a combination of sand and the eroded soils left behind by receding Ice Age glaciers. Whales offered a wealth of different, valuable resources. Their strandings were so common that towers were built to spot them and laws were passed in the seventeenth century to determine who owned the whale depending on where it landed. Eventually the colonists didn’t just wait for the whales to come ashore: spotting and directing offshore whales to desired locations (to ensure ownership) was followed by harpooning whales in shallow water and pulling them onto land. It was not long before Cape Cod whalers secured larger boats to scour the continental shelf for right whales (so named, apocryphally, because they are the “right” whales to catch, since their large blubber stores kept them afloat after being harpooned). After a few centuries of aggressive whaling, right whale populations dropped precipitously: in 2000, it was estimated that the North Atlantic right whale population numbered only three hundred individuals, low enough to deem the population ecologically extinct.12 Despite these declines, by the early nineteenth century, New England whaling had grown into the largest industry in America, employing over ten thousand men. This industry was also the first oil cartel in the world, locating its headquarters in Taunton, Massachusetts, between New Bedford, where whalers caught the whales; Boston, where merchants marketed the oil; and Providence, where merchants running rum, spice, and slaves financed the Cape Cod whaling industry. At its peak, this industry produced 6–10 million gallons of sperm oil a year and 4–5 million gallons of spermaceti, a waxy oil found in the head of sperm whales that was used to make luxury candles that burned without smoke or scent. Sperm whales were the crown jewel of the whaling industry. These whales were the most dangerous to hunt, because they were aggressive and large-toothed, and adult males average fifty feet (15 m) in length. They live in deep water off the continental shelf in order to hunt

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squid, routinely diving nearly two-thirds of a mile (1000 m) down and staying underwater for as long as two hours. Their spermaceti organ, so prized for its oil, helps them regulate buoyancy and amplify their communicative noises. Sperm whales also contain ambergris, a digestive-system waste product that was used to make perfumes. Though sperm whale numbers were heavily depleted in the nineteenth century, the dangers of hunting these whales likely prevented them from approaching extinction to the extent the right whale did. A decade after hunting sperm whales was banned, the sperm whale population was estimated at 352,000, 32 percent of its pre-whaling estimate of 1.1 million. Even after being depleted, the current population of sperm whales is estimated to consume a biomass equaling that of all human fisheries combined.13 To track these deeper ocean whales, large ships were equipped with smaller whaling boats able to stalk and kill them. These ships followed sperm whales and other large whales along their migration routes to South America and to the rich whaling grounds on both the Atlantic and Pacific coasts of South America. From South America, whalers tracked their prey up the Pacific coast and to the Hawaiian Islands during trips that lasted many months to years. Whaling facilities dotted the coasts: in 2003, I ran into a long-abandoned whaling facility while working on an isolated bit of the central Chilean coastline. The scale of the operation was staggering, with three large, long ramps to haul the massive whales onshore for processing. Steel railroad tracks lined the ramps and coal-fired steam engines were in place to pull the whales and whale parts along the facility, which also featured massive tanks the size of small houses for boiling or rendering whale blubber to oil, and large areas capable of sundrying bones, baleen, and teeth. Very little of the whales went to waste. The whaling industry fundamentally changed life in east coast American cities by lighting the night: before the eighteenth century, city streets were dark and dangerous places, but by the midnineteenth century, all the major cities from Boston to Atlanta featured streetlamps lit by whale oil, bringing safety and changing how people perceived and used the night. Whale oil illuminated the eastern seaboard of the continent for decades, until the nascent chemical industry learned how to make fuel from coal. The whal-

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ing industry also processed baleen as a luxury commodity for making Victorian era corsets and bellbottom hoop skirts, making whale baleen directly responsible for the formal look of Victorian women. As the industry was lighting civilization, influencing fashion, and creating new sources of wealth, however, it was also overhunting these large mammals. Whale populations were driven to ecological extinction in North America and Europe just as the Industrial Revolution kicked into high gear. Central to this new period in human civilization was the full transition to a new energy resource: coal. Civilization, and the world, was in for one of its largest shocks.

Digging Deeper: Coal Until seven hundred million years ago all macroscopic life on earth lived in the sea, while the land was physically harsh and barren. Fungi had colonized the land one thousand million years ago, but it wasn’t until seven hundred million years ago that plants came on the scene. This initial colonization of land by plants was facilitated by a symbiotic partnership between these photosynthetic eukaryotes (ancestral plants) and fungi. To this day, plant-fungal symbiosis remains necessary for plants to invade and persist under harsh environmental conditions.14 The fungi receive carbon products of photosynthesis from the plants, while mycorrhizal fungi enhance plants’ abilities to access nutrients.15 This ancient mutualism increased atmospheric oxygen availability, ameliorated harsh physical conditions on the land, and fueled the colonization of the land by plants and animals, all of which set the stage for an explosion of biodiversity in the Paleozoic period. Like the symbiosis among microbes that led to nucleated eukaryotic cells changing life on earth, the ancient symbiosis between proto-plants and fungi ignited a process of symbiogenesis that led to the dominance of terrestrial plants and animals, resetting the homeostatic balance of global nutrient, temperature, and atmospheric gas cycles and once again fundamentally changing life on earth. By the Carboniferous period 360 million years ago, plants had colonized the land and formed massive continental wetland forests analogous to today’s mangrove forests that cover the east coast of Indonesia. These primitive forests came to be dominated by

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lepidodendrales, long-extinct massive trees, as well as large ferns and ancestral horsetails. As the first plants on land, they faced weak competition among species and little consumer pressure, so they grew to massive sizes. The land these plants took over was lowlying and subject to fluctuating climates and sea levels that would drown these forests, depositing sea sediment on them before retreating and allowing a new forest to spring up. Repeated over and over, this process created layered deposits of fossilized plants containing over 100 million years of stored solar energy, because the soils were too waterlogged to allow for decomposition. The movement of tectonic plates over the earth’s core then squeezed and crushed these fossilized plants, resulting in different grades of coal, coal tars, and gases. While peat was the first fossil fuel mobilized by humans, it is a younger version of the material that would become coal, which takes much longer to form. Coal was also the next stage in a pattern of human fuel use: humans first used wood for fuel, until it was depleted in their local regions. They then began exploiting various forms of fossilized carbon fixed by photosynthesis, such as peat, which they found in the ground just below them. The next step was to dig even deeper below ground to use the far older material of coal. When out of energy, we seem to look below us to restock our supplies. But given that clean alternatives—water, wind, and solar energy—are found around and above us, we may have good reason to critique this pattern. Coal was initially used very sparingly and only when available; its use did not become widespread until the first coal mine charter was issued in England by King Henry III.16 Since charcoal was, at the time, known as coal, coal was called “sea coal,” given its prominence on eroding shorelines. In the United States, coal mining started in the mid-eighteenth century in Pennsylvania, where large coal deposits were discovered featuring anthracite, or jet, coal. This kind of coal is the most valuable and the purest, and it led to the first transportation system in America: a grid of shallow canals that moved coal to industrial markets. Pennsylvania became the center of the coal-fired industrial revolution in America, and soon the slower canal system was replaced with the first railroad system in the United States. By the early nineteenth century, coal was lighting

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city streets, and by the late nineteenth century, it had replaced wood as the world’s chief energy source. Coal mining and coal use have had long, contentious histories: mining for coal is dangerous not only due to mine collapses, explosions, and fires, but also because of exposure to combustible or toxic gases like carbon dioxide, carbon monoxide, and methane.17 Early miners used dogs to check air quality in mines, by lowering them into mine shafts on ropes to see if they could survive. They were soon replaced by canaries, which have faster metabolic rates and would fall off their perches if the air was bad. Mine flooding, too, was a threat, as underground rivers or water tables could be penetrated accidentally. Flooding led to the development of piston-pump-operated drains to relieve the mines of water, an innovation that would eventually lead to the revolutionary piston engine, which would displace horse-powered pumps and wagons. The dangers and disasters of coal mining served to both devalue the lives of miners and distance the working class from the wealthy coal and steel barons who viewed the miners as disposable. Coal is a dirty fuel. Early on, in the fourteenth century, it was banned in London due to perceived health risks.18 But the coal ban did not last long, since coal was a cheap, hot fuel needed by blacksmiths and brickmakers. Because deforestation had made wood difficult to obtain in large amounts, energy-intensive industries quickly came to rely on coal. Soon city dwellers were suffering from sooty smog, increased health risks, and black residue on buildings, driving the wealthy to acquire country homes as a way to avoid the polluted air. Even these obvious environmental and health hazards could not stop the economic machine that was coal use, however, which helped make nineteenth-century England simultaneously the richest, most powerful country in the world and the country with some of the dirtiest cities (Figure 10.2). Coal soot in London and Manchester ate away at the finest churches and government buildings, and clothes hung outside would become dirty from soot before they could dry. As transformative as coal was— powering iron production and home heating, leading to the first extensive railroad in the world, and energizing England’s global rise—it was as much, if not more, a curse as a blessing, further dividing workers from the wealthy and forever changing the natural

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10.2. Air pollution in late-nineteenth-century England, after the Industrial Revolution. Wood engraving by Roth, circa 1880. © INTERFOTO/Alamy Stock Photo.

history of civilization and the natural world. Coal could never be “black gold” like liquid petroleum, but if you were bad you might expect a lump of this humble material in your Christmas stocking. The health effects of coal were likewise clear: lung diseases in London caused nearly 25 percent of all deaths of children under age five, but for children of mine workers, that figure was nearly 50 percent.19 A London haberdasher named John Graunt founded demography, the subfield of statistics dealing with human population processes, while analyzing and classifying the causes of deaths of Londoners versus those outside of the large, coal-filled city. Graunt found that Londoners had shorter lives and that their deaths were more frequently due to lung and breathing complications. He also discovered that death from rickets had increased more than fivefold during his lifetime—and rickets, as we know now, is caused by a deficiency of vitamin D. Because we get most of our vitamin D from sunlight, it seems evident that the sooty haze of London was causing serious health problems for the city’s inhabitants.

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This same soot had effects in the natural world, the most famous of which was discovered by the Oxford student Bernard Kettlewell more than fifty years ago. Kettlewell observed that peppered moths from the rural countryside had black and grey colors that camouflaged them from bird predators by mimicking the lichen-covered tree trunks on which they would rest. This lichen, however, could not tolerate the sooty atmosphere of the cities, and was thus absent from tree bark surfaces there. Kettlewell noticed that peppered moths in industrial cities were almost entirely black in order to blend with the black tree bark, naked from lichen cover. These black moths may also have been more successful in the city than their more nuanced cousins because their black color allowed them to absorb heat better, an important attribute given the lack of clear sunshine (Figure 10.3). Kettlewell called this process industrial melanization, and it has been shown in plants as well, with plants near mining operations shown to have a higher tolerance for otherwise lethal metals.20 Coal was a transformative resource for human biological lives, cultural development, and technologies, just as it was for plant and animal species and the health of the world.21

Oil and What’s Next In 1859, oil was discovered in Pennsylvania, against a backdrop of overexploited whale populations, coal production’s environmental and health hazards, and the invention of the internal combustion engine. The nineteenth century’s new favorite fuel was born. By the 1880s, oil was eclipsing coal use worldwide, and in the United States, oil rushes and subsequent economic booms happened first in northwest Pennsylvania and then in California (Figure 10.4). Over the next few decades the petroleum revolution burst into Russia, Mexico, Texas, and the Middle East. Petroleum oil had been used since at least 2000 BCE in the Fertile Crescent, where oil from rare natural springs was used as a sealant in the construction of the famous towers of Babylon, but it was not until the late nineteenth century that petroleum was industrialized and poised to accelerate human civilization through the use of the engine. The engine made energy portable and powerful, while opening the path

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10.3. (above) Before the Industrial Revolution, and outside the big cities, peppered moths were light enough to be camouflaged on lichen-covered tree trunks. (facing page) In a case of rapid evolution, darker peppered moths evolved to hide from bird predators on the soot-covered tree bark that prevailed in England’s large cities during the Industrial Age. Photos by Henry Bernard Davis Kettlewell. Courtesy Wolfson College (Archives & Library), University of Oxford.

to the invention of plastics and other petrochemical products. The dirty age of the Industrial Revolution gave way to the “Age of Hydrocarbon Man,” at once shifting civilization and spurring modern technologies and their concomitant problems.22 Petroleum and natural gas are formed when sedimentary deposits of ancient fossilized marine organisms are buried and exposed to intense heat and pressure by tectonic plates. It takes tens to hundreds of millions of years for sedimentary plankton to turn into oil

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and gas, which, once formed, are lighter than the surrounding rock and thus flow into pools and pockets of oil and gas reservoirs. The first oil wells were discovered inadvertently in 400 BCE in China, in the form of natural gas (see Chapter 9). It would take the rest of human civilization a millennium to match this technology, which began in North America and Europe in the mid-nineteenth century through percussion and rotary drilling.23 Natural gas rapidly became the fuel of choice for home heating and lighting while petroleum ignited the transportation industry, leading to the replacement of horse-drawn carriages and steam engines with internal combustion engines. As traveling became quicker and easier, the world became smaller: the use of gas and oil accelerated globalization, facilitating communication, shipping, and cultural transmission. The conversion of coal and petroleum to easily transported and used electricity sped up this process even more.

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10.4. Pennsylvania oil wells in the late nineteenth century. Photo copyrighted by Mather and Bell, Library of Congress, Prints and Photographs Division.

The acceleration of civilization has come at a cost. Today, humans worldwide use 96 million barrels of oil a day.24 These resources—coal, natural gas, and petroleum—are finite and our use of them is unsustainable: current calculations suggest that we will run out of oil in fifty years or so if we continue using it at this rate. Compounding the diminishing supplies (a problem that can be ameliorated by adding in nuclear energy and renewable energy sources, like solar, wind, and hydropower) is the environmental damage that our excessive fuel use has left in its wake. Global warming, from the anthropogenic (human-caused) increase in greenhouse gases that retain heat in the earth’s atmosphere, is rapidly warming the polar ice caps, with sea levels expected to increase by at least a full meter in the next century, threatening waterfront cities like Venice, New York, and Amsterdam—not to mention the many less popular and fancy destinations where millions of humans live and work across the world. Other consequences include increased

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storm frequency and severity as well as ocean acidification, which threatens the abilities of crabs, barnacles, clams, and mussels to make their protective shells while almost ensuring the disappearance of coral reefs. The evolution of morphological and structural biodiversity that has been ongoing and developing for 550 million years may be stamped out. We once thought the ultimate solution to our voracious energy demands would be recreating the primordial energy of the Big Bang and the sun. While nuclear energy today powers much of Europe, we are now facing two imposing problems because of its use. First, like burning photosynthetic fuels, creating nuclear energy is nonrenewable and generates toxic, polluting waste that is not biodegradable. Common radioactive isotopes in spent nuclear fuel decay slowly, with half-lives (the time needed to decay to half its original radioactivity) that are longer than Homo sapiens have existed. Two of the most common long-lived waste product isotopes have half-lives of 222,000 and 15.7 million years.25 Second, nuclear technology is not only a civilization-powering fuel, but also a weapon that threatens the most terrifying magnitudes of destruction. As a weapon, nuclear energy destabilizes world peace, threatening and dividing civilizations driven to achieve selfish-gene dominance. But even as a fuel, the destruction capacity of nuclear energy is evident: the nuclear power plant accidents in Chernobyl and Japan have demonstrated how unexpected natural disasters or careless use by error-prone humans can unleash the dangers of nuclear energy. Tapping renewable energy sources from the sun, wind, waves, and the thermonuclear core of the earth—as people do effectively in Iceland where the North American and European tectonic plates meet, bringing geothermal energy close to the surface—is the only true energy solution. It is unclear, however, if we have come to this empirical realization in time to save civilization. Slowing the toxic effects of burning hydrocarbons by replacing them with renewable energy sources is like stopping an enormous ocean vessel moving at full speed: there is a vastly different reality to slowing it and fully stopping it. The atmospheric effects on the climate will actually increase for decades after our hydrocarbon fires are extinguished, due to ocean warming and other effects that we can’t reverse quickly. Similarly, another hard-to-reverse process will prevent hydrocarbon effects from

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ending quickly, even if extinguishing these fires were mechanistically possible: the financial and political influence of the petroleum industries, which have been the victors of global conflicts ever since the early twentieth century. The United States, for example, subsidizes the petroleum industry for national security reasons while barely incentivizing the development of renewable energy production—ostensibly due to the political clout of the petroleum lobby. We have discussed the wars fought over salt when it was essential for food preservation. Our twentieth-century civilizations have followed the same trajectories, fighting over the control of oil and drawing country borders not to reflect natural cultural divides, but rather as a way to secure petroleum resources. Only a cooperative political will can respond to the selfish-gene drive of the petroleum lobbies and the economic pressure to continue to exploit oil and coal across the world. Because of our advanced scientific abilities, we can predict the evolutionary chokepoints that await us—but can we act accordingly?26 Our needs for energy are real, essential, and omnipresent, yet the solutions that we have often put forward for these needs have had rippling, global side effects that we only in the last few decades are beginning to fully understand. Because of our energy use, academics believe that we have changed the geology of the world to such a degree that we have ushered in a new geological period, the Anthropocene. In the Anthropocene, the human species and its activities have become central to the question of survival for many other species that are related to us: how sensitive these relationships are to our exploitation of the natural world is uncharted territory.27 In the short, ten-thousand-year history of human civilization on our four-billion-year-old planet, we have begun to choke the earth’s life-support systems, turning off the positive feedbacks that have created them. We are uncertain how resilient these systems are, what the consequences of our actions will be, and whether it is too late to turn to nuclear and renewable energy resources to rescue our coevolved and codependent ecosystems. The natural history of our civilization may be in its final chapters if we cannot buck our drives for growth and expansion and turn instead to concerted, communal, cooperative decision-making.

chapter eleven

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et’s imagine a grazing area that is shared among cattle farmers. If the farmers neglect to decide together how many cows can feed there, each farmer will soon realize that adding a cow will increase his or her individual profits. Extra cows will go to the grazing ground, which cannot sustain the additional feeders, and before long the area will become overgrazed and unusable. The farmers made sensible economic decisions, and yet, because these decisions were made independently and without context—without understanding the needs of the shared environment—they are now all faced with an economic loss. This is the “tragedy of the commons” first articulated by the English economist William Forster Lloyd and made popular by Garrett Hardin’s 1968 paper bearing the phrase as its title.1 It is a seminal idea that has found application in a number of discourses, including ecology and conservation biology, conveying how individual exploitation of a shared resource creates a socially dispersed problem. In the years since this idea was first created, the “commons” has grown from its original meaning of local, communally owned, and shared resources to regional and now even global resource pools. The commons today symbolize the habitats and resources that humans have evolved in, around, and next to, and the tragedy is thus the general destruction of these habitats through 209

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accumulated human activities. (In economic terms, this destruction represents the “hidden costs” of the human actions that utilize the environment.) The only viable solutions to the tragedy of the commons are cooperative rules, ethics, and laws that govern civilization and overrule self-centered, selfish behaviors. Some of the first governing laws of civilization limited the harvesting of both shoreline seaweeds, which were required to make potash for manufacturing glass, and trees, which were needed for building defenses. Both regulations protected the resource base for the common good. Can similar cooperative solutions—willed, communal decisions that aim to curb our often overwhelming drive for growth and expansion— overcome the global environmental problems that local and regional selfish-gene motives have created? Today, the tragedy of the commons represents an epidemic, global problem. Overpopulation and overexploitation have transformed the entire earth into a limited feeding ground we all share. We have seen already why regions like the Fertile Crescent, the resource heavy, river-fed, mythical Garden of Eden that gave birth to human innovation and civilization, is now a spent desert and a perpetual war zone. Such an area is a microcosm of our contemporary issues: ancient Mesopotamian civilization had revolutionized plant production and agriculture through trial-and-error experiments and technologies, but its citizens did not learn the importance of sustainable resource management until it was too late. The sparse forests were razed for fuel and building materials, the lands were farmed to the point of nutrient depletion, and salt accumulation and erosion turned the cradle of civilization into an exhausted wasteland. Infrared satellite imagery of these areas today reveals ancient roadways, ghosts of the first great commercial thoroughfares that connected the towns where civilization was born.2 The tragedy of the commons is the exact point where natural history, human evolution, and culture collide—for better or worse. The very mechanisms that have led to the evolution and survival of humanity and to the heights of civilization may be those that push us to collapse: the symbiogenetic mutualisms that are vital for human life are on the brink of being undone as the mindless, futureless propulsion of evolution pushes us ahead, while a new set of

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interactive effects and feedbacks is being created. The diverse collection of human threats makes it difficult for scientists to reliably predict or even understand how human activities going forward will affect global resources and populations.3 Can humans save themselves, despite a history of failed civilizations and resource exploitation? Or are we following a familiar path difficult to turn away from, one that will lead to the demise of civilization and our eventual extinction? Will the collateral consequences of our natural, self-centered, competitive, and dominant nature trump the processes of cooperation that spawned civilization? Or will we choose and enact human processes of cooperation in our governments and daily lives, which in our natural history have often solved the lifeand-death problems that we now face on a global scale? Can cooperation lead to a triumph of the commons?

A History of Collapse Historical ecology is not only one of the most powerful tools to emerge recently in the field of ecology, it is also one of our best approaches to answering these pertinent questions about the future of our planet and civilization. Historical ecology blends ecological studies with historical methods in order to understand and describe past ecosystem changes. Pollen records and isotopic dating were initial geological methods for reconstructing the past, but today ecologists use information ranging from ship logs, fish-catch records, maps, and government records to newspapers, aristocratic diets, and tavern menus to piece together past ecosystems and ecosystem change. For example, ecologists have demonstrated that the onset of industrial ocean fishing coincided with the collapse of large pelagic predators and ground fish by collating catch data for sources around the world. In my own New England backyard, too, the die-off of salt marshes from recreational overfishing was documented with a combination of field experiments and a seventyyear-old record of aerial photographs. While these reconstructions are crucial for understanding the past, they can also elucidate for us the evidence, structures, and trajectories of civilization change relative to their natural histories and environments. What can the multitude of examples of human civilization collapse teach us

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about the present, and about the future? Can the past forecast our future?4 Walking through the earliest civilizations is instructive, because they were not only the first to flourish, but also the first to fade. While many questions remain about their demise, we can know enough to make some inferences. The first Mesopotamian civilization dominated for three millennia and was in place when human agriculture began. But Mesopotamia, unlike Egypt which existed at the same time and outlived Mesopotamian rule, was never a single state, but rather a collection of occasionally cooperating, often warring states, all of whom were experimenting with farming, urbanization, and cultural practices. The downfall of Mesopotamia as a region was not a precipitous one but a slow decline, thought to have been caused by fundamental problems in development and expansion, as well as leadership problems that such technological issues would have exposed. Specifically, Mesopotamians required irrigation systems to expand agriculture from small family ventures into larger enterprises requiring oversight and rulers. But irrigating arid fields led to the buildup of salt and minerals, which created soil fertility problems on the most-used fields. Crop failure and civil unrest disrupted the rulers who claimed divine rights to rule, and the ensuing civil wars crumbled the civilizations until they folded under the control of nearby civilizations, like Egypt.5 The pharaonic Egyptian kingdoms had similar tipping points but lasted far longer as a civilization. Agriculture in Egypt was tied to the idiosyncratic natural history of the Nile River delta, which was flooded seasonally with runoff from the Lake Victoria watershed. While weakened leadership from civil unrest and food shortages also undermined the Egyptian civilization, the cause was not irrigation as much as the region’s climate patterns. Drought conditions may have halted the life-giving flooding of the Nile Delta long enough for civil war and untrustworthy rulers to take hold.6 One of the longest-lived empires in human civilization dissolved, soon continuing only as part of the Roman Empire. One of the largest empires the world has ever seen, the Romans absorbed the remnants of the Egyptian Empire, expanding north across the European peninsula and over the English Channel to the British Isles. The Roman Republic grew into the Roman

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Empire to meet the needs and ambitions of Roman aristocrats, and to this end developed highly efficient systems and infrastructure programs, including the Appian Way and the vast road systems across Europe, which were often matched with aqueduct water supplies. Through Silk Road trade routes, the Roman Empire connected and opened Europe to China and Asia. While the empire itself lasted a mere four centuries, the infrastructure and cultural networks it developed lasted nearly two millennia, into the European Renaissance. Yet the combination of expanded borders alongside a growing population pushed this centralized empire to its breaking point: with a now thinly spread military and increasingly developed neighbors—thanks, in large part, to the trade and communication networks the Romans themselves had established—the empire was weakened and more vulnerable to new threats. Much like the early city-states, expansion proved both necessary for development and dangerous for continuity. Across the Atlantic, the Maya civilization dominated Central America for over two millennia. Large Maya ruins are still being discovered on the Yucatan peninsula, and the former glory of the Maya has long been a source of fascination, including for explorers like the nineteenth-century writer John Stephens. I too have visited the area and remember seeing centurial tropical trees growing on top of burial temples and ball courts, the chiseled stelae lying uncared for, and the juxtaposition of the far humbler thatch-roofed, dirt-floor houses of contemporary descendants. The Maya Empire drew its strength from the domestication of corn, an element so central to life that a creation myth depicted the gods creating humans from corn dough. Population growth followed this agricultural success and leaders claiming divine rule sprang up as the land was cleared and deforested for farming expansion. In turn, soil erosion and drought conditions led to famine, civil unrest, and the end of the Maya classical period.7 High Maya culture collapsed from human exploitation, which had disrupted the positive feedbacks supporting their ecosystems. Similar historical narratives have been proposed by Jared Diamond, who focuses on Easter Island and the other isolated islands in the South Pacific. Easter Island, known for its massive stone statues and for being one of the most isolated islands in the

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world, is for Diamond one of the clearest examples of ecocide on the planet. According to Diamond, the Easter Islanders deforested their lands to build the seagoing canoes they needed for their fishcentered diets. Diamond’s account is chilling: the Easter Islanders turned to land-based diets, which further strained the capacities of the island and overexploited its resources. Diamond suggests that this even led to cannibalism to compensate for the weakened diets. Others have suggested that Easter Islanders succumbed to diseases brought by exposure to European explorers or that they tried to adapt to their myopic overharvesting of island vegetation by eating rats and the plants they could coax to grow on an island now desertified from lack of foresight.8 History thus teaches us that the decline and fall of civilizations are the rule rather than the exception, and that they are often due to our shortsighted depletion of natural resources including habitat destruction—seemingly unavoidable trends given our blindly competitive, selfish nature. These activities led to the “alternate states” that we see today, where unrest, a lack of resources, and a widening gap between the rich and poor indicate a strained, unsupported community. Each civilization in its own time seemed invincible, inevitable, and enduring—just as our more globalized culture today appears— but each proved ephemeral. Our current situation—a global population increasing as habitats continue to be destroyed around the world—is providing humanity with its next test of sustainability.9

Avoiding Alternate States by Valuing Current Ecosystems Before seeing the extent and degree of the threats leveled both against and by contemporary human civilization, it is important to understand exactly what ecosystems do for us. Too often, a word like “ecosystem” comes across as something “over there,” a place outside of our worlds, like a forest or a lake, and therefore its destruction may seem sad yet not necessarily important. But humans still, just as our ancestors did throughout history and pre-history, benefit from ecosystems, which provide a number of values and services, as Gretchen Daily explains in her 1997 Nature’s Services: Societal Dependence on Natural Ecosystems. “Ecosystem services” can range from the microbial processing of runoff water, which provides clean drinking

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water, to soil stabilization through vegetation, which prevents erosion and enables agriculture, to the establishment of salt marshes, mangroves, and coral reefs, which protect coastlines from erosion and storm damage. The concept of the ecosystem service has proven essential to properly valuing the work an ecosystem does for humanity, because it puts a price tag on that work. This model helps entrepreneurs, policymakers, and the general public talk meaningfully to one another about the value of our ecosystems and allows for better prioritizing of the limits and costs of environmental impacts.10 Some of these ecosystem services have been mentioned already. Rainforests and coral reefs, for example, feature organisms with long evolutionary histories of adaptation and chemical defense manufacturing, which make these ecosystems possible banks of cures for diseases. They are irreplaceable repositories for earth and for human health. Tropical rainforests are also the largest remaining terrestrial sources of carbon sequestration—which removes carbon dioxide from the atmosphere—and oxygen production. Vegetated shorelines comprise some of the most valuable ecosystem service providers on the planet, though they are also some of the most abused geographical locations. Environmental economists have calculated that per unit area, salt marshes and mangrove forests are more valuable to humans than the charismatic ecosystems of coral reefs and tropical rainforests. This unexpected realization comes from the diverse benefits that such wetland ecosystems provide: in temperate and tropical climates, salt marshes and mangrove shorelines sequester and store carbon as sinks, over time producing from them coal and natural gas. If left intact, these sinks buffer and ameliorate changes to the earth’s climate. Vegetation also stabilizes shorelines from erosion and binds sediments left from hundreds of millions of years of weathering in order to create biogenic habitats. And coastal wetlands do something that is increasingly important due to the more intense and more frequent storms stirred by global warming: they act as bulwarks against waves, dissipating waves’ energy before they can break over terrestrial ecosystems and cities. Finally, marshes and mangroves are nature’s natural sewage-treatment facilities. The microbial assemblages in wetlands biochemically process terrestrial runoff—so well, in fact, that they are increasingly used in engineering human sewage treatment systems.11

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One example of how ecosystem services can be lost through human intervention is the Great Dust Bowl in the early twentieth century. In his 2006 book The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl, Tim Egan describes how American farmers, encouraged by 1930s government incentives, attempted to turn the tall grass prairie in the American plains into a farmland breadbasket. This led to an ecological disaster of immense proportions: plowing the ancient grassland ecosystem in an attempt to domesticate it released the topsoil of the southwest into dust clouds that darkened the skies of New York City two thousand miles away, and caused the generation of hopelessness portrayed in Steinbeck’s Grapes of Wrath. In 1935, one of the worst storms simultaneously covered Chicago, New York, and Atlanta with a dust cloud spanning 1,800 miles and weighing 350 million tons.12 The Dust Bowl of the Depression is a classic, human-driven “alternate state” (Figure 11.1). An alternate state occurs when the positive feedbacks that created, maintained, and stabilized the original state are lost and replaced by feedbacks that maintain and stabilize a degraded state, which then prevents recovery. In a word, a new nature is formed, one that is challenging for conservationists since alternate states can shift rapidly and with little, if any, warning. In the case of the American Great Plains, the original state featured grasses that had evolved to tolerate grazing animals and fire and to bind the soil substrate. The ecosystem was one of great diversity with an array of plants and animals. Because of tall prairie grasses’ dominance in so much of the North American continent, no one suspected the fragile order they supported, for example, that they had colonized and secured an otherwise wildly unstable habitat. Like icebergs, native prairie grasses have most of their biomass hidden below the surface, in deep-rooted, dense, soil-binding roots that have evolved to tolerate extreme climatic conditions like drought and strong winds. Migrant farmers were unaware of how dependent the ecosystem was on the ecological and evolutionary past of these grasses, and their symbiogenetic partner grasses, which had coevolved with humans. The binding ability of the tall prairie grasses was lost, and life on the Great Plains was subjected to severe weather, droughts, and loose soil, metamorphosing into a mobile sediment community with dynamics resembling sand dunes.13

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11.1. A dust storm cloud threatening homesteads during the American Dust Bowl. It was triggered by government efforts to turn tallgrass prairies into farmland by plowing under the native grasses. Photograph by D. L. Kernodle. Farm Security Administration—Office of War Information Photograph Collection, Library of Congress, Prints and Photographs Division.

