Human Evolution FIFTH EDITION HUMAN EVOLUTION: AN ILLUSTRATED INTRODUCTION Roger Lewin © 1984, 1989, 1993, 1999, 2005 by Blackwell Publishing Ltd 350 Main Street, Malden, MA 02148-5020, USA 108 Cowley Road, Oxford OX4 1JF, UK 550 Swanston Street, Carlton, Victoria 3053, Australia The right of Roger Lewin to be identified as the Author of this Work has been asserted in accordance with the UK Copyright, Designs, and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher. First edition published 1984 by Blackwell Publishing Ltd Second edition published 1989 Third edition published 1993 Fourth edition published 1999 Fifth edition published 2005 Library of Congress Cataloging-in-Publication Data Lewin, Roger. Human evolution : an illustrated introduction / Roger Lewin.a5th ed. p. cm. Includes bibliographical references and index. ISBN 1-4051-0378-7 (pbk. : alk. paper) 1. Human evolution. I. Title. GN281.L49 2005 599.93’8adc22 2003024250 A catalogue record for this title is available from the British Library. Set in 9/111/2pt Meridien by Graphicraft Limited, Hong Kong Printed and bound in the United Kingdom by William Clowes Ltd, Beccles, Suffolk The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing, visit our website: http://www.blackwellpublishing.com CONTENTS Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vi PART FIVE: THE HOMININ ADAPTATION . . . . . .129 Unit 20: The Australopithecines . . . . . . . . . . . . . . . . . . . . . .131 PART ONE: HUMAN EVOLUTION IN Unit 21: Early Homo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140 PERSPECTIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Unit 22: Hominin Relations . . . . . . . . . . . . . . . . . . . . . . . . .146 Unit 1: Our Place in Nature . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Unit 23: Early Tool Technologies . . . . . . . . . . . . . . . . . . . . .151 Unit 2: Human Evolution as Narrative . . . . . . . . . . . . . . . . . .7 Unit 3: Historical Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 PART SIX: HOMO ERECTUS: BIOLOGY AND Unit 4: Modern Evolutionary Theory . . . . . . . . . . . . . . . . . .18 BEHAVIOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 Unit 5: The Physical Context of Evolution . . . . . . . . . . . . . .24 Unit 24: The Changing Position of Homo erectus . . . . . . . . .159 Unit 6: Extinction and Patterns of Evolution . . . . . . . . . . . .30 Unit 25: New Technologies . . . . . . . . . . . . . . . . . . . . . . . . . .166 Unit 26: Hunter or Scavenger? . . . . . . . . . . . . . . . . . . . . . . .170 PART TWO: BACKGROUND TO HUMAN EVOLUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 PART SEVEN: THE ORIGIN OF MODERN Unit 7: Dating Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 HUMANS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177 Unit 8: Systematics: Morphological and Molecular . . . . . . .45 Unit 27: The Neanderthal Enigma . . . . . . . . . . . . . . . . . . . .179 Unit 9: Science of Burial . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Unit 28: Anatomical Evidence . . . . . . . . . . . . . . . . . . . . . . .187 Unit 10: Primate Heritage . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 Unit 29: Genetic Evidence . . . . . . . . . . . . . . . . . . . . . . . . . . .200 Unit 30: Archeological Evidence . . . . . . . . . . . . . . . . . . . . .208 PART THREE: HUMANS AS ANIMALS . . . . . . . . . . . .67 Unit 11: Bodies, Size, and Shape . . . . . . . . . . . . . . . . . . . . . .69 PART EIGHT: THE HUMAN MILIEU . . . . . . . . . . . . .215 Unit 12: Bodies, Brains, and Energy . . . . . . . . . . . . . . . . . . .75 Unit 31: Evolution of the Brain, Intelligence, and Unit 13: Bodies, Behavior, and Social Structure . . . . . . . . .80 Consciousness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217 Unit 14: Nonhuman Models of Early Hominins . . . . . . . . . .87 Unit 32: The Evolution of Language . . . . . . . . . . . . . . . . . .222 Unit 33: Art in Prehistory . . . . . . . . . . . . . . . . . . . . . . . . . . .229 PART FOUR: HOMININ BEGINNINGS . . . . . . . . . . . .93 Unit 15: Ape and Human Relations: Morphological and PART NINE: NEW WORLDS . . . . . . . . . . . . . . . . . . . . .237 Molecular Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 Unit 34: The Americas and Australia . . . . . . . . . . . . . . . . . .239 Unit 16: Origin of the Hominoidea . . . . . . . . . . . . . . . . . . .103 Unit 35: The Origin of Agriculture and the First Unit 17: Origin of Bipedalism . . . . . . . . . . . . . . . . . . . . . . . .109 