The first detailed history of the evolution of the five races of man— a pio- neer work, a milestone of scientific thought. It ad- vances Darwinian theory beyond the origin of spe- cies to the myth-ridden question of the origin of subspecies, or races.
Fhe origin of races
CARLETON S. COON
AUTHOR OF THE STORY OF MAN
<»
0.0. R A.A.K
Hitherto, it has generally been held that the five races of man became differ- entiated only very recently, in the last few tens of thousands of years, after the appearance of Homo sapiens. But Dr. Coon, in the course of his researches, uncovered startling evidence indicating that, in fact, they had separated far down on the time scale, long before Homo sa- piens appeared and at least as early as the time of the first 43S3ESS^ Homo erectus.
Was it possible that races, like the species to which they belong, were capable of evolution? If so, much of the evolution of the different existing races may have taken place separately and in parallel fashion over a period of hun- dreds, rather than tens, of thousands of years.
Dr. Coon began to collect every scrap of exist- ing information about fossil man, to find out how many racial lines could be traced back to the earliest evidence of man’s existence. He ended with five lines of descent, each as old as man himself. Now, the possibility that races could be older than species had to be inves- tigated. In order to reconstruct man’s ancestral journey, Dr. Coon undertook no less than a vast scientific exploration in time and space.
What forces, he had to know, exerted pres- sure on that plastic primate, man, to make him evolve from a lesser to a more sapient state? To answer this most fundamental and exciting question of all, Dr. Coon drew on the resources of zoogeography, primate behavior, physiology, and social anthropology; he surveyed the rules of the formation of species, of the composition of populations, of systems of mating, and of geographical adaptation at different ecological levels; he delved into the records of paleontol- ogy and surveyed the relics and artifacts of a hundred millennia. With this marshaling of (continued on hack flap)
Illustrated with photographs, drawings, charts, tables, and 13 maps drawn by Rafael Palacios
JACKET DESIGN BY GEORGE GIUST
ALSO BY
C ARLETON S. COON
THE STORY OF MAN
( i954> 1962)
THE SEVEN CAVES
(i957)
These are Borzoi Books published by Alfred A. Knopf in New York
THE ORIGIN OF RACES
THE
ORIGIN
OF
RACES
by CARLETON S. COON
i 9
6 2
NEW YORK : A L F R E D • A • K N O P F
L. C. catalog card number: 62—i4y6l
THIS IS A BORZOI BOOK, PUBLISHED BY ALFRED A. KNOPF, INC.
Copyright © 1962 by Carleton S. Coon. All rights re- served. No part of this book may be reproduced in any form without permission in writing from the publisher, except by a reviewer, who may quote brief passages and reproduce not more than three illustrations in a review to be printed in a magazine or newspaper. Manufactured in the United States of America, and distributed by Ran- dom House, Inc. Published simultaneously in Toronto, Canada, by Random House of Canada, Limited.
FIRST EDITION
T O
FRANZ WEIDENR EICH
IN MEMORIAM
INTRODUCTION
I N 1933 I was invited to rewrite Professor W. Z. Ripley’s classic The Races of Europe (New York: Appleton & Co.; 1899). My completely new version of the book was published by The Mac- millan Company in 1939. At that time I decided eventually to write a Races of the World. For twenty years, in peace and war, at home and on expeditions, I collected material with this task in mind. Finally, in 1956, thanks to an Air Force contract, I was able to make a seven months’ trip around the world, visiting countries I had never before seen and conferring with fellow physical an- thropologists on the way. From the end of that trip to the present I have been engaged almost exclusively in the preparation of the book at hand.
But this book is only half of what I set out to write. By 1959 it was clear to me that I must write two books, one on the living, as originally planned, and an introductory one on the ancestry of the living races of man. By then I could see that the visible and in- visible differences between living races could be explained only in terms of history. Each major race had followed a pathway of its own through the labyrinth of time. Each had been molded in a different fashion to meet the needs of different environments, and each had reached its own level on the evolutionary scale.
What became the first book, the one presented here, may turn out to have been the harder to write, or so it seems now that I have finished it and before I have allowed myself to become im- mersed in the other. It was difficult because I had spent less time on fossil men than on the living. Also, in 1959 I decided that the framework for the study of fossil man should be built in two di-
Introduction
viii
mensions, time and space. Most other writers had stressed only time, and had ignored or neglected geography.
A notable exception was Franz Weidenreich. While I was writ- ing The Races of Europe in Cambridge, Massachusetts, he was busy in New York, studying the Sinanthropus remains. At that time he concluded that the peculiarities that made Sinanthropus distinct from other fossil men were of two kinds, evolutionary and racial. From the evolutionary point of view, Sinanthropus was more primitive than any known living population. Racially he was Mongoloid.
Like other premature comets of science, Weidenreich’s idea flashed across the sky and was gone, obscured by the clouds of incredulity released by his fellow scientists. Most of them be- lieved, as many still do, that the living races of man could have become differentiated from a common ancestor only after the stage of Homo sapiens had been reached. Because Homo sapiens was believed to have first appeared only 30,000 years ago, in the guise of Cro-Magnon man, the living races could be only that old. Sinanthropus was not Homo sapiens. Therefore he could not have belonged to a modern race, the Mongoloid. Q.E.D. Or so the in- credulous thought.
To me there was something very pat, dogmatic, and wrong about the anti- Weidenreich point of view. For years I mulled it over in my mind, and then I decided to collect every scrap of existing information about every single fossil-man bone and tooth in the world. Once I had acquired as much information as I could, I concentrated on the dimension of space and tried to see how many racial lines, including the Mongoloid, could be traced back to the first instance that any kind of man had appeared on the earth. In the end I succeeded in tracing back five, each as old as man himself.
Realizing the enormity of my discovery in terms of its diver- gence from accepted dogma, I knew that I must provide a theo- retical foundation for the facts I had unearthed. The possibility that races can be older than species had to be explored. I soon found, by reading and through conversations with Mayr, Simpson, and other biologists, that what I had thought a revolutionary con- cept was so common an event in nature that others rarely both-
Introduction
ix
ered to mention it; to wit, that a species which is divided into geographical races can evolve into a daughter species while re- taining the same geographical races.
With this matter settled more easily than I had expected, I needed to know what forces exerted pressure on that plastic pri- mate, man, to make him evolve from a lesser to a more sapient state. To satisfy this need, I delved into zoogeography, primate behavior, physiology, and social anthropology. At the same time I kept in touch with physiologists studying the mechanisms of ad- aptation to heat, cold, and altitude, and went with some of them on a field trip to southern Chile.
Because my study made it apparent that the human races had evolved in parallel fashion, I made a brief excursion into the his- tory, anatomy, and physiology of primates, and found many strik- ing examples to back my theory. Meanwhile, the exciting new discoveries regarding fossil apes and Australopithecines drew the prehuman relatives of man forward in time past the very date of the earliest human skull, closing a temporal if not an evolutionary gap. These discoveries opened the possibility that the races of man are even older than the known specimens of Homo, a possi- bility that remains unexplored.
In the introduction to The Races of Europe I stated that I would avoid discussion of two subjects, blood groups and racial differences in intelligence. W. C. Boyd was about to publish his massive compilation of blood groups.1 And I knew next to nothing about racial intelligence and could not see that it would be very useful when applied to regional populations of a single major race, the Caucasoid.
The sequel to The Origin of Races promises to be full of talk about blood and brains, but in this present book I have little to say about these subjects — for different reasons than in 1939. De- spite claims to the contrary, the blood groups of fossil bones can- not be determined. Nor can dead men take intelligence tests. However, it is a fair inference that fossil men now extinct were less gifted than their descendants who have larger brains, that the subspecies which crossed the evolutionary threshold into the cate-
1 W. C. Boyd: “Blood Groups,” Tabulae Biologicae , Vol. 17 (1939), pp. 113- 240.
X
Introduction
gory of Homo sapiens the earliest have evolved the most, and that the obvious correlation between the length of time a sub- species has been in the sapiens state and the levels of civilization attained by some of its populations may be related phenomena.
Yet every major race, however advanced in civilization some of its component populations have become, also contains remnant bands of simple hunters and gatherers to remind us whence we all came. The monkey-hunters of the forested slopes of Central India are as Caucasoid as Charles de Gaulle, and the Ghosts of the Yellow Leaves, who haunt the hillsides of Upper Siam and Laos, as Mongoloid as the Mikado.
These, however, are not the main points of the book. This is a work of history, the history of a primate genus, and in it science is only a set of tools used to discover the pathways of human evolu- tion— pathways that have led us from a time of obscurity to a mo- ment of bright sunlight, with no man knows what fate lying ahead.
Carleton S. Coon
Devon, Pennsylvania January 23, ig62
ACKNOWLEDGMENTS
In the compilation and preparation of data for this volume I have received financial aid from one private and two gov- ernmental institutions, as follows. In 1955 the Wenner-Gren Foun- dation paid my way to and from the Third Panafrican Congress at Livingstone, Northern Rhodesia, where Mrs. Coon and I were the guests of the Rhodesian government for several weeks. Since then the Wenner-Gren Foundation has given me two other grants. In 1956-7 we went around the world on Contract AF33(6i6)- 6306 with ADTIC ( Arctic-Desert-Tropics-Information Center) of the Montgomery, Alabama, U.S. Air Force Rase. Thanks are ex- tended to Dr. Paul H. Nesbitt, chief of the ADTIC, and his staff for their helpful suggestions and courtesies. In 1957 I received a two-year grant from the National Science Foundation (NSF 03921). In 1959 I went to Wellington Island, Chile, as a member of an expedition led by T. H. Hammel of the University of Penn- sylvania Medical School and financed by the Riomedical Labora- tory of the U.S. Air Force at the Wright-Patterson Air Force Rase, Ohio.
I am also deeply indebted to those who make decisions in the University of Pennsylvania, and particularly to Froelich G. Rainey, Director of the University Museum, to Alfred Kidder II, Associate Director, and to the Museum’s Board of Trustees, headed by Percy C. Madeira, Jr., for allowing me ample writing time, granting me free use of the Museum’s facilities, and, even more important, giving me encouragement in the pursuit of what must have been, from the point of view of the Museum, a mate- rially unrewarding subject. I hope that this book will justify their confidence.
To many persons we owe debts of gratitude for fine hospitality
Acknowledgments
xii
on our travels, particularly to Dr. and Mrs. Neil Ransford, M.D., in Bulawayo, to the Gordon Brownes in Siam, to the Gordon Bowles in Japan, to Arthur Prager and the Robert Lindquists in Formosa, to the late B. S. Guha in India, to the Arthur Gardiners in Pakistan, to Colonel and Mrs. W. A. Eddy and Aramco, Saudi Arabia, to the late Baron and the Baroness A. C. Blanc in Rome, to Lidio Cipriani in Florence, to M. and Mine Frangois Trives in Paris, and to our son C. S. Coon, Jr., and his wife and children, in many places.
My wife, Lisa Dougherty Coon, went with me everywhere mentioned except Chile, and where she went she kept me in good health. She also created all but six and a half of the line drawings in this book.
No one can write a book of this scope without friends. Reprint swapping, informal correspondence, and conversations at aca- demic meetings and elsewhere are as important as library research, which itself is greatly facilitated by the interest and good will of librarians.
Below are listed the names, without rank or title, of some of those who have helped me, in one way or other, in terms of principal categories of assistance. Most heartily I thank them one and all.
FIELD TRIPS
Gordon T. Bowles
A. C. Blanc f
J. Desmond Clark
B. S. Guha f H. T. Hamm el Louis Leakey HRH Peter Roger Summers
Tokyo, Johns Hopkins Rome
Livingstone, Berkeley Ranchi
U. of Pennsylvania, Yale Nairobi
Prince of Greece and Denmark Bulawayo
TAXONOMY
F. Clark Howell Wm. W. Howells Ernst Mayr
Chicago
Harvard
Harvard
Acknowledgments xiii
Brian Patterson Alfred S. Romer George G. Simpson Wm. L. Straus, Jr.
CHROMOSOMES
M. A. Bender John Buettner-Janusch E. H. Y. Chu David Hungerford
CHRONOLOGY Bruce Howe
G. H. R. von Koenigswald Charles E. Stearns Elisabeth K. Ralph Kenneth P. Oakley
SKELETAL MATERIAL AND CASTS
Don Brothwell Georgi Debetz Paul Deraniyagala A. C. Hoffman S. Kodama Louis Leakey P. N. Mitra Emily Pettinos
Ronald Singer John T. Robinson Wm. L. Straus, Jr.
H. Suzuki Philip T. Tobias
Harvard Harvard Harvard Johns Hopkins
Oak Ridge Yale
Oak Ridge
Institute for Cancer Research, Fox Chase, Philadelphia
Harvard
Utrecht
Tufts
University of Pennsylvania British Museum (Nat. Hist.)
British Museum (Nat. Hist.)
Academy of Science, Moscow
Colombo Museum
Bloemfontein
Sapporo
Nairobi
Calcutta
University Museum, Philadel- phia
Capetown, Chicago Pretoria Johns Hopkins Tokyo
Johannesburg
XIV
Acknowledgments
GENERAL HELP, PARTICULARLY IN THE SUMMER OF 1958
Edward E. Hunt, Jr. Harvard and Forsythe
( Boston)
MAKING FLESH RECONSTRUCTIONS OF FOSSIL MEN
Maurice P. Coon Cambridge, Massachusetts
INFORMATION ABOUT THE TIWI,
Jane C. Goodale
RESEARCH: LIBRARIANS
Margaret Currier Cynthia Griffin
Margaret Palmer
BIBLIOGRAPHY
Janet M. Kliment
GLOSSARY SELECTION
Mary S. Huhn
WORK ON PHOTOGRAPHS
David Crownover Caroline Dosker Jane C. Goodale
Doris Nicholas
chapter 3
University Museum, Bryn Mawr
Peabody Museum, Harvard University Museum, University of Pennsylvania Dental School, University of Pennsylvania
J
University Museum, University of Pennsylvania
Devon, Pennsylvania
University Museum University Museum University Museum, Bryn Mawr University Museum
Acknowledgments xv
But this is not all. Books need publishers as well as authors. I am deeply indebted to Alfred A. Knopf for the privilege of having had Harold Strauss as editor of this volume, with the valuable assistance of Howard Fertig, Sophie Wilkins, and Carmen Gomezplata, and for splendid treatment at the hands of William Koshland.
I am also very happy that my British publisher, Jonanthan Cape Ltd., which has stood by me for thirty years, will publish this book in England.