We find similar processes all across the globe: dust storms driven by large-scale attempts to farm arid grassland environments have affected all continents on earth except Antarctica and have been responsible for the intercontinental movement of soils. Moreover, these events can have global implications: scientists discovered that dust and associated microbes from Saharan Africa, for example, can travel in dust clouds across the Atlantic Ocean to cause species-threatening disease outbreaks in Caribbean corals. Human disturbances of valuable ecosystem services have reached a global scale. As far as we know from collective natural history observations, experimental community ecology, and ecological theory, when ecosystems are pushed out of their self-regulated stable states, formerly maintained by positive feedbacks, and into alternate states (typically through human impacts), recovery is difficult, slow, and often improbable. The productivity of natural, native ecosystems, particularly those in marginal, potentially limiting habitats, is dependent on foundation species that improve the habitat and enable

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ecosystem biodiversity. If these foundation species—like tall prairie grasses—are lost or replaced with superficially similar, but functionally different species, the habitat will find a new stability in its alternate state, typically a less productive state complete with its own reinforcing feedbacks. Thus, human disturbance is changing the fabric and makeup of whole ecosystems, generally with the loss of the ecosystem services that had developed to maximize the productivity of native assemblages.14 Sadly, this anthropogenic transformation of productive habitats to alternate states—or to outright collapse—is happening across the invaluable ecosystems that we have described. Deforestation, which has a deep history, is still going strong, removing organisms like trees that are crucial carbon sinks, soil stabilizers, and weather and habitat modifiers. From 2000 to 2005, global forest cover loss was over 621,000 square miles (over 1.5 million square km), a loss of 0.6 percent a year, which may not seem like a lot, but is in fact equivalent to the size of Maryland. The Amazon rainforest is suffering the heaviest damages as its ground is razed for cattle and soybean production. The Amazon rainforest counts for over half of the world’s rainforests, but since the 1970s, nearly 20 percent of it has been lost.15 Corals, too, are being extirpated on our watch. Rising seawater temperature has broken down the coral-algal symbiotic mutualism and led to coral bleaching. In the Caribbean, live coral cover of coral reef habitats was estimated at nearly 60 percent in the late 1970s, but by 2012 the same sites had declined to less than an average of 10 percent of live coral cover (Figure 11.2). Today dead coral skeletons often covered by weedy algae dominate most shallow-water reef habitats in the Caribbean. This is also another example of an alternate-state habitat caused by humans: overfishing removes grazing fish that can keep rapidly growing seaweed in check. Without their limiting force, the seaweed overtakes the coral, blocking sunlight and preventing coral growth. By blindly taking what we need from this ecosystem for our own food, we have selfishly ignored the fact that grazing fish and seaweed have an essential partnership that developed over millennia of shared natural history.16 Shoreline ecosystems such as salt marshes and mangrove forests have had no greater luck, having been abused since the beginning of civilization. Often pejoratively called swamps, these ecosystems

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11.2. Caribbean coral decline has been driven by overfishing; by hurricanes, which have reduced live coral cover; and by global warming and eutrophication, which have triggered coral disease and death. Redrawn from Tropical Americas: Coral Reef Resilience Workshop Report, April 29–May 5, 2012, Tupper Center, Smithsonian Tropical Research Institute, Panama City.

have frequently been used as garbage dumps or drained and filled for agricultural use. Their value and the intricate symbiogenetic relationships that create them have been critically ignored. Tropical mangroves, for example, have been deforested for charcoal production, building materials, and for the development of shrimp farms and waterfront resorts. These activities have displaced at least 35 percent of the world’s mangroves. In just the past three decades, the mangroves that had protected the Maya Riviera shoreline in Mexico have given way to supersized resorts. In temperate zones, salt marshes have been replaced with land for farming, cattle grazing, roads, railways, housing, and strip malls, accounting for a loss of 50 percent of salt marshes worldwide. Once mangroves or salt marshes are removed, the resulting alternate state of high soil salinity and low oxygen substrate makes recovery extremely difficult: powerful new feedbacks have developed that limit the opportunities for new plant life to colonize and thrive there.17

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A final example, one analogous to American prairies, involves seagrass meadows. Seagrasses thrive in shallow water habitats— habitats that are easily exploited by humans and vulnerable to multiple stressors, like sediment runoff and algae blooms—and like tall prairie grasses, they bind sediments to make possible the diversity of life in their ecosystem. The ecosystem services of seagrass, which process water and sediment nutrient loads, have been valued at $1.9 trillion per year, but seagrass bed habitats are currently disappearing at a rate of forty-two square miles (11,000 ha) per year, with 29 percent of all known seagrass areas lost already. These loss rates are comparable to those in the ecosystems just mentioned, making seagrass beds among the most threatened ecosystems on the planet.18 Despite this bleak portrait, we have achieved major ecological successes against the long and despairing odds of environmental destruction. Birds of prey, for example, were headed mysteriously to extinction in human-dominated ecosystems forty years ago, threatening the trophic structure and balance of natural ecosystems. Then came a famous discovery by Rachel Carson in 1962, revealed in her popular book Silent Spring: the widely used miracle insecticide DDT was becoming concentrated through the food chain, making its way to birds of prey and weakening their eggshells until they could not produce viable offspring. Banning DDT led to an impressive rebirth of birds of prey in human-dominated landscapes. A similar success story occurred with the kelp forests off the west coast of North America. In the mid-twentieth century these kelp forests, which are home to a wide diversity of species, were shrinking and disappearing at an alarming rate. Experimental and correlative studies led by Jim Estes and his colleagues revealed that this collapse was being driven by the overharvesting of sea otters for popular fur hats, lapels, and coats. Fewer sea otters eating the herbivorous sea urchins meant increased urchin populations and the loss of kelp beds due to their overgrazing. Reintroducing sea otters back into areas where they had been wiped out has led to a return of kelp beds and their associated biodiversity along the west coast. These positive results bring some hope that we may be able to reverse the alternate states we have caused through disturbing our ecosystems.19

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At the end of the day, alternate states teach us two important and related truths: (1) our species is negatively impacting the ecosystems around us, and (2) the intricate and developed mechanisms of the world will seek out stability, even if that stability makes ecosystem improvement nearly impossible. By failing to acknowledge our roles as cooperative partners in the world, we are changing the very structure of ecosystems in ways that threaten the other species that inhabit them. We have shown that we can reverse some of these changes by becoming more fully aware of the reciprocal effects of our actions and limiting our effects on the natural world. But there is one more ecosystem that is currently threatened by human activity and alternate statehood, one that affects all of the environments discussed here—and reversing this human-created threat will require far more than a ban on an insecticide or the reintroduction of a species. Can our successes with ecosystem renewal be scaled up to the global level in order to remediate planetary problems of climate change, ocean acidification, and predator depletion? Can we come up with solutions that explicitly require foresight and group cooperation, even if this means overriding our hardwired selfish-gene instinct to try to “win” short-term, and at all costs?

Changing Global Systems Over the past two centuries, we have become dependent on materials made from hundreds of millions of years of accumulated solar energy. Fossilized, compressed, and liquefied carbon, buried by geological processes through the long history of our planet and its life forms, has been mined from underground deposits and excavated from wetland graves to fuel an increasingly synthetic way of life. And as we burn this fuel, we effectively transfer the hundreds of millions of years of packed solar energy from its carbon storage—as peat, coal, and gas—to the earth’s atmosphere. The concentration of this carbon dioxide in the atmosphere, which has increased by nearly 30 percent since the Industrial Revolution, creates what we refer to as the greenhouse effect: greenhouse gases absorb and trap solar energy in the lower atmosphere, warming the earth and increasing temperatures.20

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In other words, humans are emitting more and more energy into the atmosphere while at the same time sending into the sky the very compounds that prevent this energy’s absorption. Humanbased increases in greenhouse gases are the driver behind global warming, ocean acidification, and a cascade of associated problems that in turn are establishing alternate states across the planet. In fact, we might even be correct to say that we are turning the planet itself into an alternate state. Despite our relatively short history on earth—as Carl Sagan once wrote, if the history of the earth were compressed into a twenty-four-hour day, modern Homo sapiens would not arrive until 11:50 p.m., and civilization would begin just a couple minutes before midnight—we are in the process of changing global structures by changing one of their foundational elements: temperature.21 Temperature is one of the most basic forces on earth. It affects all life by controlling the rates of chemical reactions and modulating the density of gases and fluids. Consequently global warming will alter the abundance and distribution of organisms across the planet, turning historically rich farmlands to deserts and historically unproductive deserts into farmland; and it will move ocean currents, changing the habitat for marine species. These shifts will happen independent of political borders, exacerbating conflicts in a world of shrinking food resources. Our understanding of history to this point reveals, after all, that if temperature change has dramatic effects on agricultural production, the severe consequences will likely include economic inflation, war, famine, and an eventual decline in global population (Figure 11.3).22 Oceans have historically acted as an important buffer for modulating changes in the global environment—yet human disturbance is also limiting the ability of oceans to carry out this essential work. As 30 to 40 percent of anthropogenic carbon dioxide dissolves into oceans, it has formed carbonic acid, thereby acidifying our waters. This is a serious, biologically novel problem in marine ecosystems: the high acidity limits the ability of organisms like coral and snails, for example, to build their carbonate skeletons that protect them from heat, water loss, and predators; it can even dissolve existing calcium carbonate skeletons. Calcium carbonate, as saltwater aquarium enthusiasts know well, ameliorates the fluctuating acidity of

11.3. Global trends in carbon emissions, seafood species loss, population, and temperature rise. All of these trends are heavily influenced by human behavior. The hope is to reverse these steep changes through cooperative decision-making and so avoid creating alternate ecological states that will be difficult, if not impossible, to reverse. All images were redrawn based on the following sources. Global carbon emissions: M. Thorpe, “Global Carbon Emission by Type to Y2004,” Wikimedia Commons. Seafood species loss: “Global Loss of Seafood Species” in R. Black, “ ‘Only 50 Years Left’ for Sea Fish,” BBC News, November 2, 2006. World population and growth rate: World Health Organization, World Population, 1050 to 2050, https://www.who.int/gho/urban_health/en/. Realized temperature rise: IPPC Working Group I, “Policymakers Summary,” https://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_spm.pdf.

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oceans. Thus, ocean acidification could flip ocean ecosystems into unpredictable, chaotic alternate states. The consequences could be dire, involving the loss of whole species of now defenseless snails, crabs, urchins, and oysters that are part of extensive food chains, and destroying the ability for coral to grow and build their islands in tropical seas that keep them from being lethally submerged in rising seas.23 Sea level rise is the second major climate-change challenge for human populations. This is especially, and already, true for populations concentrated in coastal habitats, where rising seas are encroaching on towns and villages. The rise of global temperatures has been melting polar ice caps more quickly than predicted and thermally expanding the warming ocean, meaning that low-lying countries like Holland and China, areas like the Mississippi basin, and cities like New York, Amsterdam, Copenhagen, Saint Petersburg, and Venice are in danger of flooding over the next century. Many of these and other historical waterfront cities were built on manmade shorelines in the Middle Ages, but human-driven sea level rise is happening, now and fast, and threatening these populations. Conservative estimates of sea level rise over the next century by the Intergovernmental Panel on Climate Change (IPCC) are proving to be underestimates, though they have predicted a twentyto forty-inch (.5 to 1 m) increase at the most temperate latitudes. These changes are having immediate effects, such as a recent iceberg the size of Delaware that broke off the Antarctic ice sheet, the largest such event ever recorded. Sea level rise means that major coastal cities and countries around the globe will face a flood remediation crisis and significant land loss in our children’s lifetime. This is already the case in some cities: the former economic center of the world in the fourteenth century, Venice, is no longer developing the spice trade, but instead dealing with serious sea level issues. The last time I was there, the city plaza at high tide was flooded ankle-deep in seawater.24 Climate change is a contributing factor in another threat to coastal systems, one we refer to as eutrophication. Eutrophication occurs when excess fertilizers—usually industrial, artificial fertilizers— stimulate the overgrowth of certain organisms that then smother other organisms in an ecosystem. Eutrophication depletes oxygen

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supplies and leads to regular die-offs, some of which happen annually in the Gulf of Mexico and cover regions the size of Texas. The Mississippi River basin also suffers from these events as countless numbers of immobile and mobile marine organisms die from oxygen depletion. These annual events have become so common that they have made their way into regional culture: along the Gulf Coast, crab jubilees, complete with the coveted crowning of teenage crab jubilee queens, are held as oxygen-seeking crabs migrate en masse to the shoreline where they are easily harvested. Such jubilees have been popular since the early twentieth century when the heavy use of nitrogen fertilizer began. Similar events happen in my adopted home of Rhode Island, where the celebrated quahog, or hard-shelled clam, made popular by the series Family Guy, is one of the only large organisms that can survive in Narragansett Bay’s septic-tank-polluted waters year-round. Due to summer months of oxygen depletion, these clams’ predators and competitors are driven away or killed, and only the quahog survives, which it does by dissolving its calcium carbonate shells to buffer the acidic end-products of its now slowed anaerobic metabolism—that is, it lives through the summer by in effect holding its breath. Because it survives, Rhode Island proudly selfidentifies as the Quahog State rather than the Septic Tank State.25 These are not just North American events: coastal anoxic dead zones are becoming another new normal, another alternate state. Ever since the Chinese government mandated a change from the traditional agrarian farming style to more Western, industrial models, toxic algal blooms, or “red tides,” have increased in size and frequency by an order of magnitude, and nearly 80 percent of Chinese coral reefs have died.26 There is also an Asian analog to the quahog that over the last few decades has come to dominate anoxic Asian estuaries. The global reach of climate change only makes more difficult the task of understanding how we are altering and shaping the world and the various, diverse ecosystems within it. One of the pressing problems for scientists is the lack of a reliable framework for understanding the multiple human impacts and how they work against or with each other in a given ecosystem. We have studied these impacts individually—the next step is developing models to study combined, interactive effects. What we know so far is that

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human disturbances typically lead to synergistic, multiplicative, unpredictable surprises, rather than simple, predictable, and addictive results.27 These unpredictable problems do not bode well for the future. Moreover, already damaged ecosystems are more vulnerable to additional threats, as the food webs become simplified and thus have less margin for change. But again, multiple human stressors may cause a variety of effects. For example, nitrogen eutrophication typically leads to more of certain nitrogen-limited organisms, like weedy plants or algae. But other stresses, like climate change or predator depletion (through overfishing, for example), will have unpredictable results: warming could increase the frequency and severity of disease, impacting this production of weedy plants, and overfishing would have different results based on whether the depleted populations are predators, omnivores, or herbivores. These issues are particularly difficult when science stays in the classroom or the lab and scientists ignore Agassiz’s plea to “study nature, not books.” Only observational and active research can keep science relevant to our changing world.28 Over four decades ago, John Holdren and Paul Ehrlich argued that anthropogenic environmental degradation and deterioration are not local, reversible problems, but rather snowballing and pervasive issues with irreversible, unknown consequences for humanity.29 Unfortunately, we can no longer, as the popular bumper sticker advises, “Think globally—act locally.” The tragedy of the commons is now a global one and only by dramatically changing our relationship to the earth can we prevent further destruction of the positive feedbacks that make life on the planet possible. This requires rethinking what we are. Stanford’s Gretchen Daily has pioneered an ecosystem services perspective, and its application, the Natural Capital Project, has provided the necessary optimism in the shadow of this crisis. By monetizing ecosystem services, we can incentivize both our selfishgene motivations and our desire for conservation by favoring cooperation over competition. Just as competing primordial microbes joined forces to form eukaryotic cell mutualisms and human cooperation alleviated competition to kick-start the agricultural revolution, ecosystem service monetization can shift the natural history

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equation in favor of cooperation and conservation. This approach has led, for example, to New York City recognizing that preserving watersheds is cheaper than cleaning them up. By adopting the timetested strategy of overcoming individual competition—in this case, financial competition—through cooperation, this innovative approach can bridge global and local problems and solutions. Upscaling this idea and taking a top-down, governmental approach, more than two hundred million government officials and citizens in China are working on a proof-of-concept program of practical approaches to maximize carbon absorption, biodiversity, flood control, sandstorm control, and water purification. Conversely, a more grassroots approach, beginning at the local and regional levels and aiming to expand into national projects, is occurring in North American estuaries. Initially, the restoration of filter-feeding mussel, clam, and oyster populations in these estuaries was largely symbolic. But such organisms filter and clean nearby shore waters, and seeing these benefits has led to an expansion of these programs—as well as seagrass and salt marsh restoration projects—into regional and national initiatives. It is essential now more than ever to highlight and praise these projects because they represent the future affiliations and alliances that are possible, and indeed necessary, for the health of our own species and so many others across the planet.30

Evolution and Information It is worth remembering again how our present world has come to be, through the origination and diversification of life, when symbiogenesis created photosynthetic microbes and blue-green algae, through the hundreds of millions of years when these organisms paved the way for the oxygen-rich atmosphere that made oxidative metabolism and the creation of complex life possible, through the positive feedback mechanisms that shaped this history of life. These are the same mechanisms that work every day in our ecosystems, forming the cooperative mutualisms that support species diversity and environmental resilience. And these are the same mechanisms that we are destroying. Habitat destruction is not just the removal of a forest or the dirtying of a river: the large-scale habitat destruction we are

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engaged in today is rewriting these habitats’ very codes of existence. We are becoming generally aware of how interconnected and interdependent life is on the planet just in time to suffer the effects of the wrenches that we have thrown, and are continuing to throw, into the system. Keeping human civilization afloat has led us to engage in a host of detrimental relationships with the natural world, such as the use of pesticides in modern farming. Declines in populations of pollinating birds, bees, and bats due to the use of these pesticides is threatening the success of the plants that evolved alongside these species and need them for pollination. This has spawned a pollination service industry, where bees are trucked across continents to where they are needed, providing pollination services to crops that have lost their natural symbiotic partners. We have little to no idea what consequences pollinator decline and loss will have on natural ecosystems. Disrupting these mutualisms seems to be a theme in human history ever since humans first killed off most large predators and other human species. In the last century, industrialized ocean fishing has quietly and rapidly removed large marine predators from the planet’s oceans to about 10 percent of the biomass of the pre-industrial era, again with consequences we do not yet know.31 In other words, the evolution of Homo sapiens has led to a species able to hijack the processes of evolution and bend the world to its benefit. We are no longer a part or even simply at the top of the food web, and we are able to technologically overcome many past natural history constraints—at least in the very short term. Yet the continued pressure of natural selection means that we remain driven to dominate, an impulse tempered only somewhat by human intelligence. Consequently humans inhabit an existential position between freedom and constraint unlike that of any other organism on the planet. Now that we are facing a multitude of resource limitations, the kind that have historically and predictably incited violence, including war and genocide, we must come face to face with what we can and can’t do, knowing that we have the potential power to control and change the trajectory of civilization and life on our planet.32 The natural histories of all populations of plants and animals regularly feature resource limitations and challenges.33 In closed

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systems, these challenges are answered ecologically with population reductions or even crashes. Easter Island, for example, was an essentially closed system that crashed before humans could adapt to its low supply of resources. In open systems, resource limitation leads species to venture farther away to find more resources, expand the use of that resource, and push the environment to provide more of it, all to maintain population growth. An example of an open system would be the Fertile Crescent agricultural revolution where agrarian technology was developed and exported around the globe. To this day, agrarian technologies form the backbone of global agriculture, but the population growth it has concomitantly supported has rapidly brought us to a period of resource limitations—a formerly open system is, due to overpopulation and globalization, becoming a closed one. Some scientists think that the next stage of human civilization will involve a new coevolutionary partnership: one with artificial intelligence. In Sapiens: A Brief History of Humankind, Yuval Harari argues that this coevolution may help us to rise above our current natural history dependencies.34 Convincing arguments can be made for how this is already the case, citing the ubiquity of smartphones and GPS guidance options in our cars as extensions and surrogates for human memory. We may very well be on a path that will treat artificial intelligence much as our ancestors treated wolves, eventually making them into mutualist companions and aiding our own development. It has already been predicted that by 2020, a full 90 percent of humans will have mobile phones; after only half a century, humans have changed to rely on this technology in vast, revolutionary ways. How will natural selection react to this reliance? Will humans, like cave fish who have lost their unnecessary eyes, lose certain cognitive abilities as we become less reliant on them for survival? How will this affect population control, given that natural selection rewards high reproductive output? While it is impossible to doubt or deny the importance of technology and artificial intelligence today, I do not believe that such tool-focused developments will stave off the environmental concerns that increasingly face us, nor ensure for humanity a stable, healthy future. For that to happen, artificial intelligence would have to either immunize human mutualists to the problems of resource

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availability and environmental degradation or create cooperative solutions to these same problems. The latter option, potentially the more frightening one, would likely involve mutualist androids displacing the human dominance that our selfish genes dictate. In any case we must confront the evolutionary drivers within us that like a wound-up toy have guided our movements and development, our technologies, and our wars. We must tame, control, and harness the selfish genes that have been responsible for our success as a species, but that now drive our greed. At a fundamental level, humanity’s hopes lie in the ability to adjust our genetic wiring for dominance. The myopic selective pressure that has led to our global dominance will, if unchecked, lead to global catastrophes: we must return to our cooperative roots, a shift that will feel unnatural and counterintuitive. At every major juncture in the earth’s history, cooperation has alleviated competitive gridlock, and cooperative evolution has played a leading role in gifting our species its dominance. But it has done so blindly, without an end in sight. We must return to our symbiogenetic roots and the mutualist relationships we have developed with conscious intention, willfully choosing to live and evolve with others, whether those others are other nations, mythologies, or species. Such cooperation with the other inhabitants of our shared planet is the only way we can avoid becoming the victims of our own self-centered success.

Epilogue The Natural History of Civilizations

Examining civilization from a natural history perspective shows us that humans are not unique, but rather the products of the same self-organizing, competitive, cooperative processes that through natural selection have created all life on earth. Homo sapiens are not exceptions or immune to natural history rules, even though our big brains— synergistically fueled by cooked meat, group hunting, tool development, language, and coevolution with other plants and animals—have created this elaborate illusion. I have suggested that the symbiogenetic origin of life and the story of how these first molecular building blocks led to self-replicating molecules, complex cells, and multicellular organisms were both driven in a deterministic way by principles of selforganization and mutualisms. We are not the specially created ruling species of the planet we once thought we were; instead we are simply the latest iteration of the same symbiogenetic mechanisms that made eukaryotic cells, flowers and frogs, bacteria and blue whales. Part of this story involves the spatial distribution of human communities, which mirrors the predictable, repetitive settlement patterns of other species, all of which are ordered by the same generic rules of self-organization. These rules have determined where civilizations have geographically developed, as well as how they are organized hierarchically and apart from other competing groups. Our human ancestors’ mastery in harnessing these deterministic patterns 231

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ensured their early success, just as our cognitive powers, organizational skills, and ability to cooperate made possible our technological advancements and discoveries. This process enabled agricultural revolutions, civilization, population growth, industry, and a wholly changed world. Yet we have likewise seen that as we ascended up and out of the food chain, evolution and the natural world have kept pace: the expansion of human settlements spawned diseases and famines in the perpetual evolutionary arms race, in which evolved defenses are met by new, corresponding lines of attack. At the same time, I have stressed the key importance of mutualisms and symbiogenesis. We have long been blind to how interrelated our environments and the world are, even as these interrelations have created our dominant species. From our earliest days as skilled hunter-gatherers, to the utilization of snails and silk caterpillars for luxury resources, to the discovery of natural gas, we have grown and developed next to and with the inorganic and organic world. In this story of a connected world, human civilization emerged when symbiogenetic, cooperative impulses won out over more individualist, selfish drives. Unfortunately, as human technology grew, civilization spread, and populations rose, so too have our abilities to upend the interconnected mesh of life on the planet. Habitat destruction has progressed and accelerated, and we have ushered in an entirely new geological age, the Anthropocene, due to our unprecedented destructive activities on the planet. The coming resource limitations and upheavals to the environment that we still depend on, no matter our technological prowess, will only quicken the conflicts and violence that have marked human history so far. While our destiny is not written in stone, there are daunting challenges before us. I have already outlined some of today’s material challenges and how they must be confronted if we plan on our grandchildren surviving. Just as important, however, are the ideological challenges, especially humans’ resistance to change, or inertia.

The Problem of Inertia From our first efforts at understanding the world, science and learning have been tied to power and politics, whether by support-

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ing or undermining these powers. Early technologies—like writing and mathematics—were kept as guarded secrets by the ruling class, just as the Catholic church prevented the translation of the Bible into vernacular languages until the Reformation. That is to say, knowledge can be powerful and dangerous, especially if new knowledge offers a different perspective on the established order. By its very nature, fields like science and education are revisionary, fallible, and forward-moving: a failed experiment can be as important as a successful one, and what is most important is to keep testing, keep questioning. Governments, rulers, and cultural mythologies, however, are notably conservative (in the literal sense of the term): the hierarchies and orders in place have served them well, and if new knowledge threatens that order, they strive to prevent or hide that knowledge rather than risk losing their positions of power, wealth, and control. This is one of the factors that prevents the kind of changes that the sciences might advise for humanity’s continued thriving. We have seen its power: the religious conception of the earth as the center of the universe, for example, was challenged by Copernicus in 1512. This hypothesis was tested by Galileo, whose data supported the theory that the earth revolved around the sun. His findings famously landed him in prison and house arrest, for they challenged the belief that the world was specially created and, as such, had to be the center of the universe. The belief that the earth was flat similarly held sway, mostly in the ancient world (though Pythagoras first suggested it was spherical back in the sixth century BCE). More recently, Robert Koch’s germ theory of disease simultaneously revolutionized modern medicine while labeling microbes as negative and dangerous entities. We have seen again and again how our oldest evolutionary partners are the microbes that live on and inside of us, acting as shields and buffers against diseases. They act in concert with our own cells to drive our metabolism and bodily processes, and are crucial to our health. Yet since the arrival of germ theory, our reevaluation of what microbes are and what they do for us has been slow. Old, outdated ideas tend to attach to us and are difficult to shake off—but we must keep learning if we are to take on a more holistic and beneficial perspective toward, and relationship with, the world around us.

