Masters of the Planet
Page 1
MASTERS OF THE PLANET
MASTERS OF THE PLANET
THE SEARCH FOR OUR HUMAN ORIGINS
IAN TATTERSALL
MASTERS OF THE PLANET
Copyright © Ian Tattersall, 2012.
All rights reserved.
First published in 2012 by PALGRAVE MACMILLAN® in the United States—a division of St. Martin’s Press LLC, 175 Fifth Avenue, New York, NY 10010.
Where this book is distributed in the UK, Europe and the rest of the world, this is by Palgrave Macmillan, a division of Macmillan Publishers Limited, registered in England, company number 785998, of Houndmills, Basingstoke, Hampshire RG21 6XS.
Palgrave Macmillan is the global academic imprint of the above companies and has companies and representatives throughout the world.
Palgrave® and Macmillan® are registered trademarks in the United States, the United Kingdom, Europe and other countries.
ISBN 978-0-230-10875-2
Library of Congress Cataloging-in-Publication Data Tattersall, Ian.
Masters of the planet : the search for our human origins / Ian Tattersall.
p. cm.
Includes bibliographical references and index.
ISBN 978-0-230-10875-2 (hardback)
1. Human beings—Origin. 2. Human evolution. 3. Evolutionary psychology. I. Title.
GN281.T364 2012
599.93’8—dc23
2011034415
A catalogue record of the book is available from the British Library.
Design by Letra Libre, Inc.
First edition: March 2012
10 9 8 7 6 5 4 3 2 1
Printed in the United States of America.
For Gisela, Tat and Chub
CONTENTS
Prologue
Major Events in Human Evolution
ONE
ANCIENT ORIGINS
TWO
THE RISE OF THE BIPEDAL APES
THREE
EARLY HOMINID LIFESTYLES AND THE INTERIOR WORLD
FOUR
AUSTRALOPITH VARIETY
FIVE
STRIDING OUT
SIX
LIFE ON THE SAVANNA
SEVEN
OUT OF AFRICA . . . AND BACK
EIGHT
THE FIRST COSMOPOLITAN HOMINID
NINE
ICE AGES AND EARLY EUROPEANS
TEN
WHO WERE THE NEANDERTHALS?
ELEVEN
ARCHAIC AND MODERN
TWELVE
ENIGMATIC ARRIVAL
THIRTEEN
THE ORIGIN OF SYMBOLIC BEHAVIOR
FOURTEEN
IN THE BEGINNING WAS THE WORD
CODA
Acknowledgments
Notes and Bibliography
Index
PROLOGUE
Stare at the face of a chimpanzee. Look deep into its eyes. Your reactions will almost certainly be powerful, complex, and murky. Perhaps on balance you’ll want to recoil, as the Victorians tended to, perceiving in the apes a bestial savagery that served as an unwelcome reminder of humanity’s feared and (usually) repressed dark side. In our own day, though, you’ll much more likely see in the chimpanzee something more positive: not a failure to achieve human status, but an inchoate glimpse of the deep biological foundations on which our modern civilization and creativity are ultimately based. Still, whatever your exact reaction may be, it will certainly come from perceiving a lot of yourself in those eyes—and the side of the human coin you will see reflected will depend entirely on you, not on the chimpanzee.
This ambiguity makes it very frustrating that the chimpanzee can’t articulate his state of mind to us, or answer our questions about it. But then, for all of his physical differences, if he could talk he would be one of us. Nothing else he could do would place him more emphatically in the human camp, for it has been recognized since ancient times that language defines us as nothing else does. Indeed, the Scottish jurist James Burnett, Lord Monboddo, anticipated evolutionary thought as early as the 1770s when he suggested that the acquisition of language was the key feature that had levered humankind away from the “lower” animals: an intuitively attractive notion that has been revisited by numerous thinkers since. During the quarter millennium that has elapsed since Monboddo wrote, a vast trove of information bearing on this issue has accumulated, in numerous areas of science that range from linguistics through genomics to neurobiology. Most importantly, we have learned a great deal about the diversity and behaviors of our pre-cursors on this Earth: certainly enough to allow us to begin speculating with some confidence about how, when, and in what context humankind acquired its extraordinary habits of mind and communication.
The story of how we became human is a long one, and it is one that is best recounted from its ancient beginnings, well before there was any firm hint of what was to come. So let’s return for a moment to that chimpanzee and its relatives. It’s hardly surprising that the apes are so unsettlingly like us. They are our closest living relatives in the biosphere, sharing with us an ancestor that lived perhaps as recently as seven million years ago—a mere eye-blink in the history of Life. But in that short time no other animal lineage has changed nearly as much as ours has. This means that even though they, too, have changed, we can reasonably look to chimpanzees and their relatives for clues as to what our common ancestor was like. And if these primates serve as a reliable guide, that ancestor was an extremely complex creature indeed. Chimpanzees bond, quarrel, and reconcile; they deceive; they murder; they make tools; they self-medicate. They live in hugely complicated societies; and in the struggle for status within those societies they form intricate alliances, and indulge in intrigues that some observers have described as nothing less than “politics.” If humans had never evolved, apes would almost certainly be today the most cognitively complex animals that had ever existed.