CONTENTS
1. THE PROBLEM OF RACIAL ORIGINS
ON THE ANTIQUITY OF RACES; THE PROBLEMS OF HUMAN TAXONOMY: THE GENUS; HOMO SAPIENS; THE SPECIES CONCEPT; THE SPATIAL REQUIREMENTS OF SPECIES AND THEIR GEOGRAPHICAL DIFFERENTIATION; THE SUBSPECIES; MOSAICS, CLINES, LOCAL RACES, AND RACIAL TYPES; THE DIFFERENTIATION OF SPECIES; BALANCED POLYMORPHISM; ON THE TIMING OF THE INDIVIDUAL GROWTH CYCLE; ON SIZE AND FORM: ALLOMETRY; ON SEXUAL DIMORPHISM; HOW SPECIES HAVE EVOLVED; ON THE LIFE SPANS OF MAMMALIAN SPECIES; GENETIC PRINCIPLES AND THE ORIGINS OF RACES
2. EVOLUTION THROUGH ENVIRONMENTAL ADAPTATION
BODY SIZE, FOOD, SPACE, AND CLIMATE; THE FACE OF THE EARTH; LAND MASSES; BARRIERS AND BREEDING AREAS; GE- NETIC DRIFT; THE DOMINANCE OF GROUPS; THE SIX FAU- NAL REGIONS; WALLACEA; THE FAUNAL REGIONS AND HUMAN ORIGINS AND MOVEMENTS; ENVIRONMENTAL ADAPTATION AND EARLY MAN; THE RULES OF BERGMANN AND ALLEN; NOSE FORM AND CLIMATE; PHYSIOLOGICAL ADAPTATION TO COLD; HEAT ADAPTATION; THE SIGNIFI- CANCE OF ADAPTATION TO HEAT AND COLD; ADAPTATION TO ALTITUDE
3. EVOLUTION THROUGH SOCIAL ADAPTATION
LEADERSHIP, COMMUNICATION, AND BRAIN GROWTH; ON THE ANTIQUITY OF A HUMAN TYPE OF SOCIETY: THE BE- GINNING OF HUNTING; THE MATING SYSTEMS OF OTHER
xviii Contents
ANIMALS; THE SEXUAL BEHAVIOR OF PRIMATES, INCLUD- ING HOMO SAPIENS; THE BEGINNINGS OF HUMAN SOCIETY; SEXUAL SELECTION AMONG HIGHER PRIMATES; SPEECH, HUNTING, AND SOCIAL STRUCTURE; RITUAL, LANGUAGE, AND THE RITES OF PASSAGE; THE DISCOVERY OF FIRE AND THE CONVERSION OF ENERGY INTO SOCIAL STRUCTURE; THE EVIDENCE OF LIVING FOOD-GATHERING SOCIETIES: THE AUSTRALIAN ABORIGINES; THE ARCHAIC SOCIETY OF THE TIWI; ON COMPARING THE CULTURES OF LIVING FOOD GATHERERS AND THOSE OF FOSSIL MEN; POPULATION SIZE AMONG FOOD GATHERERS; SYSTEMS OF MATING AMONG FOOD GATHERERS; THE LONGEVITY OF FOSSIL MEN; THE ROLE OF ISOLATING MECHANISMS IN HUMAN EVOLUTION; ADAPTATION TO CROWDING: A NEW THEORY OF EVOLU- TION BY SUCCESSION; DWARFING AS A SOLUTION TO THE PROBLEM OF CROWDING; THE ENDOCRINES AND TEMPERA- MENT; PARALLELS BETWEEN ANIMAL DOMESTICATION AND SOCIAL ADAPTATION; THE UNIQUE ADAPTATIONS OF THE GENUS HOMO
4. THE ORDER OF PRIMATES
PRIMATE STUDIES AND THE CLASSIFICATION OF HUMAN RACES; THE CLASSIFICATION OF PRIMATES; THE PROSIM- IANS; THE TREE SHREWS; THE LEMURS; THE LORISES; THE TARSIERS; THE LIVING PLATYRRHINES : THE SOUTH AMERICAN MONKEYS; THE LIVING CERCOPITHECIDAE : OLD WORLD MONKEYS; THE LEAF-EATING COLOBINAE; THE CERCOPITHECINAE; THE ANTHROPOID APES; THE GIBBONS: SYMPHALANGUS AND HYLOBATES; THE ORANGUTAN (PONGO); THE CHIMPANZEE (pan); THE GORILLA ( GO- RILLA); THE HOMINIDAE ( HOMO )
5. MAN’S PLACE AMONG THE PRIMATES
THE BEARING OF PRIMATE STUDIES ON RACIAL ORIGINS; TO BRACHIATE OR NOT TO BRACHIATE; THE BEARING OF HOMINID TEETH ON THE ERECT POSTURE; A FEW DETAILS OF THE POSTURE STORY; THE EVIDENCE OF TEETH; THE EVIDENCE OF EMBRYOLOGY; DIFFERENCES IN POSTNATAL GROWTH; PHYSIOLOGICAL CLUES TO OUR RELATIONSHIPS WITH OTHER PRIMATES; PARASITES AND PRIMATES; THE
Contents
xix
COMP ARISON OF PRIMATE CHROMOSOMES; THE EVIDENCE OF BEHAVIOR
6. THE FOSSIL RECORD: FROM LEMURS TO
SWAMP APES 186
ON THE SCARCITY OF PRIMATE FOSSILS; THE PRIMATE TIME SCALE; PRIMATE PALEONTOLOGY AS A WHOLE; THE PROSIMIAN PROLIFERATION; THE EVOLUTION OF THE PLAT- YRRHINES; THE EVOLUTION OF THE CATARRHINES; THE GIBBON LINE; THE ANCESTORS OF THE THREE LIVING GREAT APES; PROCONSUL; DRYOPITHECUS IN EUROPE AND ASIA; RAMAPITHECUS, A POSSIBLE ANCESTOR OF THE HOMINIDS;
THE FORT TERNAN PRIMATE; THE PLEISTOCENE APES OF CHINA; POSSIBLE SURVIVALS OF CHINESE APES; HOMINOIDS AND HOMINIDS; OREOPITHECUS BAMBOLII, THE SWAMP APE; FOSSIL PRIMATES AND HUMAN EVOLUTION
7. THE EARLIEST HOMINIDS 217
THE ORIGIN OF THE HOMINIDS; AUSTRALOPITHECUS AND HOMO; THE LOWER PLEISTOCENE; THE NEW DATING FOR THE LOWER PLEISTOCENE; THE EVIDENCE OF TOOLS AND FIRE IN THE LOWER PLEISTOCENE; GEOGRAPHY AND NUM- BERS OF EARLY HOMINIDS; THE SOUTH AFRICAN AUSTRA- LOPITHECINES : TIME, SPACE, AND TAXONOMY; THE AUSTRALOPITHECINE CAVE SITES; DID THE AUSTRALOPITHE- CINES MAKE TOOLS?; THE POSTCRANIAL SKELETONS OF THE SOUTH AFRICAN AUSTRALOPITHECINES; THE STERK- FONTEIN VERTEBRAE AND RIBS; THE PELVIS OF AUSTRALO- PITHECUS; THE LEGS AND FEET OF AUSTRALOPITHECUS;
THE SHOULDER GIRDLE OF AUSTRALOPITHECUS; THE ARMS AND HANDS OF AUSTRALOPITHECUS; AUSTRALOPITHECUS, A PRIMATE MERMAID OR A UNIQUE HOMINID?; THE SKULLS,
JAWS, AND TEETH OF AUSTRALOPITHECUS; THE BRAIN CASE AND BRAIN OF AUSTRALOPITHECUS; THE FACES OF THE AUSTRALOPITHECINES; THE AUSTRALOPITHECINE JAWS; THE TEETH OF AUSTRALOPITHECUS; THE EARLY HOMINIDS FROM EAST AFRICA; THE OLDUVAI CHILD; THE CHILD’S MANDIBLE; THE CHILD’S TEETH; THE CHILD’S PARIETAL BONES; THE FOOT ACCOMPANYING THE CHILD’S REMAINS; THE COLLARBONE, HAND, AND FINGERS; THE EVOLUTIONARY AND TAXONOMIC POSITION OF THE OLDU-
XX
Contents
VAI CHILD; ZINJANTHROPUS: HIS TOOLS, DIET, AND ACTIV- ITIES; THE ANATOMY OF ZINJANTHROPUS: HIS CRANIUM; THE TEETH OF ZINJANTHROPUS; THE LEG BONES ATTRI- BUTED TO ZINJANTHROPUS; THE STATUS OF ZINJANTHRO- PUS; THE SPECIMEN FROM LAKE EYASI, TANGANYIKA; THE KANAM MANDIBLE; THE AUSTRALOPITHECINE FROM THE REPUBLIC OF TCHAD; THE FOSSIL HOMINID OF TELL UBEI- DIYA, JORDAN VALLEY; THE MEGANTHROPUS MANDIBLES FROM JAVA; THE DRUGSTORE AUSTRALOPITHECINES OF CHINA; THE REPLACEMENT OF AUSTRALOPITHECUS BY HOMO
8. AN INTRODUCTION TO FOSSIL MAN
OF TIME, SPACE, GRADES, AND LINES; THE DIMENSION OF TIME; THE DIMENSION OF SPACE: GLACIAL GEOGRAPHY; THE TEMPORAL AND SPATIAL DISTRIBUTION OF FOSSIL MAN SITES; TIME, SPACE, AND PALEOLITHIC TOOLS; THE CHRONOLOGY AND DISTRIBUTION OF THE USE OF FIRE; GRADES AND SPECIES OF FOSSIL MEN; THE SAPIENS- ERECTUS THRESHOLD: THE EVIDENCE OF BRAIN SIZE; THE EVIDENCE OF CRANIAL FORM; THE EVIDENCE OF TOOTH SIZE; A BRAIN-SIZE TO TOOTH-SIZE INDEX; EVOLUTIONARY CHANGES WITHIN HOMO SAPIENS: THE RISE OF THE CHIN; LINES AND SUBSPECIES OF FOSSIL MEN: THE EVIDENCE OF TEETH; RACIAL VARIATIONS IN THE FORM AND STRUCTURE OF TEETH; FACIAL FLATNESS AS A CRITERION OF RACE; RACIAL ORIGINS AND RACIAL CONTINUITIES
9. PITHECANTHROPUS AND THE AUSTRALOIDS
THE PITHECANTHROPUS LINE; THE PITHECANTHROPUS- AU STRALOID SKELETAL MATERIAL; FOSSIL MEN FROM THE D JETTS BEDS OF JAVA; PITHECANTHROPUS 4; THE PITHE- CANTHROPUS MANDIBLES FROM THE DJETIS BED; THE BRAIN CASE OF THE INFANT MODJOKERTENSIS; MEN OF THE TRINIL FAUNA; THE PITHECANTHROPUS THIGHBONES; THE TEETH OF PITHECANTHROPUS; THE THIRD KNOWN HUMAN POPULATION OF JAVA: SOLO MAN; SEX, AGE, AND INJURIES OF THE ELEVEN SKULLS; THE RACIAL ANATOMY OF THE NGANDONG SKULLCAPS; THE FACE OF SOLO MAN; THE NGANDONG LEG BONES; WHAT NAME, MR. SOLO?; THE
Contents
xxi
SOLO-LIKE BRAIN CASE FROM AITAPE, NEW GUINEA; THE FOURTH KNOWN HUMAN POPULATION OF JAVA: WADJAK MAN; THE WADJAK BRAIN CASES; THE WADJAK FACES;
THE WADJAK MANDIBLES; THE WADJAK DENTITION; THE SIGNIFICANCE OF WADJAK; FOSSIL MAN IN AUSTRALIA;
THE KEILOR SKULL; THE TALGAI SKULL; THE COHUNA SKULL; THE PITHECANTHROPUS-AUSTRALOID LINE; HUMAN EVOLUTION NORTH OF JAVA IN THE PLEISTOCENE; THE MAPA SKULLCAP; THE UPPER PLEISTOCENE SKULL FROM NIAH CAVE, NORTH BORNEO; THE MESOLITHIC-NEOLITHIC TRANSITION IN INDONESIA; MESOLITHIC AND NEOLITHIC REMAINS FROM INDOCHINA; PREHISTORIC POPULATIONS OF THE WESTERN ORIENTAL REGION; THE TAXONOMY OF THE AUSTRALOID SUBSPECIES
10. SINANTHROPUS AND THE MONGOLOIDS 428
THE LIVING MONGOLOIDS AND THE SKELETONS OF THEIR ANCESTORS; SINANTHROPUS PEKINENSIS : TIME, PLACE, AND PEOPLE; THE TAXONOMY OF SINANTHROPUS; THE SINAN- THROPUS BRAIN CASE; THE FACE OF SINANTHROPUS; THE MANDIBLES OF SINANTHROPUS; THE TEETH OF SINAN- THROPUS; THE LEG BONES OF SINANTHROPUS; THE UPPER EXTREMITY OF SINANTHROPUS; THE POSITION OF SINAN- THROPUS ON THE HUMAN FAMILY TREE; LATE MIDDLE PLEISTOCENE FINDS IN CHINA AND JAPAN; THE TING-TSUN TEETH; THE CHANGYANG MAXILLA; THE SPECIMEN FROM MAPA, KWANGTUNG; THE HUMERUS SHAFT FROM USHI- KAWA QUARRY, JAPAN; THE UPPER PLEISTOCENE WOMAN FROM TZE-YANG, SZECHUAN; THE UPPER PLEISTOCENE MAN FROM LIU-KIANG, KWANGSI; THE LIU-KIANG POST- CRANIAL BONES; THE TOOTH OF SJARA-OSSO-GOL, ORDOS;
THE REMAINS FROM TI-SHAO-GOU-WAN, ORDOS; THE UP- PER PLEISTOCENE REMAINS FROM CENTRAL HONSHU, JA- PAN; THE PEOPLE OF THE UPPER CAVE AT CHOUKOUTIEN;
THE SPECIMEN FROM KAIt’o-TUNG, LEIPIN, KWANGSI; POST-PLEISTOCENE SKELETONS; AMERICA: THE WESTERN EXTENSION OF THE MONGOLOID REALM; CONCLUSION
XXII
Contents
11. THE CAUCASOIDS
THE CAUCASOID HOME; POSSIBLE CONTACTS BETWEEN SUB- SPECIES AND CAUCASOID EVOLUTION; CONTINUITY AND CHANGE IN THE CAUCASOID QUADRANT; THE MAUER MAN- DIBLE, OR HEIDELBERG JAW; THE STEINHEIM CRANIUM; THE SWANSCOMBE CRANIAL BONES; EUROPEAN FOSSIL MEN OF THE EARLY UPPER PLEISTOCENE; FONTECHEVADE; SACCO PASTORE; THE EHRINGSDORF REMAINS; THE STONE BRAIN FROM GANOVCE, CZECHOSLOVAKIA; THE ROUND- HEADED PEOPLE OF KRAPINA; THE MANDIBLES OF THE EUROPEANS OF THE LAST INTERGLACIAL PERIOD; THE TEETH OF THE EUROPEANS OF THE LAST INTERGLACIAL; POSTCRANIAL BONES OF THE LAST INTERGLACIAL: THE EVIDENCE FROM KRAPINA; THE “NEANDERTHALS” OF EU- ROPE; THE NUMBERS AND DISTRIBUTION OF THE NEANDER- THALS; THE WESTERN NEANDERTHALS; THE WESTERN NEANDERTHAL CRANIA; THE WESTERN NEANDERTHAL MANDIBLES; THE TEETH OF THE WESTERN NEANDERTHALS; THE POSTCRANIAL SKELETONS OF THE WESTERN NEANDER- THALS; THE HEIGHT AND BUILD OF THE WESTERN NEAN- DERTHALS; THE FATE OF THE WESTERN NEANDERTHALS; THE CENTRAL EUROPEAN NEANDERTHALS; THE THREE MANDIBLES; THE POSTCRANIAL BONES FROM SUBALYUK; THE SUBALYUK CHILD S SKELETON; THE RUMANIAN NEAN- DERTHAL TOE BONE; THE SIGNIFICANCE OF THE NEANDER- THAL REMAINS FROM CENTRAL EUROPE; NEANDERTHAL REMAINS FROM THE SOVIET UNION; THE KIIK-KOBA TOOTH AND LIMB BONES; THE INFANT SKELETON OF STAROSELE; THE YOUTHFUL NEANDERTHAL OF TESHIK-TASH; THE EAST- ERN NEANDERTHALS OF SHANIDAR; THE INHABITANTS OF PALESTINE DURING WURM I; TABUN AND GALILEE; THE SKHUL SKULLS: NO. 4 AND HIS GROUP; THE SKULL OF SKHUL 5; THE MOUNT CARMEL TEETH; THE POSTCRANIAL SKELETONS OF THE SKHUL POPULATION; THE MEANING OF THE MOUNT CARMEL SKELETONS; EGBERT, THE BOY FROM KSAR AKIL; MORE ABOUT NEANDERTHAL ORIGINS; THE UP- PER PALEOLITHIC PEOPLE AND THEIR CULTURE; UPPER PALEOLITHIC SITES IN SPACE AND TIME; THE RACIAL CHARACTERISTICS OF THE UPPER PALEOLITHIC EUROPEANS;
Contents
XXlll
THE FATE OF THE UPPER PALEOLITHIC EUROPEANS; THEER ASIATIC RELATIVES
12. AFRICA
THE DARKEST CONTINENT; FOSSIL MAN IN NORTH AFRICA: THE TERNEFINE-TANGIER LINE; THE TERNEFINE DISCOVER- IES; THE LITORINA CAVE MANDIBLE; THE MANDIBLE FROM SMUGGLERS CAVE, TEMARA, MOROCCO; THE RABAT RE- MAINS; TANGIER MAN; THE TAFORALT CRANIAL FRAG- MENT; THE TERNEFINE-TANGIER LINE, CANNIBALS, AND BUSHMEN; THE MANDIBLE FROM HAUA FTEAH, CYRE- NAICA; THE EARLIEST CAUCASOID INVADERS OF NORTH AFRICA: THE MOUILLIANS; THE CAPSIANS; THE RACIAL ANATOMY OF THE MESOLITHIC NORTH AFRICANS; HUMAN EVOLUTION IN AFRICA SOUTH OF THE SAHARA; THE “MILK” TEETH FROM OLDUVAI; A POSSIBLE NEGRO EVOLUTIONARY LINE; THE CHELLIAN-3 SKULL FROM OLDUVAI; THE KAN- JERA SPECIMENS; THE SALDANHA BAY SKULLCAP; THE BROKEN HILL OR RHODESIAN SPECIMENS; THE CRANIAL FRAGMENTS FROM LAKE EYASI, TANGANYIKA; THE MAN- DIBULAR FRAGMENT FROM DIRE DAWA, ETHIOPIA; THE MANDIBLE FROM THE CAVE OF HEARTHS; THE CAPE FLATS SKULL; THE BORDER CAVE SKULL; THE CAPSIAN SETTLERS OF THE WHITE HIGHLANDS; THE ORIGIN OF THE CAPOIDS; THE SINGA SKULL FROM THE SUDAN; THE HOMA SHELL- MOUND SKULLS; THE BOSKOP BRAIN CASE AND THE “bOS- KOP RACE ; THE FLORISBAD CRANIAL FRAGMENT; THE FORMATION OF THE MODERN CAPOID PEOPLES; THE EAR- LIEST SKELETONS OF MODERN NEGROES; DO THE PYGMIES HOLD THE ANSWER?; WAS AFRICA THE CRADLE OF MAN- KIND?
588
13. THE DEAD AND THE LIVING
657
STATISTICAL APPENDIX
BIBLIOGRAPHY
GLOSSARY
667
685
711
follows page 724
INDEX
PLATES
FOLLOWING PAGE 82
I Australoid: A Tiwi from Melville Island Carleton S. Coon
II Mongoloid: A Formosan Aborigine Carleton S. Coon
III Caucasoid: A Pathan
Wilfred Thesiger
IV Congoid: A Shilluk
Lidio Cipriani
V Capoid: A Bushman Woman
Film Study Center, Peabody Museum, Harvard University
VI Environmental Adaptation: Two Dinka Girls Lidio Cipriani
VII Dr. Kristian Lange-Andersen and Lucho Carleton S. Coon Bushmen of the Kalahari N. R. Farbman, Life VIII Leadership at a Tiwi Funeral Jane C. Goodale IX Prosimians: Common Lemur Eric Kirkland, F.R.P.S.
Ring-tailed Lemur
Eric Kirkland, F.R.P.S.
Slender Loris
Fox, from Pictorial Parade Tarsius
Philadelphia Zoo
X New World Monkeys: Marmoset Eric Kirkland, F.R.P.S.
Capuchin
Eric Kirkland, F.R.P.S.
Ornate Spider Monkey
W. Marynowicz, F.I.B.P., F.R.P.S.
XXVI
Plates
XI Old World Monkeys: Pig-tailed Macaque Eric Kirkland, F.R.P.S.
Red-capped Mangabey
Eric Kirkland, F.R.P.S.
Brazza Monkey
Eric Kirkland, F.R.P.S.
Patas Monkey
Eric Kirkland, F.R.P.S.
XII Old World Monkeys: Mandrill
New York Zoological Society Proboscis Monkey
Van Nostrand, San Diego Zoo
XIII Apes: Gibbon
University Museum, University of Pennsylvania Siamang
Van Nostrand, San Diego Zoo
XIV Orangutan
W. Marynowicz, F.I.R.P., F.R.P.S.
XV Chimpanzee
Eric Kirkland, F.R.P.S.
XVI Mountain Gorilla
W. Marynowicz, F.I.B.P., F.R.P.S.
following page 370 XVII Pygmies: A Luzon Negrito Woman Carleton S. Coon
XVIII Pygmies: Onges from Little Andaman Island Lidio Cipriani
XIX Pygmies: A Kadar from the Cardamon Hills Carleton S. Coon XX A Pygmy from the Congo Lidio Cipriani
XXI The Karyotype of Man
David PIungerford, The Institute for Cancer Research, Fox Chase, Philadelphia Human Chromosomes XXII Zinjanthropus Skull, Three Views
Des Bartlett, Armand Denis Productions, Inc.; Courtesy National Geographic
XXIII Zinjanthropus Palate
Des Bartlett, Armand Denis Productions, Inc.; Courtesy National Geographic
XXIV Peculiarities of Tooth Structure
a. b. c. by A. A. Dahlberg; d. e. f. by P. O. Pedersen
XXV
XXVI
XXVII
XXVIII
XXIX
XXX
XXXI
XXXII
Plates
Broken Hill, Two Views
By permission of the British Museum (Natural History)
Saldanha Bay
Carleton S. Coon La Ferrassie 1, Three Views
George Quay, University Museum, University of Pennsylvania Teshik-Tash, Three Views
George Quay, University Museum, University of Pennsylvania Skhul 5
George Quay, University Museum, University of Pennsylvania Jebel Qafza 6
H. V. Vallois, Musee de l’Homme, Paris Grimaldi; Florisbad
George Quay, University Museum, University of Pennsylvania
Flesh Beconstructions by Maurice P. Coon Wayland Minot
Flesh Reconstructions by Maurice P. Coon Wayland Minot
An Australian Aborigine and a Chinese Sage Carleton S. Coon
xxvii
DRAWINGS
FIG.