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Overcoming our inertia to understand the underlying and powerful forces driving life is the next ideological breakthrough we must have in order to survive. Our genes will push us just as they have pushed our ancestors through history toward overexploitation of resources and competitive relations with and within communities and among other organisms. After all, selfish genes are the essence and driving force of life: without natural selection acting generationally on individual heritable variation, life and biological diversity would not exist. At the dawn of life, natural selection differentiated among microbe fitness just as today it subdues pathogen attacks on all organisms, including humans. Humans are arguably the most influential product that natural selection has ever produced (though a strong argument can be made for microbes as well). But as the impacts of human behavior threaten life on earth through habitat destruction and overexploitation, and by ripping the cooperative fabric of coexisting life on the planet, we must realize that our selfish genes have become our enemy. Can we temper and control the most basic and powerful life force the earth has ever seen, one that has been rewarded and reinforced with global dominance? Can we outsmart the natural selection rulebook and have the foresight to save the world from destruction by our own selfish genes? To do this, we must harness our cognitive dominance and turn it toward future-oriented, cooperative solutions to avoid selfdestruction, proactively mobilizing and harnessing the mutualisms all around us. Cooperation has been the catalyst and driving force for all major evolutionary turning points in the history of life on earth, beginning with the endosymbiotic origin of eukaryotic cells. It is cooperation that has confronted and diffused escalating chaos, cooperation that has improved habitats and made possible the diversity of life we have today. Cooperation in evolution is, still, another blind force and the group benefits it prefers are still bound by natural selection rules and trends. But if we mindfully employ and protect the current cooperative relationships on the planet, and encourage new ones, we can help our species to thrive, rather than collapse, in the years ahead. As I have argued throughout this book, this kind of cooperation and its product, symbiogenesis, has happened before to diffuse

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the threats posed by selfish genes. The agricultural revolutions that spread across the globe were the result of cooperative interactions, mutualisms between Paleolithic humans and a nonrandom group of plants and animals that all benefited from synergistic positive feedback. This occurred, however, without foresight, but due to generation-by-generation selection for mutual benefit. Tackling the breakdown of ecosystem services and the mutualisms that have evolved to glue natural systems and cultures together will require foresight to cover the enormous blind spots of evolution. This means that the solution to our most pressing problems falls outside the domain of simple natural selection. If selfish-gene dominance can’t be overcome, our global problems—population growth, global warming, resource limitation that leads to nationalism and tribalism, which in turn threatens civilization—will become lethal, surrendering the planet to the microbes so that the meek may truly inherit the earth. Another possibility, one suggested by the Israeli historian Yuval Harari and others, would extend the processes and advances of evolution until they leave the realm of life itself. Big-brained human creativity, unconstrained by the myopic vision of natural selection, may develop self-replicating artificial intelligence that features both hindsight and foresight and is thus unencumbered by the inability of evolution to plan for the future. In this scenario, human creativity, engineered through the cognitive revolution, could be replaced with its own creation, artificial intelligence. This evolutionary transition is well under way as we become more and more dependent on the smart technology in our phones, homes, and factories to make our daily decisions, store and replace our memory, spend our money, and build our products with human designed yet selfless artificial intelligence—an intelligence that lacks the ultimately lethal and destructive selfish motivation of survival and reproduction.

Comparing Predators—and Planets In the 1960s, the late ecologist Robert Paine of the University of Washington demonstrated experimentally that in the rocky, waveexposed habitats of Tatoosh Island, off the northwest coast of Washington State, the common purple sea star acted as a keystone

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predator. In other words, it was largely responsible for the community organization of species, and species diversity, in these habitats. It was an attractive idea, but one that, at first, was not widely adopted and extrapolated to other habitats because Paine could only generalize from his findings at a single site—his findings had not been reproduced beyond the open coast of Washington. At the time, it was instead widely believed by ecologists that physical limitations and resource availability organized and structured natural communities. These ideas, however, were entirely based on correlations. What if Tatoosh shorelines were structured differently from other habitats? What if Paine’s trampling on Tatoosh had generated his findings rather than starfish predation on mussel beds? Paine’s insight required more than correlations; it required replicated experiments. Science is slow, occasionally too slow, but over the next few decades, keystone predators like sea otters, sharks, mountain lions, and wolves took center stage: they proved time and time again to be disproportionately important in shaping ecosystem structures and processes. This now widely accepted idea suggests that keystone predators, those that impact the communities they live in disproportionately to their numbers, have strong “trophic” effects or cascades that determine the length of food chains and the complexity of food webs. In examining the natural history of civilization, we must admit to our limitations, because we also lack the ability to replicate our findings or conduct independent tests. This makes it difficult to prove the effectiveness and necessity of symbiogenetic relationships at a global, Gaia level. After all, natural history is at its foundation an observational and comparative science. We learn about habitats, organisms, and their interrelations by going into the world and studying the patterns and activities in front of us. We compare these findings across similar habitats, across temporalities, discovering the principles that work to tie organisms together. Moreover, examining civilization through a natural history lens suggests that civilization is not a serendipitous accident, but rather an evolutionary fate. The running hypothesis of this book has been that group benefits have driven all developments of life, from eukaryotic cells to the mutualisms that founded agriculture and civilization, and that these group benefits defuse the cumulatively

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negative consequences of selfish genes. How can this hypothesis be tested? To what other histories of life itself, and what other civilizations, can we compare our grandest theories and observations? The answer is in heaven—or rather past the heavens. One of the next major breakthroughs for natural history and our ability to more fully understand the past, present, and future of civilization will require the discovery of life on other planets. That our planet is unique in evolving life in general, and intelligent life in particular, is as preposterous today as it was in the Middle Ages to believe that the earth was flat and the sun was the center of the universe. Given the sheer numerical odds, life, featuring a natural history of evolution, is likely common in the universe. The Fermi paradox, named after the Italian Nobel Prize–winning physicist, is the contradiction between the astronomically large number of planets in the universe and the lack of evidence of intelligent extraterrestrial life, implying therefore that it must exist. So where is everyone? Given our technological advancements, it is increasingly likely that signs of life will be found within the next century, in our children’s lifetime. At the moment, only a dozen potentially human habitable planets have been found in the Milky Way, but estimates suggest that the universe is teeming with other galaxies able to support life. The Milky Way alone may host eighty billion habitable planets, and the universe as a whole may hold orders of magnitude more than that.1 Finding these planets and life on them is essential for wholly understanding some of the crucial elements of the natural history of life, such as how exactly inorganic surroundings led to organic life, how accurate and general is the Gaia hypothesis (discussed in Chapter 1), and if civilizations follow the same, general, inexorable trends we have seen on earth: that is, if they predictably develop from principles of self-organization, symbiogenesis, hierarchical organization, and natural selection. Finding and studying other life-bearing planets is quickly becoming a necessary element in comparing and understanding planetary systems of life. The autopoietic, self-replicating, and mutualist elements of our beginnings that led to intelligent life, and that life’s increasingly negative relationship with the world around it, will become testable hypotheses that may also teach us how to tackle possibly built-in, self-fulfilling trends of growth and collapse.

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Is the process and march of life on a given planet a cyclical one? Does life evolve, organize, become complex, become intelligent, and crash after resource exploitation and conflict? Or can a mixture of technology, cooperation, and altruism eventually change the characters and choices of a species that is able to rewire their selfish genes? Will selfless, artificially intelligent beings created with foresight replace us as perfectly designed rulers of the earth? Do selfish-gene-driven consumer interactions predictably lead to evolutionary arms races, entheogenic defensive chemistry, mythologies initiated by hallucinations, and chemical addictions? While exploring other planets, we may find that microbial life is common across the universe, developing relatively easily, but learn that the evolution of simple microbes into complex organisms is exceedingly rare. Will global habitat degradation be enough to trigger human cooperation to solve our planetary woes, or will an invasion of our planet by extraterrestrial beings be necessary to trigger global human altruism? Or we may find that artificial intelligent beings evolve competition and selfishness, renewing the battle for the survival of complex life. Regardless, there is much for us to learn, and many gaps to fill, by comparing across planets the variations in natural history and the evolution of life. If humanity lives to see this happen, it will be science rather than placating, comforting mythologies that teach us the answers to some of our oldest questions, such as “What is life? Where do we come from?” and perhaps our most pressing one: What must we do next?

Notes

Introduction 1. 2. 3. 4. 5. 6. 7.

Hutchinson, Ecological Theater. Johnston, Niles, and Rohwer, “Hermon Bumpus and Natural Selection.” Grant and Grant, “Unpredictable Evolution.” Wynne-Edwards, Animal Dispersion. Wilson, Genesis; Christakis, Blueprint. Vermeij, Biogeography and Adaptation. Kimura, Neutral Theory of Molecular Genetics; Hubbell, Unified Neutral Theory; Heisenberg, “Über den anschaulichen Inhalt der quantentheoretischen Kinematik and Mechanik.”

Chapter One. Cooperative Life 1. Lyell, Principles of Geology; Hutton, System of the Earth, 1785; Amelin, Krot, Hutcheon, and Ulyanov, “Lead Isotopic Ages”; Bond et al., “Star in the Solar Neighborhood.” 2. Lemaître, “Un universe homogène”; Hubble, “A Relation between Distance and Radial Velocity.” 3. See Ali and Das, “Cosmology from Quantum Potential.” Also important to the discovery of the universe’s expansion is the sheer enormity of the universe, and the concomitant probability of life developing on planets other than earth. This will be a central subject of the Epilogue. 4. Melosh, “Rocky Road to Panspermia.” 5. Cody et al., “Primordial Carbonylated Iron-Sulfur Compounds.” 6. Lane, Life Ascending. 7. Margulis, who married the astrophysicist Carl Sagan, died in 2011. 8. Margulis, “Symbiogenesis”; Sagan, Lynn Margulis.

239

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Notes to Pages 24–41

9. Sagan, Lynn Margulis. This reaction to Margulis’s theory was itself an unfair characterization of Darwin, who spent decades examining the role of earthworms in engineering soils, a full century before earthworms were recognized as crucial soil farmers and as partners with flowers in a reciprocally dependent relationship. It was Darwin’s overzealous disciples and the general public who overplayed the importance of competition and predation rather than Darwin himself: Darwin understood the role of positive interactions and feedbacks in evolution, but simply did not live long enough to synthesize them into his theory. 10. Barzun, From Dawn to Decadence. 11. Dayton, “Experimental Evaluation of Ecological Dominance.” 12. Crotty and Angelini, manuscript in review. 13. Maturana and Varela, Autopoiesis and Cognition, 41–47; Buss, Evolution of Individuality. 14. Simon, “Architecture of Complexity”; Wagner, “Homologues.” 15. Janzen, “Coevolution of Mutualism”; Ehrlich and Raven, “Butterflies and Plants”; Connell and Slatyer, “Mechanisms of Succession”; Schoener, “Field Experiments on Interspecific Competition.” 16. Wilson and Agnew, “Positive-Feedback Switches”; Ellison et al., “Loss of Foundation Species”; Knowlton and Jackson, “Ecology of Coral Reefs.” 17. Li et al., “Symbiotic Gut Microbes”; Koskella, Hall, and Metcalf, “Microbiome beyond the Horizon.” 18. Gill et al., “Metagenomic Analysis”; Ley, Peterson, and Gordon, “Ecological and Evolutionary Forces”; Dethlefsen, McFall-Ngai, and Relman, “Ecological and Evolutionary Perspective”; Nicholson et al., “Host-Gut Microbiota.” 19. Gill et al., “Metagenomic Analysis”; Bollinger et al., “Biofilms.” 20. Frank et al., “Molecular-Phylogenetic Characterization”; Marteau et al., “Protection from Gastrointestinal Diseases.” 21. Gill et al., “Metagenomic Analysis”; Whitman, “Song of Myself.”

Chapter Two. Life in the Food Chain 1. Susman, “Fossil Evidence.” 2. Spoor et al., “Implications of New Early Homo Fossils.” 3. Leonard and Robertson, “Rethinking the Energetics of Bipedality”; Domínguez-Rodrigo, Pickering, and Bunn, “Configurational Approach.” 4. Bramble and Lieberman, “Endurance Running”; Jablonski, “Naked Truth”; Roach et al., “Elastic Energy Storage.” 5. Wrangham, Catching Fire. 6. Koebnick et al., “Consequences of a Long-Term Raw Food Diet”; Chan and Mantzoros, “Role of Leptin.” 7. Barnosky et al., “Has the Earth’s Sixth Mass Extinction Already Arrived?”

Notes to Pages 42–50

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8. Wong, “Rise of the Human Predator”; Mourre, Villa, and Henshilwood, “Early Use of Pressure Flaking”; d’Errico et al., “Early Evidence.” 9. Ambrose, “Paleolithic Technology”; Sherby and Wadsworth, “Ancient Blacksmiths”; Henshilwood et al., “100,000-Year-Old Ochre-Processing Workshop”; Cavalli-Sforza, Luca, and Feldman, “Application of Molecular Genetic Approaches”; Hung et al., “Ancient Jades”; Craig et al., “Macusani Obsidian.” 10. Wrangham, Catching Fire; Botha and Knight, Cradle of Language; Mourre, Villa, and Henshilwood, “Early Use of Pressure Flaking”; Jacobs et al., “Ages for the Middle Stone Age of Southern Africa”; Henshilwood et al., “Middle Stone Age Shell Beads”; Henshilwood et al., “Emergence of Modern Human Behavior.” 11. Gray and Jordon, “Language Trees”; Gray and Atkinson, “LanguageTree Divergence Times”; Pagel et al., “Ultraconserved Words.” 12. Atkinson, “Phonemic Diversity.” 13. D’Anastasio et al., “Micro-Biomechanics of the Kebara 2 Hyoid”; Martínez et al., “Human Hyoid Bones.” 14. Vargha-Khadem et al., “Neural Basis”; Vargha-Khadem et al., “Praxic and Nonverbal Cognitive Deficits”; Enard et al., “Molecular Evolution of FOXP2”; Fisher and Marcus, “Eloquent Ape.” 15. Pagel et al., “Ultraconserved Words”; Pagel, “Human Language”; Gray and Jordan, “Language Trees”; Gray and Atkinson, “Language-Tree Divergence Times.” 16. Kittler, Kayser, and Stoneking, “Molecular Evolution”; Rogers, Iltis, and Wooding, “Genetic Variation”; Toups et al., “Origin of Clothing Lice”; Tattersall, Encyclopedia of Human Evolution and Prehistory; Shea and Sisk, “Complex Projectile Technology”; Goebel, Waters, and O’Rourke, “Late Pleistocene Dispersal”; Hublin, “Earliest Modern Human Colonization of Europe”; Liu et al., “Earliest Unequivocally Modern Humans in Southern China”; Erlandson et al., “Kelp Highway Hypothesis.” 17. Liu et al., “Earliest Unequivocally Modern Humans in Southern China”; Storey et al., “Radiocarbon and DNA Evidence”; Thorsby, “Polynesian Gene Pool.” 18. Hershkovitz et al., “Levantine Cranium from Manot Cave”; Sankararaman et al., “Date of Interbreeding”; Hortolà and Martínez-Navarro, “Quaternary Megafaunal Extinction”; Smith, Jankovi´c, and Karavani´c, “Assimilation Model”; Zimmer, “Human Family Tree Bristles”; Villmoare et al., “Early Homo”; Winterhalder, Smith, and American Anthropological Association, Hunter-Gatherer Foraging Strategies. 19. Underdown and Houldcroft, “Neanderthal Genomics”; Pinker, Better Angels. 20. Mittelbach, Community Ecology; Diamond, Guns, Germs, and Steel. 21. Cooper et al., “Abrupt Warming Events”; Gibbons, “Revolution”; Hewitt, “Genetic Legacy.”

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Notes to Pages 51–67

22. Freedman et al., “Genome Sequencing”; Thalmann et al., “Complete Mitochondrial Genomes.” 23. Shipman, Invaders. 24. Gould, Ontogeny and Phylogeny. 25. Martin, Twilight of the Mammoths; Firestone et al., “Evidence for an Extraterrestrial Impact”; Sandom et al., “Global Late Quaternary Megafauna Extinctions.” 26. Miller et al., “Ecosystem Collapse.” 27. Burney and Flannery, “Fifty Millennia”; Steadman, “Prehistoric Extinctions”; Duncan, Boyer, and Blackburn, “Magnitude and Variation of Prehistoric Bird Extinctions”; Blackburn et al., “Avian Extinction.”

Chapter Three. Taming Nature 1. Berna et al., “Microstratigraphic Evidence”; Mithen, After the Ice; Despriée et al., “Lower and Middle Pleistocene Human Settlements.” 2. Gause, “Experimental Analysis”; Paine, “Food Web Complexity”; Mittelbach, Community Ecology. 3. Lee and Daly, Cambridge Encyclopedia of Hunters and Gatherers. 4. Keeley and Zedler, “Evolution of Life Histories in Pinus”; Schwilk and Ackerly, “Flammability and Serotiny as Strategies”; Schwilk, “Flammability Is a Niche Construction Trait:”; Bond and Keeley, “Fire as a Global ‘Herbivore’ ”; Van Langevelde et al., “Effects of Fire and Herbivory”; Gashaw and Michelsen, “Influence of Heat Shock.” 5. Paine, “Food Web Complexity”; Belsky, “Does Herbivory Benefit Plants?”; Bertness et al., “Consumer-Controlled Community States”; Yibarbuk et al., “Fire Ecology.” 6. Ehrlich and Raven, “Butterflies and Plants”; Darwin, On the Origin of Species. 7. Purugganan and Fuller, “Nature of Selection”; Fuller et al., “Domestication Process”; De Wet and Harlan, “Weeds and Domesticates.” 8. Hamilton, “Geometry for Selfish Herd”; Kurlansky, Big Oyster; Lawrence, “Oysters.” 9. Diamond, Guns, Germs, and Steel. 10. Zeder, “Central Questions.” 11. Endler, Natural Selection; Reznick et al., “Evaluation”; Losos, Warheitt, and Schoener, “Adaptive Differentiation”; Childe, Man Makes Himself. 12. Chessa et al., “Revealing the History of Sheep Domestication”; Pedrosa et al., “Evidence of Three Maternal Lineages”; Larson et al., “Ancient DNA”; Bruford, Bradley, and Luikart, “DNA Markers.” 13. Brown et al., “Complex Origins”; Harari, Sapiens; Snogerup, Gustafsson, and Von Bothmer, “Brassica Sect. Brassica (Brassicaceae).” 14. Diamond and Bellwood, “Farmers and Their Languages.” 15. Dudley, Drunken Monkey.

Notes to Pages 67–82

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16. Vallee, “Alcohol in the Western World.” 17. Katz and Voigt, “Bread and Beer”; Revedin et al., “Thirty ThousandYear-Old Evidence.” 18. Breton et al., “Taming the Wild”; Mithen, After the Ice. 19. Krebs, “Gourmet Ape.” 20. Tishkoff et al., “Convergent Adaptation”; Kolars et al., “Yogurt”; Bloom and Sherman, “Dairying Barriers.” 21. Bloom and Sherman, “Dairying Barriers”; Jew, AbuMweis, and Jones, “Evolution of the Human Diet.” 22. Bettinger, Barton, and Morgan, “Origins of Food Production”; Flad, Jing, and Shuicheng, “Zooarcheological Evidence.” 23. Frankopan, Silk Roads. 24. Denham, Haberle, and Lentfer, “New Evidence”; Denham, “Ancient and Historic Dispersals”; Keeley and Zedler, “Evolution of Life Histories in Pinus”; Delcourt and Delcourt, Prehistoric Native Americans. 25. Childe, Man Makes Himself; Berbesque et al., “Hunter-Gatherers”; Cohen, Food Crisis in Prehistory; Diamond, “Worst Mistake.” 26. Zeder, “Domestication”; Bellwood, “Early Agriculturalist Population Diasporas?”; Diamond, “Evolution.”

Chapter Four. The Triumph and Curse of Civilization 1. Kremer, “Population Growth and Technological Change”; Bongaarts and Bulatao, Beyond Six Billion; Capra, Web of Life. 2. Margulis and Sagan, Microcosmos. 3. Pinker, Better Angels; Wilson and Wilson, “Rethinking”; Goodnight and Stevens, “Experimental Studies.” 4. Bairoch, Cities and Economic Development. 5. Pinker, Better Angels. While I find Pinker’s work essential and persuasive, his least compelling point is the assumption that hunter-gatherers were the most violent humans in our species’ history. While the extended family groups of genetic relatives that composed hunter-gatherer units certainly competed violently with other groups, Pinker’s claims are based on the frequency of lethal injuries in Paleolithic human burial sites and bodies preserved in ice or anoxic swamps. This is far from a random sampling of Paleolithic hunter-gatherers, and could be a biased sample of war heroes and/or punished criminals. Ultimately this is a small quibble, but worth pointing out: I am more prone to argue that violence was highest as human populations grew and began forming around each other, before the pacifying process of civilization worked to quell these conflicts. See Barzun, From Dawn to Decadence. 6. Pinker, Better Angels. 7. Dethlefsen, McFall-Ngai, and Relman, “Ecological and Evolutionary Perspective.”

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Notes to Pages 83–107

8. McGovern et al., “Fermented Beverages”; Diamond, Guns, Germs, and Steel; Diamond, “Double Puzzle of Diabetes”; Hodges, Technology in the Ancient World; Shipman, Invaders. 9. Postgate, Early Mesopotamia; Anati, “Prehistoric Trade”; Daniels and Bright, World’s Writing Systems. 10. Van De Mieroop, History of the Ancient Near East; Bar-Yosef, “From Sedentary Foragers to Village Hierarchies”; Johnson, “God’s Punishment.” 11. Schmidt, “Göbekli Tepe—the Stone Age Sanctuaries.” 12. Miller, Drugged; Curry, “Göbekli Tepe.” 13. Pollock, Ancient Mesopotamia. 14. Kohn, Dictionary of Wars; Larsen, “Biological Changes.” 15. Larsen, “Biological Changes”; Attenborough, First Eden; Carson, Silent Spring. 16. Lukacs, “Fertility and Agriculture”; Diamond, “Double Puzzle of Diabetes”; Lazar, “How Obesity Causes Diabetes”; Berbesque et al., “HunterGatherers.” 17. Attenborough, First Eden; Dregne, “Desertification”; Egan, Worst Hard Time.

Chapter Five. Resource Exploitation 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

11. 12.

13. 14.

Tilman, Resource Competition. Vermeij, Evolution and Escalation. Childe, Bronze Age. Akanuma, “Significance”; Williams, “Metallurgical Study.” Vermeij, Biogeography and Adaptation. Miller, Drugged; Hunt, Governance of the Consuming Passions; Elliott, “Purple Pasts”; Ball, Bright Earth. Mikesell, “Deforestation of Mount Lebanon”; Hajar et al., “Cedrus libani (A. Rich) Distribution”; Basch, “Phoenician Oared Ships.” Bradley and Cartledge, Cambridge World History of Slavery; Gordon, “Nationality of Slaves”; Beckwith, Empires of the Silk Road. Richard, “International Trafficking.” Anthony, Horse, the Wheel, and Language; Ludwig et al., “Coat Color Variation”; Outram et al., “Earliest Horse Harnessing and Milking”; Ji et al., “Monophyletic Origin of Domestic Bactrian Camel”; Hoffecker, Powers, and Goebel, “Colonization of Beringia”; Marshall, “Land Mammals.” Yagil, Desert Camel; Gauthier-Pilters and Dagg, Camel. Anthony, Horse, the Wheel, and Language; Ludwig et al., “Coat Color Variation”; Outram et al., “Earliest Horse Harnessing and Milking”; Warmuth et al., “Reconstructing the Origin and Spread of Horse Domestication.” Frankopan, Silk Roads. Edwards, Politics of Immorality.

Notes to Pages 107–125

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15. Benedictow, Black Death; Achtman et al., “Microevolution”; Morelli et al., “Yersinia pestis Genome Sequencing.” 16. Garnsey and Saller, Roman Empire. 17. Friedman, World Is Flat. 18. Weatherford, Genghis Khan. 19. Ceylan and Fung, “Antimicrobial Activity of Spices”; Arora and Kaur, “Antimicrobial Activity of Spices.” 20. Diamond, Guns, Germs, and Steel. 21. Carlton, “Blue Immigrants.” 22. Elton, Ecology of Invasions.

Chapter Six. Famine and Disease 1. Milner, Hardness of Heart/Hardness of Life; Bloch, “Abandonment, Infanticide, and Filicide”; Shahar, Childhood. 2. Zipes, Enchanted Screen. 3. Hrdy, “Infanticide as a Reproductive Strategy.” 4. Stephenson, “Flower and Fruit Abortion”; Spight, “Patterns of Change.” 5. Jacobsen and Adams, “Salt and Silt”; Berbesque et al., “Hunter-Gatherers.” 6. Livy, History of Rome; Garnsey, Famine and Food Supply; Mallory, China; Hong, “Politeness in Chinese.” 7. Goodwin, Cohen, and Fry, “Panglobal Distribution”; Wolfe, Dunavan, and Diamond, “Origins.” 8. Neel, “Diabetes Mellitus.” 9. World Health Organization, World Health Database, 2015; Fagan, Floods, Famines, and Emperors. 10. Black, Morris, and Bryce, “Where and Why”; Bryce et al., “WHO Estimates.” 11. Lee, Kyung, and Mazmanian, “Has the Microbiota Played a Critical Role?”; Moal and Servin, “Front Line.” 12. Booth et al., “Molecular Markers.” 13. Fournier et al., “Human Pathogens.” 14. Kittler, Kayser, and Stoneking, “Molecular Evolution.” 15. Booth et al., “Host Association”; Koganemaru and Miller, “Bed Bug Problem.” 16. Hosokawa et al., “Wolbachia.” 17. Sachs and Malaney, “Economic and Social Burden”; World Health Organization, World Health Database, 2015. 18. Cornejo and Escalante, “Origin and Age of Plasmodium vivax.” 19. Rich et al., “Origin of Malignant Malaria”; Ferreira et al., “Sickle Hemoglobin”; Pagnier et al., “Evidence.” 20. Waters, Higgins, and McCutchan, “Plasmodium-Falciparum”; Webb, Humanity’s Burden; Sallares, Bouwman, and Anderung, “Spread of Malaria”; McCullough, Path between the Seas.

246 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

36.

Notes to Pages 126–144 McCullough, Path between the Seas; Medlock et al., “Review.” Barry, Great Influenza. Benedictow, Black Death. Inglesby et al., “Plague as a Biological Weapon.” Benedictow, Black Death. Bilodeau, “Paradox of Sagadahoc”; Diamond, Guns, Germs, and Steel; Thornton, American Indian Holocaust and Survival. Knell, “Syphilis.” Gilman, Making the Body Beautiful. Majno, Healing Hand; Wainwright, “Moulds in Folk Medicine.” Kardos and Demain, “Penicillin.” Neu, “Crisis”; Heuer, Schmitt, and Smalla, “Antibiotic Resistance.” Bergh et al., “High Abundance of Viruses.” Behbehani, “Smallpox Story.” Banchereau and Palucka, “Dendritic Cells”; Ozawa et al., “During the ‘Decade Of Vaccines.’ ” Clay and Kover, “Red Queen Hypothesis”; Hamilton, Axelrod, and Tanese, “Sexual Reproduction”; Motulsky, “Metabolic Polymorphisms”; Chaisson et al., “Resolving the Complexity of the Human Genome”; Pennisi, “Encode Project”; Varki and Altheide, “Comparing the Human and Chimpanzee Genomes.” Bauch and McElreath, “Disease Dynamics”; Baker and Armelagos, “Origin and Antiquity of Syphilis.”