Villagers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247 Unit 18: Jaws and Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . .116 Unit 19: The Earliest Hominins: a History of Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253 Discoveries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .257 PREFACE The pattern of treatment of issues in this new edition follows human behavior. Was it recent and dramatic, or more grad- that established with the fourth edition; nevertheless there ual, with deeper roots? Evidence for the latter is growing. All are important changes. For instance, in the preface to the these aspects of the debate are updated in this edition in what previous edition I wrote, “The five years since the third edi- remains a strong contribution to Human Evolution. tion of Human Evolution: An Illustrated Introductionhave been The trend continues in paleoanthropology from viewing an extraordinarily productive time for paleoanthropology,” human evolution as having occurred under special circum- not least because of the number of new species of early stances to accepting humans as animals and having evolved humans that had been discovered. The same can be said of the in ways similar to other animals. Humans are special in many period between the fourth and fifth editions. Since 1999 four ways, of course, but this specialness is a feature that emerges new species of hominin have been announced. (Hominin is relatively late in our evolutionary history. This is recognized the term now used for members of the human family.) here in discussions of life-history factors and the impact of Of the four new species, three have been assigned to new body size and shape. genera. Two of them are older than anything known pre- Many new finds and insights are included in this new ed- viously, dated at 6 to 7 million years old. One of them was ition, including, among others, the redating of an important found in Chad, rather than in East Africa. And another, specimen in Australia, at Lake Mungo. Previously thought to Kenyanthropus platyops (3.5 million years old, from Kenya), be 25,000 years old, the Lake Mungo cranium is now shown has the kind of flat face that was thought to have arisen much to be 42,000 years old, and tools at a nearby site are close to later in hominin history. Clearly, hominin history is turning 50,000 years old, establishing a relatively early occupation of out to be much more complex than previously assumed. the continent. Another important change is the realization Description and discussion of these finds represents one of that Homo ergastermay not, after all, have experienced pro- the major changes from the fourth edition, which involves a longed infancy. That change in human development appears thorough reorganization of units dealing with this period. to have occurred later in the lineage. And Morris Goodman The origin of modern humans continues to be a major continues to tweak paleoanthropologists’ tails by suggesting topic in paleoanthropology, as Curtis Marean and Jessica that both humans and chimpanzees be placed in the same Thompson noted in their report of the 2002 meeting of the genus, Homo. Paleoanthropology Society.* The debate over the mode of Obviously, paleoanthropology continues to be a healthy, the origin of modern humansawas it a single, recent origin robust science, embracing new facts and reinterpretations or global and gradualacontinues, but new genetic evidence in the search for the pattern of human history. As always, adds further support to the notion of a single, recent origin. however, it is worth remembering that when the subject of Some of this evidence comes in the form of mitochondrial scientific scrutiny is ourselves and how we came to be who DNA analysis of a Neanderthal specimen from the northern we are, subjectivity is a constant trap. As I noted in the pre- Caucasus. The announcement, in mid-2003, of a 160,000- vious edition, “Armed with this knowledge, the student is year-old specimen of early Homo sapiens from Ethiopia also better prepared to assess what is being said in one debate or strengthens the argument for a single, recent origin, in another in the science.” Africa. Becoming more center stage in discussions over Christopher Ruff, Ian Tattersall, and Alan Walker were modern human origins, however, is the evolution of modern kind enough to comment on new material in the book. The responsibility for the final product is, of course, mine. * Marean CW, Thompson JC. Research on the origin of