1. How One Polytypic Species Can Evolve into Another
2. The Speech Organs of Primates
3. The Skull of an Aye- Aye
4. The Molars of Old World Monkeys and Apes
5. The Jumping Skeleton
6. Transverse Rib-Cage Sections of Jumpers,
Brachiators, and Men
7. The Carrying Angle in Apes and Men
8. Feet of Apes and Men
9. Occlusion of Canines in Apes and Hominids
10. Body Proportions of Newborn Primates
11. Changes in Skull Form from Newborn to Adult
12. The Primate Time Scale: The Cenozoic Clock
13. Mesopithecus, a Miocene Leaf -eating Monkey ( Colobinae )
14. Proconsul africanus
15. Ramapithecus brevirostis
16. The Skull of Oreopithecus: Hiirzeler’s Reconstruction
17. The Skull of Oreopithecus: Drawn from a Photograph
18. The Specialized Dentition of Oreopithecus
19. The Pelvis and Femora of Oreopithecus
20. The Anatomy of the Human Pelvic Bone ( Os coxae )
21. Pelvic Bones of Ape, Australopithecus, and Man
22. The Distal End of the Femur of Australopithecus,
Ape, and Man
23. The Bones of the Human Foot, Seen from Above
24. The Astragalus of the Australopithecines and
Other Primates
25. The Foot Bones Found with the Olduvai Child
29
75
127
135
155
157
158
160
163
167
169
188
i94
200
204
210
210
211 213
242
243
245
246
248
Drawings
xxix
26. The Australopithecine Scapula
27. The Australopithecine Hand Bones
28. Skull Profiles of Australopithecines, Gorilla, and
Baboon
29. From Proconsul to the Smaller Australopithecines
to the Larger Ones
30. Variations in the Area of Neck-Muscle Attach-
ment in Apes and Australopithecines 31- Sections Through the Nasal Passages of Australo- pithecus, Ape, and Man
32. The Anatomy of the Mandible (Swartkrans, female)
33. The Australopithecine Mandibles 34a. Australopithecine Teeth: Incisors 34b. Australopithecine Teeth: Canines
35- Australopithecine Teeth: Premolars and Molars
36. Irregularly Shaped Molars of Australopithecus robustus
37. The Upper Canine and First Premolar in Aus-
tralopithecines, Apes, and Men
38. The Teeth of Telanthropus
39. The Australopithecine Features of the Lower
First Molar of Meganthropus
40. A Section Through the Pleistocene Beds at Olduvai
Gorge
41. The Olduvai Child’s Mandible
42. A Primate Family Tree
43. Basic Tools of Early Men
44. Grades and Lines of Fossil Hominids
45. Anatomy of the Skull
46. Sagittal Arcs and Chords in Homo erectus and
Homo sapiens
47. The Lateral Pterygoid Muscles and the Chin
48. How Brow Bidges Protect the Eyes against Blows
49. Racial Variations in Tooth Structure: Shoveling
and Ridging
50. Racial Variations in Tooth Structure: the Pre-
molar Cone
51. Racial Variations in Tooth Structure: the Cingu-
lum, Wrinkling, Taurodontism, and Ena- mel Extensions
52. Lower Molar Crown Patterns
53. The Four Indices of Facial Flatness
249
254
257
261
262
263
265
266
269
270 274
274
275
276
279
281
303
326
335
338
342
348
350
355
357
358
361
366
XXX
Drawings
54. Transverse Sections of the Skulls of a Female Go-
rilla, Pithecanthropus 4, and Solo 11 378
55. The Faces of Homo erectus 379
56. Mandibles of Meganthropus, Pithecanthropus B,
and Wadjak 2 381
57. The skulls of Homo erectus and Homo sapiens at
the Age of Two 383
58. Profiles: Australoid Skulls from Trinil to Niah 396
59. Middle Meningeal Artery Patterns of Fossil Men 443
60. Profiles: from Sinanthropus to the Upper Cave
Male 444
61. Alveolar Prognathism in Sinanthropus and in
Modern Chinese 446
62. Mandibles: Sinanthropus and Ternefine 3 448
63. Torus mandibularis 451
64. The Continuity of Mongoloid Teeth: Shovel In-
cisors from Sinanthropus to the Recent
Chinese 454
65. Mandibles: Krapina J, Ehringsdorf, Montmaurin,
and Heidelberg 490
66. Profiles: Steinheim, Swanscombe, and
Fontechevade 493
67. Profiles: Saccopastore 1, Krapina, and
Ehringsdorf 501
68. Saccopastore Inca Bones 503
69. The Mask of Krapina 509
70. From Neanderthal to Nordic in Wiirm I 529
71. Why the Neanderthals Were Not Homo erectus:
Occipital Views of Six Skulls 530
72. Caucasoid Neanderthal Mandibles: Skhul 4,
Tabun 2, La Ferrassie 1, and Circeo 3 536
73. Mandibles of Heidelberg, La Ferrassie 1, and
Skhul 4, Seen from Above 538
74. The Upper Incisors of Neanderthals and Other
Early Caucasoids 54°
75. Neanderthal Hands and Feet 55^
76. The Human Face and Hand in Upper Paleolithic
Art 586
77. The Ternefine Parietal 592
78. Mandibles: Ternefine x and Rabat 594
79. The Tangier Maxilla and Teeth 599
Drawings xxxi
80. The Molar from Olduvai Bed II g1;i
81. Profiles: Chellian 3, Saldanha, and Broken Hill 616
82. Profiles: A Possible Negro Line— Broken Hill,
Cape Flats, and Border Cave 624
83. The Florisbad Site g
84. The Capoid Line: Profiles of Homa, Fish Hoek,
and a Modern Bushman 646
MAPS
DRAWN BY RAFAEL PALACIOS
1 The Five Subspecies of Homo sapiens in a.d. 14Q2 6-7
2 The Sunda and Sahid Shelves and Wallacea 45
3 The Six Faunal Regions of Sclater and Wallace 51
4 Distribution of Living Primates 124-125
5 Faunal Movements into Java 224
6 South African Australopithecine Sites 233
7 East African Australopithecine and Early Man Sites 280
8 The Wiirm Glaciation in Europe and Contemporary
Sea Levels g!g
9 Australoid Fossil Man Sites 372~373
10 Mongoloid Fossil Man Sites 429
11 Human Skeletal Remains in Europe, Western Asia,
and North Africa 483
12 Fossil Man Sites in Africa South of and in the Sahara 615
13 Shifts of Human Subspecies from Pleistocene to Post-
Pleistocene 659
TABLES
1 Order of Primates, Living Genera
2 Numbers of Chromosomes Among the Primates
3 The Cenozoic Era in Millions of Years
4 The Distribution of Early Hominids
5 Australopithecine Postcranial Bones
6 Skidls, Jaws, and Teeth of Australopithecines
7 Numbers of Australopithecine Teeth
8 Crown Dimensions of Australopithecine Teeth
9 A Comparison of the Crown Areas of Canines and Pre- molars in Australopithecus and Homo
10 Tentative Cranial Measurements and Indices of the Australopithecines and of Proconsul africanus n Fossil-Man Sites in Time and Space
12 The Brain-Palate Index and the Brain-Molar Index
13 Flowers Index
14 Racial Variations in Tooth Form
15 The Four Indices of Facial Flatness of Woo and Morant
16 Pithecanthropus- Australoid Skeletal Material
17 The Ngandong Skulls
18 Dimensions of the Hypophyseal Fossa
19 Early Skeletal Material from China and Japan
20 The Sinanthropus Specimens by Sex and Age
21 Loci and Sex of Sinanthropus Specimens
22 Internal Dimensions of the Sinanthropus and Solo Skulls
23 Facial Dimensions of Sinanthropus ( Female ) and Wadjak 1
24 Angles of Inclination and Indices of Robusticity of Sinanthropus and Other Mandibles
122
180-182
188
231
241
256
268
272
273
291
322
345
353
354
367
376
392
395
430
433
434
439
445
450
XXXIV
Tables
25 Pre-Wurm Fossil Man Remains from Europe and Western Asia
26 Internal Dimensions and Capacities of Steinheim and of Female erectus Skulls
27 Postcranial Bones from Krapina
28 Neanderthal and Other Remains of Wiirm I or Later
29 Simple Dimensions of the Neanderthal Cranial Base
30 Upper Paleolithic Fossil Man Sites
31 Pre-Mouillian Skeletal Material from North Africa
32 Mouillian Skeletal Material
33 Capsian Skeletal Material
34 Skeletal Material from Africa South of and Including the Sahara
35 The Teeth from Bed II of Olduvai
APPENDIX
36 Arcs and Chords of the Frontal, Parietal, and Occipital Bones in the Sagittal Plane
3 7 Cranial Dimensions and Indices
38 Dimensions and Indices of Mandibles
39 Dimensions and Indices of Teeth
487
494
517
524
53i
580
591
605
606
612
613
667
668
675
678
PERIODICALS
AND THEIR ABBREVIATIONS
AA
AAE
AAnz
AB
ActG
AE
AEB
Afbica
AGMG
AIPH
AJAn
AJHG
AJPA
AJSc
AK
AMN
AN
Anatolia
Antiquity
ANYA
AP
APa
American Anthropologist, Washington Archivio per TAntropologia e la Etnologia, Florence Anthropologischer Anzeiger, Stuttgart Archaeological Bulletin, New York Acta Genetica et Statistica Medica, Basel Annals of Eugenics, London Abhandlungen zur exakten Biologie, Berlin Journal of the International Institute of African Lan- guages and Cultures, London Acta Geneticae Medicae et Gemellologiae, Rome Archives de I’Institut de Paleontologie Humaine, Paris American Journal of Anatomy, Philadelphia American Journal of Human Genetics, Baltimore American Journal of Physical Anthropology, Philadel- phia
American Journal of Science, New Haven Animal Kingdom, New York American Museum Novitates, New York American Naturalist, Lancaster, Pa.
Revue annuelle de Tlnstitut d’Archaeologie de I’Uni- versite d’ Ankara, Ankara
Cambridge, England (formerly Newbury, Berkshire) Annals of the New York Academy of Sciences, New York
Asian Perspectives, Hong Kong Annales de paleontologie, Paris
xxxvi
APAM
AQ
AR
ARSI
AS
ASAG
ASAM
ASPR
ATM
AuS
RAM
BAMN
BASP
BBMNH
Belleten
BGI
BGSC
BIAF
Biometrika
BMFM
BMSA
BPGO
BRCI
BS
BSA
BSGI
BSPC
BSPF
BUM
Periodicals and Their Abbreviations
Anthropological Papers of the American Museum of Natural History, New York Anthropological Quarterly, Washington, D.C. Anatomical Record, Philadelphia Annual Report of the Smithsonian Institution, Wash- ington, D.C.
Archives des sciences physiques et naturelles, Geneva Archives suisses d’ Anthropologie g enerale, Geneva Annals of the South African Museum, Cape Town American School of Prehistoric Research, Cambridge, Mass.
Annals of the Transvaal Museum, Pretoria The Australian Scientist, Sydney
Bulletin d’Archeologie Marocaine, Rabat Bulletin of the American Museum of Natural History, New York
Bidletin of the American School of Prehistoric Re- search, Cambridge, Mass, (formerly New Haven) Bulletin of the British Museum of Natural History, London
Belleten Turk Tariha Kururnu Basimevi, Ankara Bollettino della Societa geologica italiana, Rome Bidletin of the Geological Society of China, Peking Bulletin d Plnstitut francais d’Afrique Noire, Paris London
British Museum Fossil Mammals of Africa, London Bulletins et Memoires de la Societe d’ Anthropologie, Paris
Beitrage zur Paldontologie und Geologie Oesterreich- Ungarns und des Orients, Vienna Bulletin of the Research Council of Israel, Jerusalem Bulletin Scientifique, Conseil des Academies de la RPF de Yugoslavie, Zagreb.
Bulletin de la Societe d’ Anthropologie de Paris, Paris Bulletin du Service Geologique de Vlndochine, Hanoi Boletim da Sociedade P ortuguesa de Sciencias Natu- rais, Coimbra
Bulletin de la Societe Prehistorique Franqaise, Paris Bulletin of the University Museum, University of Penn- sylvania, Philadelphia
CA
CH
CHM
Circulation
CIWP
CMES
CMJ
CNHS
CRAS
CSHS
Cytologia
DAKM
Diogenes
DR
Endocrinol-
ogy
ER
Evolution
Expedition
Experjentia
FICA
GHSP
GS
HAS
HB
IGC
IJNS
ILN
IVPM
Periodicals and Their Abbreviations xxxvii
Current Anthropology, Chicago Collection Hesperis, Paris Cahiers d’Histoire Mondiale, Paris New York
Carnegie Institution of Washington Publications, Washington, D.C.
Ceylon Museum Ethnographic Series, Colombo Chinese Medical Journal, Shanghai Ceylon National Museums Natural History Series, Co- lombo
Comptes-rendus Hebdomadaires des Seances de T Aca- demic des Sciences, Paris
Cold Spring Harbor Symposia on Quantitative Bi- ology, Cold Spring Harbor, New York Tokyo
Deutsches Archiv fur klinische Medizin, Leipzig Chicago
The Dental Record, London
Los Angeles
Eugenics Review, London Hempstead, New York Philadelphia Basel
Fifth International Congress of Anthropological and Ethnological Science, 1956, Philadelphia
Geologica Hungarica, Series Paleontologica, Budapest Gottinger Studien, Gottinger
Harvard African Studies, Cambridge, Mass.
Human Biology, Detroit
International Geological Congress, London, 1948 Indonesian Journal for Natural Science, Jakarta Illustrated London News, London Institute of Vertebrate Paleontology Memoirs, Peking
xxxviii
TAnat
JAP
JCPP
JEAN
JFS
JGen
JJP
JMBR
JPh
JPLS
JPSI
JRAI
JRAS
L’anth
Man
Mankind
MB
MJA
MKNA
MNGB
MNMM
MOG
MRSE
Nature
NC
NG
NH
P eriodicals and Their Abbreviations
Journal of Anatomy, London Journal of Applied Physiology, Washington, D.C. Journal of Comparative and Physiological Psychology, Baltimore
Journal of the East Africa Natural History Society, Nairobi, Kenya
Journal of Forensic Sciences, Chicago Journal of Genetics, Cambridge, England Japanese Journal of Physiology, Nagoya Journal of the Malayan Branch of the Royal Asiatic Society, Singapore Journal of Physiology, London
Journal of the Proceedings of the Linnaean Society of London, London
Journal of the Paleontological Society of India, Luck- now
Journal of the Royal Anthropological Institute of Great Britain and Ireland, London Journal of the Royal Asiatic Society of Great Britain and Ireland, Ceylon Branch, Colombo
L’Anthropologie, Paris London
Sydney, Australia
Monographiae Biologicae, The Hague Medical Journal of Australia, Sydney, Australia Mededelingen Koninklijke Akademie van Wetenschap- pen, Amsterdam
Mitteilungen der Naturforschenden Gesellschaft in Bern, Bern
Memoires of the National Museum of Melbourne, Vic- toria, Australia
Medelelser om Gronland, Copenhagen Memorias Real Socieclad Espahola de Historia Natural, Madrid
London
Neanderthal Centenary, Utrecht
National Geographic Magazine, Washington, D.C.
Natural History, New York
Periodicals and Their Abbreviations
XXXIX
NMRI Naval Medical Research Institute Lecture and Review
Series, Bethesda, Md.
NYT The New York Times
Oceania
OJS
PAf
PAPS
PASA
PBM
PKAW
PKSF
PLSL
PMP
PNAS
PNHB PPS PRSM PS— D PS— NS— D PTCPFA
PTPA
PYMP
Sydney, Australia
Ohio Journal of Science, Columbus
Paleontologia Africana, Johannesburg Proceedings of the American Philosophical Society, Philadelphia
Proceedings of the Academy of Science of Amsterdam, Amsterdam
Perspectives in Biology and Medicine, Chicago Proceedings: Koninklijke nederlandse akademie van Wetenschappen, Amsterdam Publications under the Keith Sheridan Foundation for Medical Research, Adelaide, S. Australia Proceedings of the Linnaean Society of London Peabody Museum Papers, Cambridge, Mass. Proceedings of the National Academy of Science, Washington, D.C.
Peking Natural History Bulletin, Peking Proceedings of the Prehistoric Society, Cambridge Proceedings of the Royal Society of Medicine, London Paleontologia Sinica, Series D, Peking Paleontologia Sinica, New Series D, Peking Proceedings of the Third Congress on the Prehistory of the Far East, 1938
Proceedings of the Third Pan-African Congress on Prehistory held in N. Rhodesia, Livingstone, 1955, pub. London, 1957
Postilla Yale Peabody Museum, New Haven, Conn.
QJGS Quarterly Journal of Geological Sciences, London
QRB Quarterly Review of Biology, Washington, D.C.
Quartar Bonn
Quaternary Rome
RA Rivista di Antropologia, Rome
RBMO Research Bulletin, University of Missouri, College of
Agriculture, Agricultural Research Station, Co- lumbia, Mo.
xl
Periodicals and Their Abbreviations
RGA
RM
RQS
RR
RSAM
Revista Geografica Americana, Buenos Aires Richerche di Morfologia, Rome La Revue des Questions Scientifiques, Louvain Radical Review, New Bedford, Mass.
Records of the South Australian Museum, Adelaide, S. Australia
SA
SAAB
SAJS
Science
SD
SE
SIAr
SM
SMC
SMJ
SNNM
SRP
SSF-CB
Sumer
SVfZ
SWJA
SZC
Scientific American, New York South African Archaeological Bulletin, Cape Town South African Journal of Science, Johannesburg Washington, D.C.
Science Digest, Chicago Sovetskaia Etnografiia, Moscow Slovenska archeologia, Brno Saugetierkundliche Mitteilungen, Stuttgart Smithsonian Miscellaneous Collections, Washington, D.C.
Saraivak Museum Journal, Kuching, Borneo Sodlogiese naborsing nasionale Museum, Bloemfontein, S. Africa
Smithsonian Report, Publication, Washington, D.C. Societas Scientiarum Fennica, Commentationes Biolo- gicae, Helsinki Baghdad
Schweizerische Viertelfahrsschrift fur Zahnheilkunde, Zurich
Southwestern Journal of Anthropology, Albuquer- que, N.M.
Spolia Zeylanica, Colombo
TB
The Leech TI
TIBS
TLAB
TMM
TNYA
Triangle
Tabulae Biologicae, The Hague Johannesburg, S. Africa The Interamerican, Denton, Texas Trabajos del Institute “Bernadino de Sahagun” de Antropologia y Etnologia, Madrid Travaux du Laboratoire d’Anthropologie et d’Archeo- logie Prehistoriques du Musee du Bardo, Algiers Transvaal Museum Memoires, Pretoria Transactions of the New York Academy of Sciences, New York Basel
Periodicals and Their Abbreviations
xli
TRSL
TRSS
UMM
VGR
VGPA
VP
WADC
WMDM
YAPS
ZA
ZfE
ZfMuA
ZfNF
ZfRK
ZOOLOGICA
zv
ZZ
Transactions of the Royal Society of London, London Transactions of the Royal Society of South Africa, Cape Town
University Museum Memoirs, University of Pennsyl- vania, Philadelphia
Verhandlungen der Geologischen Bundesanstalt, Vi- enna
V erhandlungen der Gesellschaft fur physische Anthro- pologie, Stuttgart Vertebrata Paleasiatica, Peking
Wright Air Development Center Technical Reports, Wright-Patterson Air Force Rase, Ohio W etenschappelijke Mededelingen Dienst van de Mijn- bouw, Bandoeng
Yearbook of the American Philosophical Society, Phila- delphia
Zoologischer Anzeiger, Leipzig Zeitschrift fiir Ethnologie, Berlin Zeitschrift fiir Morphologie und Anthropologie, Stutt- gart
Zeitschrift fiir Naturforschung, Tubingen Zeitschrift fiir Rassenkunde, Stuttgart New York
Zoologische Verhandelingen, Leyden Zinruigaku Zassu, Journal of the Anthropological So- ciety of Nippon, Tokyo University
THE ORIGIN OF RACES
a
1
THE PROBLEM OF RACIAL ORIGINS
A On the Antiquity of Races
t the dawn of history, which is another way of saying beginning with Herodotus,” literate people of the ancient world were well aware that mankind was divided into a number of clearly differentiated races. Even before that, racial differentia- tion can be traced back to at least 3,000 b.c., as evidenced in Egyptian records, particularly the artistic representations. We also have pictures of white people on the walls of western European caves which are as much as 20,000 years older.
How many kinds of people there were in the world was not really known until after the voyages of discovery that tore the veil from the Americas, the Pacific islands, and Australia. Even then the problem of classifying the races remained, and it has not been settled to this day.
For present purposes I am using a conservative and tentative classification of the living peoples of the world into five basically geographical groups: the Caucasoid, Mongoloid, Australoid, Con- goid, and Capoid. The first includes Europeans and their overseas kinsmen, the Middle Eastern Whites from Morocco to West Paki- stan, and most of the peoples of India, as well as the Ainu of Ja- pan. The second includes most of the East Asiatics, Indonesians, Polynesians, Micronesians, American Indians, and Eskimo. In the third category fall the Australian aborigines, Melanesians, Papu- ans, some of the tribal folk of India, and the various Negritos of South Asia and Oceania. The fourth comprises the Negroes and
4 The Problem of Racial Origins
Pygmies of Africa. I have named it Congoid after a region ( not a specific nation) which contains both kinds of people. The term Negroid has been deliberately omitted to avoid confusion. It has been applied both to Africans and to spiral-haired peoples of southern Asia and Oceania who are not genetically related to each other, as far as we know.1 Negroid will be used in this book to denote a condition, not a geographical subspecies. The fifth group includes the Bushmen and Hottentots and other relict tribes, like the Sandawe of Tanganyika. It is called Capoid after the Cape of Good Hope. If this subspecies once occupied Morocco (see Chap- ter 13), the cape can be thought of as Cape Spartel. Either way, the term is appropriate.
My aim in this book is to see how far back in prehistoric an- tiquity these human racial groups can be traced. Did they all branch off a common stem recently, that is, within a few tens of thousands of years, after mankind had evolved as a single unit to the evolutionary state of the most primitive living peoples? Or did their moment of separation lie lower down on the time scale, when long-extinct types like the so-called ape men of Java and China were still alive? If the second is true, much of the evolution of the different existing races may have taken place separately and in parallel fashion over a period of hundreds, rather than tens, of thousands of years. The first hypothesis is the one more commonly held, but it presents some impressive stumbling blocks.2
If all races had a recent common origin, how does it happen that some peoples, like the Tasmanians and many of the Australian aborigines, were still living during the nineteenth century in a manner comparable to that of Europeans of over 100,000 years ago? Either the common ancestors of the Tasmanians cum Aus- tralians and of the Europeans parted company in remote Pleisto- cene antiquity, or else the Australians and Tasmanians have done some rapid cultural backsliding, which archaeological evidence disproves.
If the ancestors of the living races of mankind were a single
1 They differ completely in blood-group patterns, particularly in the Rhesus genes.
2 See W. W. Howells, Jr.: Mankind in the Making (New York: Doubleday and Company; 1959), especially p. 236; and C. S. Coon’s review of same in Science, Vol. 130, No. 3386 (1959), pp. 1399-1400.
On the Antiquity of Races
5
people a few thousands of years ago and they all spoke a single language, how does it happen that the world contains thousands of languages, hundreds of which are unrelated to each other, and some of which even use such odd sounds as clicks? Some lan- guages are tonal and others are not, and the difference between a tonal and a nontonal language is basic and profound. Eskimo and Aleut, which are closely related languages, have been separated for about two thousand years. It takes at least twenty thousand years for two sister languages to lose all semblance of relation- ship.3 If, therefore, all languages are derived from a single mother tongue, the original separation must go back many times that figure. The only alternative is that more than one line of ancestral man discovered speech independently. Even so, the number of languages spoken by a single subspecies, the Mongo- loid, is great enough to imply a vast antiquity.