Chapter Seven. Domination versus Cooperation 1. Arnold, “Archaeology of Complex Hunter-Gatherers.” 2. Wilson, Sociobiology; Bruno, Stackowitz, and Bertness, “Including Positive Interactions.” 3. Sidanius and Pratto, Social Dominance. 4. Ibid.; Wilson, Sociobiology. 5. Pringle et al., “Spatial Pattern”; Barnes and Powell, “Development, General Morphology”; Bertness, Gaines, and Yeh, “Making Mountains out of Barnacles.” 6. Wilson, Sociobiology; Lewontin, Rose, and Kamin, Not in Our Genes; Pinker, Blank Slate. 7. Sidanius and Pratto, Social Dominance; Bairoch, Cities and Economic Development. 8. Houston and Stuart, “Of Gods, Glyphs and Kings”; Wilson, Insect Societies; Gordon, “Organization of Work”; Friedman, World Is Flat. 9. Pinker, Better Angels. 10. Finley, Ancient Economy. 11. Taylor, Castration; Anderson, Hidden Power; Tracy, Castration and Culture; Tougher, Eunuch.

Notes to Pages 145–169

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12. Baudoin, “Host Castration”; O’Donnell, “How Parasites Can Promote”; Yu and Pierce, “Castration Parasite”; Lafferty and Kuris, “Parasitic Castration.” 13. Robertson, “Social Control.” 14. Pinker, Better Angels. 15. Rockley, Primogeniture; Contamine, War. 16. Barnes and Powell, “Development, General Morphology.” 17. Sidanius and Pratto, Social Dominance; Huntington, Clash of Civilizations. 18. Fagan, Fish on Friday. 19. Diamond, Guns, Germs, and Steel; Coe, Breaking the Maya Code. 20. Danziger and Gillingham, 1215. 21. Reilly, Closing of the Muslim Mind. 22. Brown, Rare Treasure. 23. Castells, Rise of the Network Society; Bottéro, Mesopotamia; Scholz, Eunuchs and Castrati; Tanye, “Access and Barriers to Education”; Bäuml, “Varieties and Consequences”; Goodell, American Slave Code.

Chapter Eight. Our Ethnocentric, Entheogenic Universe 1. 2. 3. 4.

5. 6.

7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Dennett, From Bacteria to Bach. Huxley, Brave New World. Huxley, Doors of Perception. Graves, World’s Sixteen Crucified Saviors. These virgin birth narratives may have developed out of translation errors or exaggerations due to the similar words commonly used for young girls and virgins. Ibid.; Acharya S, Suns of God. Frankopan, Silk Roads; Reneke, “Was the Christmas Star Real?”; Bullinger, Companion Bible; McGrath, Introduction to Christianity; Huskinson, “Some Pagan Mythological Figures”; Emmel, Hahn, and Gotter, Destruction and Renewal. Huntington, Clash of Civilizations. Curry, “Göbekli Tepe”; Schmidt, “Göbekli Tepe”; Merlin, “Archaeological Evidence”; Guerra-Doce, “Origins of Inebriation.” Huffman, “Current Evidence.” Miller, Drugged; Fuller, Stairways to Heaven; Wright et al., “Caffeine.” Eliade, Shamanism; McKenna, Food of the Gods. Guerra-Doce, “Origins of Inebriation.” Leroi-Gourhan, “Flowers”; Bakels, “Der Mohn”; Guerra-Doce, “Origins of Inebriation.” Znamenski, Shamanism in Siberia; Siefker, Santa Claus; Renterghem, When Santa was a Shaman; McKenna, “When Santa Was a Mushroom.” Allegro, Sacred Mushroom. Wasson et al., Persephone’s Quest. El-Seedi et al., “Prehistoric Peyote Use.” Pahnke, “Drugs and Mysticism.”

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Notes to Pages 173–188

Chapter Nine. Preserving Food and Improving Health 1. Caporael, “Ergotism”; Alm, “Witch Trials”; Hofmann, “Historical View”; Haarmann et al., “Ergot.” 2. More generally, the witchcraft culture (of flying on broomsticks, casting spells, peddling potions, and living in a separate world) was in fact due to cults based on experimentation with, knowledge of, and use of plant natural products that supposedly gave witches otherworldly powers. Thompson, “How Witches’ Brews”; Dongen and de Groot, “History of Ergot Alkaloids”; Miller, Drugged. 3. Dog, “Reason to Season.” 4. Bowers et al., “Discovery.” 5. Brower and Glazier, “Localization of Heart Poisons.” 6. Huffman, “Current Evidence”; Singh, “From Exotic Spice to Modern Drug?”; Young et al., “Why on Earth?” 7. Dog, “Reason to Season”; Brul and Coote, “Preservative Agents”; Huffman et al., “Seasonal Trends”; Leonard and Robertson, “Evolutionary Perspectives”; Hockett and Haws, “Nutritional Ecology.” 8. Sherman and Billing, “Darwinian Gastronomy”; Ratkowsky et al., “Relationship”; Kirchman, Morán, and Ducklow, “Microbial Growth.” 9. Sherman and Billing, “Darwinian Gastronomy.” 10. Strobel and Daisy, “Bioprospecting”; Dethlefsen, McFall-Ngai, and Relman, “Ecological and Evolutionary Perspective”; Collins and Gibson, “Probiotics, Prebiotics, and Synbiotics”; Qin et al., “Human Gut Microbial Gene Catalogue.” 11. Ewald, “Evolutionary Perspective”; Lantz and Booth, “Social Construction”; Safe, “Environmental and Dietary Estrogens”; Peto et al., “Cervical Cancer.” 12. Ewald, Evolution of Infectious Disease. 13. Food and Agriculture Organization of the United Nations, “Guide”; Bellwood et al., “Confronting the Coral Reef Crisis”; Bruno and Selig, “Regional Decline.” 14. Tracy and McNaughton, “Elemental Analysis”; Jones and Hanson, Mineral Licks. 15. Our primate relatives, for example, have discriminating palates for salt licks. See Krishnamani and Mahany, “Geophagy among Primates.” 16. Kurlansky, Salt. 17. Curtin, Cross-Cultural Trade. 18. Megaw, Morgan, and Stöllner, “Ancient Salt-Mining”; Stöllner et al., “Economy of Dürrnberg-Bei-Hallein.” 19. Kurlansky, Salt; Easwaran, Gandhi the Man. 20. Kurlansky, Salt; James and Thorpe, Ancient Inventions. 21. Wood, “America’s Natural Ice Industry.” 22. MacKenzie, “History of Oystering.” 23. Troost, “Causes and Effects”; Carlton and Geller, “Ecological Roulette.”

Notes to Pages 191–211

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Chapter Ten. Civilization on Fire 1. Miller, “Paleoethnobotanical Evidence”; Horne, “Fuel for the Metal Worker”; Ottaway, “Innovation, Production, and Specialization.” 2. Wilson and Agnew, “Positive-Feedback Switches.” 3. Hughes and Thirgood, “Deforestation, Erosion”; Kaplan, Krumhardt, and Zimmermann, “Prehistoric and Preindustrial Deforestation”; Hughes, “Ancient Deforestation Revisited.” 4. Hallett and Wright, Life without Oil; Williams, “Metallurgical Study”; Williams, “Dark Ages.” 5. Burt, Edward I; Diamond, Collapse; Patinkin, “Rape.” 6. Redfield, “Development”; Shotyk et al., “History”; Redfield, “Ontogeny.” 7. De Vries and van der Woude, First Modern Economy. 8. Ibid.; Kaijser, “System Building.” 9. Rodhe and Svensson, “Impact.” 10. Bradshaw, Evans, and Hindell, “Mass Cetacean Strandings”; Brabyn and McLean, “Oceanography and Coastal Topography”; Ellis, Men and Whales. 11. Kirk and Daugherty, Hunters of the Whale. 12. Barkham, “Basque Whaling Establishments”; Allen, “Whalebone Whales”; Fujiwara and Caswell, “Demography.” 13. Ellis, Men and Whales; Dolin, Leviathan; Watwood et al., “Deep-Diving”; Whitehead, “Estimates.” 14. Heckman et al., “Molecular Evidence.” 15. Bonfante and Genre, “Mechanisms.” 16. Nef, Rise of the British Coal Industry. 17. Freese, Coal. 18. Brimblecombe, Big Smoke. 19. Freese, Coal. 20. Antonovics, “Metal Tolerance in Plants”; Kettlewell, “Phenomenon of Industrial Melanism.” 21. Conti and Cecchetti, “Biological Monitoring.” 22. Yergin, Prize. 23. Kurlansky, Salt. 24. Economist editors, “World in a Barrel.” 25. Vandenbosch, Nuclear Waste Stalemate. 26. Sala et al., “Global Biodiversity Scenarios”; Yergin, Prize. 27. Crain, Kroeker, and Halpern, “Interactive and Cumulative Effects.”

Chapter Eleven. Unnatural Nature 1. Hardin, “Tragedy of the Commons.” 2. Menze and Ur, “Mapping Patterns.” 3. He et al., “Economic Development.”

250

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4. Lotze and McClenachan, “Marine Historical Ecology”; Myers and Worm, “Rapid Worldwide Depletion”; Coverdale et al., “Indirect Human Impacts.” 5. Tainter, Collapse of Complex Societies; Fraser and Rimas, Empires of Food. 6. Dalfes, Kukla, and Weiss, Third Millennium BC Climate Change. 7. Haug et al., “Climate.” 8. Diamond, Collapse; Hunt and Lipo, Statues That Walked; Stevenson et al., “Variation.” 9. Tilman et al., “Forecasting.” 10. Daily, Nature’s Services; de Groot, Wilson, and Boumans, “Typology.” 11. Gersberg et al., “Role of Aquatic Plants.” 12. Egan, Worst Hard Time; Steinbeck, Grapes of Wrath. 13. Beisner, Haydon, and Cuddington, “Alternative Stable States”; Scheffer et al., “Anticipating Critical Transitions.” 14. Griffin and Kellogg, “Dust Storms”; Rypien, Andras, and Harvell, “Globally Panmictic Population Structure.” 15. Hansen, Stehman, and Potapov, “Quantification”; Fearnside, “Deforestation.” 16. Hughes, “Catastrophes”; Gardner et al., “Long-Term Region-Wide Declines.” 17. Valiela, Bowen, and York, “Mangrove Forests”; Gedan and Silliman, “Patterns”; Ellison and Farnsworth, “Mangrove Communities.” 18. Costa, Santos, and Cabral, “Comparative Analysis”; Orth et al., “Global Crisis”; Waycott et al., “Accelerating Loss.” 19. Carson, Silent Spring; Estes et al., “Trophic Downgrading”; Steneck et al., “Kelp Forest Ecosystems.” 20. Vitousek, “Beyond Global Warming.” 21. Meinshausen et al., “Greenhouse-Gas Emission Targets”; Feely et al., “Evidence”; Sagan, Dragons of Eden. 22. Daily, Nature’s Services; Zhang et al., “Global Climate Change.” 23. Feely et al., “Impact of Anthropogenic CO2”; Hoegh-Guldberg et al., “Coral Reefs.” 24. Mouginot et al., “Fast Retreat”; Kirwan and Megonigal, “Tidal Wetland Stability”; Solomon, Qin, and Manning, Climate Change, 2007; Voosen, “Delaware-Sized Iceberg.” 25. He et al., “Economic Development”; Diaz and Rosenberg, “Spreading Dead Zones”; Carr and Carr, Naturalist in Florida; Altieri, “Dead Zones.” 26. He et al., “Economic Development.” 27. Crain, Kroeker, and Halpern, “Interactive and Cumulative Effects.” 28. Vitousek et al., “Human Domination”; Valiela and Teal, “Nutrient Limitation”; Harvell et al., “Review.” 29. Holdren and Ehrlich, “Human Population.” 30. Daily et al., “Value of Nature.” 31. Daily, Nature’s Services; Winfree, “Pollinator-Dependent Crops”; SteffanDewenter, Potts, and Packer, “Pollinator Diversity”; Baum et al., “Collapse and Conservation.”

Notes to Pages 228–237

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32. Huntington, Clash of Civilizations. 33. Elton, Animal Ecology; Harper, Population Biology of Plants. 34. Harari, Sapiens.

Epilogue 1. Leconte et al., “Increased Insolation Threshold”; Petigura, Howard, and Marcy, “Prevalence of Earth-Size Planets.”

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Bibliography

Acharya S (Dorothy Milne Murdock). Suns of God: Krishna, Buddha, and Christ Unveiled. Kempton, IL: Adventures Unlimited, 2004. Achtman, Mark, Giovanna Morelli, Peixuan Zhu, Thierry Wirth, Ines Diehl, Barica Kusecek, Amy J. Vogler, et al. “Microevolution and History of the Plague Bacillus, Yersinia pestis.” PNAS 101, no. 51 (2004): 17837–17842. Akanuma, Hideo. “The Significance of the Composition of Excavated Iron Fragments Taken from Stratum III at the Site of Kaman-Kalehöyük, Turkey.” Anatolian Archaeological Studies 14 (2005): 147–158. Ali, Ahmed Farag, and Saurya Das. “Cosmology from Quantum Potential.” Physics Letters B 741 (2015): 276–279. Allegro, John M. The Sacred Mushroom and the Cross: A Study of the Nature and Origins of Christianity within the Fertility Cults of the Ancient Near East. New York: Doubleday, 1970. Allen, Glover Morrill. “The Whalebone Whales of New England.” Memoirs of the Boston Society of Natural History 8, no. 2 (1916). Alm, Torbjørn. “The Witch Trials of Finnmark, Northern Norway, during the 17th Century: Evidence for Ergotism as a Contributing Factor.” Economic Botany 57, no. 3 (2003): 403–416. Altieri, Andrew H. “Dead Zones Enhance Key Fisheries Species by Providing Predation Refuge.” Ecology 89, no. 10 (2008): 2808–2818. Ambrose, Stanley H. “Paleolithic Technology and Human Evolution.” Science 291, no. 5509 (2001): 1748–1753. Amelin, Yuri, Alexander N. Krot, Ian D. Hutcheon, and Alexander A. Ulyanov. “Lead Isotopic Ages of Chondrules and Calcium-AluminumRich Inclusions.” Science 297, no. 5587 (2002): 1678–1683. Anati, Emmanuel. “Prehistoric Trade and the Puzzle of Jericho.” Bulletin of the American Schools of Oriental Research 167 (1962): 25–31. Anderson, Mary M. Hidden Power: The Palace Eunuchs of Imperial China. Amherst, MA: Prometheus Books, 1990.

253

254

Bibliography

Anthony, David W. The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World. Princeton, NJ: Princeton University Press, 2007. Antonovics, Janis. “Metal Tolerance in Plants: Perfecting an Evolutionary Paradigm.” Paper presented at the International Conference on Heavy Metals in the Environment, Toronto, October 27–31, 1975. Arnold, Jeanne E. “The Archaeology of Complex Hunter-Gatherers.” Journal of Archaeological Method and Theory 3, no. 1 (1996): 77–126. Arora, Daljit S., and Jasleen Kaur. “Antimicrobial Activity of Spices.” International Journal of Antimicrobial Agents 12, no. 3 (1999): 257–262. Atkinson, Quentin D. “Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa.” Science 332, no. 6027 (2011): 346–349. Attenborough, David. The First Eden: The Mediterranean World and Man. First American edition. New York: Little, Brown, 1987. Bairoch, Paul. Cities and Economic Development: From the Dawn of History to the Present. Chicago: University of Chicago Press, 1991. Bakels, Corrie C. “Der Mohn, Die Linearbandkeramik Und Das Westliche Mittelmeergebiet.” Archäologisches Korrespondenzblatt 12, no. 1 (1982): 11–13. Baker, Brenda J., and George J. Armelagos. “The Origin and Antiquity of Syphilis: Paleopathological Diagnosis and Interpretation.” Current Anthropology 29, no. 5 (1988): 703–737. Ball, Philip. Bright Earth: Art and the Invention of Color. Chicago: University of Chicago Press, 2003. Banchereau, Jacques, and A. Karolina Palucka. “Dendritic Cells as Therapeutic Vaccines against Cancer.” Nature Reviews Immunology 5, no. 4 (2005): 296–306. Barkham, Selma Huxley. “The Basque Whaling Establishments in Labrador, 1536–1632: A Summary.” Arctic 37, no. 4 (1984): 515–519. Barnes, Harold, and Harold T. Powell. “The Development, General Morphology and Subsequent Elimination of Barnacle Populations, Balanus-crenatus and B-balanoides, after a Heavy Initial Settlement.” Journal of Animal Ecology 19, no. 2 (1950): 175–179. Barnosky, Anthony D., Nicholas Matzke, Susumu Tomiya, Guinevere O. U. Wogan, Brian Swartz, Tiago B. Quental, Charles Marshall, et al. “Has the Earth’s Sixth Mass Extinction Already Arrived?” Nature 471 (2011): 51–57. Barry, John M. The Great Influenza: The Story of the Deadliest Pandemic in History. New York: Penguin, 2004. Bar-Yosef, Ofer. “From Sedentary Foragers to Village Hierarchies: The Emergence of Social Institutions.” Proceedings of the British Academy 110 (2001): 1–38. Barzun, Jacques. From Dawn to Decadence: 1500 to the Present, 500 Years of Western Cultural Life. New York: Harper Collins, 2001.

Bibliography

255

Basch, Lucien. “Phoenician Oared Ships.” Mariner’s Mirror 55, no. 2 (1969): 139–162. Bauch, Chris T., and Richard McElreath. “Disease Dynamics and Costly Punishment Can Foster Socially Imposed Monogamy.” Nature Communications 7 (2016). Baudoin, Mario. “Host Castration as a Parasitic Strategy.” Evolution 29, no. 2 (1975): 335–352. Baum, Julia K., Ransom A. Myers, Daniel G. Kehler, Boris Worm, Shelton J. Harley, and Penny A. Doherty. “Collapse and Conservation of Shark Populations in the Northwest Atlantic.” Science 299, no. 5605 (2003): 389–392. Bäuml, Franz H. “Varieties and Consequences of Medieval Literacy and Illiteracy.” Speculum 55, no. 2 (1980): 237–265. Beckwith, Christopher I. Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present. Princeton, NJ: Princeton University Press, 2009. Behbehani, Abbas M. “The Smallpox Story—Life and Death of an Old Disease.” Microbiology Reviews 47, no. 4 (1983): 455–509. Beisner, Beatrix, Daniel Haydon, and Kim Cuddington. “Alternative Stable States in Ecology.” Frontiers in Ecology and the Environment 1, no. 7 (2003). Bellwood, David R., Terence Patrick Hughes, Carl Folke, and Magnus Nyström. “Confronting the Coral Reef Crisis.” Nature 429 (2004): 827–833. Bellwood, Peter. “Early Agriculturalist Population Diasporas? Farming, Languages, and Genes.” Annual Review of Anthropology 30 (2001): 181–207. Belsky, A. Joy. “Does Herbivory Benefit Plants? A Review of the Evidence.” American Naturalist 127, no. 6 (1986): 870–892. Benedictow, Ole Jørgen. The Black Death, 1346–1353: The Complete History. Woodbridge, UK: Boydell, 2004. Berbesque, J. Colette, Frank W. Marlowe, Peter Shaw, and Peter Thompson. “Hunter-Gatherers Have Less Famine than Agriculturalists.” Biology Letters 10, no. 1 (2014). Bergh, Øivind, Knut Yngve Børsheim, Gunnar Bratbak, and Mikal Heldal. “High Abundance of Viruses Found in Aquatic Environments.” Nature 340, no. 6233 (1989): 467–468. Berna, Francesco, Paul Goldberg, Liora Kolska Horwitz, James Brink, Sharon Holt, Marion Bamford, and Michael Chazan. “Microstratigraphic Evidence of in Situ Fire in the Acheulean Strata of Wonderwerk Cave, Northern Cape Province, South Africa.” PNAS 109, no. 20 (2012): E1215–E1220. Bertness, Mark D., Steven D. Gaines, and Mark E. Hay, eds. Marine Community Ecology. Sunderland, MA: Sinauer Associates, 2001. Bertness, Mark D., Steven D. Gaines, and Su Ming Yeh. “Making Mountains out of Barnacles: The Dynamics of Acorn Barnacle Hummocking.” Ecology 79, no. 4 (1998): 1382–1394.

256

Bibliography

Bertness, Mark D., Geoffrey C. Trussell, Patrick J. Ewanchuk, Brian R. Silliman, and Caitlin Mullan Crain. “Consumer-Controlled Community States on Gulf of Maine Rocky Shores.” Ecology 85, no. 5 (2004): 1321– 1331. Bettinger, Robert L., Loukas Barton, and Christopher Morgan. “The Origins of Food Production in North China: A Different Kind of Agricultural Revolution.” Evolutionary Anthropology 19, no. 1 (2010): 9–21. Billing, Jennifer, and Paul W. Sherman. “Antimicrobial Functions of Spices: Why Some Like It Hot.” Quarterly Review of Biology 73, no. 3 (1998): 3–49. Bilodeau, Christopher J. “The Paradox of Sagadahoc: The Popham Colony, 1607–1608.” Early American Studies: An Interdisciplinary Journal 12, no. 1 (2014): 1–35. Black, Robert E., Saul S. Morris, and Jennifer Bryce. “Where and Why Are 10 Million Children Dying Every Year?” Lancet 361, no. 9376 (2003): 2226–2234. Blackburn, Tim M., Phillip Cassey, Richard P. Duncan, Karl L. Evans, and Kevin J. Gaston. “Avian Extinction and Mammalian Introductions on Oceanic Islands.” Science 305, no. 5692 (2004): 1955–1958. Bloch, Harry. “Abandonment, Infanticide, and Filicide: An Overview of Inhumanity to Children.” American Journal of Diseases of Children 142, no. 10 (1988): 1058–1060. Bloom, Gabrielle, and Paul W. Sherman. “Dairying Barriers Affect the Distribution of Lactose Malabsorption.” Evolution and Human Behavior 26 (2005): 301–312. Bollinger, R. Randal, Andrew S. Barbas, Errol L. Bush, Shu S. Lin, and William Parker. “Biofilms in the Large Bowel Suggest an Apparent Function of the Human Vermiform Appendix.” Journal of Theoretical Biology 249, no. 4 (2007): 826–831. Bond, Howard E., Edmund P. Nelan, Don A. VandenBerg, Gail H. Schaefer, and Dianne Harmer. “Hd 140283: A Star in the Solar Neighborhood That Formed Shortly after the Big Bang.” Astrophysical Journal Letters 765, no. 12 (2013): 1–5. Bond, William J., and Jon E. Keeley. “Fire as a Global ‘Herbivore’: The Ecology and Evolution of Flammable Ecosystems.” Trends in Ecology & Evolution 20, no. 7 (2005): 387–394. Bonfante, Paola, and Andrea Genre. “Mechanisms Underlying Beneficial Plant-Fungus Interactions in Mycorrhizal Symbiosis.” Nature Communications 1 (2010): 48. Bongaarts, John, and Rodolfo A. Bulatao, eds. Beyond Six Billion: Forecasting the World’s Population. Washington, DC: National Academies Press, 2000. Booth, Warren, Ondrˇej Balvín, Edward L. Vargo, Jitka Vilímová, and Coby Schal. “Host Association Drives Genetic Divergence in the Bed Bug, Cimex lectularius.” Molecular Ecology 24, no. 5 (2015): 980–992.

Bibliography

257

Booth, Warren, Virna L. Saenz, Richard G. Santangelo, Changlu Wang, Coby Schal, and Edward L. Vargo. “Molecular Markers Reveal Infestation Dynamics of the Bed Bug (Hemiptera: Cimicidae) within Apartment Buildings.” Journal of Medical Entomology 49, no. 3 (2012): 535–546. Botha, Rudolf, and Chris Knight, eds. The Cradle of Language: Studies in the Evolution of Language. Oxford, UK: Oxford University Press, 2009. Bottéro, Jean. Mesopotamia: Writing, Reasoning, and the Gods. Chicago: University of Chicago Press, 1992. Bowers, William S., Tomihisa Ohta, Jeanne S. Cleere, and Patricia A. Marsella. “Discovery of Insect Anti-Juvenile Hormones in Plants.” Science 193, no. 4253 (1976): 542–547. Brabyn, Mark W., and Ian G. McLean. “Oceanography and Coastal Topography of Herd-Stranding Sites for Whales in New Zealand.” Journal of Mammalogy 73, no. 3 (1992): 469–476. Bradley, Keith, and Paul Cartledge, eds. The Cambridge World History of Slavery: The Ancient Mediterranean World, vol. 1. Cambridge, UK: Cambridge University Press, 2011. Bradshaw, Corey J. A., Karen Evans, and Mark A. Hindell. “Mass Cetacean Strandings—A Plea for Empiricism.” Conservation Biology 20, no. 2 (2006): 584–586. Bramble, Dennis M., and Daniel E. Lieberman. “Endurance Running and the Evolution of Homo.” Nature 432 (2004): 345–352. Breton, Catherine, Jennifer Ross Guerin, Catherine Ducatillion, Frédéric Médail, Christian A. Kull, and André Bervillé. “Taming the Wild and ‘Wilding’ the Tame: Tree Breeding and Dispersal in Australia and the Mediterranean.” Plant Science 175, no. 3 (2008): 197–205. Brimblecombe, Peter. The Big Smoke: A History of Air Pollution in London since Medieval Times. New York: Routledge, 2011. Brower, Lincoln P., and Susan C. Glazier. “Localization of Heart Poisons in the Monarch Butterfly.” Science 188, no. 4183 (1975): 19–25. Brown, Don. Rare Treasure: Mary Anning and Her Remarkable Discoveries. New York: Houghton Mifflin Harcourt, 2003. Brown, Terence A., Martin K. Jones, Wayne Powell, and Robin G. Allaby. “The Complex Origins of Domesticated Crops in the Fertile Crescent.” Trends in Ecology & Evolution 24, no. 2 (2009): 103–109. Bruford, Michael W., Daniel G. Bradley, and Gordon Luikart. “DNA Markers Reveal the Complexity of Livestock Domestication.” Nature Reviews Genetics 4 (2003): 900–910. Brul, Stanley, and Peter Coote. “Preservative Agents in Foods—Mode of Action and Microbial Resistance Mechanisms.” International Journal of Food Microbiology 50, nos. 1–2 (1999): 1–17. Bruno, John F., and Elizabeth R. Selig. “Regional Decline of Coral Cover in the Indo-Pacific: Timing, Extent, and Subregional Comparisons.” PLoS One 2, no. 8 (2007): e711. doi:artn e711 10.1371/journal.pone.0000711.

258

Bibliography

Bruno, John F., John J. Stackowitz, and Mark D. Bertness. “Including Positive Interactions in Ecological Theory.” Trends in Ecology and Evolution 18 (2003): 119–125. Bryce, Jennifer, Cynthia Boschi-Pinto, Kenji Shibuya, Robert E. Black, and WHO Child Health Epidemiology Reference Group. “WHO Estimates of the Causes of Death in Children.” Lancet 365, no. 9465 (2005): 1147–1152. Bullinger, Ethelbert W. The Companion Bible. Grand Rapids, MI: Kregel, 1999. Burney, David A., and Timothy F. Flannery. “Fifty Millennia of Catastrophic Extinctions after Human Contact.” Trends in Ecology & Evolution 20, no. 7 (2005): 395–401. Burt, Caroline. Edward I and the Governance of England, 1272–1307. Cambridge, UK: Cambridge University Press, 2013. Buss, Leo W. The Evolution of Individuality. Princeton, NJ: Princeton University Press, 1988. Cantor, Norman F. In the Wake of the Plague: The Black Death and the World It Made. New York: Free Press, 2001. Caporael, Linnda R. “Ergotism: The Satan Loosed in Salem?” Science 192, no. 4234 (1976): 21–26. Capra, Fritjof. The Web of Life. London: Harper Collins, 1997. Carlton, James T. “Blue Immigrants: The Marine Biology of Maritime History.” The Log (Mystic Seaport Museum) 44 (1992): 31–36. Carlton, James T., and Jonathan B. Geller. “Ecological Roulette: The Global Transport of Nonindigenous Marine Organisms.” Science 261, no. 5117 (1993): 78–82. Carr, Archie, and Marjorie Harris Carr. A Naturalist in Florida: A Celebration of Eden. New Haven: Yale University Press, 1996. Carson, Rachel. Silent Spring. New York: Houghton Mifflin, 1962. Castells, Manuel. The Rise of the Network Society. Cambridge, MA: Blackwell, 1996. Cavalli-Sforza, L. Luca, and Marcus W. Feldman. “The Application of Molecular Genetic Approaches to the Study of Human Evolution.” Nature Genetics 33 (2003): 266–275. Ceylan, Erdogan, and Daniel Y. C. Fung. “Antimicrobial Activity of Spices.” Journal of Rapid Methods and Automation in Microbiology 12, no. 1 (2004): 1–55. Chaisson, Mark J. P., John Huddleston, Megan Y. Dennis, Peter H. Sudmant, Maika Malig, Fereydoun Hormozdiari, Francesca Antonacci, et al. “Resolving the Complexity of the Human Genome Using Single-Molecule Sequencing.” Nature 517 (2015): 608–611. Chan, Jean L., and Christos S. Mantzoros. “Role of Leptin in EnergyDeprivation States: Normal Human Physiology and Clinical Implications for Hypothalamic Amenorrhoea and Anorexia Nervosa.” Lancet 366, no. 9479 (2005): 74–85.