Yet here we are. And the story of how we got here from there, leaving our ape relatives in the dust (or at least in the trees), is perhaps the most intrinsically fascinating and complex story that our narrative-loving species has ever tried to tell. But at the same time it is an elusive one. For while comparing ourselves with apes may help us establish a starting point for our long evolutionary trajectory, it turns out that we modern human beings are not simply an improved version of them. Instead, we are an altogether unprecedented presence on our planet; and explaining the unique has always been a thankless task.
Despite the difficulties inherent in trying to explain ourselves, we have a solid foundation on which to start. The past century and a half has witnessed the accumulation of a remarkable fossil record that, although it will never be complete, already gives us a substantial glimpse of the appearances and astonishing diversity of those ancestral and collateral relatives who preceded us. What’s more, these human precursors are unusual in having left behind an archaeological record— butchered bones, stone artifacts, living sites—that speaks eloquently of their daily activities, and of how those activities became more complex as time progressed.
Documenting the huge physical and technological changes that accompanied the long trek from ancient ape to modern human is, at least in principle, a relatively straightforward task. But the secret to the particular kind of success our species enjoys today lies in the very unusual way in which our brains handle information. And mindset is something that is very hard to read from bones or material leavings, at least up to the point at which we have overwhelming evidence for the presence of an intellect equivalent to our own. What is evident, though, is that this final point was reached very late in time—at least compared to the earliest appearance of the human family, although in modern historical terms it was dizzyingly early. Many may find this tardiness rathe
r surprising, because traditionally we have been taught to view the long human story as an extended and gradual struggle from primitiveness toward perfection—in which case, we might anticipate finding early harbingers of our later selves. The reality, however, is otherwise, for it is becoming increasingly clear that the acquisition of the uniquely modern sensibility was instead an abrupt and recent event. Indeed, it was an event that took place within the tenure on Earth of humans who looked exactly like us. And the expression of this new sensibility was almost certainly crucially abetted by the invention of what is perhaps the single most remarkable thing about our modern selves: language.
This final communicative and cognitive leap is far from the whole story. The underpinnings of the modern body and mind reach far back into the past, and most of this book is devoted to examining the deep foundations on which the amazing human phenomenon was built. For nothing of what we are today would have been possible in the absence of any aspect of our unique history. And although it is in Africa that we find the earliest stirrings of the modern mind, the vagaries of the record are such that it is only when we contemplate the astonishing cave art of Ice Age Europe that we encounter the first evidence of human beings who not only thought as we do, but who left behind an overwhelmingly powerful body of evidence to prove it.
SYMBOLISM AND THE ART OF THE CAVES
Best exemplified by the famous animal images on the ceilings and walls of caves such as Spain’s Altamira and France’s Lascaux and Chauvet, the raw power and sophistication of this ancient art is somehow magnified by the knowledge that its painters lived in an unthinkably remote epoch of modern human history. For, despite their brilliance in color and concept, these extraordinary works were the product of hunter-gatherers who lived around the peak of the last Ice Age, between about thirty-five thousand and ten thousand years ago. These were harsh times of cool summers and bitterly long winters, during which trees were often almost entirely banished from a landscape that is thickly wooded today. The antiquity of this art is astonishing; but exposure to it nonetheless makes you fully understand Picasso’s alleged remark that the Ice Age painters had left him little to accomplish. Certainly, it’s impossible to imagine better evidence that the wonderful and unprecedented human creative spirit was already fully formed at that distant point in modern prehistory.
This realization had not come easily. Intuitively, it was difficult for nineteenth-century scientists to accept that the ancient Ice Age inhabitants of southern France and northern Spain had created an artistic tradition—embracing painting, engraving, sculpture, and bas-reliefs—that, at its best, had equaled or even exceeded in its power anything achieved since. After the first (and among the finest) cave paintings were discovered at Altamira in 1879, immediate admiration rapidly gave way to doubts. How could such refined and accomplished art possibly be the work of hugely ancient people? How could it have been produced by “savages” without fixed abode: mere hunters and gatherers who had roamed the landscape and availed themselves of its bounty, quite the antithesis of civilized nineteenth-century folk who worshiped in magnificent cathedrals, built sturdy houses for shelter, and put the land and what grew on it to work for them? It took repeated discoveries of ancient art, in virgin caves and at untouched archaeological sites, to convince the world that you could indeed have both a sophisticated mind and a “primitive” life-style: to make acceptable the notion that, those many tens of millennia ago, people had existed who did not live in houses and till the fields, but who nonetheless made fabulous art, led mysteriously complex lives, and were just like us in all their cognitive essentials.
Monochrome rendering of a now badly faded polychrome wall painting, probably around 14,000 years old, in the cave of Font de Gaume, France. A female reindeer kneels before a male that is leaning forward and delicately licking her forehead. Drawing by Diana Salles after a rendering by H. Breuil.