All the evidence available from comparative ethnology, linguis- tics, and prehistoric archaeology indicates a long separation of the principal races of man. This is contrary to the current idea that Homo sapiens arose in Europe or western Asia about 35,000 b.c., fully formed as from the brow of Zeus, and spread over the world at that time, while the archaic species of men who had preceded him became conveniently extinct. Actually, the homines sapientes in question were morphologically the same as living Europeans. To derive an Australian aborigine or a Congo Pygmy from European ancestors of modern type would be biologically impossible.
The current idea is based on the study of comparative anatomy without reference to evolution, and a misunderstanding of pale- ontology. One anatomist, Morant,4 found by means of a number of measurements taken on less than ten Neanderthal skulls that this ancient population differed in mean measurements from a number of modern populations more than the modern skulls differ from each other. The differences reflected mainly the fact that Nean-
3 D. H. Hymes: “Lexicostatistics So Far,” CA, Vol. 1, No. l (i960), p. 3-44. The 20,000-year calculation, a conservative figure, is my own, based on Hymes’s data.
4 G. M. Morant: “Studies of Paleolithic Man, II, A Biometric Study of Nean- derthaloid Skulls and of Their Relationships to Modern Racial Types,” Biometrika, Vol. 2 (1927), pp. 318-80.
° The Problem of Racial Origins
deithal men had low, flattish cranial vaults and protruding faces; but these features could have come from a small number of genes concerned with adaptation to cold weather. Since 1927, when Morant’s study was published, “progressive” and “transitional” high-headed Neanderthals have been unearthed in western Asia. These new discoveries suggest that the total extinction of that fossil race is unlikely. We now have fossil skulls from China, Af- rica, and Europe, found since Morant studied the Neanderthals, which closely resemble the modern races in features that seem to have evolved and been handed down locally. Such features in- clude the extent to which the face is flat or beak-like, the shape of the nasal bones, and the size ratio of front teeth to molars. If we grant that races, like the species to which they belong, can evolve, our problem becomes simpler.
The misinterpretation of paleontology by nonpaleontologists came about naturally. Anyone who studies the family trees of various lines of animals over millions of years is bound to be im- pressed by the multitude of extinct species, and to notice that the living animal species are descended from very few ancestral ones. When this observation is applied to many forms of life over the span of geological time, it holds true; but for man it does not. Man is little more than a half million years old. Geologically speaking, we were born yesterday. The fossil men now extinct differed from each other in race, and were not members of separate species except in the sense that one species grew out of another.
As human beings are animals, they are subject to the same laws of evolutionary change that govern the rises and falls of other species and their transmutations into increasingly complex and efficient forms. Therefore we have two jobs to do: (1) to survey the rules of species formation and the differentiation of races, in- cluding the composition of populations, systems of mating, dif- ferential fertility, and geographical adaptation at different ecolog- ical levels, as they may apply to man; and (2) to go over with a fine-toothed comb all the original evidence about fossil specimens of man and his predecessors which can be found. This includes actual specimens, casts, and technical reports, some lying on the bottom shelves of library stacks, with pages still uncut, and un- disturbed for decades. Because few textbook writers have both-
The Problems of Human Taxonomy: the Genus g
ered to consult these primary sources, few new ideas about the evolution of races have reached the public for a long time.
The Problems of Human Taxonomy: the Genus
Over two hundred years ago Linnaeus, the father of taxonomy,5 or systematics as he called it, initiated the practice of giving each species in nature an italicized double name, or binominal, one of which was Homo sapiens. The first word is the name of the genus and the second that of the species itself. In the species Homo sapiens he included all living peoples. At that time no fossil men had been discovered, and the genus Homo had therefore but a single species.
Linnaeus used only one word to designate biological units smaller than the species: variety. At that time the concept had not yet arisen that the unit of inheritance and evolution is the population to which an individual belongs rather than the indi- vidual himself, and the exact meaning of variety was not clear. In recent years taxonomists, in reviewing the nomenclature of spe- cies, have found that many units given specific rank in the past were subspecies, or geographical races, of larger units, and that what had been called varieties were races of one magnitude or another, or even individual variants.
In order to obtain material for classification, zoologists were kept busy collecting skins and skulls of many kinds of animals, and paleontologists removing bones, teeth, claws, and shells of ancient animals from the ground. Rarely did the paleontologists have whole skeletons to work with; and even when they did, characteristics studied by zoologists, such as hair form and color, skin structure, and the number of mammary glands, could not be determined except in a very few cases, as when mammoths were found frozen in the ground.
Whereas zoologists could collect large numbers of contempo- rary specimens, paleontologists sometimes possessed only unique
For a lucid introduction to this subject, see G. G. Simpson: Principles of Animal Taxonomy (New York: Columbia University Press; 1961) and “The Principles of Classification and a Classification of Mammals,” BAMN, Vol. 85 (i945)-
10 The Problem of Racial Origins
specimens, which had to be related to others from different times and different places. Often the time gap between apparently re- lated specimens was so great that it was unlikely that they could have belonged to a single species. Being cautious men, most paleontologists considered it more conservative to give separate generic names to unique or rare fossils of different periods than to assume their identity, particularly when in living animals such as the sheep and goat, which belong to different genera, the only difference visible in the skelton is the relative lengths of the seg- ments of the forelimb. Paleontologists therefore formed the habit of giving new and unique specimens separate generic names, setting aside the finer classification of related species until more bones had been found.
When, in the second half of the nineteenth century, paleontolo- gists and archaeologists began turning up the bones of fossil men, some of them applied this practice to the much more limited field of anthropology, and we find such designations as Pithecanthro- pus erectus, Sinanthropus pekinensis, and more recently, Atlan- thropus mauretanicus tagged to specimens some of which differ from one another no more than do individuals in the living species.
Homo sapiens
The final difficulty with this type of taxonomy is that it can- not be reconciled with our time scale. Simpson, Kurten, and others have shown that, within the geological periods with which we are concerned, a genus of mammals requires about eight million years to establish itself, and it usually makes no difference whether the animals are large or small, or fast or slow to mature.6
The oldest fossil-man remains that are definitely and indu- bitably Homo may be no more than 700,000 years old. If there really were, during the last 700,000 years, four genera of fossil men, including Homo, Pithecanthropus, Sinanthropus, and Atlan-
6 Simpson: The Major Features of Evolution (New York: Columbia University Press; 1953).
B. Kurten: “Rates of Evolution in Fossil Mammals,” CSHS, Vol 24 (1959) pp. 205-15.
11
The Species Concept
tkropus, then these genera must have parted company early in the Pliocene, and we have neither manlike bones nor tools from this period.
Later on, after tools had appeared, we find that both Atlan- thropus in North Africa and Homo in Europe were making stylis- tically similar stone implements. Although a great many claims can be made for parallel evolution, it is inconceivable that men of two distinct genera could have made similar tools.
The concept that the fossil men so far found, who lived during the last half million years, belonged to more than one genus is impossible both anatomically and in terms of behavior, as re- vealed by archaeology. This concept must be abandoned, and indeed many zoologists and anthropologists have already dis- carded it. Of the names proposed for our genus, Homo has two centuries of priority, and Homo is what we are, what our known ancestors were, and what our unknown ancestors could have been for as long as eight million years.
The Species Concept
In the whole field of taxonomy no identification is as impor- tant as that of the species of an animal. Higher categories, such as the genus, family, order, and so on, are subject to argument and revision, and lower categories, the subspecies and local race, are also more difficult to establish. The species, however, is the pivot of the entire structure because it is the unit of evolutionary change.
In the early days of taxonomy, a collector would shoot a bird or animal, keep its skin and skull, compare it with others in exist- ing collections to determine whether it was something new, and if it was, he would write up a detailed description, giving the bird or animal a new name. It thus became the type specimen, or holotijpe, of its species, and future collectors would compare their discoveries with it. This practice was applied to the anthropologi- cal field. Blumenbach, whose classification of mankind in the familiar fivefold skin-color system is still used in some school geo-
1 2 The Problem of Racial Origins
graphy books, selected a particularly handsome skull from a Eu- ropean collection as the type specimen of the white race, and as it had belonged in life to a native of the Caucasus Mountains, white people came to be called Caucasians, or Caucasoids, and still are. As late as 1912 Boule selected the skeleton of La Chapelle aux Saints as the type specimen of Neanderthal man, which he com- pared to the skeletons of one Frenchman and three anthropoid apes.
As early as Darwin, however, it was recognized that a species is not just the specimen that happened to be killed or unearthed first, and others later found to resemble it, but a population. In- deed, Darwin based his theory of natural selection on his obser- vation that individuals of a species are variable, and that one need not be more typical than another. As time went on, it became clear that a species is a breeding unit or population, which has a gene pool of its own, and not just a collection of individuals, and that each population is a separate entity, living in two related states of dynamic equilibrium. The first regulates the balance be- tween the individuals that compose the population. The second governs its relations with the other species in its environment.
Another early observation was that members of different spe- cies do not interbreed, at least in a state of nature. It was first thought that this was not for lack of trying but simply because each species was incapable of fertility with any other. However, early in the twentieth century the rising science of genetics made it clear that some animals of different species could produce fer- tile offspring if they could be made to come together. Sterile hy- brids like the mule were known from antiquity, and tiger-lion mix- tures have been produced in zoos, but hybridization, it was found, is not a common or important mechanism of evolutionary change in the higher animals, as it is in plants. Furthermore, as each spe- cies is in genetic equilibrium with its environment, the addition of new genes from an animal with a different kind of equilibrium could be expected to produce offspring less viable than either parent.
The important distinction is that members of potentially inter- fertile species do not ordinarily interbreed either because their
13
The Species Concept
breeding periods fall at different seasons or because they simply do not attract each other: they do not recognize each other’s mat- ing symbols — visual, olfactory, auditory, or whatever.
In any case, whether or not unconfined animals of different populations interbreed when given the opportunity is the critical test of a zoological species. Paleontologists, of course, cannot use this test, which may be another reason why they prefer to deal in the more readily identified unit of the genus. In the case of living human populations, we can confirm Linnaeus’s decision that all men belong to the same species, not only because all races are in- terfertile but also because some individuals among them inter- breed, although others oppose mixture. In the case of early human populations unearthed by archaeologists, we cannot be sure whether interbreeding has or has not taken place; and at only one site, the Mt. Carmel caves of Palestine, is there any evidence — a high degree of individual variability combined with a mingling of tool forms — to suggest that the races were mixing, but even that is inconclusive. Therefore, the statements commonly made that Pithecanthropus, Sinanthropus, Neanderthal man, or a member of any other ancient population was unable to interbreed with his neighbors, if he had any, is speculative and cannot be demon- strated.
These statements are based on the old idea that if in some char- acteristic the ranges of variability of two populations fail to over- lap, then these populations are different species. If this were true, then the Pygmies and Watusi of Ruanda-Urundi in Central Af- rica, who live near each other, would be different species on the basis of stature, and the black-skinned and white-skinned races of the world would also be different species.
This obsolete concept of single-character taxonomy has long since been abandoned. Zoologists now base their decisions on all the characteristics they can identify and measure, characteristics which together give the animal its essential nature, its (to borrow a psychological term) gestalt. The determination of species can- not be made by feeding figures into a computer. It is in a sense an art, practiced by men of experience who know, first of all, how species are formed.
14
The Problem of Racial Origins
The Spatial Requirements of Species and Their Geographical Differentiation
Zoologists recognize two kinds of species, monotypic and polytypic.7 A monotypic species contains a single pattern of ge- netic composition, usually because it is a single population that occupies a single, environmentally unified lebensraum in which interbreeding is easy from one end of its territory to the other. Monotypic species are in the minority. A polytypic species, on the other hand, is broken up into a number of separate populations, each occupying its own territory. Usually these territories adjoin each other but are partially separated by environmental barriers. Gene flow across the barriers is infrequent enough to permit the development of separate genetic patterns but frequent enough to prevent the different populations from becoming individual spe- cies. When these barriers become absolute, local speciation can occur. Once a new species has arisen, it is likely to expand into a number of territories, where adaptation to new conditions will be rapid. This is undoubtedly what happened to our ancestors once they had acquired the erect posture and begun to use their hands for something beside locomotion and their mouths for something other than feeding and biting.
Regional populations of a polytypic species, once it has become established and has spread, are normally allopatric, a term which means simply occupying different territories.” If they were not allopatric, they would compete with each other for food, and one would drive out or absorb the other. Normally the one longest in situ has the advantage over newcomers because it has adapted it- self to its new environment by favorable genetic changes, unless a geographical principle is involved, as in the case of isolated popu- lations like those that arise on islands. Because they evolved with- out competition, such populations are usually vulnerable when
This term should not be confused with the word polymorphic , which means, in the language of geneticists, that inside a given population more than one gene is available for a given position on a chromosome; the father may carry one, & the mother another. The best-known example is the possibility of having a gene for A, B, or O on a single chromosome in the ABO blood-group system.
The Subspecies
15
their territories are invaded by newcomers which evolved on large continental areas where competition is keen.
Related species, however, can be sympatric, which is zoologese for saying that they can occupy a single territory without inter- fering with each other, just as zebras, wildebeeste, and giraffes feed together on an African plain. Sympatric occupation is the rule for animals that belong to different genera, families, orders, and even higher categories of classification, which is why we have regional faunas. It is not very common among closely related spe- cies because they usually compete for food.
Whether or not related species are sympatric or allopatric de- pends to a large extent on their eating habits. If a species special- izes in a narrow dietary range, it can coexist with another that specializes in a different range. The Australian koala lives essen- tially on the leaves of a few kinds of eucalyptus, the presence of which limits its range but allows it to coexist with other species of marsupials on the ground below; the giant panda of western China subsists largely on bamboo shoots whereas the smaller red panda eats a variety of foods.
Animal species that specialize in food are called stenophagous, the Greek term for narrow-feeding. Those that eat many kinds of food are called euryphagous, or wide-feeders. Like any other spe- cialty, stenophagy permits a rapid expansion in a narrow milieu, but it is not the road to evolutionary success. Euryphagy involves an animal in heavy competition, but if it survives, it has a better chance of expanding over areas with differing food supplies, and of undergoing further speciation.
In the case of man, he is euryphagous and always has been. Man can eat roots, succulent leaves, fruits, berries, eggs, and flesh. Except for grass, he can eat virtually everything that other ani- mals eat, and this puts him in competition with many other spe- cies and with other populations of his own and related species.
The Subspecies
The next taxonomic division below that of species is the sub- species. A subspecies is a regional population of a polytypic spe-
*6 The Problem of Racial Origins
cies (a species with a number of separate populations) which meets two tests: (1) it occupies a distinct geographical territory ; (2) it differs from other subspecies of the same species in measur- able characteristics to a considerable degree (to be specified shortly).
Subspecies must by definition be allopatric: if several subspe- cies were to inhabit a single region, they would breed together and the differences between them would be obliterated. Within its own geographical territory, which has an environmental char- acter of its own, the subspecies has achieved, or is in the process of achieving, an adjustment to its local food supply, to the local climate, and to the behavior patterns of other animal species with which it shares its domain. After each subspecies has worked out a balance with all other elements in its local environment, it is not likely to change very much until its situation changes: natural se- lection will prune off unfavorable mutations that arise locally and keep the favored gene ratio constant.
Over the border, which may be a natural barrier such as a range of mountains or a patch of desert, or even a critical isotherm, may be found another subspecies of the same species, equally well es- tablished in a state of equilibrium with its environment. As the two environments differ in certain details, so do the genetic struc- tures of its occupants. What is good for A is less advantageous for B, and vice versa. In each territory, natural selection keeps the gene structure of the local subspecies constant by also eliminat- ing unfavorable genes that flow over the border. However, genes which are unfavorable in both environments may be eliminated in both populations, so that A and B may evolve together into a new polytypic species that retains its original set of subspecies. This is what we think happened when a number of human sub- species passed the threshold from Homo erectus to Homo sapiens.
Taxonomists have set up an arbitrary procedure to determine whether two or more populations within a species are morpho- logically different enough to qualify as subspecies. It is called the overlap test and is applied both to visible criteria, such as tooth size, and to invisible ones, such as blood groups. If in any well- defined, presumably heritable morphological character, a repre- sentative sample of population A differs from a representative
17
Mosaics, Clines, Local Races, and Racial Types
sample of population B to or beyond a critical degree, then we are dealing with subspecies. The critical degree is 75 per cent. If 75 per cent or more individuals of A are different from 100 per cent of B, then the two are probably subspecies.8
This method was devised for use on large samples of living ani- mal populations and it can be applied to modern anthropometric series, but it is rarely if ever useful in the study of fossil man be- cause we have few samples large enough for analysis by proba- bility statistics. When applied to modern human populations, this test shows that Homo sapiens is at present a polymorphic species divided into a number of clearly differentiated subspecies, each centered in its own territory.
The concept of subspecies is essentially zoological and is used almost entirely to describe regional variations in animal species. However, paleontologists also use it occasionally, to describe steps in a single evolutionary line which they consider too small to merit the rank of separate species. Such units may be called suc- cessional subspecies, or waagenons — named for a mid-nineteenth- century paleontologist, W. Waagen.9 In order to keep confusion to a minimum I shall not use the word subspecies in this book to designate such successive units. When successive species must be split, I shall do it in terms of the evolutionary levels or grades through which they have passed.
Mosaics, Clines, Local Races, and Racial Types
Below the taxonomic level of the subspecies, zoologists find a sometimes bewildering array of local racial variations of a minor nature, which exist because subspecies as well as species can be polytypic. This is as true of men as it is of mice, for man is the
8E. Mayr, E. G. Linslev, and R. L. Usinger: Methods and Principles of Sys- tematic Zoology (New York: McGraw-Hill Book Company; 1953), p. 146. When biometric statistical constants are available, this test can be performed without
plotting frequency curves by using the formula C.D. = ^ in which C.D.
equals Coefficient of Difference, Mi and M» the means of two series, and <r, and <r._. their standard deviations. If the C.D. is 1.28 or higher, subspecific rank is indi- cated. Attributes expressed in percentile values rather than means may be com- pared directly.
9 Simpson: Principles of Animal Taxonomy, pp. 175-6.
The Problem of Racial Origins
most mobile of mammals. He walks the land, flies the skies, and rides the oceans.
Part of the racial complexity of Homo sapiens disappears if we disregard for the moment the distribution of modern peoples like white and Negroid Americans, Latin Americans, South Africans, and white Australians and New Zealanders, whose ancestors reached their homes by ocean-going ships in recent times. Before then each of the five subspecies recognized in this book was firmly and uniquely installed in its geographical center. Between the nu- clei of these five centers lie intermediate regions of two kinds.
One of them is the mosaic, which contains relict populations living as enclaves in refuge areas. For example, in India at least two forms of Australoids, classified as “tribal peoples,” dwell in the hills, surrounded by Caucasoids whose home is the plains. Such a mosaic pattern is the product of earlier, but not geologi- cally ancient, migrations that have not had time to fuse. As will be shown in the next chapter, it is typical of the tropics of the Old World.
The other is a region of racial transition, a frontier-in-depth within which a subspecies grades into another through intermedi- ate forms. It may be called a clinal zone because in it the popula- tion of the species intergrades in one or more measurable charac- ters. In each heritable feature, the gradient is called a cline.1 For example, the living Europeans grade from a high frequency of blue eyes in the northwest, particularly in Ireland and Scandina- via, to a high frequency of brown eyes in the southeastern part of the continent. This eye-color gradient is a cline.
Whole complexes of related clines are found in clinal zones. For example, in central Asia north of the Himalayas Caucasoids merge into Mongoloids through the persons of several Turkic- speaking peoples like the Kirghiz, Uzbeks, and Turkomans. This clinal zone is a broad one. On the southern face of the Himalayan wall a similar but narrow clinal zone stretches through a steep in- termediate altitude zone, in northern India, Nepal, Sikkim, Bhu- tan, and NEFA (Northeast Frontier Agency). As can be seen by
1J' S- Huxley: “Clines: An Auxiliary Taxonomic Principle,” 'Nature, Vol. 142 (1938), p. 219. See also Simpson: Principles of Animal Taxonomy, pp. 178-80.
Mosaics, Clines, Local Races, and Racial Types lg
these examples, the sharper the environmental barrier the nar- rower the clinal zone between subspecies.