Bibliography

259

Chessa, Bernardo, Filipe Pereira, Frederick Arnaud, Antonio Amorim, Félix Goyache, Ingrid Mainland, Rowland R. Kao, et al. “Revealing the History of Sheep Domestication Using Retrovirus Integrations.” Science 324, no. 5926 (2009): 532–536. Childe, V. Gordon. The Bronze Age. Cambridge, UK: Cambridge University Press, 1930. ———. Man Makes Himself. London: Watts, 1936. Christakis, Nicholas A. Blueprint: The Evolutionary Origins of a Good Society. New York: Little, Brown Spark, 2019. Clay, Keith, and Paula X. Kover. “The Red Queen Hypothesis and Plant/ Pathogen Interactions.” Annual Review of Phytopathology 34 (1996): 29–50. Cochi, Stephen L., and Walter R. Dowdle, eds. Disease Eradication in the 21st Century: Implications for Global Health. Cambridge, MA: MIT Press, 2011. Cody, George D., Nabil Z. Boctor, Timothy R. Filley, Robert M. Hazen, James H. Scott, Anurag Sharma, and Hatten S. Yoder, Jr. “Primordial Carbonylated Iron-Sulfur Compounds and the Synthesis of Pyruvate.” Science 289, no. 5483 (2000): 1337–1340. Coe, Michael D. Breaking the Maya Code. London: Thames & Hudson, 1992. Cohen, Mark Nathan. The Food Crisis in Prehistory: Overpopulation and the Origins of Agriculture. New Haven: Yale University Press, 1977. Collins, James, and Richard K. Blot. Literacy and Literacies: Texts, Power, and Identity. Cambridge, UK: Cambridge University Press, 2003. Collins, M. David, and Glenn R. Gibson. “Probiotics, Prebiotics, and Synbiotics: Approaches for Modulating the Microbial Ecology of the Gut.” American Journal of Clinical Nutrition 69, no. 5 (1999): 1052s–1057s. Connell, Joseph H., and Ralph O. Slatyer. “Mechanisms of Succession in Natural Communities and Their Role in Community Stability and Organization.” American Naturalist 111, no. 982 (1977): 1119–1144. Contamine, Philippe. War in the Middle Ages. Oxford, UK: Blackwell, 1984. Conti, Marcelo Enrique, and Gaetano Cecchetti. “Biological Monitoring: Lichens as Bioindicators of Air Pollution Assessment—A Review.” Environmental Pollution 114, no. 3 (2001): 471–492. Cooper, Alan, Chris Turney, Konrad A. Hughen, Barry W. Brook, H. Gregory McDonald, and Corey J. A. Bradshaw. “Abrupt Warming Events Drove Late Pleistocene Holarctic Megafaunal Turnover.” Science 349, no. 6248 (2015). Cornejo, Omar E., and Ananias A. Escalante. “The Origin and Age of Plasmodium vivax.” Trends in Parasitology 22, no. 12 (2006): 558–563. Costa, Maria Jose, Carmen I. Santos, and Henrique N. Cabral. ”Comparative Analysis of a Temperate and a Tropical Seagrass Bed Fish Assemblages in Two Estuarine Systems: The Mira Estuary (Portugal) and the Mussulo Lagoon (Angola).” Cahiers de Biologie Marine 43, no. 1 (2002): 73–81.

260

Bibliography

Coverdale, Tyler C., Caitlin P. Brisson, Eric W. Young, Stephanie F. Yin, Jeffrey P. Donnelly, and Mark D. Bertness. “Indirect Human Impacts Reverse Centuries of Carbon Sequestration and Salt Marsh Accretion.” PLoS ONE 9 (2014). Craig, Nathan, Robert J. Speakman, Rachel S. Popelka-Filcoff, Mark Aldenderfere, Luis Flores Blanco, Margaret Brown Vega, Michael D. Glascock, and Charles Stanish. “Macusani Obsidian from Southern Peru: A Characterization of Its Elemental Composition with a Demonstration of Its Ancient Use.” Journal of Archaeological Science 37, no. 3 (2010): 569–576. Crain, Caitlin Mullan, Kristy Kroeker, and Benjamin S. Halpern. “Interactive and Cumulative Effects of Multiple Human Stressors in Marine Systems.” Ecology Letters 11 (2008): 1304–1315. Crotty, Sinead, and Christine H. Angelini. “Mussel Control of Salt Marsh Development and Self-Organization.” Manuscript in review. Curry, Andrew. “Göbekli Tepe: The World’s First Temple?” Smithsonian Magazine 3 (2008): 1–4. Curtin, Philip D. Cross-Cultural Trade in World History. Cambridge, UK: Cambridge University Press, 1984. Daily, Gretchen C. Nature’s Services: Societal Dependence on Natural Ecosystems. Washington, DC: Island Press, 1997. Daily, Gretchen C., Tore Söderqvist, Sara Aniyar, Kenneth Arrow, Partha Dasgupta, Paul R. Ehrlich, Carl Folke, et al. “The Value of Nature and the Nature of Value.” Science 289, no. 5478 (2000): 395–396. Dalfes, H. Nüzhet, George Kukla, and Harvey Weiss, eds. Third Millennium BC Climate Change and Old World Collapse. New York: Springer, 1997. D’Anastasio, Ruggero, Stephen Wroe, Claudio Tuniz, Lucia Mancini, Deneb T. Cesana, Diego Dreossi, Mayoorendra Ravichandiran, et al. “MicroBiomechanics of the Kebara 2 Hyoid and Its Implications for Speech in Neanderthals.” PLoS ONE 8, no. 12 (2013). Daniels, Peter T., and William Bright, eds. The World’s Writing Systems. Oxford: Oxford University Press, 1996. Danziger, Danny, and John Gillingham. 1215: The Year of Magna Carta. New York: Simon & Schuster, 2004. Darwin, Charles. On the Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in the Struggle for Life. London: John Murray, 1861. Dayton, Paul K. “Experimental Evaluation of Ecological Dominance in a Rocky Intertidal Algal Community.” Ecological Monographs 45, no. 2 (1975): 137–159. Delcourt, Paul A., and Hazel R. Delcourt. Prehistoric Native Americans and Ecological Change: Human Ecosystems in Eastern North America since the Pleistocene. Cambridge, UK: Cambridge University Press, 2004. Denham, Tim. “Ancient and Historic Dispersals of Sweet Potato in Oceania.” PNAS 110, no. 6 (2013): 1982–1983.

Bibliography

261

Denham, Tim, Simon Haberle, and Carol Lentfer. “New Evidence and Revised Interpretations of Early Agriculture in Highland New Guinea.” Antiquity 78, no. 302 (2004): 839–857. Dennett, Daniel C. From Bacteria to Bach and Back: The Evolution of Minds. New York: W.W. Norton, 2017. d’Errico, Francesco, Lucinda Backwell, Paola Villa, Ilaria Degano, Jeannette J. Lucejko, Marion K. Bamford, Thomas F. G. Higham, Maria Perla Colombini, and Peter B. Beaumont. “Early Evidence of San Material Culture Represented by Organic Artifacts from Border Cave, South Africa.” PNAS 109, no. 33 (2012): 13214–13219. Despriée, Jackie, Pierre Voinchet, Hélène Tissoux, Marie-Hélène Moncel, Marta Arzarello, Sophie Robin, Jean-Jacques Bahain, et al. “Lower and Middle Pleistocene Human Settlements in the Middle Loire River Basin, Centre Region, France.” Quaternary International 223–224 (2010): 345–359. Dethlefsen, Les, Margaret McFall-Ngai, and David A. Relman. “An Ecological and Evolutionary Perspective on Human-Microbe Mutualism and Disease.” Nature 449 (2007): 811–818. De Wet, Johannes M. J., and Jack R. Harlan. “Weeds and Domesticates: Evolution in the Man-Made Habitat.” Economic Botany 29, no. 2 (1975): 99–107. Diamond, Jared. Collapse: How Societies Choose to Fail or Succeed. New York: Viking Penguin, 2005. ———. “The Double Puzzle of Diabetes.” Nature 423 (2003): 599–602. ———. “Evolution, Consequences and Future of Plant and Animal Domestication.” Nature 418 (2002): 700–707. ———. Guns, Germs, and Steel: A Short History of Everybody for the Last 13,000 Years. New York: W.W. Norton & Company, 1999. ———. “The Worst Mistake in the History of the Human Race.” Discover Magazine (May 1, 1987): 64–66. Diamond, Jared, and Peter Bellwood. “Farmers and Their Languages: The First Expansions.” Science 300, no. 5619 (2003): 597–603. Diaz, Robert J., and Rutger Rosenberg. “Spreading Dead Zones and Consequences for Marine Ecosystems.” Science 321, no. 5891 (2008): 926–929. Dog, Tieraona Low. “A Reason to Season: The Therapeutic Benefits of Spices and Culinary Herbs.” Explore 2, no. 5 (2006): 446–449. Dolin, Eric Jay. Leviathan: The History of Whaling in America. New York: W.W. Norton, 2007. Domínguez-Rodrigo, Manuel, Travis Rayne Pickering, and Henry T. Bunn. “Configurational Approach to Identifying the Earliest Hominin Butchers.” PNAS 107, no. 49 (2010): 20929–20934. Dongen, Pieter W. J. van, and Akosua N. J. A. de Groot. “History of Ergot Alkaloids from Ergotism to Ergometrine.” European Journal of Obstetrics & Gynecology and Reproductive Biology 60, no. 2 (1995): 109–116.

262

Bibliography

Dregne, Harold E. “Desertification of Arid Lands.” Economic Geography 53, no. 4 (1977): 322–331. Dudley, Robert. The Drunken Monkey: Why We Drink and Abuse Alcohol. Berkeley: University of California Press, 2014. Duncan, Richard P., Alison G. Boyer, and Tim M. Blackburn. “Magnitude and Variation of Prehistoric Bird Extinctions in the Pacific.” PNAS 110, no. 16 (2013): 6436–6441. Easwaran, Eknath. Gandhi the Man: The Story of His Transformation. Tomales, CA: Nilgiri Press, 1997. Ebrey, Patricia Buckley. The Cambridge Illustrated History of China. Cambridge, UK: Cambridge University Press, 2010. Economist editors. “The World in a Barrel.” Economist, December 19, 2017. Edwards, Catharine. The Politics of Immorality in Ancient Rome. Cambridge, UK: Cambridge University Press, 1993. Egan, Timothy. The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl. Boston: Houghton Mifflin, 2006. Ehrlich, Paul R., and Peter H. Raven. “Butterflies and Plants: A Study in Coevolution.” Evolution 18, no. 4 (1964): 586–608. Eliade, Mircea. Shamanism: Archaic Techniques of Ecstasy. Princeton, NJ: Princeton University Press, 1964. Elliott, Charlene. “Purple Pasts: Color Codification in the Ancient World.” Law & Social Inquiry 33, no. 1 (2008): 173–194. Ellis, Richard. Men and Whales. New York: Knopf, 1991. Ellison, Aaron M., Michael S. Bank, Barton D. Clinton, Elizabeth A. Colburn, Katherine Elliott, Chelcy R. Ford, David R. Foster, et al. “Loss of Foundation Species: Consequences for the Structure and Dynamics of Forested Ecosystems.” Frontiers in Ecology and the Environment 3, no. 9 (2005): 479–486. Ellison, Aaron M., and E. J. Farnsworth. “Mangrove Communities.” Pp. 423– 442 in M. D. Bertness, S. Gaines, and M. E. Hay, eds., Marine Community Ecology. Sunderland, MA: Sinauer, 2001. El-Seedi, Hesham R., Peter A. G. M. De Smet, Olof Beck, Göran Possnert, and Jan G. Bruhn. “Prehistoric Peyote Use: Alkaloid Analysis and Radiocarbon Dating of Archaeological Specimens of Lophophora from Texas.” Journal of Ethnopharmacology 101, nos. 1–3 (2005): 238–242. Elton, Charles S. Animal Ecology. New York: Macmillan, 1927. ———. The Ecology of Invasions by Animals and Plants. Methuen, 1958. Emmel, Stephen, Johannes Hahn, and Ulrich Gotter, eds. Destruction and Renewal of Local Cultic Topography in Late Antiquity. Religions in the Graeco-Roman World series. Leiden: Brill, 2008. Enard, Wolfgang, Molly Przeworski, Simon E. Fisher, Cecilia S. L. Lai, Victor Wiebe, Takashi Kitano, Anthony P. Monaco, and Svante Pääbo. “Molecular Evolution of FOXP2, a Gene Involved in Speech and Language.” Nature 418 (2002): 869–872.

Bibliography

263

Endler, John A. Natural Selection in the Wild. Monographs in Population Biology. Princeton, NJ: Princeton University Press, 1986. Erlandson, Jon M., Michael H. Graham, Bruce J. Bourque, Debra Corbett, James A. Estes, and Robert S. Steneck. “The Kelp Highway Hypothesis: Marine Ecology, the Coastal Migration Theory, and the Peopling of the Americas.” Journal of Island and Coastal Archaeology 2, no. 2 (2007): 161–174. Estes, James A., John Terborgh, Justin S. Brashares, Mary E. Power, Joel Berger, William J. Bond, Stephen R. Carpenter, et al. “Trophic Downgrading of Planet Earth.” Science 333, no. 6040 (2011): 301–306. Ewald, Paul W. Evolution of Infectious Disease. Oxford, UK: Oxford University Press, 1994. ———. “An Evolutionary Perspective on Parasitism as a Cause of Cancer.” Advances in Parasitology 68 (2009): 21–43. ———. Plague Time: How Stealth Infections Cause Cancers, Heart Disease, and Other Deadly Ailments. New York: Simon and Schuster, 2000. Fagan, Brian M. Fish on Friday: Feasting, Fasting, and Discovery of the New World. New York: Basic Books, 2006. ———. Floods, Famines, and Emperors: El Niño and the Fate of Civilizations. New York: Basic Books, 1999. Fearnside, Philip M. “Deforestation in Brazilian Amazonia: History, Rates, and Consequences.” Conservation Biology 19, no. 3 (2005): 680–688. Feely, Richard A., Christopher L. Sabine, J. Martin Hernandez-Ayon, Debby Ianson, and Burke Hales. “Evidence for Upwelling of Corrosive ‘Acidified’ Water onto the Continental Shelf.” Science 320, no. 5882 (2008): 1490–1492. Feely, Richard A., Christopher L. Sabine, Kitack Lee, Will Berelson, Joanie Kleypas, Victoria J. Fabry, and Frank J. Miller. “Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans.” Science 305, no. 5682 (2004): 362–366. Ferreira, Ana, Ivo Marguti, Ingo Bechmann, Viktória Jeney, Ângelo Chora, Nuno R. Palha, Sofia Rebelo, et al. “Sickle Hemoglobin Confers Tolerance to Plasmodium Infection.” Cell 145, no. 3 (2011): 398–409. Finley, Moses I. The Ancient Economy. Berkeley: University of California Press, 1973. Firestone, Richard B., Allen West, James P. Kennett, L. Becker, Ted E. Bunch, Zsolt S. Revay, Peter H. Schultz, et al. “Evidence for an Extraterrestrial Impact 12,900 Years Ago That Contributed to the Megafaunal Extinctions and the Younger Dryas Cooling.” PNAS 104, no. 41 (2007): 16016–16021. Fisher, Simon E., and Gary F. Marcus. “The Eloquent Ape: Genes, Brains and the Evolution of Language.” Nature Reviews Genetics 7 (2006): 9–20. Flad, Rowan K., Yuan Jing, and Li Shuicheng. “Zooarchaeological Evidence for Animal Domestication in Northwest China.” Developments in Quaternary Sciences 9 (2007): 167–203.

264

Bibliography

Food and Agriculture Organization of the United Nations. “Guide to Implementation of Phytosanitary Standards in Forestry.” In FAO Forestry Paper 164 (2010). Fournier, Pierre E., Jean-Bosco Ndihokubwayo, Jo Guidran, Patrick Kelly, and Didier Raoult. “Human Pathogens in Body and Head Lice.” Emerging Infectious Diseases 8, no. 12 (2002): 1515–1518. Frank, Daniel N., Allison L. St. Amand, Robert A. Feldman, Edgar C. Boedeker, Noam Harpaz, and Norman R. Pace. “Molecular-Phylogenetic Characterization of Microbial Community Imbalances in Human Inflammatory Bowel Diseases.” PNAS 104, no. 34 (2007): 13780–13785. Frankopan, Peter. The Silk Roads: A New History of the World. London: Bloomsbury, 2015. Fraser, Evan D. G., and Andrew Rimas. Empires of Food: Feast, Famine, and the Rise and Fall of Civilizations. New York: Free Press, 2010. Freedman, Adam H., Ilan Gronau, Rena M. Schweizer, Diego Ortega-Del Vecchyo, Eunjung Han, Pedro M. Silva, Marco Galaverni, et al. “Genome Sequencing Highlights the Dynamic Early History of Dogs.” PLoS Genetics 10 (2014). Freese, Barbara. Coal: A Human History. Cambridge, MA: Perseus, 2003. Friedman, Thomas L. The World Is Flat: The Globalized World in the TwentyFirst Century. New York: Farrar, Straus and Giroux, 2006. Fujiwara, Masami, and Hal Caswell. “Demography of the Endangered North Atlantic Right Whale.” Nature 414 (2001): 537–541. Fukuyama, Francis. The Origins of Political Order: From Prehuman Times to the French Revolution. New York: Farrar, Straus and Giroux, 2011. Fuller, Dorian Q., Ling Qin, Yunfei Zheng, Zhijun Zhao, Xugao Chen, Leo Aoi Hosoya, and Guo-Ping Sun. “The Domestication Process and Domestication Rate in Rice: Spikelet Bases from the Lower Yangtze.” Science 323, no. 5921 (2009): 1607–1610. Fuller, Robert C. Stairways to Heaven: Drugs in American Religious History. Boulder, CO: Westview, 2000. Gardner, Toby A., Isabelle M. Côté, Jennifer A. Gill, Alastair Grant, and Andrew R. Watkinson. “Long-Term Region-Wide Declines in Caribbean Corals.” Science 301, no. 5635 (2003): 958–960. Garnsey, Peter. Famine and Food Supply in the Graeco-Roman World: Responses to Risk and Crisis. Cambridge, UK: Cambridge University Press, 1988. Garnsey, Peter, and Richard Saller. The Roman Empire: Economy, Society and Culture. London: Bloomsbury, 2014. Gashaw, Menassie, and Anders Michelsen. “Influence of Heat Shock on Seed Germination of Plants from Regularly Burnt Savanna Woodlands and Grasslands in Ethiopia.” Plant Ecology 159, no. 1 (2002): 83–93. Gause, Georgy F. “Experimental Analysis of Vito Volterra’s Mathematical Theory of the Struggle for Existence.” Science 79, no. 2036 (1934): 16–17.

Bibliography

265

Gauthier-Pilters, Hilde, and Anne Innis Dagg. The Camel: Its Evolution, Ecology, Behavior, and Relationship to Man. Chicago: University of Chicago Press, 1981. Gedan, K. B., and B. R. Silliman. “Patterns of Salt Marsh Loss within Coastal Regions of North America: Pre-Settlement to Today.” In B. R. Silliman, E. D. Grosholz, and M. D. Bertness, Human Impacts on Salt Marshes: A Global Perspective. Berkeley: University of California Press, 2009. Gersberg, Richard M., B. V. Elkins, Stephen R. Lyon, and Charles R. Goldman. “Role of Aquatic Plants in Waste-Water Treatment by Artificial Wetlands.” Water Research 20, no. 3 (1986): 363–368. Gibbons, Ann. “Revolution in Human Evolution.” Science 349, no. 6246 (2015): 362–366. Gill, Steven R., Mihai Pop, Robert T. DeBoy, Paul B. Eckburg, Peter J. Turnbaugh, Buck S. Samuel, Jeffrey I. Gordon, et al. “Metagenomic Analysis of the Human Distal Gut Microbiome.” Science 312, no. 5778 (2006): 1355–1359. Gilman, Sander L. Making the Body Beautiful: A Cultural History of Aesthetic Surgery. Princeton, NJ: Princeton University Press, 1999. Goebel, Ted, Michael R. Waters, and Dennis H. O’Rourke. “The Late Pleistocene Dispersal of Modern Humans in the Americas.” Science 319, no. 5869 (2008): 1497–1502. Goodell, William. The American Slave Code in Theory and Practice: Its Distinctive Features, Shown by Its Statutes, Judicial Decisions, and Illustrative Facts. New York: American and Foreign Anti-Slavery Society, 1853. Goodnight, Charles J., and Lori Stevens. “Experimental Studies of Group Selection: What Do They Tell Us about Group Selection in Nature?” American Naturalist 150, no. S1 (1997): s59–s79. Goodwin, Stephen B., Barak A. Cohen, and William E. Fry. “Panglobal Distribution of a Single Clonal Lineage of the Irish Potato Famine Fungus.” PNAS 91, no. 24 (1994): 11591–11595. Gordon, Deborah M. “The Organization of Work in Social Insect Colonies.” Nature 380 (1996): 121–124. Gordon, Mary L. “The Nationality of Slaves under the Early Roman Empire.” Journal of Roman Studies 14, no. 1924 (1924): 93–111. Gould, Stephen Jay. Ontogeny and Phylogeny. Cambridge, MA: Belknap Press of Harvard University Press, 1977. Grant, Peter R., and B. Rosemary Grant. “Unpredictable Evolution in a 30Year Study of Darwin’s Finches.” Science 296, no. 5568 (2002): 707–711. Graves, Kersey. The World’s Sixteen Crucified Saviors; or, Christianity before Christ, Containing New, Startling, and Extraordinary Revelations in Religious History, Which Disclose the Oriental Origin of All the Doctrines, Principles, Precepts, and Miracles of the Christian New Testament, and Furnishing a Key for Unlocking Many of Its Sacred Mysteries, Besides Comprising the History of

266

Bibliography

16 Heathen Crucified Gods. 6th ed. New Hyde Park, NY: University Books, 1971. Gray, Russell D., and Quentin D. Atkinson. “Language-Tree Divergence Times Support the Anatolian Theory of Indo-European Origin.” Nature 426 (2003): 435–439. Gray, Russell D., and Fiona M. Jordan. “Language Trees Support the Express-Train Sequence of Austronesian Expansion.” Nature 405 (2000): 1052–1055. Griffin, Dale W., and Christina A. Kellogg. “Dust Storms and Their Impact on Ocean and Human Health: Dust in Earth’s Atmosphere.” EcoHealth 1 (2004): 284–295. Groot, Rudolf S. de, Matthew A. Wilson, and Roelof M. J. Boumans. “A Typology for the Classification, Description and Valuation of Ecosystem Functions, Goods and Service.” Ecological Economics 41, no. 3 (2002): 393–408. Guerra-Doce, Elisa. “The Origins of Inebriation: Archaeological Evidence of the Consumption of Fermented Beverages and Drugs in Prehistoric Eurasia.” Journal of Archaeological Method and Theory 22, no. 3 (2015): 751–782. Haarmann, Thomas, Yvonne Rolke, Sabine Giesbert, and Paul Tudzynski. “Ergot: From Witchcraft to Biotechnology.” Molecular Plant Pathology 10, no. 4 (2009): 563–577. Hajar, Lara, Louis François, Carla Khater, Ihab Jomaa, Michel Déqué, and Rachid Cheddadi. “Cedrus libani (A. Rich) Distribution in Lebanon: Past, Present and Future.” Comptes Rendus Biologies 333, no. 8 (2010): 622–626. Hallett, Steve, and John Wright. Life without Oil: Why We Must Shift to a New Energy Future. Amherst, MA: Prometheus, 2011. Hamilton, William D. “Geometry for Selfish Herd.” Journal of Theoretical Biology 31, no. 2 (1971): 295–311. Hamilton, William D., Robert Axelrod, and Reiko Tanese. “Sexual Reproduction as an Adaptation to Resist Parasites (a Review).” PNAS 87 (1990): 3566–3573. Hansen, Matthew C., Stephen V. Stehman, and Peter V. Potapov. “Quantification of Global Gross Forest Cover Loss.” PNAS 107, no. 19 (2010): 8650–8655. Harari, Yuval. Sapiens: A Brief History of Humankind. New York: Harper, 2015. Hardin, Garrett. “The Tragedy of the Commons.” Science 162, no. 3859 (1968): 1243–1248. Harper, John L. Population Biology of Plants. Academic Press, 1977. Harvell, C. Drew, Kiho Kim, JoAnn M. Burkholder, Rita R. Colwell, Paul R. Epstein, D. Jay Grimes, Eileen E. Hofmann, et al. “Review: Marine Ecology—Emerging Marine Diseases—Climate Links and Anthropogenic Factors.” Science 285, no. 5433 (1999): 1505–1510.

Bibliography

267

Haug, Gerald H., Detlef Günther, Larry C. Peterson, Daniel M. Sigman, Konrad A. Hughen, and Beat Aeschlimann. “Climate and the Collapse of Maya Civilization.” Science 299, no. 5613 (2003): 1731–1735. He, Qiang, Mark D. Bertness, John F. Bruno, Bo Li, Guoqian Chen, Tyler C. Coverdale, Andrew H. Altieri, et al. “Economic Development and Coastal Ecosystem Change in China.” Scientific Reports 4 (2014). Heckman, Daniel S., David M. Geiser, Brooke R. Eidell, Rebecca L. Stauffer, Natalie L. Kardos, and S. Blair Hedges. “Molecular Evidence for the Early Colonization of Land by Fungi and Plants.” Science 293, no. 5532 (2001): 1129–1133. Heisenberg, Werner. “Über den anschaulichen Inhalt der Quantentheoretischen Kinematik und Mechanik.” Zeitschrift für Physik 43 (1927): 172–198. Henshilwood, Christopher S., Francesco d’Errico, Marian Vanhaeren, Karen van Niekerk, and Zenobia Jacobs. “Middle Stone Age Shell Beads from South Africa.” Science 304, no. 5669 (2004): 404. Henshilwood, Christopher S., Francesco d’Errico, Karen L. van Niekerk, Yvan Coquinot, Zenobia Jacobs, Stein-Erik Lauritzen, Michel Menu, and Renata García-Moreno. “A 100,000-Year-Old Ochre-Processing Workshop at Blombos Cave, South Africa.” Science 334, no. 6053 (2011): 219–222. Henshilwood, Christopher S., Francesco d’Errico, Royden Yates, Zenobia Jacobs, Chantal Tribolo, Geoff A. T. Duller, Norbert Mercier, et al. “Emergence of Modern Human Behavior: Middle Stone Age Engravings from South Africa.” Science 295, no. 5558 (2002): 1278–1280. Hershkovitz, Israel, Ofer Marder, Avner Ayalon, Miryam Bar-Matthews, Gal Yasur, Elisabetta Boaretto, Valentina Caracuta, et al. “Levantine Cranium from Manot Cave (Israel) Foreshadows the First European Modern Humans.” Nature 520 (2015): 216–219. Heuer, Holger, Heike Schmitt, and Kornelia Smalla. “Antibiotic Resistance Gene Spread Due to Manure Application on Agricultural Fields.” Current Opinion in Microbiology 14, no. 3 (2011): 236–243. Hewitt, Godfrey. “The Genetic Legacy of the Quaternary Ice Ages.” Nature 405 (2000): 907–913. Hockett, Bryan, and Jonathan Haws. “Nutritional Ecology and Diachronic Trends in Paleolithic Diet and Health.” Evolutionary Anthropology 12, no. 5 (2003): 211–216. Hodges, Henry. Technology in the Ancient World. New York: Knopf, 1994. Hoegh-Guldberg, Ove, Peter J. Mumby, Anthony J. Hooten, Robert S. Steneck, Patrick Greenfield, Elizabeth Gomez, C. Drew Harvell, et al. “Coral Reefs under Rapid Climate Change and Ocean Acidification.” Science 318, no. 5857 (2007): 1737–1742. Hoffecker, John F., W. Roger Powers, and Ted Goebel. “The Colonization of Beringia and the Peopling of the New World.” Science 259, no. 5091 (1993): 46–53.