Of course those ancient people, and the larger societies whose beliefs and values those images at Lascaux and Altamira embodied, vanished long ago. So, although we have at our disposal miraculously preserved material evidence of the creative spirit of those long-gone humans, we will never know for sure just what those beliefs and values were. Nonetheless, for all their cultural and temporal remoteness, we can be secure in the knowledge that those ancient people of Altamira and Lascaux and elsewhere were us in all essentials, imbued with the same remarkable human spirit that animates us today.
Significantly, the walls of Lascaux and other caves are not decorated only with animal images, drawn with the deftness, observation, and clever stylization that place their creators among the greatest artists ever. Among and upon those instantly recognizable animal figures, the artists placed geometric motifs—grids, lines of dots, dartlike signs—that clearly had very specific meaning to their creators. Sadly, today we have no way of knowing just what it was the artists had intended to express; but if you consider the clear specificity of the images together with the complex ways in which they are juxtaposed, you rapidly begin to realize that this art was not simply representational. It was symbolic. Every image in this cave and others, realistic or geometric, is drenched with meaning that goes far beyond its mere form.
Even though we can’t know exactly what the art of Lascaux meant either to its creators or to those for whom it was intended (whether the two were the same, we’ll never be certain), what is undeniable is that this art signified something well beyond what we are able to observe directly. And this is, oddly enough, one of the most powerful of the many reasons why so many of us resonate to Ice Age art at the most profound of levels. Because, for all the infinite cultural variety that has marked the long road of human experience, if there is one single thing that above all else unites all human beings today, it is our symbolic capacity: our common ability to organize the world around us into a vocabulary of mental representations that we can recombine in our minds, in an endless variety of new ways. This unique mental facility allows us to create in our heads the alternative worlds that are the very basis of the cultural variety that is so much a hallmark of our species. Other creatures live in the world more or less as Nature presents it to them; and they react to it more or less directly, albeit sometimes with remarkable sophistication. In contrast, we human beings live to a significant degree in the worlds that our brains remake—though brute reality too often intrudes.
Human beings are unusual in many ways, physical as well as cognitive. But our unique mode of processing information is without any question the element that, more than any other, marks us off as different from other creatures; and it’s certainly what makes us feel different. What is more, as I hope this book will convince you, it is entirely without precedent. Not only is the ability for symbolic reasoning lacking among our closest living relatives, the great apes; such reasoning was apparently also absent from our closest extinct relatives—and even from the earliest humans who looked exactly like us. At the same time, we modern humans have a huge amount in common intellectually with all of those relatives, vanished and living; and, even more to the point, no matter how much we may vaunt our rationality, we are most certainly not entirely rational beings: a point that should need no belaboring to any observer of our species. One major reason for this is that, through the vagaries of a long and eventful evolutionary history, some of the newest components of our brains—those strange, complex organs in our heads that govern our behavior and experience—communicate with each other via some very ancient structures indeed.
Because of the peculiar construction resulting from their complex history, our brains are far from directly comparable to a feat of human engineering. Indeed, they are probably not comparable at all. For engineers always strive, even where they are consciously or unconsciously constrained, for optimal solutions to the problems they are facing. In contrast, during the long and untidy process that gave rise to the modern human brain, what was already there was always vastly more influential on the historical outcome—what actually did happen—than any potent
ial for future efficiencies could be. And thank goodness for that. After all, if our brains had been designed like machines, if they had been optimized for any particular task, they would be machines, with all of the predictability and tedious soullessness that this would imply. For all their flaws, it is the very messiness and adventitiousness of our brains that makes them—and us—the intellectually fertile, creative, emotional, and interesting entities that they and we are.
This perspective conflicts with the view of evolution that most of us were taught in school—where, if it was mentioned at all, this most fundamental of biological phenomena was usually presented as a matter of slow, inexorable refinement, constantly tending toward achieving the perfect. So, before we embark on the human story, it seems reasonable to take a few moments to look more closely at the remarkable process that operated to produce us—because, extraordinary as we may justifiably think ourselves, we are actually the result of a perfectly ordinary biological history.
THE VAGARIES OF EVOLUTION
Let’s start right at the beginning, with the overarching pattern in which Nature is organized, because this is the clearest tip-off we have to the mechanisms lying behind our appearance on the planet. There is a clear order in the living world. The way in which the diversity of animals and plants around us is structured is not haphazard in the least. Instead, it shows an across-the-board pattern of groups within groups. Among the mammals, for example, human beings are most similar to apes; the apes and humans together are most similar to the monkeys of the Old and New Worlds; and apes, humans, and monkeys all resemble lemurs more closely in their anatomies than they do anything else. Jointly, these primates form a distinctive cluster within Mammalia, the order that groups together all the warm-blooded, furry animals that suckle their young. All mammals in turn belong to a bigger group known as Vertebrata (the backboned animals—fish, amphibians, reptiles, and birds, as well as mammals), and so on.