Not only in relict enclaves and clinal zones, but also within the nuclear territories of subspecies, regional populations of minor rank may be found which differ from each other in perceptible ways short of the requirements of subspecies. These are known as local races. As they rise and disappear rapidly, they receive little attention from zoologists and usually none from paleontologists. In man they are considered important by people without a bio- logical background, usually because such groups may be identi- fied to a certain extent with social, political, or religious units.
How many local races could be identified and counted among living men is difficult to say, and different anthropologists might each find a different number. Such details are of no importance in this book, but it is important for us to know that local races exist and are formed by the same biological mechanisms that have fostered larger taxonomic units in the past.
Races like the Nordic, Alpine, Mediterranean, East Baltic, and Dinaric, which loom large in the Europe-centered literature of anthropology, are neither subspecies nor, in a strict sense, local races, although some local races may be defined in these terms. These words have also been used in the sense of tijpes, which can be picked out of local populations. One may find a Spaniard who is typically Nordic in the midst of a population of Mediterra- neans, including his own brothers. In a sense the situation is genetically comparable to finding a man of blood group B whose father’s group was A. Types selected in this fashion are interesting to observe, and we notice them every day. Whether or not they reflect the origins of a population in one way or another, we must remember that from the taxonomic point of view such types are not races but simply the visible expressions of the genetic varia- bility of the intermarrying groups to which they belong.
However, if we return to the first test of subspecies, geographi- cal integrity, we are at first sight on shakier ground. Whites, Ne- groes, and American Indians occupy the United States sympat- rically. Hindus, Fijians, and Europeans similarly occupy the Fiji Islands, and many other examples might be cited. As we study
20
The Problem of Racial Origins
each instance, we find that this situation is a recent one, as time is measured biologically, and it is always associated with the expan- sion of peoples who have left the food-gathering stage of sub- sistence far behind.
Let us omit, for the moment, the agricultural peoples of the world and the colonists, and consider only the peoples who still aie, or until recently were, food gatherers. These hunters and col- lectors are drawn from all five geographical races listed on page 3. Each race is confined to a single territory without overlap except in two regions: India, and southeast Asia plus Indonesia. Owing to a lack of skeletal material, we do not know when the ancestors of the various food gatherers moved into India, nor indeed which race was eailiest there. In southeast Asia and Indonesia we know, as will be explained in Chapter 10, that Mongoloids began re- placing Australoids about 10,000 years ago, after the invention of the bow and the domestication of the dog had made some hunters more efficient than others.
This southward movement was a trickle compared to what hap- pened in many other places 4,000 years later. By or after 6,000 b.c. a number of local populations began to advance from the ecologi- cal niche of hunters and gatherers to that of food producers, and territorial expansions followed. These movements started no more than four hundred generations ago, counting twenty-five years to a generation. The colonial movements that brought Europeans to America, South Africa, Australia, and New Zealand took place less than twenty-five generations ago; only about twelve genera- tions separate most descendants of passengers on the Mayflower from their celebrated forebears.
These various movements have greatly restricted the territo- ries of aboriginal food gatherers, but gatherers are still present in reduced numbers. Many more have been absorbed into the new food-producing populations or have borrowed the techniques of food production from newcomers to their territories. Since the be- ginning of agriculture no new subspecies have arisen; the princi- pal changes that have taken place have been vast increases in the numbers of some populations and decreases to the threshold of ex- tinction in others. All this points to one conclusion: the living sub- species of man are ancient. The origins of races of subspecific rank
21
The Differentiation of Species
go back into geological antiquity, and at least one of them is as old, by definition, as our species.
The Differentiation of Species
Species formation is believed to be the product of four principal factors: mutation, recombination, selection, and isola- tion.2 A mutation is a heritable, spontaneous, and within certain limits random change in the chemical composition of a molecular segment of a chromosome known as a gene or gene locus.3 These changes take place normally in all organisms at individual fre- quency rates that can be predicted. As most mutations produce unfavorable effects, relatively few are passed on or participate in species formation. The same mutation, favorable or otherwise, can appear time after time, at its own rate, in individuals of different races. Yet mutation is the primary element in evolution. The other three are secondary.
Recombination, known as Mendel’s second law, is the process by which rows of gene-molecules strung together on chromosomes break up and form new associations.4 At meiosis, that critical mo- ment in fertilization when a single array of paternal chromosomes lines up with and joins a single set of maternal chromosomes, the pairs do not always merge with each other in a regular fashion. Some chromosomes cross over each other at various loci and trade strings of genes. Others break up and the fragments attach them- selves to other chromosomes or get lost. These new arrangements can also cause changes in the resultant organism.
Selection is the well-known pruning process by which the envi- ronment determines which novelty produced by mutation or re-
2 E. Mayr: “Change of Genetic Environment and Evolution,” in J. Huxley, A. C. Hardy, and E. B. Ford, eds.: Evolution as a Process (London: George Al- len and Unwin; 1954), pp. 157-80.
3 More technically, it is a change in the sequence of nucleotides within a DNA ( dexoribonucleic acid) molecule of a single chromosome. See P. Alexander: “Radiation-Imitating Chemicals,” SA, Vol. 202, No. 1 (i960), pp. 99-108. Ac- cording to Demarec, there are about 10 to 15 genes to each DNA molecule, or 20 to 30 to a pair of molecules. M. Demarec: “The Nature of the Gene,” AJHG, Vol. 13, No. 1 (1961), pp. 122-7.
4 For present purposes this process is not also called a mutation. See Simpson: The Major Features of Evolution, pp. 82-3.
22 The Problem of Racial Origins
combination shall gradually spread through the group because of its superiority to the old trait it replaces, and which novelty shall be eliminated because it is unfavorable. As most mutations are unfavorable, when a species is not perceptibly changing, se- lection serves almost entirely to preserve the status quo. However, the process of replacement is characteristically slow. Old genes have a habit of hanging on as minorities, and if the environment changes back once more, they may re-emerge as majorities, in new combinations.
Isolation, the fourth factor, is necessary for the rise of new spe- cies because, unless a breeding population is self-contained, natu- ral selection may be unable to eliminate old, unfavorable genes from its pool. A constant gene flow from neighboring populations may renew the old genes as fast as they are being lost. In a mono- typic species such gene flow is impossible by definition. But in a polytypic species only those genes can be eliminated which are unfavorable to all its component units. When this happens, the species evolves as a whole, whereas its component populations may retain their local differences.
Balanced Polymorphism
Sometimes it is disadvantageous for a population to elimi- nate its old genes completely. An old gene may possess the ability to meet an old crisis, if that crisis should return. Furthermore, the old gene and the new one with which it shares, as an alternate, its position on a chromosome may do things together that neither could do alone.
In genetic shorthand, AB may be better under some conditions than either AA or BB. The best-known example of this effect in man is probably the so-called sickling trait common among West African Negroes. This is expressed by the letters S and s. S means that you have the trait, s that you don’t. The S gene curls the red corpuscles in the blood, impeding oxygen flow; the s gene has no known effect. The S gene alone resists malignant malaria, which kills many children. But an SS child may die of oxygen starvation, and an ss child of malaria, whereas an Ss child is likely to survive
23
On the Timing of the Individual Growth Cycle
both diseases. The population profits by the retention of both genes, each of which has a disadvantage in that particular envi- ronment.
The example just cited may explain the presence of genetic variability in many populations even though we don’t yet under- stand why it is there in each case. It may also in part explain the re-emergence of “types.”
On the Timing of the Individual Growth Cycle
In addition to mutation, recombination, selection, and iso- lation, biologists have discovered a fifth evolutionary process which is tertiary because it depends on combinations of the other four, only one of which, mutation, is primary. This is a heritable change in the time of appearance of different characters in the growth cycle of the individual.
Each organism passes through three principal stages of devel- opment. It starts as an embryo, a fertilized egg in the process of cell division which has not yet reached the point where an em- bryologist can tell its species. In man this condition lasts about nine weeks. Then in mammals it becomes a fetus, in birds a chick, and in insects a larva.5 After it has been born, pecked its way out of its shell, or left its cocoon, it starts on the road to adult life in different stages of preparation, depending on the class of animal it belongs to.
Both in fetal and postnatal life, the individual must be adjusted to its environment, or it will perish. Certain traits that are neces- sary to the fetus and useless to an adult appear in fetal life and then disappear. Other traits appear as they are needed. Inciden- tally, it is not true that every individual recapitulates the forms of all its ancestors from the beginning of life on earth. We do, how- ever, recapitulate many of the fetal traits of our ancestors, but not all of them, and not all in the original order. Nevertheless, the fetus possesses a vast store of transient genetic characteristics that could be used in adult life under different circumstances.
One of the features that all animals inherit is a built-in timing
5 G. R. de Beer: Embryos and Ancestors, 2nd. ed., (New York: Oxford Uni- versity Press; 1951).
24
The Problem of Racial Origins
schedule which regulates the order of appearance and the dura- tion of growth of different bodily systems. This schedule can be upset through standard genetic mechanisms, such as mutation and recombination. The survival of fetal traits into adult life occa- sioned by such a change is called neoteny.
The classic example of neoteny is the life cycle of an amphibian of the salamander group, the axolotl. This animal arrives at sexual
maturity during its tadpole stage and never leaves the water to become an air breather like other salamanders, frogs, and toads, but reproduces and dies in its original medium. Other examples are found among certain birds that have lost the power of flight. They retain throughout life the down that covers the chick before it breaks out of its shell. Ostriches, emus, cassowaries, and pen- guins have all acquired this neotenous change independently.
In man’s ancestors neoteny may have been at play before the appearance of Homo erectus. The position of the head on the neck at right angles to the axis of the vertebral column is neotenous; it is found in the fetuses of all the primates and indeed in those of other mammals. In the fetuses of primates in general the thumb is relatively long in proportion to the length of the other fingers. Among many monkeys and all apes the adult animals have short thumbs, which in man remain neotenously long throughout life.
In insects, which are born fully grown and completely adult, all changes in timing have to be neotenous. In mammals, which are small when bom and dependent on their mothers for food and
protection, the infantile form differs markedly from the adult in many ways. A baby mammal has to grow mightily and in most species rapidly, and in the higher species it has much to learn. As
growth is largely controlled by the endocrines, any shift in endo- crine balance can cause radical changes in the form and appear- ance of the adult animal.
In man some laces appear infantile in certain respects throughout life, whereas the children of other races look like miniature adults. In some races the color of the hair never changes during an individual s lifetime, except among persons who reach advanced senility. In others the hair may start out blond, become brown at puberty, and turn white by the age of thirty.
The classbook issued to the members of the Harvard class of
25
On Size and Form: Allometry
1925 at our twenty-fifth anniversary contains two portraits of each man who was still alive in 1950 and who could be reached. One portrait was taken at graduation, the other twenty-five years later. In some individuals almost no change can be detected; others had changed so much that they were unrecognizable. Yet nearly all these men were of the same racial origin. Age changes, then, vary within populations as well as between them. Not one of my class- mates, however, looked like a Pygmy or a Bushman.
Races that retain a number of infantile features throughout life are called pedomorphic; those in which mature features appear early are called g erontomorphic, after the Greek words pais, a child, and geron, an old man. Pedomorphism and gerontomorph- ism are most conspicuous in external, visible anatomy, but they can also affect the nervous system, the vocal cords, other covert systems and structures, and behavior. Most fossil men that we know were gerontomorphic, as witness their heavy brow ridges and long faces. Homo sapiens as a whole seems to be relatively pedomorphic, although variable in this respect both racially and individually.
On Size and Form: Allometry
We must be careful, in seeking for relationships between dif- ferent races, not to confuse pedomorphy and gerontomorphy with normal variations that take place when animals of the same or re- lated species grow smaller or larger. A mouse has a larger brain, in proportion to its body size, than a rat does. A Great Dane’s eye- balls are proportionately smaller, although absolutely larger, than those of a terrier.
Animals that are otherwise genetically similar vary in propor- tions according to size, the small ones being more compact, the larger ones more attenuated. The principle governing these dif- ferences is called allometry. Zoologists not only recognize this rule but express it in formulas. For example, in the horse family face length equals .3 times skull length, to the 1.2 power.13 A big horse
6 de Beer: op. cit., p. 27.
A classic work on this subject is D’A. W. Thompson’s Growth and Form (New York: The Macmillan Company; 1945).
26
The Problem of Racial Origins
has a longer face, both absolutely and relatively, in proportion to his skull length, than a small horse does. By the same token, an average African Pygmy has relatively shorter legs and a relatively larger head than does an average African Negro.
On Sexual Dimorphism
Another factor to be considered in comparing races and spe- cies is the degree of differentiation between adult males and fe- males in a population. This is called sexual dimorphism. It varies greatly both in mammals and birds. Male and female cardinals have feathers of different colors; yet it is difficult for a nonorni- thologist to tell a male from a female robin. Among the primates, a male gorilla may be twice as large as any member of his harem, whereas the only visible difference in gibbons in the wild is the protrusion, through the fur, of nipples in the female that has borne offspring.
Sexual dimorphism serves two principal purposes. First, it may be part of the selective process in mating, as when male birds strut their plumage in the nuptial ceremony, and as when stags lock their horns in mortal combat in competition for a doe. Sec- ond, among some animals that inhabit distinct territories, as for example lions, or baboons living in a forest, the exaggerated size and fighting equipment of the males permit them to serve the function of a border patrol in human communities. The male keeps rivals off his feeding ground and away from his wife or wives. Neither the male lion nor the male baboon is any better at obtaining food than his womenfolk; in fact, among lions the fe- male excels at hunting. These animals expend their biological capital for territorial defense, just as we spend the bulk of our tax money for atomic submarines and missiles.
In fossil man there is evidence of sexual dimorphism, but it is clouded by the paucity of material available for study. In living races a great variability can be seen. Australian aborigines and western Europeans are highly variable; Mongoloids little. As Ti- betans dress and wear their hair alike, it is sometimes difficult to
27
How Species Have Evolved
tell whether any one person is a man or a woman. This does not mean that sexual dimorphism is the same as pedomorphy, for some populations with little sexual dimorphism are in certain ways gerontomorphic. No one could call a Plains Indian infan- tile, and his women can be huge and craggy. It is difficult, then, to decide whether certain racial traits, like the absence of a beard in many Mongoloid males, are the result of pedomorphy, of a lack of sexual dimorphism, or of some other aspect of the endocrine story yet to be discovered.
In any case, the presence or absence of marked sexual dimor- phism is an inherited racial trait that distinguishes some living populations from others. This trait may date back to remote an- tiquity since it was not involved in the complex of evolutionary changes that led from Homo erectus to Homo sapiens. Of this we may be fairly confident because the two races that have achieved the greatest cultural advancement, the Caucasoid and the Mongo- loid, stand at opposite poles in this respect. At the other end of the cultural scale, so do the Australian aborigines, who show marked sexual dimorphism, and the African Bushmen, who show little of it.
How Species Have Evolved
Like all men, all species must eventually die. Just as some men perish with neither issue nor close kin and others achieve partial immortality through the transmission of some of their genes to their offspring, or more remotely, by the survival and reproduction of their brothers and sisters — so some species become utterly extinct whereas others live on, in a shadowy way, through one or both of two evolutionary mechanisms, succession and branching. Succession is also called phijletic evolution or anagenesis; the technical word for branching is kladogenesis.
Evolution through succession occurs when a genetically iso- lated population acquires a new and favorable hereditary trait that is controlled by a single gene or by a complex of genes op- erating in concert. Then the new trait gradually replaces the old one through natural selection.
2 ^ The Problem of Racial Origins
Evolution through branching occurs when two or more geo- graphically separate populations of a single, polytypic species be- come genetically isolated from one another and then evolve into species of their own.
Succession tends to favor a process known as general adapta- tion whereas branching works rather through special adaptation, but the two are not mutually exclusive.
General adaptation involves the acquisition of a new trait or trait complex that is useful in more than one environment and un- der various different circumstances. Warm-bloodedness in birds and mammals is one example. Another is an increasing intelli- gence, which many forms of animal life have developed through- out geological history. A more limited example is the power of speech, which is useful to all men.
Special adaptation involves the acquisition of a new trait or trait complex that is useful in a single environment under special circumstances. It is the process which enables an animal to resist heat, cold, or bright light, to see well in dim light, to run faster or to swim better than its fellows, or to live without water in deserts, and which gives it many other such specializations. Special adap- tation led the ancestors of the whales from the land back into the sea, and general adaptation gave them the intelligence needed to communicate with one another, by a system similar to sonar, and to survive, as mammalian populations, in their aqueous medium.
General adaptation tends to lead a species into evolution by succession because most species are polytypic, and a polytypic species includes several populations living in different environ- ments. Each of these populations becomes adapted to its special environment to a certain degree, but it cannot speciate by branch- ing as long as it remains in genetic contact with its sister popula- tions, since new traits involved in local specialization cannot com- pletely replace old ones while genes continue to flow back and forth. If, however, in one or more populations a new trait appears which is equally favorable to all the populations and in all the en- vironments occupied by the species, then the existing gene flow will help the new trait replace its predecessor in all the compo- nent populations, including that or those in which it started. By this process the old species evolves as a unit into a new species. At
How Species Have Evolved 29
the same time speciation need not prevent the component popu- lations from carrying their old, partial specializations, such as to heat and cold, from one species into another.
If, however, a single population of a polytypic species becomes physically isolated from its fellows, so that gene flow is completely interrupted, then that population can evolve by branching. Now special traits that have no general value can completely replace the old ones that used to flow in over the border. If such a popula-
Fig. 1 How One Polytypic Species Can Evolve Into Another. Above: Five subspecies, in peripheral contact with each other, are illustrated by five circles, numbered 1 through 5. A mutation favorable to all five arises in No. 3. It spreads to Nos. 2 and 4, and is carried by further peripheral gene flow to Nos. 1 and 5. When all five subspecies have it, the species has begun to evolve into a new one by anagenesis — evolution through succes- sion. Below: In this example the fa- vorable mutation arises independently in Nos. 3 and 5, and, except for the direction of gene flow between Nos. 4 and 5, speciation takes place as in the first example.
tion happens to be confined to a small space, such as an island, and has no natural enemies, it can become a monotypic species as specialized as the dodo, the classic example of this process.
Although the component populations of a polytypic species evolve as a unit, they cannot do so simultaneously since it takes time for a mutation to spread from one population to another. If we measure time on the broad scale of tens of millions of years used by paleontologists, these changes may appear simultaneous.
3° The Problem of Racial Origins
but if we measure it on the geologically microscopic scale of the last 700,000 years, which is the age of man, we will see that related populations, which in our case are subspecies, passed from species A, which is Homo erectus, to species B, Homo sapiens, at different times, and the time at which each one crossed the line depended on who got the new trait first, who lived next to whom, and the rates of gene flow between neighboring populations.
Whether a new species is polytypic or monotypic, whenever it arises the evolutionary process is essentially the same. The new, critical trait responsible for speciation first appears in a few indi- viduals, and its presence makes little difference to the population in which it arises. It may even appear and disappear several times before it takes hold. But after it has begun to spread, a point is reached when those who have it begin to outnumber those who don t. This point is marked by a rapid growth in population. The particular population has gained an advantage over competing species in its own lebensraum, and in the process it has become a new species of its own.
It need not, however, have completely lost the gene or genes for the old trait that is on the way out. After the new species has es- tablished itself, become stable in numbers, and reached a new equilibrium with the other species of plants and animals in its en- vironment, the old trait may completely disappear. At that point a second and final threshold of speciation has been crossed. One may say that a new species has come into existence when it has acquired a new and more favorable ecological position, and that it has reached maturity when the traits responsible for these changes have completely replaced their predecessors. By the time the second threshold has been crossed, as likely as not a new spe- cies-forming mutation shall have begun to appear, and the cycle has started over again.
It is easy to understand, then, why some populations within any polytypic species have come closer, at any given time, to the sec- ond threshold of speciation than other populations. In man some groups of people alive today have preserved archaic traits, diag- nostic of Homo erectus, in a higher percentage of individuals than other populations. For example, more natives of New Caledonia
3i
How Species Have Evolved
have big teeth and heavy brow ridges than a corresponding per- centage of Japanese.
This and similar disparities can be explained in two ways.
( 1 ) The more archaic population acquired the new trait complex that led to speciation later than the more modern population did.
(2) After crossing the first threshold of speciation, the more ar- chaic population has been discarding its old traits at a slower rate than the more modern population.