268

Bibliography

Hofmann, Albert. “Historical View on Ergot Alkaloids.” Pharmacology 16, supp. no. 1 (1978): 1–11. Holdren, John P., and Paul R. Ehrlich. “Human Population and the Global Environment: Population Growth, Rising Per Capita Material Consumption, and Disruptive Technologies Have Made Civilization a Global Ecological Force.” American Scientist 62, no. 3 (1974): 282–292. Hong, Beverly. “Politeness in Chinese: Impersonal Pronouns and Personal Greetings.” Anthropological Linguistics 27, no. 2 (1985): 204–213. Horne, Lee. “Fuel for the Metal Worker: The Role of Charcoal and Charcoal Production in Ancient Metallurgy.” Expedition: The Magazine of the University of Pennsylvania 25, no. 1 (1982): 6–13. Hortolà, Policarp, and Bienvenido Martínez-Navarro. “The Quaternary Megafaunal Extinction and the Fate of Neanderthals: An Integrative Working Hypothesis.” Quaternary International 295 (2013): 69–72. Hosokawa, Takahiro, Ryuichi Koga, Yoshitomo Kikuchi, Xian-Ying Meng, and Takema Fukatsu. “Wolbachia as a Bacteriocyte-Associated Nutritional Mutualist.” PNAS 107, no. 2 (2010): 769–774. Houston, Stephen, and David Stuart. “Of Gods, Glyphs and Kings: Divinity and Rulership among the Classic Maya.” Antiquity 70, no. 268 (1996): 289–312. Hrdy, Sarah Blaffer. “Infanticide among Animals: A Review, Classification, and Examination of the Implications for the Reproductive Strategies of Females.” Ethology and Sociobiology 1, no. 1 (1979): 13–40. ———. “Infanticide as a Reproductive Strategy—A Citation-Classic Commentary on ‘Infanticide among Animals: A Review, Classification, and Examination of the Implications for the Reproductive Strategies of Females.’ ” Agriculture Biology and Environmental Sciences 40 (1991). Hubbell, Stephen P. The Unified Neutral Theory of Biodiversity and Biogeography. Monographs in Population Biology. Princeton, NJ: Princeton University Press, 2001. Hubble, Edwin. “A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae.” PNAS 15, no. 3 (1929): 168–173. Hublin, Jean-Jacques. “The Earliest Modern Human Colonization of Europe.” PNAS 109, no. 34 (2012): 13471–13472. Huffman, Michael A. “Current Evidence for Self-Medication in Primates: A Multidisciplinary Perspective.” Yearbook of Physical Anthropology 104, no. S25 (1997): 171–200. Huffman, Michael A., Shunji Gotoh, Linda A. Turner, Miya Hamai, and Kozo Yoshida. “Seasonal Trends in Intestinal Nematode Infection and Medicinal Plant Use among Chimpanzees in the Mahale Mountains, Tanzania.” Primates 38, no. 2 (1997): 111–125. Hughes, J. Donald. “Ancient Deforestation Revisited.” Journal of the History of Biology 44, no. 1 (2011): 43–57. Hughes, J. Donald, and Jack V. Thirgood. “Deforestation, Erosion, and Forest Management in Ancient Greece and Rome.” Journal of Forest History 26, no. 2 (1982): 60–75.

Bibliography

269

Hughes, Terence P. “Catastrophes, Phase Shifts, and Large-Scale Degradation of a Caribbean Coral Reef.” Science 265, no. 5178 (1994): 1547–1551. Hung, Hsiao-Chun, Yoshiyuki Iizuka, Peter Bellwood, Kim Dung Nguyen, Bérénice Bellina, Praon Silapanth, Eusebio Dizon, et al. “Ancient Jades Map 3,000 Years of Prehistoric Exchange in Southeast Asia.” PNAS 104, no. 50 (2007): 19745–19750. Hunt, Alan. Governance of the Consuming Passions: A History of Sumptuary Law. New York: St. Martin’s, 1996. Hunt, Terry, and Carl Lipo. The Statues That Walked: Unraveling the Mystery of Easter Island. New York: Simon & Schuster, 2011. Huntington, Samuel P. The Clash of Civilizations and the Remaking of World Order. New York: Simon & Schuster, 1997. Huskinson, Janet. “Some Pagan Mythological Figures and Their Significance in Early Christian Art.” Papers of the British School at Rome 42 (1974): 68–97. Hutchinson, G. Evelyn. The Ecological Theater and the Evolutionary Play. New Haven, CT: Yale University Press, 1965. Hutton, James. System of the Earth, 1785: Theory of the Earth, 1788. Observations on Granite, 1794. Together with Playfair’s Biography of Hutton. Contributions to the History of Geology series. New York: Hafner, 1970. Huxley, Aldous. Brave New World. New York: Harper & Brothers, 1932. ———. The Doors of Perception and Heaven and Hell. New York: HarperCollins, 1954. Inglesby, Thomas V., David T. Dennis, Donald A. Henderson, John G. Bartlett, Michael S. Ascher, Edward Eitzen, Anne D. Fine, et al. “Plague as a Biological Weapon: Medical and Public Health Management.” JAMA 283, no. 17 (2000): 2281–2290. Jablonski, Nina G. “The Naked Truth: Why Humans Have No Fur.” Scientific American (Feb. 2010): 42–49. Jacobs, Zenobia, Richard G. Roberts, Rex F. Galbraith, Hilary J. Deacon, Rainer Grün, Alex Mackay, Peter Mitchell, Ralf Vogelsang, and Lyn Wadley. “Ages for the Middle Stone Age of Southern Africa: Implications for Human Behavior and Dispersal.” Science 322, no. 5902 (2008): 733–735. Jacobsen, Thorkild, and Robert M. Adams. “Salt and Silt in Ancient Mesopotamian Agriculture.” Science 128, no. 3334 (1958): 1251–1258. James, Peter, and Nick J. Thorpe. Ancient Inventions. New York: Ballantine, 1994. Janzen, Daniel H. “Coevolution of Mutualism between Ants and Acacias in Central America.” Evolution 20, no. 3 (1966): 249–275. Jew, Stephanie, Suhad S. AbuMweis, and Peter J. H. Jones. “Evolution of the Human Diet: Linking Our Ancestral Diet to Modern Functional Foods as a Means of Chronic Disease Prevention.” Journal of Medicinal Food 12, no. 5 (2009): 925–934. Ji, Rimutu, Peng Cui, Feng Ding, Hongwei Gao, Heping Zhang, Jun Yu, Songnian Hu, and He Meng. “Monophyletic Origin of Domestic Bactrian

270

Bibliography

Camel (Camelus bactrianus) and Its Evolutionary Relationship with the Extant Wild Camel (Camelus bactrianus ferus).” Animal Genetics 40, no. 4 (2009): 377–382. Johnson, Dominic D. P. “God’s Punishment and Public Goods: A Test of the Supernatural Punishment Hypothesis in 186 World Cultures.” Human Nature 16, no. 4 (2005): 410–446. Johnston, Richard F., David M. Niles, and Sievert A. Rohwer. “Hermon Bumpus and Natural Selection in the House Sparrow Passer domesticus.” Evolution 26, no. 1 (1972): 20–31. Jones, Robert L., and Harold C. Hanson. Mineral Licks, Geophagy, and Biogeochemistry of North American Ungulates. Ames: Iowa State University Press, 1985. Kaijser, Arne. “System Building from Below: Institutional Change in Dutch Water Control Systems.” Technology and Culture 43, no. 3 (2002): 521–548. Kaplan, Jed O., Kristen M. Krumhardt, and Niklaus Zimmermann. “The Prehistoric and Preindustrial Deforestation of Europe.” Quaternary Science Reviews 28, nos. 27–28 (2009): 3016–3034. Kardos, Nelson, and Arnold Demain. “Penicillin: The Medicine with the Greatest Impact on Therapeutic Outcomes.” Applied Microbiology and Biotechnology 92, no. 4 (2011): 677–687. Katz, Solomon H., and Mary M. Voigt. “Bread and Beer.” Expedition: The Magazine of the University of Pennsylvania 28, no. 2 (1986): 23–34. Keeley, Jon E., and Paul H. Zedler. “Evolution of Life Histories in Pinus.” Pp. 219–250 in David Richardson, ed., Ecology and Biogeography of Pinus. Cambridge, UK: Cambridge University Press, 1998. Kellum, Barbara A. “Infanticide in England in the Later Middle Ages.” History of Childhood Quarterly 1, no. 3 (1974): 367–388. Kettlewell, Henry Bernard D. “Phenomenon of Industrial Melanism in Lepidoptera.” Annual Review of Entomology 6 (1961): 245–262. Kimura, Motoo. The Neutral Theory of Molecular Genetics. Cambridge, UK: Cambridge University Press, 1983. Kirchman, David L., Xosé Anxelu G. Morán, and Hugh Ducklow. “Microbial Growth in the Polar Oceans—Role of Temperature and Potential Impact of Climate Change.” Nature Reviews Microbiology 7 (2009): 451–459. Kirk, Ruth, and Richard D. Daugherty. Hunters of the Whale: An Adventure of Northwest Coast Archaeology. New York: Morrow, 1974. Kirwan, Matthew L., and J. Patrick Megonigal. “Tidal Wetland Stability in the Face of Human Impacts and Sea-Level Rise.” Nature 504 (2013): 53–60. Kittler, Ralf, Manfred Kayser, and Mark Stoneking. “Molecular Evolution of Pediculus humanus and the Origin of Clothing.” Current Biology 13, no. 16 (2004): 1414–1417. Knell, Robert J. “Syphilis in Renaissance Europe: Rapid Evolution of an Introduced Sexually Transmitted Disease?” Proceedings of the Royal Society B: Biological Sciences 271, no. 4 (2004): S174–S176.

Bibliography

271

Knowlton, Nancy, and J. B. C. Jackson. “The Ecology of Coral Reefs.” Pp. 395–417 in Mark D. Bertness, Steven D. Gaines, and Mark E. Hay, eds., Marine Community Ecology. Sunderland, MA: Sinauer Associates, 2001. Koebnick, Corinna, Carola Strassner, Ingrid Hoffmann, and Claus Leitzmann. “Consequences of a Long-Term Raw Food Diet on Body Weight and Menstruation: Results of a Questionnaire Survey.” Annals of Nutrition and Metabolism 43, no. 2 (1999): 69–79. Koganemaru, Reina, and Dini M. Miller. “The Bed Bug Problem: Past, Present, and Future Control Methods.” Pesticide Biochemistry and Physiology 106, no. 3 (2013): 177–189. Kohn, George C. Dictionary of Wars. New York: Checkmark, 2006. Kolars, Joseph C., Michael D. Levitt, Mostafa Aouji, and Dennis A. Savaiano. “Yogurt—An Autodigesting Source of Lactose.” New England Journal of Medicine 310, no. 1 (1984): 1–3. Koskella, Britt, Lindsay J. Hall, and C. Jessica E. Metcalf. “The Microbiome beyond the Horizon of Ecological and Evolutionary Theory.” Nature Ecology & Evolution 1, no. 11 (2017): 1606. Krebs, John R. “The Gourmet Ape: Evolution and Human Food Preferences.” American Journal of Clinical Nutrition 90, no. 3 (2009): 707s–711s. Kremer, Michael. “Population Growth and Technological Change: One Million B.C. to 1990.” Quarterly Journal of Economics 108, no. 3 (1993): 681–716. Krishnamani, R., and William C. Mahaney. “Geophagy among Primates: Adaptive Significance and Ecological Consequences.” Animal Behaviour 59, no. 5 (2000): 899–915. Kurlansky, Mark. The Big Oyster: History on the Half Shell. New York: Random House, 2007. ———. Salt: A World History. New York: Walker, 2002. Lafferty, Kevin D., and Armand M. Kuris. “Parasitic Castration: The Evolution and Ecology of Body Snatchers.” Trends in Parasitology 25, no. 12 (2009): 564–572. Lane, Nick. Life Ascending: The Ten Great Inventions of Evolution. New York: W.W. Norton, 2009. Langevelde, Frank Van, Claudius A. D. M. Van De Vijver, Lalit Kumar, Johan Van De Koppel, Nico De Ridder, Jelte Van Andel, Andrew K. Skidmore, et al. “Effects of Fire and Herbivory on the Stability of Savanna Ecosystems.” Ecology 84, no. 2 (2003): 337–350. Lantz, Paula M., and Karen M. Booth. “The Social Construction of the Breast Cancer Epidemic.” Social Science & Medicine 46, no. 7 (1998): 907–918. Larsen, Clark Spencer. “Biological Changes in Human Populations with Agriculture.” Annual Review of Anthropology 24, no. 1 (1995): 185–213. Larson, Greger, Umberto Albarella, Keith Dobney, Peter Rowley-Conwy, Jörg Schibler, Anne Tresset, Jean-Denis Vigne, et al. “Ancient DNA, Pig

272

Bibliography

Domestication, and the Spread of the Neolithic into Europe.” PNAS 104, no. 39 (2007): 15276–15281. Lawrence, David R. “Oysters as Geoarchaeologic Objects.” Geoarchaeology 3, no. 4 (1988): 267–274. Lazar, Mitchell A. “How Obesity Causes Diabetes: Not a Tall Tale.” Science 307, no. 5708 (2005): 373–375. Leconte, Jérémy, François Forget, Benjamin Charnay, Robin Wordsworth, and Alizée Pottier. “Increased Insolation Threshold for Runaway Greenhouse Processes on Earth-Like Planets.” Nature 504 (2013): 268– 271. Lee, Richard B., and Richard Daly, eds. The Cambridge Encyclopedia of Hunters and Gatherers. Cambridge, UK: Cambridge University Press, 1999. Lee, Yun Kyung, and Sarkis K. Mazmanian. “Has the Microbiota Played a Critical Role in the Evolution of the Adaptive Immune System?” Science 330, no. 6012 (2010): 1768–1773. Lemaître, Georges. “Un univers homogène de masse constante et de rayon croissant rendant compte de la vitesse radiale des nébuleuses extra-galactiques.” Annals of the Scientific Society of Brussels A 47 (1927): 49–59. Leonard, William R., and Marcia L. Robertson. “Evolutionary Perspectives on Human Nutrition: The Influence of Brain and Body Size on Diet and Metabolism.” American Journal of Human Biology 6, no. 1 (1994): 77–88. ———. “Rethinking the Energetics of Bipedality.” Current Anthropology 38, no. 2 (1997): 304–309. Leroi-Gourhan, Arlette. “The Flowers Found with Shanidar Iv: A Neanderthal Burial in Iraq.” Science 190, no. 4214 (1975): 562–564. Lewontin, Richard, Steven Rose, and Leon Kamin. Not in Our Genes: Biology, Ideology and Human Nature. New York: Pantheon, 1984. Ley, Ruth E., Daniel A. Peterson, and Jeffrey I. Gordon. “Ecological and Evolutionary Forces Shaping Microbial Diversity in the Human Intestine.” Cell 124, no. 4 (2006): 837–848. Li, Min, Baohong Wang, Menghui Zhang, Mattias Rantalainen, Shengyue Wang, Haokui Zhou, Yan Zhang, et al. “Symbiotic Gut Microbes Modulate Human Metabolic Phenotypes.” PNAS 105, no. 6 (2008): 2117–2122. Liu, Wu, María Martinón-Torres, Yan-jun Cai, Song Xing, Hao-wen Tong, Shu-wen Pei, Mark Jan Sier, et al. “The Earliest Unequivocally Modern Humans in Southern China.” Nature 526 (2015): 696–699. Livy, Titus. The History of Rome—Book V. New York: Macmillan, 1905. Losos, Jonathan B., Kenneth I. Warheitt, and Thomas W. Schoener. “Adaptive Differentiation Following Experimental Island Colonization in Anolis Lizards.” Nature 387 (1997): 70–73. Lotze, H. K., and L. McClenachan, L. “Marine Historical Ecology: Informing the Future by Learning from the Past.” In M. D. Bertness, J. F. Bruno, and J. J. Stachowicz, eds., Marine Community Ecology and Conservation. Sunderland, MA: Sinauer, 2013.

Bibliography

273

Ludwig, Arne, Melanie Pruvost, Monika Reissmann, Norbert Benecke, Gudrun A. Brockmann, Pedro Castaños, Michael Cieslak, et al. “Coat Color Variation at the Beginning of Horse Domestication.” Science 324, no. 5926 (2009): 485. Lukacs, John R. “Fertility and Agriculture Accentuate Sex Differences in Dental Caries Rates.” Current Anthropology 49, no. 5 (2008): 901–914. Lyell, Charles. Principles of Geology: Being an Attempt to Explain the Former Changes of the Earth’s Surface, by Reference to Causes Now in Operation. London: J. Murray, 1830. MacKenzie, Clyde L., Jr. “History of Oystering in the United States and Canada, Featuring the Eight Greatest Oyster Estuaries.” Marine Fisheries Review 58, no. 4 (1996): 1–78. Majno, Guido. The Healing Hand: Man and Wound in the Ancient World. Cambridge, MA: Harvard University Press, 1975. Mallory, Walter H. China: Land of Famine. New York: American Geographical Society, 1926. Margulis, Lynn. 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: Yale University Press, 1970. ———. “Symbiogenesis: A New Principle of Evolution Rediscovery of Boris Mikhaylovich Kozo-Polyansky (1890–1957).” Paleontological Journal 44, no. 12 (2010): 1525–1539. Margulis, Lynn, and Dorion Sagan. Microcosmos: Four Billion Years of Microbial Evolution. Mono, ON: Summit, 1986. Marshall, Larry G. “Land Mammals and the Great American Interchange.” American Scientist 76, no. 4 (1988): 380–388. Marteau, Philippe R., Michael de Vrese, Christophe J. Cellier, and Jürgen Schrezenmeir. “Protection from Gastrointestinal Diseases with the Use of Probiotics.” American Journal of Clinical Nutrition 73, no. 2 (2001): 430s–436s. Martin, Paul S. Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America. Berkeley: University of California Press, 2005. Martínez, Ignacio, Juan Luis Arsuaga, Rolf Quam, José Miguel Carretero, Ana Gracia, and Laura Rodríguez. “Human Hyoid Bones from the Middle Pleistocene Site of the Sima de los Huesos (Sierra de Atapuerca, Spain).” Journal of Human Evolution 54, no. 1 (2008): 118–124. Maturana, Humberto, and Francisco Varela. Autopoiesis and Cognition: The Realization of the Living. New York: Springer Netherlands, 1980. McCullough, David. The Path between the Seas: The Creation of the Panama Canal, 1870–1914. New York: Simon and Schuster, 1977. McGovern, Patrick E., Juzhong Zhang, Jigen Tang, Zhiqing Zhang, Gretchen R. Hall, Robert A. Moreau, Alberto Nuñez, et al. “Fermented Beverages of Pre- and Proto-Historic China.” PNAS 101, no. 51 (2004): 17593–17598. McGrath, Alister E. An Introduction to Christianity. Malden, MA: WileyBlackwell, 1997.

274

Bibliography

McKenna, Caitlin. “When Santa Was a Mushroom: Amanita muscaria and the Origins of Christmas.” Entheology.com, Oct. 1, 2013. McKenna, Terence. Food of the Gods: The Search for the Original Tree of Knowledge: A Radical History of Plants, Drugs and Human Evolution. New York: Random House, 1992. Medlock, Jolyon M., Kayleigh M. Hansford, Francis Schaffner, Veerle Versteirt, Guy Hendrickx, Hervé Zeller, and Wim van Bortel. “A Review of the Invasive Mosquitoes in Europe: Ecology, Public Health Risks, and Control Options.” Vector Borne and Zoonotic Diseases 12 (2012): 435–447. Megaw, Vincent, Graham Morgan, and Thomas Stöllner. “Ancient SaltMining in Austria.” Antiquity 74, no. 283 (2000): 17–18. Meinshausen, Malte, Nicolai Meinshausen, William Hare, Sarah C. B. Raper, Katja Frieler, Reto Knutti, David J. Frame, and Myles R. Allen. “Greenhouse-Gas Emission Targets for Limiting Global Warming to 2°C.” Nature 458 (2009): 1158–1162. Meiroop, Marc Van De. A History of the Ancient Near East, ca. 3000–323 BC. Malden, MA: Wiley-Blackwell, 2009. Melosh, H. Jay. “The Rocky Road to Panspermia.” Nature 332 (1988): 687–688. Menze, Bjoern H., and Jason A. Ur. “Mapping Patterns of Long-Term Settlement in Northern Mesopotamia at a Large Scale.” PNAS 109, no. 14 (2012): E778–E787. Merlin, Mark. D. “Archaeological Evidence for the Tradition of Psychoactive Plant Use in the Old World.” Economic Botany 57, no. 3 (2003): 295–323. Mikesell, Marvin W. “The Deforestation of Mount Lebanon.” Geographical Review 59, no. 1 (1969): 1–28. Miller, Gifford H., Marilyn L. Fogel, John W. Magee, Michael K. Gagan, Simon J. Clarke, and Beverly J. Johnson. “Ecosystem Collapse in Pleistocene Australia and a Human Role in Megafaunal Extinction.” Science 309, no. 5732 (2005): 287–290. Miller, Naomi F. “Paleoethnobotanical Evidence for Deforestation in Ancient Iran: A Case Study of Urban Malyan.” Journal of Ethnobiology and Ethnomedicine 5, no. 1 (1985): 1–19. Miller, Richard J. Drugged: The Science and Culture behind Psychotropic Drugs. Oxford, UK: Oxford University Press, 2013. Milner, Larry Stephen. Hardness of Heart/Hardness of Life: The Stain of Human Infanticide. Lanham, MD: University Press of America, 2000. Mithen, Steven. After the Ice: A Global Human History, 20,000–5000 BC. Cambridge, MA: Harvard University Press, 2004. Mittelbach, Gary George. Community Ecology. Sunderland, MA: Sinauer Associates, 2012. Moal, Vanessa Liévin-Le, and Alain L. Servin. “The Front Line of Enteric Host Defense against Unwelcome Intrusion of Harmful Microorganisms: Mucins, Antimicrobial Peptides, and Microbiota.” Clinical Microbiology Reviews 19, no. 2 (2006): 315–337.

Bibliography

275

Morelli, Giovanna, Yajun Song, Camila J. Mazzoni, Mark Eppinger, Philippe Roumagnac, David M. Wagner, Mirjam Feldkamp, et al. “Yersinia pestis Genome Sequencing Identifies Patterns of Global Phylogenetic Diversity.” Nature Genetics 42 (2010): 1140–1143. Motulsky, Arno G. “Metabolic Polymorphisms and the Role of Infectious Diseases in Human Evolution (Reprinted).” Human Biology 61, nos. 5–6 (1989): 834–869. Mouginot, Jeremie, Eric Rignot, Bernd Scheuchl, Ian Fenty, Ala Khazendar, Mathieu Morlighem, Arnaud Buzzi, and John Paden. “Fast Retreat of Zachariæ Isstrøm, Northeast Greenland.” Science 350, no. 6266 (2015): 1357–1361. Mourre, Vincent, Paola Villa, and Christopher S. Henshilwood. “Early Use of Pressure Flaking on Lithic Artifacts at Blombos Cave, South Africa.” Science 330 (2010): 659–662. Myers, Ransom A., and Boris Worm. “Rapid Worldwide Depletion of Predatory Fish Communities.” Nature 423 (2003): 280–283. National Center for Emerging and Zoonotic Infectious Diseases. “Antibiotic/ Antimicrobial Resistance (Ar/Amr).” CDC.gov, https://www.cdc.gov/ drugresistance (accessed August 21, 2019). Neel, James V. “Diabetes Mellitus: A ‘Thrifty’ Genotype Rendered Detrimental by ‘Progress.’ ” American Journal of Human Genetics 14 (1962): 353–362. Nef, John Ulric. The Rise of the British Coal Industry. Abingdon, UK: Routledge, 1932. Neu, Harold C. “The Crisis in Antibiotic Resistance.” Science 257, no. 5073 (1992): 1064–1073. Nicholson, Jeremy K., Elaine Holmes, James Kinross, Remy Burcelin, Glenn Gibson, Wei Jia, and Sven Pettersson. “Host-Gut Microbiota Metabolic Interactions.” Science 336, no. 6086 (2012): 1262–1267. O’Donnell, Sean. “How Parasites Can Promote the Expression of Social Behaviour in Their Hosts.” Proceedings of the Royal Society B: Biological Sciences 264, no. 1382 (1997): 689–694. Orth, Robert J., Tim J. B. Carruthers, William C. Dennison, Carlos M. Duarte, James W. Fourqurean, Kenneth L. Heck, A. Randall Hughes, et al. “A Global Crisis for Seagrass Ecosystems.” BioScience 56, no. 12 (2006): 987–996. Ottaway, Barbara S. “Innovation, Production and Specialization in Early Prehistoric Copper Metallurgy.” European Journal of Archaeology 4, no. 1 (2001): 87–112. Outram, Alan K., Natalie A. Stear, Robin Bendrey, Sandra Olsen, Alexei Kasparov, Victor Zaibert, Nick Thorpe, and Richard P. Evershed. “The Earliest Horse Harnessing and Milking.” Science 323, no. 5919 (2009): 1332–1335. Ozawa, Sachiko, Meghan L. Stack, David M. Bishai, Andrew Mirelman, Ingrid K. Friberg, Louis Niessen, Damian G. Walker, and Orin S.

276

Bibliography

Levine. “During the ‘Decade of Vaccines,’ the Lives of 6.4 Million Children Valued at $231 Billion Could Be Saved.” Health Affairs 30, no. 6 (2011): 1010–1020. Pagel, Mark. “Human Language as a Culturally Transmitted Replicator.” Nature Reviews Genetics 10 (2009): 405–415. Pagel, Mark, Quentin D. Atkinson, Andreea S. Calude, and Andrew Meade. “Ultraconserved Words Point to Deep Language Ancestry across Eurasia.” PNAS 110, no. 21 (2013): 8471–8476. Pagnier, Josee, J. Gregory Mears, Olga Dunda-Belkhodja, Kim E. SchaeferRego, Cherif Beldjord, Ronald L. Nagel, and Dominque Labie. “Evidence for the Multicentric Origin of the Sickle-Cell Hemoglobin Gene in Africa.” PNAS 81, no. 6 (1984): 1771–1773. Pahnke, Walter M. “Drugs and Mysticism: An Analysis of the Relationship between Psychedelic Drugs and the Mystical Consciousness.” PhD thesis, Harvard University, 1963. Paine, Robert T. “Food Web Complexity and Species Diversity.” American Naturalist 100, no. 910 (1966): 65–75. Patinkin, Jason. “Rape Stands Out Starkly in S. Sudan War Known for Brutality.” Christian Science Monitor, July 27, 2014. Pedrosa, Susana, Metehan Uzun, Juan-José Arranz, Beatriz Gutiérrez-Gil, Fermín San Primitivo, and Yolanda Bayón. “Evidence of Three Maternal Lineages in Near Eastern Sheep Supporting Multiple Domestication Events.” Proceedings of the Royal Society B: Biological Sciences 272, no. 1577 (2005): 2211–2217. Pennisi, Elizabeth. “Encode Project Writes Eulogy for Junk DNA.” Science 337, no. 6099 (2012): 1159–1161. Petigura, Erik A., Andrew W. Howard, and Geoffrey W. Marcy. “Prevalence of Earth-Size Planets Orbiting Sun-Like Stars.” PNAS 110, no. 48 (2013): 19273–19278. Peto, Julian, Clare Gilham, Olivia Fletcher, and Fiona E. Matthews. “The Cervical Cancer Epidemic That Screening Has Prevented in the UK.” Lancet 364, no. 9430 (2004): 249–256. Pinker, Steven. The Better Angels of Our Nature: Why Violence Has Declined. New York: Penguin, 2012. ———. The Blank Slate: The Modern Denial of Human Nature. New York: Viking, 2002. Pollock, Susan. Ancient Mesopotamia: The Eden That Never Was. Cambridge, UK: Cambridge University Press, 1999. Postgate, J. Nicholas. Early Mesopotamia: Society and Economy at the Dawn of History. New York: Routledge, 1994. Pringle, Robert M., Daniel F. Doak, Alison K. Brody, Rudy Jocqué, and Todd M. Palmer. “Spatial Pattern Enhances Ecosystem Functioning in an African Savanna.” PloS Biology 8, no. 5 (2010).