modern humans Roger Lewin continues to dominate paleoanthropology. Evol Anthropol2003;12:165–167. Cambridge, Massachusetts PART 1 HUMAN EVOLUTION IN PERSPECTIVE 1 Our Place in Nature 2 Human Evolution as Narrative 3 Historical Views 4 Modern Evolutionary Theory 5 The Physical Context of Evolution 6 Extinction and Patterns of Evolution OUR PLACE IN NATURE 1 The Darwinian revolution forced people to face the fact that humans intellectuals, in both pre- and post-evolutionary eras. One are part of nature, not above nature. Nevertheless, anthropologists difference between the two eras was that, after Darwin, nat- struggled with explaining the special features of Homosapiens,such uralistic explanations had to account not only for the human as our great intelligence, our sense of right and wrong, our esthetic physical form but also for humans’ exceptional intellectual, sensibilities. Only since the latter part of the twentieth century have spiritual, and moral qualities. Previously, these qualities had anthropologists fully embraced naturalistic explanations of our been regarded as God-given. special qualities. As a result, said the late archeologist Glynn Isaac, “Under- standing the literature on human evolution calls for the In 1863 Charles Darwin’s friend and champion, Thomas recognition of special problems that confront scientists who Henry Huxley, published a landmark book, titled Evidences report on this topic.” He made the remark at the 1982 cente- as to Man’s Place in Nature. The book, which appeared a little nary celebration of Darwin’s death. “Regardless of how more than three years after Darwin’s Origin of Species, was scientists present them, accounts of human origins are read based principally on evidence from comparative anatomy as replacement materials for Genesis. They...do more than and embryology among apes and humans. (There was essen- cope with curiosity, they have allegorical content, and they tially no fossil evidence of early humans available at that convey values, ethics and attitudes.” In other words, in addi- time, apart from the early Neanderthal finds, which were tion to reconstructing phylogeniesaor evolutionary family not yet accepted as early humans by most anthropologists; treesapaleoanthropological research also addresses “Man’s see unit 27.) Huxley’s conclusionathat humans share a close place in nature” in more than just the physical sense. As we evolutionary relationship with the great apes, particularly shall see, that “place” has long been regarded as being special the African apesawas a key element in a revolution in the in some sense. history of Western philosophy: humans were to be seen as The revolution wrought by Darwin’s work was, in fact, the being a part ofnature, no longer as apart fromnature. second of two such intellectual upheavals within the history Although Huxley was committed to the idea of the evolu- of Western philosophy. The first revolution occurred three tion of Homo sapiens from some type of ancestral ape, he centuries earlier, when Nicholaus Copernicus replaced the nevertheless considered humans to be a very special kind of geocentric model of the universe (see figure 1.1) with a animal. “No one is more strongly convinced than I am of the heliocentric model. Although the Copernican revolution vastness of the gulf between...man and the brutes,” wrote deposed humans from being the cosmic center of all of God’s Huxley, “for, he alone possesses the marvellous endowment creation and transformed humans into the occupants of a of intelligible and rational speech [and]...stands raised upon small planet cycling in a vast universe, humans nevertheless it as on a mountain top, far above the level of his humble fel- remained the pinnacle of God’s works. From the sixteenth lows, and transfigured from his grosser nature by reflecting, through the mid-nineteenth centuries, those who studied here and there, a ray from the infinite source of truth.” humans and nature as a whole were coming close to the wonder of those works. This pursuitaknown as natural philosophyapositioned Explaining the “gap” between humans science and religion in close harmony, with the remarkable and animals design so clearly manifested in creatures great and small being seen as evidence of God’s hand. In addition to design, a The explanation of this “gap” between humans and the rest second feature of God’s created world was natural hierarchy, of animate nature has always exercised the minds of Western from the lowest to the highest, with humans being near the