Both explanations can be true at the same time. There is no necessary correlation between the time at which a threshold was crossed and the rate of change that follows the crossing. In either case, the critical mutation may have been original to the popula- tion concerned, or it may have been acquired by gene flow from a neighboring population. The older the trait the more likely that it was original; the younger the trait the more likely that it was de- rived from outside.
In any event, once a species has come into being, the old spe- cies from which it evolved is extinct. There are several kinds of ex- tinction: utter extinction without issue, which is commonest among monotypic species; extinction through absorption, by which a subspecies ceases to exist as a separate entity when its re- maining members are taken into the body of another; and extinc- tion through successive evolution, which is the process we have just described.7
In the case of man, only the second and the third kinds of ex- tinction can be traced. The Tasmanian aborigines who died out in the nineteenth century have living survivors among the racially mixed inhabitants of the islands between Tasmania and Austra- lia, and the Fuegian Indians of South America are disappearing into the mixed population of that continent. But neither Tasma- nians nor Fuegians were whole subspecies. The Australoid and Mongoloid divisions of man to which they belong survive in large numbers elsewhere. There are also, in a sense, degrees of extinc- tion, for it takes a long time, on our human time scale, for one
7 E. H. Colbert: “Some Paleontological Principles Significant in Human Evo- lution,” in W. W. Howells, ed.: Early Man in the Far East (Philadelphia: Am. Assn. Phys. Anth.; 1949), pp. 103-47.
32 The Problem of Racial Origins
species to replace another completely, and in that sense some hu- man races are more nearly extinct than others.
On the Life Spans of Mammalian Species 8
Although the antiquity of Homo sapiens will be the subject of detailed study in later chapters, we may here profit from a con- sideration of the life spans of our fellow mammals during the Pleistocene and Recent (or post-Pleistocene) periods, the only periods in which man or any of his close kin are known to have lived. By international agreement the beginning of the Pleisto- cene has been established at the point when modern genera of elephants, horses, oxen, deer, and some other large mammals were first seen on the continents of the Old World, excluding Australia. The movement that brought them in, mostly from the New World, took place about one million years ago.
Before that stretched the vast temporal expanse of the Tertiary — Paleocene, Eocene, Oligocene, Miocene, and Pliocene— com- prising some 77 million years, the Pliocene alone taking up some 12 million. During this long span individual species were born, flowered, and died at what seems to us a leisurely pace. The life expectancy of a mammalian species was then anywhere from one to eight million years.
During the first 300,000 or 400,000 years of the Pleistocene this pace continued, but it was suddenly quickened in various parts of the Old World, particularly its northern portions, by geological events. The planet’s crust wrinkled more rapidly than before, rais- ing the toothed edges of mountain ranges and creating great con- trasts of climate, both regional and seasonal. First mountain gla- ciers, then continental icecaps crawled forth and melted away, blowing, like pairs of bellows, alternately cold and warm. In large tropical land masses, as in much of Africa, the bellows blew wet and dry.
8 This section is based on many sources, including books by G. G. Simpson. However, specific facts and figures come principally from two works of Bjorn Kurten: “Rates of Evolution in Fossil Mammals,” CSHS, Vol. 24 (1959), pp. 205-i5, and “Chronology and Faunal Evolution of the Earlier European Glacia- tions, SSF-CB, Vol. 31, No. 5 ( i960) pp. 1—62.
33
On the Life Spans of Mammalian Species
In response to these changes, new species evolved rapidly. Many became extinct, but others survived. The life expectancy of a species now dropped to a mere 360,000 years. At a point in time pegged at 300,000 years ago, all or nearly all the living mam- mals of the European and neighboring fauna, which were fox- sized or larger, had come into existence. The species which have since appeared are bats, insectivores, and rodents, all small ani- mals. During the last 75,000 years, no new mammalian species seem to have evolved at all. Three hundred thousand years ago the evolution of new species of medium-sized and large mammals came to a halt. The heyday of speciation was over.
The oldest known Homo erect us is believed to be 700,000 years old. He appeared during the period of frenzied mammalian spe- ciation mentioned above, and seems to have lasted until less than 100,000 years ago in remote parts of the Old World. His known life span as a species, about 600,000 years, was within the normal range for a mammal of his size and vintage. As I shall show in Chapter 11, Homo sapiens appeared about 250,000 years ago in an archaic form. Completely modern forms of our species ap- peared at least 35,000 years ago. Unless our species is a curious exception to the rules by which the game of speciation is played, Homo sapiens should go back to 360,000 or 300,000 years ago. This figure would place Homo sapiens in the fauna to which he belonged, and would give Homo erectus, who appeared exactly when he should have, ample time for speciation by succession.
So much for the actuarial statistics of Pleistocene and Recent species. With subspecies the reckoning is more difficult because subspecies are not easy to sort out when found among fossils. We have no satisfactory information except that subspecies of the ibex have been traced back at least 230,000 years.9 In the case of man, the subspecies of Homo sapiens are probably of different ages, de- pending on the times at which regional populations of Homo erectus, in one way or another, crossed the sapiens threshold. But all of them did this before the end of the Pleistocene.
In modern times we have seen whole tribes and peoples disap- pear after their lands had been invaded by Europeans and other
9F. Zeuner: Dating the Past (London: Methuen & Co.; 1952), pp. 383-4.
34
The Problem of Racial Origins
culturally dominant strangers. The native Tasmanians are gone, and so aie the Indians of Lower California. The Andamanese of the main islands, the Fuegians, and many others are on their way out. These sad cases of ethnic oblivion give us a feeling that hu- man history is a long record of utter extinctions, but this is not true.
All species are destined to become extinct, but, except as they are parts of species, subspecies need not follow this rule. By defi- nition, species do not ordinarily interbreed, but subspecies do. The Tasmanians were absorbed by the Caucasoids who replaced them on their island. A mixed Tasmanian-European population survives today. If the Indians of Lower California left no mixed descendants— which is unlikely— other Indians very much like them are still alive. When subspecies disappear, they usually, if not always, do so by absorption. Their genes linger on polymor- phously with those of their conquerors, to re-emerge, now and then, when needed. The principle is that when a population has been invaded by members of another race the genes that give it its special adaptation to its local environment retain their selective advantage and eventually come to characterize the mixed popu- lation through the process of natural selection. For example, cen- tral Europe was invaded from the East many times from the Neo- lithic through the Iron Age, but central Europeans still look more like the hunters of the Mesolithic than like the invaders.1 Without the concepts of absorption and re-emergence it would be difficult for us to explain the physical diversity and geographical distribu- tion of the living human races.
Part of this diversity may be relatively new. I refer here espe- cially to the reduction in body size that has affected many species of mammals since the end of the Pleistocene, some 10,000 years ago. As will be explained in Chapter 3, extreme cases of size re- duction in plants and animals take the form of dwarfing, which means that an irreversible genetic change has taken place. Our species includes a dozen or more populations of dwarfs, living in Africa, southern Asia, and Indonesia. As far as we know, all hu- man dwarf populations are geologically recent.
1C. S. Coon: The Races of Europe (New York: The Macmillan Co.; 1939).
Genetic Principles and the Origins of Races
35
Genetic Principles and the Origins of Races
In recent decades the pursuit of anthropometry has de- clined, except for applied anthropology. Instead of measuring the bodies of the last remnants of aboriginal populations, anthro- pometrists measure military personnel and civilians in order to de- sign railroad and airplane seats and space suits. Doctors of Phi- losophy have become tailors to the new age of science. On the other hand, the pursuit of human genetics has become popular, paiticularly the study of the frequency in populations of blood- gioup genes, taste thresholds, mid-digital hair, and hairy ears.
In tracking down the lines of descent of fossil men, none of these characteristics is useful. Thieme and others have shown that it is impossible, using present techniques, to determine the blood type of samples of bone, for they all tend to absorb a group A sub- stance fiom the ground." Dead men cannot taste noxious chemi- cals, and the hair on their fingers and ears has long since de- cayed. What could be done, however, is to work out the relation- ships between fossil specimens and populations in terms of details of tooth structure, for teeth do not change with age except to be worn down. Molar cusp-numbers, the presence or absence of a kind of curvature of the incisors known as shoveling, and many other features that are preserved in the fossil record are just as useful for genetic studies as blood groups are among the living, and paleontologists have long relied on teeth. Although much work has been done on human teeth no one has yet produced a work of synthesis covering all fossil specimens by means of which they could be compared with living populations.
Limited as the direct application of genetics is in the study of fossil man, the theoretical aspects of that science have helped us greatly. They have taught us that the unit of inheritance is neither the individual nor the arbitrarily chosen type, often identified with an individual, like Nordic, Dinaric, Neanderthal, and Cro- Magnon, but the population, and that each population has its pool
2 F- P- Thieme and C. M. Otten: “The Unreliability of Blood Typing Ancient Bone,” AJPA, Vol. 15, No. 3 (1957), pp. 387-97.
36 The Problem of Racial Origins
of genes with several possible alternates, known as alleles, from many if not all loci. We also know that because individual muta- tions recur at characteristic rates, resemblances between popula- tions of the same species do not necessarily imply recent common descent. All curly-haired populations do not have to be descended from a common curly-haired ancestor. Pockets of blondism found among nonwhites need not be explained by Viking invasions, nor all Pygmies be considered as having derived from a single tribe.
An acquaintance with the principles of genetics may also help us solve the central problem of this book— that is, to discover how long ago the ancestors of the human subspecies parted com- pany. We have learned, for example, that evolution proceeds trait by trait, one mutation, recombination, or whatever, at a time. If parallel mutations have been occuring in two populations, we cannot expect a large number of identical changes to have taken place at once in each group. Changes in the skeletons of fossil men from period to period in each major area seem to have in- volved very few factors, not many of them visible below the neck.
Brains have grown larger and brow ridges smaller. Jaws have sprouted chins and teeth have grown smaller in various degrees. Whole sets of these changes can be linked together as common products of one or more shifts in endocrine balance, shifts advan- tageous in an increasingly group-oriented society in which self- control comes to be more conducive to survival than a hot temper. Other changes may simply reflect a reduction in chewing, espe- cially after the invention of cooking. If in each of several related populations, living in its own territory, changes like these took place not all at once but in sequence, it is possible that each sin- gle, parallel mutation prepared the ground for the selective ad- vantage of the one that followed it.
On the other hand, if these sequences of genetic change were initiated in some of the populations by sexual contacts with peo- ple from other regions (peripheral gene flow), it would be diffi- cult for us to detect this outside influence from an examination of the skeletons of the resulting mixed population because other genes transferred by the same contact might be disadvantageous in that particular area and would have been eliminated by natural selection.
Genetic Principles and the Origins of Races 37
Although we cannot hope to settle the question of parallel evolution versus peripheral gene flow in the evolution of each race by examining fossil bones and nothing else, such a study may show us how far back in time the various geographical races go. Some of our subspecies are characterized by traits that seem to have had little relation to either climate or culture during the known history of man, and whatever selective advantages or dis- advantages they may have must have been acquired long ago. Among these traits are the architecture of the teeth, the shape of the nasal bones, and the degree of flatness of the face. If various combinations of these traits can be seen to have persisted in their special geographical regions despite other changes of a more clearly phyletic evolutionary nature, then the antiquity of indi- vidual races may be established. In any case, no form of evidence is unwelcome and only by a close study of detail can we hope to solve this and related problems.
8
2
K
K
K
EVOLUTION THROUGH ENVIRONMENTAL ADAPTATION
In this chapter we shall discuss the effects of size, space, numbers, and climate on the direction and rate of evolution. Other principles of change will be examined, in addition to those mentioned in the first chapter. By comparing man with other ani- mals we shall see, in particular, how adaptation to the external, nonhuman environment helped shape the living races of man into their present forms.
Body Size, Food, Space, and Climate
At some turning point in the evolution of our ancestors men became hunters. Instead of relying on roots, fruits, and small, slow-moving animals for their food, they began to compete suc- cessfully with the great carnivores and could feed themselves and their families wherever meat was to be found.
Among other carnivores a natural relationship exists between the size of the predator and that of his prey. A fox cannot kill a zebra, but a zebra is the favorite food of lions. Properly armed, however, a man can kill an animal of any size. As he began to do so, it was probably advantageous, all else being equal, for him to be large as well as muscular. At any rate, we have indirect evi- dence that our ancestors grew larger at about that time. This placed them in the elite company of large land mammals and sub-
Body Size, Food, Space, and Climate 39
jected them to some of the special evolutionary rules that govern such species.
One is that they are few. At present there may not be more than sixty other species of our size or larger,1 out of 3,500 species in the class of mammals. A second is that most of these have only one species to a genus. This ratio is characteristic of the other large primates — the orang, the chimpanzee, and the gorilla — as well as of the elephant, the hippopotamus, the rhinoceros, and the bear. The larger these animals the more likely that they will be the only species in their genus, at least at any one time. In his utilization of terrain man is in a class with the largest mammals of all; primitive hunters destroy more forest by burning than ele- phants do by uprooting trees. If, after the beginning of hunting, the genus Homo ever consisted of more than one species at a time, not counting species in the act of transition, as from Homo erec- tus to Homo sapiens, he would have constituted a curious excep- tion to a well-established rule.2
A third rule is that individual animals of large size take up dis- proportionately more room than small animals, and that the rela- tionship between the sizes of their ranges is believed to be loga- rithmic.3 A large animal needs a great deal of space not only for feeding and drinking but also for concealment in the heat of the day and for sleeping and reproduction.
From the time that man became a hunter, if not before, he was a social animal living in groups of families with an optimum popu- lation somewhere between twenty and forty persons.4 As the area required per person must be multiplied by the total in the group, the territory of a feeding unit of this size had to be considerable. Once the ability to eat meat had extended the potential range of man as a species to the limits of the continental land masses of the Old and New Worlds, nothing could stop him from filling these
1 The uncertainty is due mainly to a lack of agreement on the classification of the Bovidae — cattle, sheep, goats, antelope, etc.
2E. Mayr: “Taxonomic Categories in Fossil Hominids,” CSHS, Vol. 15 (1951), pp. 109-18.
3 G. E. Hutchinson and R. H. MacArthur: “A Theoretical Ecological Model of Size Distributions among Species of Mammals,” AN, Vol. 93, No. 869 (1959), pp. 117-25.
4 The basis of this calculation will be stated later.
40 Evolution through Environmental Adaptation
spaces except natural barriers, such as glaciated mountains, bodies of water, empty deserts, and extremes of environment to which he was not accustomed, such as great cold, heat, drought, and high altitude.
Some of these extremes he overcame by cultural means, par- ticularly after he had acquired fire. His ability to invent and make adequate housing, clothing, and containers as well as effective weapons must have placed a premium on the kind of intelligence that governs these capacities. In every region where, in addition to hunting, environmental problems had to be mastered by tech- nology, parallel evolution in the direction of higher intelligence must have been in operation.
Once man s inventive genius had made it possible for him to live in extreme environments previously barred to him, a new burden was placed on his physiology because he could not, with his incipient skills, overcome all climatic obstacles. We must ex- pect to see the results of genetic responses, through natural selec- tion, to differences in environment, and we must know how to in- terpret them, for the patterns they take will tell us much about the early history of our genus and species.
If such differences occur and the subspecies of man turn out to be clearly divided on this basis, so that one is adapted for wet heat, another for dry heat, a third for cold, a fourth for high alti- tude, and so on, then it will be likely that at the time of the dis- persal of the subspecies the ancestors of all of them belonged to a single, monotypic population. If, on the other hand, the existing subspecies do not entirely fit this scheme, and if in addition cer- tain subspecies include regional populations adapted for different climates, then it will appear that Homo has been polytypic for a very long time and that the dispersal of our ancestors into differ- ent regions took place very early, before the beginning of man’s career as a hunter and before he possessed the cultural means to invade and inhabit the regions of the earth s surface previously unavailable to him.
In pursuing this inquiry we shall not be exploring virgin terri- tory. Zoologists have been faced with similar problems for over a hundred years. What happened to human beings once they had come to live in diverse environments had happened to other ani-
The Face of the Earth 41
mal species many times before. The study of animal evolution through environmental adaptation is a part of zoogeography,5 a well-documented scientific discipline more than a hundred years old. By reviewing its major principles and studying some of the data it has uncovered we may determine what to look for in man.
The Face of the Earth
As our telescopes improve and we learn more and more about the surfaces of other planets — most of which are excessively hot or cold, or vary from one extreme to the other between night and day, and lack the friendly mists and rain that water our woods and fields — the more we appreciate the infinite variety and manifold advantages, to creatures like us, of the face of the earth, our home.
Far from being simply a playground to run about, sleep, feed, and breed in, the skin of our planet, with its myriad variations, has been a major determinant in the evolutionary process. Evolu- tion, itself a product of variability and change, has been cumula- tive, keeping pace through geological time with the ever increas- ing rate of differentiation of the surface features of the earth. The planet s crust has wrinkled faster, in cooling, than wind, rain, snow, ice, and all the other forces of erosion have been able to wash away, grind down, flatten, and otherwise homogenize it. The same forces have made the products of evolution increasingly complex and heterogeneous, increasingly sensitive, and increas- ingly aware of themselves and of their surroundings.
Eight factors have affected the face of the earth from the zoo- geographic point of view: the clockwise rotation of our planet, which creates westerly winds; the zonal differentation of the earth, which makes some latitudes cold and others warm; the tilt of the earth’s axis, which creates seasons; the relative sizes of land masses, which emphasize or diffuse seasonal change and give populations breeding grounds of different magnitudes; the rise of
5 The study of plant distribution is called phytogeography. Phytogeography + zoogeography = biogeography, the study of the distribution of living things. Bio- geography is a unit; its two components are interdependent.
42 Evolution through Environmental Adaptation
mountain ranges, which permit altitude to substitute for latitude as a climate maker; the bodies of salt water, which prevent ter- restrial animals from crossing from one land mass to another; and the land bridges and strings of islands, which allow certain quali- fied animals to filter through. The eighth factor is time, particu- larly the last million years, which have seen the icecaps of the world alternately crawl forth and shrink back three times, with consequent stress and displacement of many forms of animal life, including that far-ranging genus, Homo.
Land Masses 6
According to standard school geographies, the world con- tains seven continents, but for present purposes these will be con- sidered as five. Antarctica can be disregarded because it is un- inhabited. Europe is not a real continent; the Greeks distin- guished their own peninsula from Asia, which lay on the other side of the Aegean, and this split has since been carried north past the Caspian Sea barrier onto the steppes of Russia. Europe is a highly favored peninsula of Asia. We shall call the combination Eurasia, as do most geographers.
Of the five continents remaining — Eurasia, Africa, North America, South America, and Australia — the first four are strung together in one fashion or another. The Isthmus of Suez ties Af- rica to Eurasia as it has done for a long time. Both the Bab el Mandeb and the Straits of Gibraltar are deep but narrow salt- water channels, and botli were open and ice-free throughout the Pleistocene. Eurasia, the greater and more varied of the two seg- ments, is nearly twice as large as Africa, with 21 to the latter’s 12 million square miles, and it contains bits and pieces of all the cli- mates of the world, whereas Africa lacks mid-latitude forests, bo- real forests, and taiga.7
G In this and the following two sections of Chapter 2, I am drawing heavily on P. J. Darlington, Jr.: Zoogeography (New York: John Wiley & Sons; 1957).
For the Pleistocene, the best source is J. K. Charlesworth : The Quaternary Era, 2 vols. (London: Edward Arnold; 1957).
7 These terms are taken from Preston James’s Outline of Geography (Boston: Ginn and Co.; 1935).
Land Masses
43
Eurasia and Africa are tied together at a latitude of 30° N., and as Suez is normally frost-free, it is not too cold at sea level for most forms of terrestrial life to traverse. Africa is mostly a plateau bent around a cup of low-lying equatorial rain forest; and from the edge of the Sahara to the Cape of Good Hope there stretches an essentially homogeneous environment of grasslands, savannas, and seasonal forests high enough so that temperatures vary little from one latitude to another and grazed throughout by more or less the same kinds of animal herds. By contrast, Eurasia is built like a tent with a pole in the middle and drooping sides. The lofty land mass of Tibet brings an approximation of arctic conditions to a large area partly located in the same latitude zone as Suez. It also partitions off much of southern Asia. The line of mountains reaching diagonally across the map from the Tian Shan to the Ber- ing Strait cuts the northern half of the continent into a north- western and a far-eastern segment.
The erstwhile land bridge across the Bering Strait, which con- nected Eurasia with North America, was a broad, flat, ice-free highway that appeared during periods of glaciation whenever the ocean level was lowered by the immobilization of water in the form of ice at the poles. The land bridge last appeared probably between 70,000 and 8,000 b.c., either during this entire period or in parts of it. Although it lay at an altitude of 66° N., the south- ern shore of the bridge may have had mild winters at this time, being protected from the arctic waters and tempered by the west- ward flow of the Japanese current. Animals able to live through a moderately cold winter could have crossed the bridge in either direction, and many of them did.