Bibliography

277

Purugganan, Michael D., and Dorian Q. Fuller. “The Nature of Selection during Plant Domestication.” Nature 457 (2009): 843–848. Qin, Junjie, Ruiqiang Li, Jeroen Raes, Manimozhiyan Arumugam, Kristoffer Solvsten Burgdorf, Chaysavanh Manichanh, Trine Nielsen, et al. “A Human Gut Microbial Gene Catalogue Established by Metagenomic Sequencing.” Nature 464 (2010): 59–65. Ratkowsky, David A., J. Olley, Thomas. A. McMeekin, and Andrew Ball. “Relationship between Temperature and Growth Rate of Bacterial Cultures.” Journal of Bacteriology 149, no. 1 (1982): 1–5. Redfield, Alfred C. “Development of a New England Salt Marsh.” Ecological Monographs 42, no. 2 (1972): 201–237. ———. “Ontogeny of a Salt Marsh Estuary.” Science 147, no. 3653 (1965): 50–55. Reilly, Robert R. The Closing of the Muslim Mind: How Intellectual Suicide Created the Modern Islamist Crisis. Wilmington, DE: ISI Books, 2010. Reimold, Robert J., and William H. Queen, eds. Ecology of Halophytes. Cambridge, MA: Academic Press, 1964. Reneke, Dave. “Was the Christmas Star Real?” Australasian Science (Nov./Dec. 2009). Renterghem, Tony Van. When Santa Was a Shaman: The Ancient Origins of Santa Claus and the Christmas Tree. Woodbury, MN: Llewellyn, 1995. Revedin, Anna, Biancamaria Aranguren, Roberto Becattini, Laura Longo, Emanuele Marconi, Marta Mariotti Lippi, Natalia Skakun, et al. “Thirty Thousand-Year-Old Evidence of Plant Food Processing.” PNAS 107, no. 44 (2010): 18815–18819. Reznick, David N., Frank H. Shaw, F. Helen Rodd, and Ruth G. Shaw. “Evaluation of the Rate of Evolution in Natural Populations of Guppies (Poecilia reticulata).” Science 275, no. 5308 (1997): 1934–1937. Rich, Stephen M., Fabian H. Leendertz, Guang Xu, Matthew LeBreton, Cyrille F. Djoko, Makoah N. Aminake, Eric E. Takang, et al. “The Origin of Malignant Malaria.” PNAS 106, no. 35 (2009): 14902–14907. Richard, Amy O’Neill. “International Trafficking in Women to the United States: A Contemporary Manifestation of Slavery and Organized Crime.” Intelligence monograph. Washington, DC: Center for the Study of Intelligence, 1999. Richardson, David, ed. Ecology and Biogeography of Pinus. Cambridge, UK: Cambridge University Press, 1998. Roach, Neil T., Madhusudhan Venkadesan, Michael J. Rainbow, and Daniel E. Lieberman. “Elastic Energy Storage in the Shoulder and the Evolution of High-Speed Throwing in Homo.” Nature 498 (2013): 483– 486. Robertson, D. Ross. “Social Control of Sex Reversal in a Coral-Reef Fish.” Science 177, no. 4053 (1972): 1007–1009.

278

Bibliography

Rockley, Evelyn Cecil. Primogeniture: A Short History of Its Development in Various Countries and Its Practical Effects. London: J. Murray, 1895. Rodhe, Henning, and Bo Svensson. “Impact on the Greenhouse Effect of Peat Mining and Combustion.” Ambio 24, no. 4 (1995): 221–225. Rogers, Alan R., David Iltis, and Stephen Wooding. “Genetic Variation at the MC1R Locus and the Time since Loss of Human Body Hair.” Current Anthropology 45, no. 1 (2004): 105–108. Ruck, Carl A. P., Jeremy Bigwood, Danny Staples, Jonathan Ott, and R. Gordon Wasson. “Entheogens.” Journal of Psychedelic Drugs 11, no. 1 (1979): 145–146. Rypien, Krystal L., Jason P. Andras, and C. Drew Harvell. “Globally Panmictic Population Structure in the Opportunistic Fungal Pathogen Aspergillus sydowii.” Molecular Ecology 17, no. 18 (2008): 4068–4078. Sachs, Jeffrey, and Pia Malaney. “The Economic and Social Burden of Malaria.” Nature 415 (2002): 680–685. Safe, Stephen H. “Environmental and Dietary Estrogens and Human Health: Is There a Problem?” Environmental Health Perspectives 103, no. 4 (1995): 346–351. Sagan, Carl. The Dragons of Eden: Speculations on the Evolution of Human Intelligence. New York: Random House, 1977. Sagan, Dorion, ed. Lynn Margulis: The Life and Legacy of a Scientific Rebel. White River Junction, VT: Chelsea Green, 2012. Sala, Osvaldo E., III, F. Stuart Chapin, Juan J. Armesto, Eric Berlow, Janine Bloomfield, Rodolfo Dirzo, Elisabeth Huber-Sanwald, et al. “Global Biodiversity Scenarios for the Year 2100.” Science 287, no. 5459 (2000): 1770–1774. Sallares, Robert, Abigail Bouwman, and Cecilia Anderung. “The Spread of Malaria to Southern Europe in Antiquity: New Approaches to Old Problems.” Medical History 48, no. 3 (2004): 311–328. Sandom, Christopher, Søren Faurby, Brody Sandel, and Jens-Christian Svenning. “Global Late Quaternary Megafauna Extinctions Linked to Humans, Not Climate Change.” Proceedings of the Royal Society B: Biological Sciences 281, no. 1787 (2014). Sankararaman, Sriram, Nick Patterson, Heng Li, Svante Pääbo, and David Reich. “The Date of Interbreeding between Neandertals and Modern Humans.” PLoS Genetics 8 (2012). Scheffer, Marten, Stephen R. Carpenter, Timothy M. Lenton, Jordi Bascompte, William Brock, Vasilis Dakos, Johan van de Koppel, et al. “Anticipating Critical Transitions.” Science 338, no. 6105 (2012): 344–348. Schmidt, Klaus. “Göbekli Tepe, Southeastern Turkey: A Preliminary Report on the 1995–1999 Excavations.” Paléorient 26, no. 1 (2000): 45–54. ———. “Göbekli Tepe—the Stone Age Sanctuaries: New Results of Ongoing Excavations with a Special Focus on Sculptures and High Reliefs.” Documenta Praehistorica 37 (2010): 239–256.

Bibliography

279

Schoener, Thomas W. “Field Experiments on Interspecific Competition.” American Naturalist 122, no. 2 (1983): 240–285. Scholz, Piotr O. Eunuchs and Castrati: A Cultural History. Princeton, NJ: Markus Wiener, 2001. Schwilk, Dylan W. “Flammability Is a Niche Construction Trait: Canopy Architecture Affects Fire Intensity.” American Naturalist 162, no. 6 (2003): 725–733. Schwilk, Dylan W., and David D. Ackerly. “Flammability and Serotiny as Strategies: Correlated Evolution in Pines.” Oikos 94, no. 2 (2001): 326–336. Shahar, Shulamith. Childhood in the Middle Ages. New York: Routledge, 1989. Shea, John J., and Mathew L. Sisk. “Complex Projectile Technology and Homo sapiens Dispersal into Western Eurasia.” PaleoAnthropology 2010 (2010): 100–122. Sherby, Oleg D., and Jeffrey Wadsworth. “Ancient Blacksmiths, the Iron Age, Damascus Steels, and Modern Metallurgy.” Journal of Materials Processing Technology 117, no. 3 (2001): 347–353. Sherman, Paul W., and Jennifer Billing. “Darwinian Gastronomy: Why We Use Spices; Spices Taste Good Because They Are Good for Us.” BioScience 49, no. 6 (1999): 453–463. Shipman, Pat. The Invaders: How Humans and Their Dogs Drove Neanderthals to Extinction. Cambridge, MA: Belknap Press of Harvard University Press, 2015. Shotyk, William, Dominik Weiss, Peter G. Appleby, Andriy K. Cheburkin, Marlies Gloor, Robert Frei, Jan D. Kramers, Stephen Reese, and William O. Van Der Knaap. “History of Atmospheric Lead Deposition since 12,370 C-14 Yr BP from a Peat Bog, Jura Mountains, Switzerland.” Science 281, no. 5383 (1998): 1635–1640. Sidanius, Jim, and Felicia Pratto. Social Dominance: An Intergroup Theory of Social Hierarchy and Oppression. Cambridge, UK: Cambridge University Press, 1999. Siefker, Phyllis. Santa Claus, Last of the Wild Men: The Origins and Evolution of Saint Nicholas, Spanning 50,000 Years. Jefferson, NC: McFarland, 1996. Silliman, Brian R., Edwin Grosholz, and Mark D. Bertness, eds. Human Impacts on Salt Marshes: A Global Perspective. Berkeley: University of California Press, 2009. Simon, Herbert A. “The Architecture of Complexity.” Proceedings of the American Philosophical Society 106, no. 6 (1962): 467–482. Singh, Seema. “From Exotic Spice to Modern Drug?” Cell 130, no. 5 (2007): 765–768. Smith, Fred H., Ivor Jankovi´c, and Ivor Karavani´c. “The Assimilation Model, Modern Human Origins in Europe, and the Extinction of Neandertals.” Quaternary International 137, no. 1 (2005): 7–19.

280

Bibliography

Snogerup, Sven, Mats Gustafsson, and Roland Von Bothmer. “Brassica Sect. Brassica (Brassicaceae) I. Taxonomy and Variation.” Willdenowia 19, no. 2 (1990): 271–365. Solomon, Susan, Dahe Qin, and Martin Manning. Climate Change, 2007: The Physical Science Basis, ed. Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press, 2007. Spight, Thomas M. “Patterns of Change in Adjacent Populations of an Intertidal Snail, Thais lamellose.” PhD thesis, University of Washington, 1972. Spoor, Fred, Meave G. Leakey, Patrick N. Gathogo, Frank H. Brown, Susan C. Antón, Ian McDougall, Christopher Kiarie, Frederick K. Manthi, and Louise N. Leakey. “Implications of New Early Homo Fossils from Ileret, East of Lake Turkana, Kenya.” Nature 448, no. 7154 (2007): 688–691. Steadman, David W. “Prehistoric Extinctions of Pacific Island Birds: Biodiversity Meets Zooarchaeology.” Science 267, no. 5201 (1995): 1123– 1131. Steffan-Dewenter, Ingolf, Simon G. Potts, and Laurence Packer. “Pollinator Diversity and Crop Pollination Services Are at Risk.” Trends in Ecology & Evolution 20, no. 12 (2005): 651–652. Steinbeck, John. The Grapes of Wrath. New York: Viking, 1939. Steneck, Robert S., Michael H. Graham, Bruce J. Bourque, Debbie Corbett, Jon M. Erlandson, James A. Estes, and Mia J. Tegner. “Kelp Forest Ecosystems: Biodiversity, Stability, Resilience and Future.” Environmental Conservation 29, no. 4 (2002): 436–459. Stephenson, Andrew G. “Flower and Fruit Abortion: Proximate Causes and Ultimate Functions.” Annual Review of Ecology and Systematics 12 (1981): 253–279. Stevenson, Christopher M., Cedric O. Puleston, Peter M. Vitousek, Oliver A. Chadwick, Sonia Haoa, and Thegn N. Ladefoged. “Variation in Rapa Nui (Easter Island) Land Use Indicates Production and Population Peaks Prior to European Contact.” PNAS 112, no. 4 (2015): 1025–1030. Stöllner, Thomas, Horst Aspöck, Nicole Boenke, Claus Dobiat, Hans-Jürgen Gawlick, Willy Groenman-van Waateringe, Walter Irlinger, et al. “The Economy of Dürrnberg-Bei-Hallein: An Iron Age Salt-Mining Centre in the Austrian Alps.” Antiquaries Journal 83 (2003): 123–194. Storey, Alice A., José Miguel Ramírez, Daniel Quiroz, David V. Burley, David J. Addison, Richard Walter, Atholl J. Anderson, et al. “Radiocarbon and DNA Evidence for a Pre-Columbian Introduction of Polynesian Chickens to Chile.” PNAS 104, no. 25 (2007): 10335–10339. Strobel, Gary, and Bryn Daisy. “Bioprospecting for Microbial Endophytes and Their Natural Products.” Microbiology and Molecular Biology Reviews 67, no. 4 (2003): 491–502. Susman, Randall L. “Fossil Evidence for Early Hominid Tool Use.” Science 265, no. 5178 (1994): 1570–1573.

Bibliography

281

Szathmáry, Eörs, and John Maynard Smith. “The Major Evolutionary Transitions.” Nature 374, no. 6519 (1995): 227–232. Tainter, Joseph A. Collapse of Complex Societies. New Studies in Archaeology series. Cambridge, UK: Cambridge University Press, 1990. Tanye, Mary. “Access and Barriers to Education for Ghanaian Women and Girls.” Interchange 39, no. 2 (2008): 167–184. Tattersall, Ian. Encyclopedia of Human Evolution and Prehistory, vol. 768, ed. Eric Delson and John Van Couvering. Garland Reference Library of the Humanities. New York: Garland, 1988. Taylor, Gary. Castration: An Abbreviated History of Western Manhood. New York: Routledge, 2000. Thalmann, Olaf, Elizabeth Shapiro, Pin Cui, Verena J. Schuenemann, Sussana K. Sawyer, Daniel. L. Greenfield, Mietje B. Germonpré, et al. “Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs.” Science 342, no. 6160 (2013): 871–874. Thompson, Helen. “How Witches’ Brews Helped Bring Modern Drugs to Market.” Smithsonian Magazine, October 31, 2014. Thornton, Russell. American Indian Holocaust and Survival: A Population History since 1492. Civilization of the American Indian series. Norman: University of Oklahoma Press, 1987. Thorsby, E. “The Polynesian Gene Pool: An Early Contribution by Amerindians to Easter Island.” Philosophical Transactions of the Royal Society B: Biological Sciences 367, no. 1590 (2012): 812–819. Tilman, David, Joseph Fargione, Brian Wolff, Carla D’Antonio, Andrew Dobson, Robert Howarth, David Schindler, et al. “Forecasting Agriculturally Driven Global Environmental Change.” Science 292, no. 5515 (2001): 281–284. Tilman, G. David. Resource Competition and Community Structure. Princeton, NJ: Princeton University Press, 1982. Tishkoff, Sarah A., Floyd A. Reed, Alessia Ranciaro, Benjamin F. Voight, Courtney C. Babbitt, Jesse S. Silverman, Kweli Powell, et al. “Convergent Adaptation of Human Lactase Persistence in Africa and Europe.” Nature Genetics 39 (2007): 31–40. Tougher, Shaun. The Eunuch in Byzantine History and Society. New York: Routledge, 2008. Toups, Melissa A., Andrew Kitchen, Jessica E. Light, and David L. Reed. “Origin of Clothing Lice Indicates Early Clothing Use by Anatomically Modern Humans in Africa.” Molecular Biology and Evolution 28, no. 1 (2011): 29–32. Tracy, Benjamin F., and Samuel J. McNaughton. “Elemental Analysis of Mineral Lick Soils from the Serengeti National Park, the Konza Prairie and Yellowstone National Park.” Ecography 18, no. 1 (1995): 91–94. Tracy, Larissa, ed. Castration and Culture in the Middle Ages. Cambridge, UK: D.S. Brewer, 2013.

282

Bibliography

Troost, Karin. “Causes and Effects of a Highly Successful Marine Invasion: Case-Study of the Introduced Pacific Oyster Crassostrea gigas in Continental NW European Estuaries.” Journal of Sea Research 64, no. 3 (2010): 145–165. Underdown, Charlotte J., and Simon J. Houldcroft. “Neanderthal Genomics Suggests a Pleistocene Time Frame for the First Epidemiologic Transition.” American Journal of Physical Anthropology 160, no. 3 (2016): 379–388. Valiela, Ivan, Jennifer L. Bowen, and Joanna K. York. “Mangrove Forests: One of the World’s Threatened Major Tropical Environments.” BioScience 51, no. 10 (2001): 807–815. Valiela, Ivan, and J. M. Teal. “Nutrient Limitation in Salt Marsh Vegetation.” Pp. 547–563 in R. J. Reimold and W. H. Queen, eds., Ecology of Halophytes. New York: Academic Press, 1974. Vallee, Bert L. “Alcohol in the Western World.” Scientific American 278, no. 6 (1998): 80–85. Vandenbosch, Robert. Nuclear Waste Stalemate: Political and Scientific Controversies. Salt Lake City: University of Utah Press, 2007. Vargha-Khadem, Faraneh, Kate Watkins, Katherine J. Alcock, Paul Fletcher, and Richard E. Passingham. “Praxic and Nonverbal Cognitive Deficits in a Large Family with a Genetically Transmitted Speech and Language Disorder.” PNAS 92, no. 3 (1995): 930–933. Vargha-Khadem, Faranah, Kate E. Watkins, Cathy J. Price, John Ashburner, Katherine J. Alcock, Alan Connelly, Richard S. J. Frackowiak, et al. “Neural Basis of an Inherited Speech and Language Disorder.” PNAS 95, no. 21 (1998): 12695–12700. Varki, Ajit, and Tasha K. Altheide. “Comparing the Human and Chimpanzee Genomes: Searching for Needles in a Haystack.” Genome Research 15 (2005): 1746–1758. Vermeij, Geerat J. Biogeography and Adaptation: Patterns of Marine Life. Cambridge, MA: Harvard University Press, 1977. ———. Evolution and Escalation: An Ecological History of Life. Princeton, NJ: Princeton University Press, 1987. Villmoare, Brian, William H. Kimbel, Chalachew Seyoum, Christopher J. Campisano, Erin N. DiMaggio, John Rowan, David R. Braun, J Ramón Arrowsmith, and Kaye E. Reed. “Early Homo at 2.8 Ma from LediGeraru, Afar, Ethiopia.” Science 347, no. 6228 (2015): 1352–1355. Vitousek, Peter M. “Beyond Global Warming: Ecology and Global Change.” Ecology 75, no. 7 (1994): 1861–1876. Vitousek, Peter M., Harold A. Mooney, Jane Lubchenco, and Jerry M. Melillo. “Human Domination of Earth’s Ecosystems.” Science 277, no. 5325 (1997): 494–499. Voosen, Paul. “Delaware-Sized Iceberg Splits from Antarctica.” Science On Line, July 12, 2017, https://www.sciencemag.org/news/2017/07/delaware-sized-iceberg-splits-antarctica (accessed August 21, 2019).

Bibliography

283

Vries, Jan de, and Ad van der Woude. The First Modern Economy: Success, Failure, and Perseverance of the Dutch Economy, 1500–1815. Cambridge, UK: Cambridge University Press, 1997. Wagner, Günter P. “Homologues, Natural Kinds and the Evolution of Modularity.” American Zoologist 36, no. 1 (1996): 36–43. Wainwright, Milton. “Moulds in Folk Medicine.” Folklore 100, no. 2 (1989): 162–166. Warmuth, Vera, Anders Eriksson, Mim Ann Bower, Graeme Barker, Elizabeth Barrett, Bryan Kent Hanks, Shuicheng Li, et al. “Reconstructing the Origin and Spread of Horse Domestication in the Eurasian Steppe.” PNAS 109, no. 21 (2012): 8202–8206. Wasson, R. Gordon, Stella Kramrisch, Jonathan Ott, and Carl A. P. Ruck. Persephone’s Quest: Entheogens and the Origins of Religion. New Haven: Yale University Press, 1986. Waters, Andrew P., Desmond G. Higgins, and Thomas. F. McCutchan. “Plasmodium-Falciparum Appears to Have Arisen as a Result of Lateral Transfer between Avian and Human Hosts.” PNAS 88, no. 8 (1991): 3140–3144. Watwood, Stephanie L., Patrick J. O. Miller, Mark Johnson, Peter T. Madsen, and Peter L. Tyack. “Deep-Diving Foraging Behaviour of Sperm Whales (Physeter macrocephalus).” Journal of Animal Ecology 75, no. 3 (2006): 814–825. Waycott, Michelle, Carlos M. Duarte, Tim J. B. Carruthers, Robert J. Orth, William C. Dennison, Suzanne Olyarnik, Ainsley Calladine, et al. “Accelerating Loss of Seagrasses across the Globe Threatens Coastal Ecosystems.” PNAS 106, no. 30 (2009): 12377–12381. Weatherford, Jack. Genghis Khan and the Making of the Modern World. New York: Crown, 2004. Webb, James L. A., Jr. Humanity’s Burden: A Global History of Malaria. Cambridge, UK: Cambridge University Press, 2008. Whitehead, Hal. “Estimates of the Current Global Population Size and Historical Trajectory for Sperm Whales.” Marine Ecology Progress Series 242 (2002): 295–304. Whitman, Walt. “Song of Myself.” 1892. Williams, Alan. “A Metallurgical Study of Some Viking Swords.” Gladius 29 (2009): 121–184. Williams, Michael. “Dark Ages and Dark Areas: Global Deforestation in the Deep Past.” Journal of Historical Geography 26, no. 1 (2000): 28–46. Wilson, David Sloan, and Edward O. Wilson. “Rethinking the Theoretical Foundation of Sociobiology.” Quarterly Review of Biology 82, no. 4 (2007): 327–348. Wilson, Edward O. Genesis: The Deep Origin of Societies. New York: Liveright, 2019. ———. The Insect Societies. Cambridge, MA: Belknap Press of Harvard University Press, 1972.

284

Bibliography

———. Sociobiology. Cambridge, MA: Harvard University Press, 1975. Wilson, J. Bastow, and Andrew D. Q. Agnew. “Positive-Feedback Switches in Plant Communities.” Advances in Ecological Research 23 (1992): 263–336. Winfree, Rachael. “Pollinator-Dependent Crops: An Increasingly Risky Business.” Current Biology 18, no. 20 (2008): R968–R969. Winterhalder, Bruce, Eric Alden Smith, and American Anthropological Association. Hunter-Gatherer Foraging Strategies: Ethnographic and Archeological Analyses. Chicago: University of Chicago Press, 1981. Wolfe, Nathan D., Claire Panosian Dunavan, and Jared Diamond. “Origins of Major Human Infectious Diseases.” Nature 447, no. 7142 (2007): 279–283. Wong, Kate. “Rise of the Human Predator.” Scientific American 310 (2014): 46–51. Wood, Paul. “America’s Natural Ice Industry.” Chronicle of the Early American Industries Association 66, no. 3 (2013): 91–111. World Health Organization. World Health Database, 2015. Geneva: WHO, 2016. https://www.who.int/gho/publications/world_health_statistics/2015 /en (accessed August 21, 2019). ———. World Malaria Report, 2013. Geneva: WHO, 2014. Wrangham, Richard. Catching Fire: How Cooking Made Us Human. New York: Basic Books, 2009. Wrangham, Richard W., William C. McGrew, Frans B. M. de Waal, and Paul G. Heltne, eds. Chimpanzee Cultures. Cambridge, MA: Harvard University Press, 1994. Wright, Geraldine. A., Danny D. Baker, Mary J. Palmer, Daniel Stabler, Julie A. Mustard, Eileen F. Power, Anne M. Borland, and Philip C. Stevenson. “Caffeine in Floral Nectar Enhances a Pollinator’s Memory of Reward.” Science 339, no. 6124 (2013): 1202–1204. Wynne-Edwards, V. C. Animal Dispersion in Relation to Social Behaviour. Edinburgh: Oliver & Boyd, 1962. Yagil, Reuven. The Desert Camel: Comparative Physiological Adaptation. New York: John Wiley & Sons, 1985. Yergin, Daniel. The Prize: The Epic Quest for Oil, Money & Power. New York: Simon & Schuster, 1991. Yibarbuk, Dean, Peter J. Whitehead, Jeremy Russell-Smith, Donna Jackson, Charles Godjuwa, Alaric Fisher, Peter Cooke, David Choquenot, and David M. J. S. Bowman. “Fire Ecology and Aboriginal Land Management in Central Arnhem Land, Northern Australia: A Tradition of Ecosystem Management.” Journal of Biogeography 28, no. 3 (2001): 325–343. Young, Sera L., Paul W. Sherman, Julius B. Lucks, and Gretel H. Pelto. “Why on Earth?: Evaluating Hypotheses about the Physiological Functions of Human Geophagy.” Quarterly Review of Biology 86, no. 2 (2011): 96–120.

Bibliography

285

Yu, Douglas W., and Naomi E. Pierce. “A Castration Parasite of an Ant-Plant Mutualism.” Proceedings of the Royal Society B: Biological Sciences 265, no. 1394 (1998): 375–382. Zeder, Melinda A. “Central Questions in the Domestication of Plants and Animals.” Evolutionary Anthropology: Issues, News, and Reviews 15, no. 3 (2006): 105–117. ———. “Domestication and Early Agriculture in the Mediterranean Basin: Origins, Diffusion, and Impact.” PNAS 105, no. 33 (2008): 11597–11604. Zhang, David D., Peter Brecke, Harry F. Lee, Yuan-Qing He, and Jane Zhang. “Global Climate Change, War, and Population Decline in Recent Human History.” PNAS 104, no. 49 (2007): 19214–19219. Zimmer, Carl. “The Human Family Tree Bristles with New Branches.” New York Times, May 27, 2015. Zipes, Jack. The Enchanted Screen: The Unknown History of Fairy-Tale Films. New York: Routledge, 2011. Znamenski, Andrei. Shamanism in Siberia: Russian Records of Indigenous Spirituality. New York: Springer Netherlands, 2003.

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Illustration Credits

Figure 1.2 is based on Signbrowser, Theory of Endosymbiosis, and Development of Eukaryotic Cells, https://en.wikipedia.org/wiki/File:Endosymbiosis.svg, available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. Figure 2.1 is based on Maqsoodshah01, Evolution-Theory, and other public domain images. Figure 2.2 was adapted from Spreading Homo Sapiens by Urutseg and Spreading Homo Sapiens over the World by Altaileaopard; see also public domain wikimedia based on Göran Burenhult: Die ersten Menschen (Augsburg: Weltbild, 2000). Figure 2.3. The dodo bird image was redrawn from “Dodo,” Encyclopaedia Britannica, https://www.britannica.com/animal/dodo-extinct-bird. The woolly mammoth image was adapted from Mauricio Antón, “Artwork of Fauna during the Pleistocene Epoch in Northern Spain” (2004), reprinted in Caitlin Sedwick, “What Killed the Woolly Mammoth?,” PLoS Biology 6, no. 4 (2008): e99, doi:10.1371/journal.pbio.0060099. PLoS content is available under the Creative Commons license Attribution 4.0 International. Figure 3.1 was redrawn from numerous public domain sources, including John Doebley, Adrian Stec, Jonathan Wendel, and Marlin Edwards, “Genetic and Morphological Analysis of a Maize-Teosinte F2 Population: Implications for the Origin of Maize,” Proceedings of the National Academy of Science 87 (December 1990): 9888–9892, https://doi.org/10.1073/pnas.87.24.9888; and Hugh Iltis, “From Teosinte to Maize: The Catastrophic Sexual Transmutation,” Science 222, no. 4626 (November 25, 1983): 886–894. Figure 4.4 is based on the photo City of David 390 by Wayne Stiles, in Stiles, “Sights and Insights: The Oldest Part of J’lem,” Jerusalem Post, February 27, 2012, https://www.jpost.com/travel/around-Israel/sights -and-insights-the-oldest-part-of-Jlem.