North America, with 8.3 million square miles, is smaller than Eurasia or Africa and differs from both in land formation. Whereas Africa is predominantly a plateau and Eurasia a ring of subcontinents with most of its mountains running east and west, in North America the western and eastern ranges run north and south, leaving a wide trough in the middle which creates extremes of climate at many widely separated points, so that one can shiver in Houston in winter and swelter in summer in Saskatoon.
South America, with 6.8 million square miles, has been con- nected to North America by the Isthmus of Panama since the be-
44 Evolution through Environmental Adaptation
ginning of the Pleistocene a million years ago, but during the en- tire 60 million years of the preceding Tertiary it was isolated by salt water. Like Africa, it has a plateau running across the equa- tor, and this plateau is as high as the Tibetan one although its sur- rounding peaks are a little lower. But it is narrower, and the equatorial rain forest it shelters is, at the present geological mo- ment, the world’s largest.
However, if we return in time to the last glacial advance, and in space to southeast Asia (see Map 2), we see that a vast area of some 800,000 to a million square miles, known as the Sunda Shelf, was then incorporated, as geologists believe, onto Indochina, Ma- laya, and the islands of Indonesia east of the Bali and Macassar Straits. If, as may be presumed, this lowland was largely covered with rain forest — for it was a wet period — it may well have been as large as the South American rain forest, or even larger. A rain forest of this size is a fertile breeding ground.
Five hundred miles to the south and east lay a continental area of nearly four million square miles, including the present Austra- lia (3 million square miles), Tasmania, New Guinea (300,000 square miles), and some of the Melanesian Islands, joined by an- other now-submerged stretch of lowland, the so-called Sahul Shelf (over 580,000 square miles). When the sea rose at the end of the Pleistocene, this land mass was split into its present com- ponents.
Zoologically these now separated regions are still a unit. An- thropologically we can likewise consider New Guinea, Tasmania, and some of the Melanesian Islands as recently separated periph- eries of a fair-sized continent the center of which is the Australian desert. More specifically, woolly hair is characteristic of the Papuans, Tasmanians, and a few of the coastal Australian aborigi- nes. Most of the Australians have straight or wavy hair. Woolly hair, therefore, is geographically peripheral to straight hair in what is left of the former, larger continent.
The significance of the Sunda and Sahul shelves is clear. In no part of the world other than southeast Asia, Indonesia, and Aus- tralia are the seas so shallow that vast interconnecting land masses could have been created when the icecaps of the polar regions trapped enough water to lower the sea levels in many parts of
THALIA
46 Evolution through Environmental Adaptation
the world by forty fathoms below their present shorelines. The Snnda and Sahul shelves are the only real “lost continents.” Not only did they join lands now separate, but they may also have served as bellows to suck in and blow out early human popula- tions.
Two important facts emerge from this survey of global land masses. The Northern Hemisphere is the land hemisphere, and the Southern the realm of ocean. Therefore the land masses situ- ated in the north are more continental in climate, that is, more extreme in seasonal change, and stormier than the southern lands, where less meteorological change is taking place. The Old World with its combined mass of Eurasia and Africa, which are divided only by narrow seas, is a huge and varied breeding ground com- pared to the New with its smaller masses of North and South America, which meet effectively at a single point only. One would expect more to have happened biologically to land animals in the Northern than in the Southern Hemisphere, and also in the Old World than in the New. These expectations have been fulfilled, particularly in the case of man.
Barriers and Breeding Areas
The most conspicuous barriers in the world are probably mountains, especially such lofty breath-takers as the Himalayas, but even their rims can be crossed, by animals as well as people’ and the principal hindrance they offer is the rapid temperature giadient rather than the steepness of terrain. Deserts, too, are baniers; there lack of moisture, more than temperature, does the screening, and except in sandy stretches the terrain itself offers little impediment to travel.
The greatest barriers of all, however, are stretches of salt water. That is why the Azores, when first occupied in the fifteenth cen- tury, had no land animals except birds and a local lizard, and why the Australian continent contained aboriginally no placental mammals except man, the rat and dog, which went with him, and the air-borne bat. That is why South America contained an almost unique vertebrate fauna when the North American animals
Genetic Drift 47
began infiltrating over the newly formed Panama bridge at the end of the Pliocene. Lesser barriers such as mountains and des- erts serve as screens rather than as roadblocks. While holding back most species, they let dominant ones through to take over new territories. In the case of subspecies, especially qualified in- dividuals can get from one breeding ground to another and spread their genes in the new population.
It is a general rule that relatively numerous populations living in large breeding grounds tend to be dominant over others that have lived in smaller areas. The larger the number of animals in a population, the greater the mathematical chance they have of un- dergoing a rare, favorable mutation that can spread through- out the group by means of natural selection. Since in small, iso- lated populations there are fewer individuals there are also fewer mutations, too few in some cases to include any of the uncommon, favorable ones. At the same time, owing to lack of competition in a sheltered environment, some of the commoner, unfavorable mu- tations can spread unhindered through such a small, sheltered population and eventually bring about deterioration or even ex- tinction. That is why islands are being constantly repopulated by stray sets of dominant species that happen to drift or be blown in from continental land masses.
Genetic Drift
Nevertheless, all mutations need not be perceptibly or measurably favorable or unfavorable in any given situation. In Europe, for example, it can make no conceivable difference to a man’s chances of survival and reproduction whether his hair is straight or slightly wavy. In a large population, a neutral or in- different mutation will not ordinarily spread rapidly, nor will it necessarily be lost. It can be expected, all else being equal, to maintain a low frequency in a large gene pool. In a small popula- tion, on the other hand, it can easily be lost through sheer chance — if, for example, the three persons out of ten who have it are eaten by a tiger. The mutation could also spread through the same small breeding unit if the tiger ate the people who did not
48 Evolution through Environmental Adaptation
have it instead of the others. Gene frequencies, then, change more rapidly in small than in large populations. The process by which such fortuitous changes become major characteristics of popula- tions is called genetic drift, or the Sewall Wright effect, after its discoverer.8
Once genetic drift has taken place, the chances are that the population in which it has occured will become extinct, because: ( 1 ) the reduction in population which permitted the drift may also have reduced the total number of breeding individuals below the safety level needed for survival; and (2) few genes chosen by chance are likely to be superior to their alternate alleles from the standpoint of survival.
If the population survives and multiplies, this may be because the genetic characteristic or characteristics chosen by drift were favorable for survival in the first place, and the drift merely sped up the process of selection. In the long run, the frequency of this gene or of these genes in the pool would have risen to an optimum level in any case, without danger of extinction.
Genetic drift is often invoked to explain differences between species and subspecies in characteristics that are of no detectable value in natural selection. As our knowledge of genetic processes grows and as our ability to detect selective values increases, we need this theory less and less.
The Dominance of Groups
Dominance has two meanings in zoology: the dominance of in- dividuals in social groups, as shown by the peck order and the like, and the dominance of one kind of animal over another. We are concerned here with the second meaning only.
Groups of dominant animals may range in diversity from whole orders to families to genera and even to species. Examples are the carps (family Cyprinidae ); the common frogs (genus Rana ); the common snakes (family Colubridae) ; the perching birds
8 S. Wright: ‘On the Role of Directed and Random Changes in Gene Fre- quency in the Genetics of Populations,” Evolution, Vol. 2, No. 4, (1948), pp. 279-94-
49
The Dominance of Groups
(order Passer es ); the rats and mice (family Muridae ); and the human species ( Homo sapiens). Even within a species such as ours, certain subspecies and races may show dominance over others. This is part of the evolutionary process.
Dominant groups result from a combination of factors that render them particularly successful in withstanding climatic stress, especially cold; in finding and utilizing food; and in re- producing efficiently under varying circumstances. The perching birds, for example, achieve these ends partly by migration; the rats and mice by storing food and by burrowing underground to escape predators and the rigors of the weather. In the case of man, he is capable not only of using fire and tools intelligently in organized social units but also of undergoing a certain amount of physical adaptation to certain environments.
As a rule, the breeding grounds of dominant animal groups are situated in the centers of the land masses they occupy, with the result that the animals are forced into competition for their eco- logical niches by rivals from all sides. If in addition to being cen- trally located, the breeding grounds are in cool regions, then the species living there will produce more offspring than the same or corresponding species in the tropics,9 not because of greater fer- tility, but because in warm regions many fetuses are lost through the failure of sufficient pituitary hormone ACTH to reach the embryo from the mother. As this hormone normally balances the adrenal cortisone, which has no difficulty getting through, an ex- cess of cortisone causes the resorptions.1
This and other observations partially explain why the cooler portions of the Old World had fewer species, but larger popula- tions, than its tropical regions, and why some of these populations reinvaded the tropics, with varied success.
Zoogeography can also explain many instances in which groups
9B. Rensch: “Some Problems of Geographical Variation and Species Forma- tion,” PLSL, 149th session (1936-7), pp. 275-85. Also Homo Sapiens, vom Tier zum Halbgott (Gottingen: Vandenhoeck and Ruprecht; 1959).
1 W. V. Macfarlane, P. R. Pennycuik, and E. Thrift: “Resorption and Loss of Fetuses in Rats Living at 350 C.” J. Physiol., Vol. 135, No. 3 (1957), pp. 451-9. Also S. Brody, A. C. Ragsdale, R. G. Yeck, and D. Worstell: “Milk Production, Feed and Water Consumption, and Body Weight of Jersey and Holstein Cows in Relation to Several Diurnal Temperature Rhythms,” RBMO, Vol. 578 (1955), pp. 1-26.
50 Evolution through Environmental Adaptation
failed to acquire dominance. Animals that inhabit peripheral shores or small islands lead sheltered lives and may develop local peculiarities without facing the pruning effect of rivalry. That is why early mariners found dodo birds strutting around Mauritius and giant tortoises ambling over the glades of the Galapagos. These facts, incidentally, were not lost on the youthful Darwin who voyaged on the Beagle. That is also why rabbits and foxes, when let loose in Australia, raised such havoc with the local fauna, and why, in another sense but following the same principle, the white settlers have replaced the aborigines in the wetter sections of the same continent.
The Six Faunal Regions
As long ago as 1857, two years before the appearance of Darwin’s The Origin of Species, an ornithologist named Sclater published a paper 2 in which he divided the world into six faunal regions: Ethiopian, Indian, Palearctic, Nearctic, Neotropical, and Australian. In 1876 Wallace 3 confirmed this division but changed the name of the “Indian” region to “Oriental”; this change has persisted in the corresponding literature. Although a century has passed since Sclater’s work was published, zoologists still divide the world in this fashion. The faunal regions, which designate the distribution of the terrestrial and land-locked vertebrates — the fresh-water fishes, amphibians, reptiles, birds, and mammals — proved to have been actual divisions during most of the Cenozoic, or Age of Mammals, except that some of their boundaries shifted during the glacial and interglacial stages of the Pleistocene epoch. In earlier times, of course, the surface of the world was divided differently, but these earlier differences do not concern us in this book.
Matthew, an influential zoogeographer writing in 1915, 4 indi- cated that the region of primary evolutionary change was the
2 P. L. Sclater: “On the General Distribution of the Class Aves,” JPLS-Zool., Vol. 2 (1857), pp. 130-45.
3 A. R. Wallace: The Geographical Distribution of Animah (London: Mac- millan & Co.; 1876).
4W. D. Matthew: “Climate and Evolution,” ANYA, Vol. 24 (1915-1939), pp. 171-318.
THE SIX FAUNAL REGIONS OF SCLATER AND WALLACE
MAP
5 2 Evolution through Environmental Adaptation
Holarctic, a term combining the Palearctic and Nearctic, and in- deed those regions were active centers of change during the first glacial advances of the Pleistocene, when many species of mam- mals were becoming adapted to cold. However, Darlington now believes that the tropical regions of the Old World, the Ethiopian and particularly the Oriental, have been the principal centers of speciation over a longer period.
The Ethiopian region consists of Africa south of the middle of the Sahara, which in times of drought acts as a barrier to the move- ments of many animals, and the southwestern corner of Arabia south and west of the Arabian desert. But until the end of the Pleistocene North Africa had an Ethiopian fauna; about ten or twelve thousand years ago it was invaded by Palearctic mammals, including Caucasoid men. Madagascar, with an extremely spe- cialized and archaic fauna, is a special province of its own and was not inhabited by human beings until about the time of Christ. South Africa, which lies as far from the equator as South Carolina, has a Mediterranean climate, but as there is no barrier to separate it fiom the main part of Africa it has not been isolated enough to have developed a special fauna of its own. The fresh-water fishes, amphibia, and reptiles of the Ethiopian region resemble those of both the Nearctic and the Oriental regions; the birds, as might be expected, have world-wide relationships, though they are particu- larly linked to the Oriental region; and the mammals can be di- vided into certain widely distributed families, some related to the Oriental region, some purely local, and a few with other con- nections. However, for the mammals as for the other classes of land vertebrates, the greatest ties are to be found with the Orien- tal fauna.
The Oriental region consists of tropical Asia with its fringing islands, including Ceylon, the Andamans, Sumatra, Java, Borneo, Formosa, and in certain respects the Philippines. On the east it encompasses southern China north to Hong Kong, and on the west it runs a few degrees north of the tropics in northern India. There is heavy rain forest in much of Indochina, the Malay penin- sula, Siam, and western Indonesia, and patches of it in the Car- damon Hills (Kadar country) of southern India and in the Khasi plateaus of Assam, which is the wettest place in the world.
53
The Six Faunal Regions
Oriental fresh-water fishes form a rich and dominant assem- blage lacking archaic groups; Oriental amphibia and reptiles are partly similar to and partly unlike the Ethiopian ones; and whereas Africa has more species of lizards, the Oriental region is particularly rich in snakes. Both its birds and mammals are strongly related to the Ethiopian groups, as for example its ele- phant, its rhinoceros, and the lion, but the Oriental fauna is less sealed off than the Ethiopian. It is also related to the Palearctic, in common with which it has bears and tigers. Both of these are lacking in the Ethiopian region. This relatively open character is reflected in the fact that the Oriental region has fewer purely local (endemic) groups of vertebrates than any other tropical area. Darlington says: Either it has been a center from which vertebrates have tended to spread into other regions, or it has been a main crossroads in dispersal, or both.” 5 Within the Orien- tal region the fauna can be divided into four regional assem- blages. The richest and most varied is in the northeastern part, including southeast China, Indochina, Siam, and Burma; the poorest is in the principal, drier part of India.
Furthermore, the boundary between the Oriental and Pale- arctic regions which verges on the richest subarea — the south Chinese border — is wide open. Nothing except a very gradual climatic cline stands in the way of free passage northward by Oriental animals, and vice versa. The width of this frontier is greatly extended by a series of cool mountain ridges stretching like fingers from the Chinese highlands southward between the rivers of southeast Asia. In no other place in the world does an open border exist between a tropical and a temperate faunal re- gion. As we shall presently discover, this has been significant for man as well as for other animals.
On the western side of the Oriental region the mountain bar- riers are formidable, but there are passes, particularly the Khyber and Shibar passes, into Palearctic territory, and during certain warm interglacial periods the Mediterranean and western Europe had Oriental faunas. The road to the Ethiopian region now runs along the barren Makran coast of Baluchistan and the connecting piece of the south Persian coast, then either across a small salt-
5 Darlington: op. cit., p. 436.
54 Evolution through Environmental Adaptation
water gap or around the head of the Persian Gulf, and down into the Green Mountain of Oman, and finally along the southern coast of Arabia, where only one undessicated pocket, the Dhofar region, remains. During the times when the main movements of animal groups took place between Africa and India, this whole route must have been much wetter than now and easier to cross.
The Palearctic region includes the nontropical parts of Eurasia and the Barbary states. Climatically speaking, it ranges from arctic to Mediterranean conditions, but in all or nearly all of it there is winter frost, which means that all the animals who live in it achieved some kind of adaptation to cold. This fauna is consequently far less rich in species than the Oriental or the Ethiopian. As the principal flow of animal groups has been from southeast Asia to China and thence to points north and west, it is not surprising that the land vertebrate fauna of China is the most varied of the whole Palearctic region, whereas that of the British Isles is quite poor. Furthermore, the animals differ more from east to west than they do from north to south. This is of special interest to anthropologists, because the same thing is true of human sub- species. A Norwegian and a Berber resemble each other far more than either resembles a Chinese, and many a Tibetan could pass for a Chukchi of northeastern Siberia. The diagonal mountain barrier running from the Tian Shan range to the Bering Strait, which partially separates the Caucasoid and Mongoloid realms, has had its effect on other animals as well.
The Nearctic fauna, which occupies all of North America north of the tropical part of Mexico, is relatively poor in species, most of which are derived from the Palearctic, although a few have moved up from tropical Middle and South America. Greenland is part of this area, and contains American mammals only, although some of its birds are European.
South and Central America, the tropical lowland of Mexico, and Trinidad comprise the Neotropical region. The other islands of the West Indies have a greatly reduced fauna, which is transi- tional in a minor way. On the whole, the Neotropical fauna is a mixture of old forms that developed locally during the Tertiary, and new ones, including man, which came in from North America
Wallacea
55
during the Pleistocene. A few of its mammals, notably the arma- dillo and the opossum, have migrated northward.
The Australian faunal region encompasses Australia itself, Tas- mania, New Guinea, and some of the fringing islands off New Guinea. That this region has been cut off from the rest of the world for a very long time is evidenced by the fact that it is very poor in fresh-water fishes and amphibia, and that its mam- mals are composed of monotremes (the platypus and echidna) and of six exclusive families of marsupials. Its closest relationships are with the almost equally residual fauna of South America, and it has very little in common with the neighboring Oriental region.
Wallacea
The region between the Oriental and the Australian realms is named Wallacea. Across it the world’s richest and poorest con- tinental vertebrate faunas face each other. In i860 Wallace drew his famous deep-water line between Bali and Lombok, Borneo and Celebes, and Mindanao and the islands of Sangi and Talaud. Although Bali and Lombok are only 15 miles apart, the Oriental fauna is cut off at that point almost as though with a knife. This line is the western frontier of Wallacea; the eastern is close to the so-called bird-head, a peninsula of western New Guniea. The island of Kei is inside Wallacea; and Misol, Waigeo, Batanta, and Salawati go with New Guinea in the Australian region. A third line, known as Weber’s, runs down the middle; it is called the line of faunal balance.
Very few land mammals have crossed Wallace’s Line, and those that have done so live almost exclusively in the northern part of Wallacea. Celebes was reached by shrews, tarsiers, ma- caques, squirrels, four genera of weasels, several kinds of pigs, in- cluding the endemic Barbirussa deer, and an endemic breed of cattle known as the anoa. During the Pleistocene Celebes also harbored a pygmy elephant. Some of these animals reached the Moluccas, but they did not go south. In the Lesser Sundas, east of Bali, porcupines, shrews, crab-eating monkeys, pigs, and deer
56 Evolution through Environmental Adaptation
all reach as far as Timor. All these animals may have been intro- duced by man, who probably brought them along as pets, food, or both.1’ On the other side, a few Australian marsupials have penetrated into Wallacea as well. There is a bandicoot on Ceram, and phalangers live on Halmahera, Timor, and Celebes.
Wallacea is unique in the world as a barrier-filter. It is of great anthropological significance because it isolated the Australian aboriginal population virtually unchanged since its arrival from the southeastern Oriental region during the late Pleistocene. Even today the population of these small islands is racially inter- mediate between the more recently arrived Mongoloid peoples of western Indonesia and the natives of New Guinea. As the ancient barrier between the erstwhile Sahul and Sunda shelves, it must be taken into account in any attempt to unravel the complex racial distributions in southeast Asia and Oceania.
The Faunal Regions and Human Origins and Movements
Man, it is becoming increasingly clear, must have originated in some form in one of the two realms of tropical fauna in the Old World, or in an erstwhile extension of one of them into what is now the Palearctic during a period warmer than the present. Whereas the exchange of animals between Africa and south Asia was intermittent and mutual during the Tertiary and Pleistocene, the Oriental region supplied most of the vertebrate groups to the Palearctic. One principle of the movements of animals may help us decide which way the animals moved. When older, less domi- nant forms are replaced by spreading dominant forms, the domi- nant ones do not push the others to the peripheries ahead of them; rather, they overrun them, leaving small, disconnected ref- ugee pockets in their wake.