287

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Figure 5.2 is based on the Course-Notes.org flashcard “The Early Phoenicians,” http://www.course-notes.org/flashcards/ap_world_history _unit_1_flashcards_14. Figure 5.5. For a downloadable image of the camel caravan, see https://www .loc.gov/item/2007675298/. Figure 6.2. To view the original Lice Capades image, go to Daily Kos, https:// www.dailykos.com/stories/2011/11/10/1035046/-The-Lice-Capades. Figure 6.3. For the original Wolgemut image, see Wikimedia.org, https:// commons.wikimedia.org/wiki/File:Danse_macabre_by_Michael _Wolgemut.png. Figure 6.4 is based on the public domain illustration The Red Queen’s Race by John Tenniel, published in Lewis Carroll, Through the Looking Glass (1871). Figure 7.5 is based on an image of the fossil that can be seen at http:// biodiversitylibrary.org/page/48435496 (digitized by Natural History Museum, London). Figure 9.1. For a downloadable image of the engraving of the Salem witch trial, see https://commons.wikimedia.org/wiki/File:Witchcraft_at_Salem _Village.jpg. Figure 10.1. For a downloadable image of the beached whale engraving, see https://www.rijksmuseum.nl/en/collection/RP-P-OB-4635. Figure 10.4, a public domain photograph titled The Shoe & Leather Petroleum Company and the Foster Farm Oil Company (ca. 1895, Mather & Bell), can be viewed at https://www.loc.gov/item/2005686702/. Figure 11.1, a public domain photograph by D. L. Kernodle titled Dust Storm, Baca County, Colorado (ca. 1936), can be viewed at https://www.loc. gov/item/2017759525/. Figure 11.2. The graph on which this image is based can be viewed at https://www.icriforum.org/sites/default/files/GCRMN_Tropical_ Americas_Coral_Reef_Resilience_Final_Workshop_Report.pdf. Figure 11.3. The background data for global carbon emissions were obtained from G. Marland, T. A. Boden, and R. J. Andres, “Global, Regional, and National Fossil-Fuel CO2 Emissions,” in Trends: A Compendium of Data on Global Change (Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2008).

Index

Note: Page numbers in italics refer to illustrations abiogenesis, 18–22 Academy of Gondishapur, Iran, 150 Africa, human migration out of, 46–50, 47 Agassiz, Louis, 3, 226 Age of Enlightenment, 150 agriculture: as catastrophic, 74; and changing diets and digestion, 70–72; colonization and revolutions in, 73; domestication of plants and animals (see domestication of plants and animals); global diffusion of farming technology, 70; human ancestral connections to, 56–57; importance of agricultural revolutions, 57, 75; as inevitable, 74–75; pre-agricultural land management, 59–61; revolutions in China, 72–73 AI. See artificial intelligence AIDS, 126 air pollution, 201–203, 202 alcohol, use and abuse of, 66–68, 163– 164, 175 algal blooms, 225 Allegro, John Marco, 165 Alpha Helix expedition, 35–37

alternate states, 214, 216, 217, 218, 220, 222, 224 Amanita muscaria (fly agaric), 158–159, 165, 166 American Revolution, 186 Anning, Mary, 151, 152 Anthropocene era, 11, 208, 232 anthropocentric point of view, 1 antibiotics, 5–6, 33, 130–131, 163, 178–181 appendixes, 31–32 arms races: among marine organisms, 97–98; bacterial resistance as, 180–181; and defensive chemicals, 95; metal tools and weapons and, 95–97; plant defense compounds and, 175–176; snails and crabs, 94–95, 96 artificial intelligence, 229–230 artificial selection, 59, 65–66, 140, 142. See also domestication of plants and animals asymmetries, 137 Australopithecines, 37–39 autopoiesis, 25–28, 27, 38. See also feedback loops, positive

289

290

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bacterial resistance, 131, 180 baleen, 199 Balsam fir and gypsy moths, 174–175 barnacle communities, 139, 140 Barzun, Jacques, 81 bedbugs, 122, 122, 123–124 behavioral asymmetries, 137 Belyaev, Dmitry K., 51 Better Angels of Our Nature, The (Pinker), 81–83 Big Bang, 17 Billing, Jennifer, 178 birds of prey and DDT, 220 bireme, 102, 102 Black Death (plague), 107, 126–129, 127 body hair, 46–47 bola balls, 43 Brassica oleracea, 65–66 Brave New World (Huxley), 159 bread making, 67–68 bronze alloying, 95–96, 191 bubonic plague (Black Death), 107, 126–128, 127 Buddha, 155, 160 Bumpus, Hermon Carey, 6 Buss, Leo, 29 cabbage varieties, 65–66 camels, 103–104, 105 cannabis, 164 Caporael, Linnda, 172–173 carbon dioxide (CO2), 221–222, 223 Carson, Rachel, 220 castration, 144–145 cattle, 60, 61–62, 71–72, 218. See also herbivores charcoal, 190–193 cheese, 71 chemical self-organization hypothesis, 19–21 chemosynthetic bacteria, 21 child dumping, 114–116 China: and deforestation, 192; and drilling for natural gas, 184, 184,

205; and environmental programs, 227; famines in, 117–118; and nasal insufflation for smallpox, 131–132; salt production facilities, 183–184, 184; silkworms and cloth production, 105–107; trade, 105, 107 Christianity, 160–161, 165, 167 chronic energy deficiency, 41 cities, earliest, 83–86, 85, 91 civilization, evolution and growth of, 79–92; cooperative farming and, 82–83; earliest cities, 83–86, 85, 91; and environmental degradation, 90– 91; establishment of year-round farms, 80–81; evaluating benefits and costs, 91–92; and health problems, 90; and need for hierarchical organization, 83–84; population and development feedback loops, 79; and religions, 86–88; and trade networks, 84–85; and violence/wars, 81–83, 88–90, 89; writing systems and, 83–84 civilizations, decline and fall of, 209– 214; Easter Island, 213–214, 229; Egyptian Empire, 212; failure to change and, 232–235; Maya Empire, 213; Mesopotamian civilization (Fertile Crescent), 210, 212, 229; natural history rules and, 231– 232; Roman Empire, 212–213; tragedy of the commons and, 209–211 Clash of Civilizations and the Remaking of World Order, The (Huntington), 161 class systems. See hierarchical organization climate change, 221–227; and eutrophication and dead zones, 224–225, 226; global reach of, 225–226; greenhouse gasses and global warming, 221–222, 223; ocean acidification, 222, 224; sea level rise, 224 clothing, development of, 46–47

Index coal, 199–203 coevolution: with artificial intelligence, 229–230; defined, 10; and domestication of plants and animals, 56–57, 61, 74–75; of humans and entheogens, 167–168; of humans and microbes, 31–34, 120–122, 170–171; of humans and plants, 162–164 cognitive revolution, 43–44 colonization, 110–113 commensalisms, 50, 51, 63–64 competition: cultural conflict, 111–112; Darwin and, 240n9; between differing human species, 49; exploitation competition, 49; innovation and, 10; interference competition, 49; as overriding force in natural selection, 4–5. See also arms races competitive exclusion principle, 58 cooking food, 40–41 cooperation: and continued survival of humans, x–xi, 230, 234–235; Darwin and, 240n9; in early civilizations, 82–83; and human evolution, 38, 55; human microbiome as, 31–34; importance of in evolution, x, 22–23; industrial revolutions and, 150–151; language and, 44; and limited resources, 94; and spatial organization, 137–140, 138, 139, 141; and strength, 80, 83; vital role of, 5. See also symbiogenesis coral reefs, 8, 31, 94, 98, 181, 218, 219 cordgrass, marsh, 28 crab jubilees, 225 crabs and snails arms race, 94–95, 96 Crepidula fornicata, 145 cultural conflict, 111–112 cyanobacteria, 25–26 Daily, Gretchen, 214–215, 226 dairy farming and lactose tolerance, 71–72 Darwinian medicine, 181

291

Darwin’s finches, 6 Daugherty, Richard, 196 Dawkins, Richard, x, 5 DDT, 124, 220 dead zones, 224–225 deforestation, 181, 191, 214, 218 demography, 202 Descartes, René, 155 determinism, 9, 10–11 Diamond, Jared, ix, 70, 74, 213–214 dinosaur fossils, 151, 152 dirt eating, 176 diseases: AIDS, 126; antibiotics and, 5–6, 33, 130–131, 163, 178–181; civilization and health, 90; coal and, 202; coevolution and, 120–122; exploration and spread of, 128–129; human microbes as defense against, 33, 121; lice and bedbugs, 46–47, 121–122, 122, 122–123; malaria, 124–126; monogamy and, 134; Native Americans and, 129; natural selection as defensive strategy, 132– 134; New World exploration and, 111; plague (bubonic plague, Black Death), 107, 126–128, 127; prevention versus control, 180–181; Spanish flu pandemic, 126; syphilis, 129; trade and, 120, 127; urbanization and, 119; viruses and, 131–132 disparities in wealth and resources, 83, 88–89, 92, 108, 109–110, 154 dodo, extinction of, 54 dogs, 51–52 domestication of plants and animals, 56–69; camels, 103–104; in China, 72–73; as coevolutionary mutualism, 56–57; defined, 63; and farmer and shepherd lifestyles, 63; in the Fertile Crescent, 64–65; grains and grasses, 61, 65–67, 66; horses, 103, 104; and human dominance, 140, 142; as natural extensions of coevolution, 74– 75; olives, 68–69.69; versus one-way

292

Index

domestication of plants and animals (cont.) commensal relationships, 63–64; sheep and cattle, 61–63, 65; silkworms, 106–107; wolves, 51–52 dominance. See humans, as dominant species; social dominance Doors of Perception, The (Huxley), 159 Drawing Hands (Escher), 27 Drugged—The Science and Culture behind Psychotropic Drugs (Miller), 163 Dudley, Robert, 67, 163, 164 dust storms, 216, 217 Earth: age of, 16–17; formation of, 18; life on, 18–22 Easter Island, 213–214, 229 ecology, historical, 211 ecosystems and ecosystem services, 214–221; coral reefs, 8, 31, 94, 98, 181, 218, 219; destruction of, and human survival, 227–230; estuary restoration in North America, 227; forests, 181, 191, 214, 218; keystone predators and, 220, 235–236; mangrove forests, 215, 218–219; monetizing ecosystem services, 226–227; recovery of, 217–218, 220–221; salt marshes, 28–31, 30, 215, 218, 219; seagrass meadows, 220; vegetated shorelines, 215 Egan, Tim, 216 Egyptian Empire, 176, 184–185, 212 Egyptian mythology, 160 Ehrlich, Paul, 31, 33, 226 endosymbiosis theory, 23–24, 24 energy: coal, 199–203; environmental consequences of fossil fuels, 206– 207; nuclear, 207; peat, 193–194; petroleum, 203–207; renewable sources of, 207–208; solar, 189–190; whale oil, 194–199, 195; wood and charcoal for heat and light, 190–193 England: and coal use, 201–203, 202, 204, 205; and dinosaur bones, 132;

and smallpox vaccine, 132; wood harvesting laws, 192 entheogens: alcohol, 163–164; Amanita mushrooms (fly agaric, Soma), 158– 159, 165, 166; Christianity and, 165, 167; and coevolution, 167–168; ephedra, 164; and human-plant coevolution, 162–164; Maya and, 167, 168; opioid poppies, 161, 164; peyote, 167; Psilocybe mushrooms, 165, 167, 169; scientific studies of, 168– 169 environmental degradation: civilization and, 90–91; coal and, 201–203, 202; deforestation, 181, 191, 214, 218; and fossil fuels, 206–207; as global problem, 226; and the search for new medicines, 181. See also civilizations, decline and fall of; ecosystems and ecosystem services ephedra, 164 ergot and ergotism, 172–173 Escher, M. C., 27 Estes, Jim, 220 estuary restoration, 227 eukaryotic cells, 23–24, 24, 80 European salt mines, 185 eutrophication, 224–225 evolution by natural selection: competition and, x, 22–23; cooperation and (see cooperation); of eukaryotic cells, 23–24, 24; group selection, 6–8; human (see human evolution); humans as agents of (see artificial selection); randomness and, 9–10; slow versus rapid, 5–6, 204; and social behaviors, Wilson on, 140 Ewald, Paul, 121 execution and torture, 143–146 exotic species, 112–113, 188 exploitation competition, 49. See also resource exploitation exploration, 110–113; food preservation and, 182; planetary, 237–238,

Index 239n3; and spread of diseases, 128–129 extinction: of human species, 48–49; of megafauna during human migration, 52–55, 54 famines, 114–119; causes of, 116–117, 118, 119; and child dumping, 114– 116; earliest documented, 117–118; evolutionary legacy of, 118; fatalities caused by, 118 feedback loops, positive: autopoiesis, 25– 28, 27; Great Oxygenation Event, 25; and human evolution, 38; population growth and hierarchical organization, 84; resource exploitation and population growth, 96; salt marsh mussels and fiddler crabs, 28–31 fermentation, 66–68 Fermi paradox, 237 Fertile Crescent: and agriculture, 86; and domestication, 64–65; environmental degradation, 90, 229; and environmental degradation, 210; ice houses in, 186–187, 187; and language, 45, 46 fiddler crabs and salt marsh mussels, 28–31 fire: domestication of, 39–41, 190; as land management technique, 59; some plants dependence on, 60 fleas, 127–128 flowers and insect pollinators, 56–57 flu pandemic, 126 Food of the Gods (McKenna), 167–168 food preservation, 181–188; electric refrigeration, 188; garum, 182; ice, 186– 187; lye, 182; salt, 182–186; smoking, 182; spices, 171, 179–180, 181–182 fossil fuels, 189–190; and carbon dioxide, 221; coal, 199–203; environmental consequences of, 206–207; natural gas, 184, 184, 204–205; peat, 193–194; petroleum, 203–207

293

foundation species, 28, 217–218 FOXP2, 46 free time and innovation, 44 Friedman, Thomas, 109–110 Fukuyama, Francis, 90 fungal-plant symbiosis, 199 Gaia hypothesis, 24–28 geophagy, 176 geothermal energy, 207 glacial maxima, 49–50 glass, 102 global warming, 206, 221–222, 223 Göbekli Tepe, 87–88, 162 Gould, Stephen J., 9 grains and grasses, domestication of, 65–67, 66 Grant, Peter and Rosemary, 6 grasslands, 58–61, 216–217 Graunt, John, 202 Graves, Kersey, 160 Great Chain of Being, 147–150 Great Dust Bowl, 216–217, 217 Great Oxygenation Event, 25 group selection, 6–7 gruel, 68 guillotines, 143–144 Gulf Coast crab jubilees, 225 Guns, Germs, and Steel (Diamond), 70 gypsy moths and Balsam fir, 174–175 Haida culture, 196 hair, loss of, 46–47 Haldane, J. B. S., 133 Hallstatt salt mines, 185 Hamilton, W. D., 62 Hansel and Gretel, 115 Harari, Yuval, ix, 229, 235 Harvard Marsh Chapel experiment, 169 health problems. See diseases; medicine herbivores: domestication of, 62; and forest burning, 60; herding behaviors, 62, 94; and savannas/grasslands, 58–59, 60

294

Index

Herodotus, 125 Heyerdahl, Thor, 48 hierarchical organization: causes of, 142; in earliest civilizations, 83–84; the Great Chain of Being, 147, 148, 149; and oppression and violence, 142– 146; overview, 8–11; as process of natural history, 4; in salt marshes, 29– 31, 30; and wars, 88–89; women and, 146–147. See also social dominance Hinduism, 158–159, 160 historical ecology, 211 hitchhikers of human lifestyles, 64 Hofmann, Albert, 173 Holdren, John, 226 Holmes, Arthur, 17 homeostatic mechanisms, 25 hominid morphology, 40 Homo erectus, 2, 38, 39, 125 Homo heidelbergensis, 45 Homo neanderthalensis, 45, 48, 164, 177– 178 horses, 103, 104 housing developments, 137, 138, 139 Hubble, Edwin, 17 human evolution: and agriculture (see agriculture; domestication of plants and animals); cognitive revolution, 43–44; cooperative hunting, 39; and extinctions, 48–49, 52–55, 54; fire and cooking and, 39–41; and free time, 44; hominid morphology, 40; huntergatherers, 2, 36–37, 43, 58–59, 72, 135, 243n5; language and, 44–46; and large-scale habitat destruction, 227– 230; migration out of Africa, 46–50, 47; processes of, 37–38; and relationships with macroorganisms, 50–55; savannas and grasslands and, 58–61; tool making and use, 38–39, 41–42, 43; and trade (see trade). See also coevolution; competition; cooperation human genome, disease and, 133–134 humanity, definition of, 15–16

human microbiome, 31–34, 121 humans, as dominant species, 2–3, 55, 171, 211, 228, 232 hunter-gatherers, 2, 36–37, 43, 58–59, 72, 135, 243n5 Huntington, Samuel, 161 Hutchinson, G. Evelyn, 5 Hutton, James, 16, 24 Huxley, Aldous, 159 hydrothermal vents, 20–21 hyoid bone, 45 ice ages, 49–50 ice houses and ice boxes, 186–187 imprinting, 62 India, salt tax protests, 186 industrial melanization, 203, 204, 205 industrial revolutions, 79, 150–151, 154, 194, 200–201 infanticide, 114–116 information dissemination: control of information and dominance, 151, 153–154, 232–233; industrial revolutions and, 150–151; and trade networks, 43, 109–110; universities, 150. See also science and technology insect pollinators and flowers, 56–57 interference competition, 49 Irian Jaya, 35–37 Irish Potato Famine, 118 iron smelting, 97, 191 irrigation projects, 82–83 Janzen, Dan, 31 Jericho, Mesopotamia, 83, 89, 91, 98 Karaouine, Morocco, 150 kelp forests, 220 Kelvin, Lord, 16–17 Kettlewell, Bernard, 203, 204, 205 keystone predators, 220, 235–236 labroids, 145 lactose tolerance and intolerance, 70–72

Index Lane, Nick, 22 Laveran, Charles, 126 leadership/management. See hierarchical organization Lemaître, Georges, 17 Levittown housing developments, 137, 138, 139 lice, 46–47, 122, 122–123 life, origins of, 18–22 Life Ascending (Lane), 22 Lloyd, William Forster, 209 Lorenz, Konrad, 62 Lovelock, James, 25 LSD, 173 Lyell, Charles, 16 lysergic acid, 173 Madagascar, megafauna extinction on, 53 Makah culture, 196 malaria, 124–126 mangrove forests, 215, 218–219 Margulis, Lynn, 23–24, 24, 25, 240n9 Marine Biological Laboratory, Woods Hole, 3 Marsh Chapel experiment, 169 Maturana, Humberto, 26 Maya civilization, 73, 167, 168, 213 McKenna, Terence, 167–168 Mechnikov, Ilya Ilyich, 33 medicines, 170–181; antibiotics, 5–6, 33, 130–131, 163, 178–181; endophytes, 180; and environmental degradation, 181; ergot, 172–173; lysergic acid and LSD, 172–173; plant defensive compounds and, 174–176; self-medication behaviors, 10, 162, 175–176, 177–178; spices, 176–180, 179 Mediterranean region: olives and olive processing, 69; trade, 98–103, 99, 102 megafauna extinction, 52–55, 54 Mendel, Gregor, 59

295

Mesopotamian civilization, 210, 212. See also Fertile Crescent metallurgy, 95–97, 191 microbiomes, 31–34, 121 migration out of Africa, 46–50, 47 Miller, Richard, 163 Miller, Stanley, 19, 20 mobile phones, 229–230 monarch butterflies, 175 Mongols, 110, 176 monogamy and venereal diseases, 134 mosquitoes, 124–126 Murex snails, 98–101, 101, 116 mushrooms, 158–159, 165, 166, 169 mussels and fiddler crabs, 28–31 mutualisms: ancient cyano- and aerobic bacteria, 23; defined, 4–5, 50; flowers and insect pollinators, 56–57; humans and dogs, 51–52; importance of, 232; plant-fungal symbiosis, 199; salt marshes, 28–31. See also domestication of plants and animals; symbiogenesis nasal insufflation, 132 National Science Foundation, 35 Native Americans, 48, 111–112, 129. See also Maya civilization Natufians, 67–68 Natural Capital Project, 226–227 natural gas, 184, 184, 204–205 natural history and human history: civilizations and, 231–232, 236–237; defined, 2; definition of humanity, 15–16; as intertwined, 1–3 (see also symbiogenesis); as separate, ix–x natural selection. See evolution by natural selection nature, red in tooth and claw, 4 Nature’s Services (Daily), 214–215 Neanderthals. See Homo neanderthalensis neoteny, 51–52, 71

296

Index

Netherlands (Holland): peat mining and land reclamation, 193–194; and whaling, 195, 195 New England whaling industry, 196–198 New World exploration and colonization, 110–113 nitpicking, 122–123 non-native species, 112–113, 188 nuclear energy, 207 obligate commensals, 63–64 obligate domestication, 107 ocean acidification, 222, 224 olives and olive processing, 68–69.69 opioid poppies, 161, 164 Origins of Political Order, The (Fukuyama), 90 oxygenation of Earth’s atmosphere, 25 oyster industry, 188 oysters/oyster reefs, 62 Ozette site, 196 pacification process, 81–83 Pacific Northwest: oyster industry, 188; purple sea star, 235–236; whaling history, 196 Pahnke, Walter, 169 Paine, Robert, 235–236 Panama Canal, 125 panspermia hypothesis, 19 Papua New Guinea, 35–37 Parable of the Watchmakers, 29–30 parasites, 121–126 parrotfish, 145 peat, 193–194 penguin colony, Patagonia, 42–43 penicillin, 30–131 Pennsylvania: coal mining, 200–201; oil wells, 203, 206 peppered moths, 203, 204, 205 petroleum, 203–207 peyote, 167 Phoenician civilization: alphabet and language, 83–84; and

Mediterranean trade, 98–103, 99, 103 photosynthesis, 25 Pinker, Steven, 49, 81–83, 143, 243n5 plague (bubonic plague, Black Death), 107, 126–128, 127 Plague Time (Ewald), 121 planetary exploration, 237–238 plants: coevolution with humans, 162– 163; defensive (secondary) compounds, 174; domestication of (see domestication of plants and animals); entheogens (see entheogens); exploitation of plant defenses (see medicines); partnership with fungi, 199; psychotropic, 86, 87–88, 158– 159, 248n2 Plasmodium spp., 124–126 pollinator decline, 228 population growth, 223; agriculture and, 79, 81, 82, 83, 88, 135, 142; civilization and, 79, 188; cooperation and, 7, 23, 75; and deforestation, 191–192; and diseases, 127, 128, 134; and famines, 116–117, 119; and hierarchical organization, 84; and resources, 7, 22, 84, 93, 94, 96, 113, 154, 181–182 Pratto, Felicia, 137 primogeniture, 146 primordial soup, 18, 19 Psilocybe mushrooms, 165, 167, 169 psychotropic plants, 86, 87–88, 158– 159, 173, 248n2. See also entheogens purple clothing dye, 99–101, 101 purple sea star, 235–236 quahog (hard-shelled clam), 225 rabbits, 113 rainforests, 8–9, 180, 181, 215, 218 randomness versus intent and design, 9–10 Raven, Peter, 31

Index raw food diets, 40–41 Red Queen Hypothesis, 132–133, 133 red tides, 225 religions, mythologies, and beliefs, 157–169; and child dumping, 115– 116; and conflict, 161–162; and entheogens (see entheogens); at Göbekli Tepe site, 87–88, 162; and hierarchical organization, 147–150; increasing secularism, 169; and inertia, 232–233; parallelism in, 159– 162; political motivations for, 161–162; as social glue, 161; theories on birth of, 86–88; as uniquely human, 157–158; and use of psychotropic plants, 158–159 renewable energy sources, 207–208 resource exploitation, 93–113; and age of exploration and colonization, 110–113; and arms races, 94–98; Mongols and, 110; Phoenicians and Murex snails, 98–103; population and, 93 (see also population growth); Roman highway system and, 108– 110, 109; Silk Road trade network and, 105–107, 106; and tragedy of the commons, 209–211 resource limitations, 228–229, 232. See also population growth Rhode Island, as the Quahog State, 225 Rig Veda, 158–159 Roman Empire: decline and fall of, 212–213; and deforestation, 192; and famines, 117; highway system, 107, 108–110; map, 109; salt production, 185; use of peat, 193 Ross, Ronald, 126 rulers. See dominance; hierarchical organization Sacred Mushroom and the Cross, The (Allegro), 165 Sagan, Carl, 13, 222 salt and salt production, 182–186, 184

297

salt marshes, 28–31, 30, 215, 218, 219 salt taxes, 186 Sapiens: A Brief History of Humankind (Harari), 229 savannas and grasslands, 58–61, 216– 217 science and technology: artificial intelligence, 229–230; and increasing secularism, 169; natural history as, 150; and planetary exploration, 237–238; and power, 150–154; as revisionary, 232–233 seagrass meadows, 220 sea level rise, 224 sea otters, 220 seashores, human affinity for, 2 sea star, purple, 235–236 secondary compounds, 174 secularization, 151–153, 169 self-creation through self-feedback, 26 selfish genes, x, 5, 230, 234–235 selfish herd behavior, 62, 94 self-medication behaviors, 10, 162, 175–176, 177–178 self-organization: autopoiesis, 25–28, 2728; chemical self-organization hypothesis, 19–21; rules of, 231– 232; salt marshes, 28–31; types of group organization, 136. See also hierarchical organization self-replicating molecules, 21–22 sex change, 145 sexual reproduction and diseases, 132– 133 shaman culture, 163, 166 sheep, 60, 61, 62, 65 Sherman, Paul, 178 sickle cells, 125 Sidanius, James, 137 siege warfare, 118–119 Silent Spring (Carson), 220 silk, 105–107 Silk Road, 73, 85, 105–107, 106 Simon, Herbert, 29–30

298

Index

slave trade, 102–103 slipper limpets, 145 smallpox, 131–132 Smith, John Maynard, 7 snails: arms race with crabs, 94–95, 96; and filicide (sibling eating), 116; and Phoenician trade routes, 98–103, 101, 102 snail shells, diversity of, 36 social dominance: control of information and, 151, 153–154; epidemics and famines and, 149; evolution of, 135–136; pacification and civilization as consequences of, 145–146; religious mythologies and, 147–150; rules of, 136–137; by ruling elites using violence, 142–146; science and technology and, 150–151; and spatial organization, 137–140, 138, 139, 141 Sociobiology (Wilson), 140 solar energy, 189–190 Soma, 158–159 Spanish flu pandemic, 126 sparrows, rapid evolution in, 6 spatial organization, 137–140, 138, 139, 141, 231–232 speech genes, 46 sperm whales and spermaceti, 197–198 spices, 110–111, 171, 176–180, 179 spontaneous generation, 18–19 St. Anthony’s Fire, 173 starlings, 113 steel metallurgy, 95–97 Stephens, John, 213 stone tools, 38–39, 41–42, 43 study nature, not books, 3, 226 survival of the fittest, x, 4, 6–7. See also competition symbiogenesis, 4–9; defined, 5; group selection, 6–8; human microbiome, 33–34; importance of, 232; and origin of eukaryotic cells, 23–24, 24. See also mutualisms

symbiosis, 4, 5, 7–8, 23, 30, 32–33, 121, 199 syphilis, 129 Szathmáry, Eörs, 7 tallgrass prairies, 216–217, 217 Tatoosh Island, Washington, 235–236 teleology, 9, 27 termite colonies, 137–138, 138 tools making and using, 38–39, 41–42, 95–97 torture and execution, 143–146 trade: and diseases, 120, 127; early trade for tool stones and pigments, 42–43; Egypt and salt export, 184– 185; and evolution of civilization, 84–85; Mongols and, 110; olive oil and, 69; Phoenicians and Mediterranean Sea routes, 98–103, 99, 102; Roman highway system, 108–110; Silk Road network, 73, 85, 105–107, 106; and slaves, 102–103; use of horses and camels, 103–105, 105 tragedy of the commons, 209–211 Twain, Mark, 77 uniformitianism, 16, 24 universe, origin of, 16–18 universities, 150 Ur, Mesopotamia, 85 Urey, Harold, 19 vaccinations, 131–132 Varela, Francisco, 26 venereal diseases and monogamy, 134 Venice flooding, 224 Vermeij, Geerat “Gary,” 35–37, 94–95 Vikings and slave trade, 103 violence: in early civilizations, 81–83; hunter-gatherers and, 243n5; and maintaining dominance, 143–146 viruses, 131–132

Index wars: famine and, 118–119; hierarchical organization and, 88–90, 89; over salt and salt taxes, 185–186; religion and, 161–162 Wasson, Gordon, 167 wealth disparities, 83, 88–89, 92, 108, 109–110, 154 wetlands, 215 whaling and whale oil, 194–199, 195 wheat, 65, 66 Whitman, Walt, 34 Wilson, Edward O., 140 witches and witch trials, 171–173, 172, 248n2

299

wood (energy), 190–193 Woods Hole Marine Biological Laboratory, 3 woolly mammoth, 54 World’s Sixteen Crucified Saviors, The (Graves), 160 Worst Hard Time, The (Egan), 216 Wrangham, Richard, 40, 67 writing systems, 83–84 Wynne-Edwards, Vero, 6 yogurt, 71 Zeder, Melinda, 63