The Oriental region contains many such small, marginal popu- lations of Australoids, Asiatic Negritos, and primitive, food-gath- ering Caucasoids, which indicates that these races inhabited that zoogeographic region before its invasion by Mongoloids and modern kinds of Caucasoids from the north. In the Ethiopian re-
6 Darlington: op. cit., pp. 466-7.
Faunal Regions and Human Origins and Movements 57
gion the distribution of Pygmies follows a similar refugee pattern, and in East Africa pockets of Bushmen indicate the earlier distri- bution of Capoids to the north of their historic home. The only comparable relict population in the Palearctic or Nearctic is that of the Ainu, and both their antiquity in northern Japan and their origin are questionable.
Returning to straight zoology, we find that, as many Palearctic genera originated in south Asia, greater dominance was required for some of them to move northward through the eastern part of the Palearctic region and then into Europe and the Americas than for others to reach the Ethiopian realm, particularly in a period of greater moisture than the present. Furthermore, as Rensch 7 points out, more evolution has been taking place in the Northern Hemisphere than in the Southern since the end of Tertiary times, or in other words, since the beginning of the Pleistocene. As a great deal of human evolution occurred during the Pleistocene, the Oriental region, being the more northerly, is a better candi- date than the Ethiopian as a possible place of dispersal of the re- mote ancestors of the living races of man.
Certain complications, however, qualify this interpretation. In the Palearctic region the diagonal mountain barrier that crosses central and northeastern Asia imposes a bar sinister of cold cli- mate between the eastern and western halves of this faunal re- gion. Animals that enter the eastern half from the Oriental region do not all cross it. During parts of the Pleistocene this barrier was glaciated. Also, during the Early Pleistocene and the interglacials of the Middle Pleistocene southern and western Europe were tropical regions, connected by the Near Eastern land bridge to both the Oriental and the Ethiopian regions. Asiatic species were commoner in Europe at these times than African ones, although both were present.
Therefore, if man did not originate in Europe, which we can almost take for granted, he could have arrived there from either southwest Asia or Africa, or from both. It is very unlikely that ini- tially he came across the mountains of central Asia from China. At any rate, once Europe had been populated, alternate periods of glacial and warm or temperate climates gave Europeans more
7 Rensch: op. cit., pp. 275-85.
58 Evolution through Environmental Adaptation
than one chance to adapt themselves to new conditions and, like other members of their faunas, to reinvade the tropics.
In sum, the rules of zoogeography apply to man as they do to other animals. They offer us probabilities as to where the genus Homo evolved and over what paths different groups of men moved to found regional populations. They also help explain the dominance of some populations over others.
These rules can be applied in another way as well. Animals of many species have become adapted morphologically and phys- iologically to the exigencies of different climates. As members of a species that inhabits all climates, some of the races of man may have undergone selection for extremes of climate.
Environmental Adaptation and Early Man
Zoogeography leads by tiny steps into ecology, which deals with the ways different plant and animal species get along together in various environments, and ecology in turn carries us into the study of environmental adaptation. How the polar bear can sit on a cake of ice without melting it, and how desert rodents live without water, are fascinating subjects discussed in an exten- sive literature. The adaptations of living races of men to climatic extremes have also been studied, to a lesser extent. But for present purposes, since we are concerned only with the history of fossil human races, only two aspects of this subject need be explored here.
( 1 ) We need to know whether the fragmentary remains of our fossil ancestors contain any telltale indications of adaptation to climatic extremes, in order to determine whether such adapta- tions aie chaiacteristic of subspecies, and to keep ourselves from confusing them with general, evolutionary characters.
(2) We need to determine what extremes of climate our an- cestors could have tolerated with a minimum of cultural equip- ment and we can do this by studying and comparing the physi- ology of living primitive peoples.
The results of both these investigations may help us determine how old the existing subspecies are, and whither and whence they could have migrated during the Pleistocene.
The Rules of Bergmann and Allen 59
Simply by observing the geographical distribution of living peoples, we can see that no single subspecies is limited to a single climate. Caucasoids live all the way from Norway to India. The aborigines of Tasmania, who were spiral-haired Australoids, went about nearly naked in a climate as cold as England’s. Mongoloids may be found from the Arctic to the wet tropics, and both the Australian aborigines and the South African Bushmen, whose ranges are more limited, live through broiling heat and freezing weather at different seasons, with a minimum of cultural assist- ance. Given time, a population derived from any human sub- species could probably adjust itself to most local conditions. Adaptations to climate, therefore, could occur independently in more than one subspecies and need not be interpreted as evidence of genetic relationship.
In only three kinds of environment are land mammals rigor- ously selected for their abilities to resist stress: arctic and other cold areas, deserts, and high mountains. The first entails heat regulation; the second both heat regulation and water conserva- tion; and the third oxygen consumption, particularly oxygen transfer from the mother to the fetus. Physiologists have done a great deal of work to explain how the caribou can live in the snow, why the camel can go for days in the summer heat without drink- ing, and how the llama can bear its young in the thin air of the Andean plateau.
The Rules of Bergmann and Allen
These adaptations found among living mammals in- volve fur, skin, blood vessels, interstitial fluids, and blood cor- puscles, i.e., soft parts, which ordinarily disappear after death. If geologically ancient human beings also had such adaptations, very few details of these can be detected among the bones at our disposal. Yet certain uniformities which reflect relationships be- tween the bodies of animals and climate may show in the skeleton as a whole. These are the old, nineteenth-century rules. Berg- mann s rule,8 for example, states that in a given species the warm-
8 Carl Bergmann: Uber die Verhaltnisse der Warmeokonomie der Thiere zu ihrer Grosse,” Gottinger Studien, No. 8 (1848).
60 Evolution through Environmental Adaptation
blooded animals which live in cold places tend to have greater body bulk than those which live in hot regions. Allen’s rule 9 further states that in a given species animals living in cold areas tend to have shorter extremities than those in warm climates. This does not mean that in cold places animals’ ears, legs, or tails become too short to function, only that within functional limits they will become shorter than they might have been had cold stress been absent.
Both these rules concern the physics of heat loss from a warm body to a usually cooler surrounding atmosphere. As a body has three dimensions and its surface only two, the bigger the body, all else being equal, the less the heat loss per unit of volume (Bergmann). Furthermore, the nearer the body comes to being a perfect sphere, the smaller is its surface area per unit of volume (Allen). Each species of animal usually has its own system of conserving and losing heat, so that these rules cannot be used in interspecific comparisons.
In recent years these venerable rules have been criticized by physiologists, some of whom were unaware that the rules apply only to single species; and they have been defended by taxono- mists and physical anthropologists.1 As they represent results rather than processes, they are naturally less useful in studying adaptation than physiological experiments are, but they can be applied to much larger population samples than physiologists can test. As a supplement to physiological experiments, they can be applied to living men, particularly to old, long-established food- gathering populations.
Peoples who live in cold regions are generally heavier than the
9 J. A. Allen: “The Influence of Physical Conditions in the Genesis of Species,” RR, Vol. 1 (1877), pp. 108-40. (Reprinted in ARSI for 1905 [1906], pp. 375-402. )
1 For this controversy see:
P. F. Scholander: “Evolution of Climatic Adaptation in Homeotherms,” Evo- lution, Vol. 9, No. 1 ( 1955), pp. 15-26.
Scholander: “Climatic Rules,” Evolution, Vol. 10, No. 3 (1956), pp. 339-40.
Mayr: “Geographical Character Gradients and Climatic Adaptation,” Evolu- tion, Vol. 10, No. 3 ( 1956) pp. 105-8.
M. T. Newman: “Adaptation of Man to Cold Climates,” Evolution, Vol. 10, No. 3 (1956), pp. 101-5.
C. G. Wilber: “Physiological Regulations and the Origins of Human Types,” HB, Vol. 29, No. 4 (1957), pp. 329-36.
The Rules of Bergmann and Allen 61
inhabitants of the tropics, and the ratio of trunk length to leg length is greater in the peoples who dwell in cold areas, who weigh more per unit of stature.2 As expected, these regional dif- ferences are found in all subspecies that encompass wide ranges of climate.
For our present purpose of detecting climatic adaptation in fossil men these rules are rarely useful, with a few exceptions. Several nearly complete skeletons of European Neanderthals have bones so short and heavy that their body weights must have been great per unit of stature, as with living peoples of the Arctic. With these exceptions, we rarely have enough bones from a single individual to calculate both stature and relative trunk height; in- deed, stature is usually calculated from the limb bones alone, which defeats our purpose. Also, there is no formula for calculat- ing body weight from the skeleton.
Now and then we find the cervical vertebrae, which tell us whether necks were long or short. This is useful because peoples in cold climates tend to have short necks. We can also estimate the amount of warm arterial blood that flows into the cheeks through the infraorbital foramen (a hole in the zygomatic bone just under the eye socket) by the diameter of that opening. A strong flow of blood through that hole helps keep the cheeks of the Greenland Eskimo warm.3 Similarly, the size of the mental foramen (mental means chin in this case), a comparable hole in the lower jaw, affects the amount of warm blood that reaches the chin.
The shape of the foot is also significant, for people who go bare- foot in cold water or snow tend to have short broad feet with short toes. In a few sites whole feet of fossil men have been re- covered; in others footprints have been found.
Among living peoples who dwell near or above the Arctic Circle, whether they are Caucasoid or Mongoloid, there is a tendency for the tympanic plate, a bony structure below the ear
2 D. F. Roberts: “Body Weight, Race, and Climate,” AJPA, Vol. 11, No. 4 (i953), pp. 553-8.
Newman: The Application of Ecological Rules to the Racial Anthropology of the Aboriginal New World,” AA, Vol. 55, No. 3 (1953), pp. 311-27.
3 W. S. Laughlin and J. B. Jprgensen: “Isolate Variation in Greenlandic Eskimo Crania,” ActG, Vol. 6 (1956), pp. 3-12.
62 Evolution through Environmental Adaptation
hole, to become thickened — why we do not know. This thickening has also been observed among the Moriori, the original Poly- nesian inhabitants of the Chatham Islands, who lived in a cool climate.
Nose Form and Climate
A further adaptation concerns the nose. In places where the air is dry the nasal aperture tends to be narrow; where it is damp, the openings may be broader. This adaptation involves the function of the nasal passages in moistening inhaled air. Noses also tend to be narrower in cold than in hot climates, because of the heat exchange between the lungs and the inhaled air, but the protection of the lungs from frost is not as critical as the humidi- fying function.4
Ridges and surface irregularities on the skull and mandible in- dicate how much and how hard a prehistoric individual chewed. This can also be determined, in mature specimens, from the amount of tooth wear. In the earliest fossil hominid remains, par- ticularly those from periods and places without fire, powerful jaws and large, heavily worn teeth reflect a coarse diet without clean- ing, cooking, or other effete ways of demineralizing or softening food. Later on, in advanced prehistoric populations living in cold places, jaw muscles (as indicated by the effects they left on bone) again became massive and teeth excessively worn. Like the Eski- mo, these people used their teeth in preparing skins for clothing.
Physiological Adaptation to Cold
These imperishable details of skull morphology tell us much less about adaptation to climate than the soft parts would have done had they been preserved, as those of mammoths were. Cli- matic adaptation is physiological, and the physiology of heat and cold adaptation is mostly a matter of oxygen consumption, blood flow, and details of muscles, fat, skin, and nervous tissue. Because
4 A- Thomson and D. Buxton: “Man’s Nasal Index in Relation to Certain Climatic Conditions, JRAI, Vol. 53 (1923), pp. 53—92.
J. S. Weiner: “Nose Shape and Climate,” A]? A, Vol. 12, No. 4 ( 1954), pp. 1-4.
Physiological Adaptation to Cold 63
differences in physiology are racial, and racial differences are as old as Homo sapiens, we may venture to project physiological dif- ferences in living races backward into the time of fossil men. Many such differences, long suspected, have recently been estab- lished.
During the 1940’s the global nature of modern warfare stimu- lated the interest of several nations in man’s ability to live in all climates, particularly the arctic. It soon became clear to some researchers that living races differ in their tolerance of heat and cold. Although much work remains to be done, at least seventeen experimental studies published between 1950 and i960 reported tests of this nature on all five subspecies of Homo sapiens.5 6
These tests have shown that Mongoloids are adapted to sleep- ing and working in the cold as a result of one kind of physiological adaptation; that Australoids and one group of Caucasoids, the Lapps, are cold-adapted in an entirely different way; that Ne- groes are both adapted to wet heat and sensitive to cold; and that most European Caucasoids and all Bushmen studied lack special adaptations to either heat or cold.
In the Arctic, fur keeps the bodies of most mammals warm. The same furs, tailored into clothing, keep people warm out of doors. But despite the use of warm clothing, blankets, and camp- fires, Alaskan Indians sleep under conditions of moderate cold while camping out on their trapping routes in the winter. Then- bodies, however, compensate for the incurred heat loss by an in- creased basal metabolism. By burning extra oxygen and calories they are able to sleep without discomfort at temperatures that keep white men tossing and waking.0 This physiological capacity, which is inherited, is not a seasonal phenomenon. It keeps them warm, with little cover, on chilly summer nights as well as in winter.7
5 Europeans were used as controls in all these experiments except that given in footnote 3, page 65, the Japanese tests. Thus Caucasoid Europeans, other than Lapps, who were tested separately, constitute the norms.
6 L. Irving, K. L. Anderson, A. Bolstad, R. Eisner, J. A. Hildes, Y. Lpyning, J. D. Nelms, L. J. Peyton, and R. D. Whaley: “Metabolism and Temperature of Arctic Indian Men During a Cold Night,” JAP, Vol. 15, No. 4 (i960), pp. 635-44.
R. W. Eisner, K. L. Anderson, and L. Hermanssen: “Thermal and Metabolic Responses of Arctic Indians to Moderate Cold Exposure at the End of Winter,” JAP, Vol. 15, No. 4 (i960), pp. 659-66.
64 Evolution through Environmental Adaptation
A far more spectacular and much better known example of cold adaptation is that of the Canoe Indians of Tierra del Fuego and adjacent South American shores and islands. In 1959 Hammel, Scholander, and others, including myself, went to the islands and glaciers of the southern Chilean archipelago to study the cold adaptation of the Alakaluf,8 the only one of the four original Fuegian tribes still numerous enough and unmixed enough to war- rant investigation.
When first discovered by Magellan, these Indians were going about in canoes in freezing weather with no clothing except an occasional sea-otter skin cape, and with their bodies smeared with sea-mammal fat and ocher. At night they usually slept in small, domed huts covered with skins and heated by fires of Nothofagus, an evergreen tree closely related to the beech. This wood throws oflf great heat and burns nearly all night.
Except for the early morning hours, these Indians were as warm indoors as we are. Out of doors they exposed themselves un- clothed to heavy winds and pelting sleet and snow. Furthermore, they walked and swam in the icy water, and dived for shellfish. The work of Hammel and his associates shows that the Fuegians, taking the Alakaluf as an example, were able to survive freezing temperatures without clothing by burning off a large quantity of calories, much more than the Alaskan Indians needed to keep warm at night. The Alakaluf live mostly on shellfish and the flesh of sea mammals, and they eat heartily. Their basal metabolism is 160 per cent higher than the norm for whites of the same weight and stature.
Returning for a moment to arctic mammals, and also to arctic birds, we observe that no matter how warm their fur and down keep their bodies, certain extremities, like seals’ flippers, caribou’s lower legs, and birds’ beaks, remain relatively unprotected. In some species, as for example the fur seal with its exposed flippers, warmth is provided to these extremities by a massive flow of arterial blood close below the surface. This flow of blood burns up many calories, thus enabling the seal to swim in comfort.
On anatomical evidence alone, we have already inferred that
s H. T. Hammel: Thermal and Metabolic Responses of the Alacaluf Indians to Moderate Cold Exposure, WADD Technical Report 60-633, December i960.
Physiological Adaptation to Cold 65
the cheeks of the Greenland Eskimo receive an extra flow of blood which keeps them warm, but as far as I know this has not yet been tested physiologically. The Eskimo’s hands, however, have been tested for the same phenomenon, and they show an increased flow of blood when held in cold water.9
The hands of Alaskan Indians respond in the same fashion, producing twice as much blood flow as those of white men tested under the same conditions.1 The same response was obtained from the hands of Alakaluf women,2 who collect shellfish by hand in cold water. In Manchuria four groups of Mongoloids were tested by the Japanese for this same phenomenon,3 and a grada- tion, or cline, was found which corresponds to the climates of the regions inhabited by the peoples studied. The Orochons, a no- madic, reindeer breeding and hunting tribe of northern Man- churia, had the most adaptation; the Mongols and north Chinese came next (the two were the same); and the Japanese had the least response.
Similar tests performed on the hands of Lapp reindeer herders, who have been living since prehistoric times under the same con- ditions as the Orochons, showed no cold adaptation in the hands.4 White Norwegian fishermen living above the Arctic Circle, men whose hands are constantly in cold water, came out the same as the Lapps, and as the white men in the control group, who were mostly scientists.5
The experiments reported above indicate that cold adaptation
9 G. M. Brown and J. Page: “The Effect of Chronic Exposure to Cold on Temperature and Blood Flow of the Hand,” JAP, Vol. 5, No. 5 ( 1953), pp. 221-7.
1 Eisner, Nelms, and Irving: “Circulation of Heat to the Hands of Arctic In- dians,” JAP, Vol. 15, No. 4, pp. 662-6.
2 H. T. Hammel: “Thermal and Metabolic Responses. . . .”
3 H. Yoshimura and T. Iida: “Studies on the Reactivity of Skin Vessels to Extreme Cold. Part II: Factors Governing the Individual Difference of the Reac- tivity, or the Resistance Against Frostbite,” JJP, Vol. 1 (1950-51), pp. 177-85.
4 J- Krog, B. Folkow, R. H. Fox, and Andersen: “Hand Circulation in the Cold of Lapps and North Norwegian Fisherman,” JAP, Vol. 15, No. 4 (i960), pp. 654-8.
B. Hellstrom and Andersen: “Heat Output in the Cold from Hands of Arctic Fishermen,” JAP, Vol. 15, No. 5 (ig6o), pp. 771-5.
5 Ibid.
Andersen, Lpyning, Nelms, D. Wilson, Fox, and A. Bolstad: “Metabolic and Thermal Response to a Moderate Cold Exposure in Nomadic Lapps,” JAP, Vol. 15, No. (i960), pp. 649-53.
66 Evolution through Environmental Adaptation
through increased basal metabolism and increased peripheral blood flow is confined to the Mongoloid subspecies, at least as far as we know. They also indicate that the Lapps are Caucasoids, as most physical anthropologists now believe, and not Mongoloid, as was frequently stated in the past by writers who had not seen them.
The second kind of cold adaptation requires no increase in caloric expenditure or in peripheral blood flow. It involves instead an insulation in depth of the body core; the limbs and the sur- faces of the trunk serve to insulate the more vulnerable internal organs. This effect is found in domestic swine reared in Alaska, and in hair seals, which have no more fur than the swine do. It is also characteristic of the legs of caribou and of arctic birds. Like the Mongoloid adaptation, this type involves both the body as a whole and the extremities.
In man, cold adaptation through insulation was first observed in Australia, among the aborigines. In west-central Australia the members of the Pitjendjera tribe live naked in the desert. During the day the air is hot, but at night the temperature can go down to freezing or a little lower. Ordinarily the aborigines sleep naked on the ground between rows of small, smudgelike fires, but when the wind is blowing the fires are useless. Scholander, Hammel, and others found that, while sleeping in light sleeping bags without fires at 32 ° F, the Pitjendjera men maintain an almost normal in- ternal body temperature, as shown by rectal readings, whereas their limbs become chilled. The temperature of their feet read as low as 540 to 590 F.
In the morning these men get up and stamp around, and by the time the sun is up they are as fit as ever. White volunteers who took the same tests lost internal body heat before morning, because the surfaces of their arms and legs threw it off into the atmosphere. The aborigines slept comfortably, but their Cauca- soid counterparts spent a miserable night.6 Later on, these experi- ments were repeated in midsummer at Darwin, North Australia, on other aborigines from several different tribes. Cold condi-
6 P. F. Scholander, Hammel, J. S. Hart, D. H. LeMessurier, and J. Steen: “Cold Adaptation in Australian Aborigines,” JAP, Vol. 13, No. 2 (1958), pp. 211-18.
Physiological Adaptation to Cold 67
tions were created by having them sleep in a refrigerated meat van. The physiological response was the same as that of the first group, tested in winter, thereby confirming the fact that the cold adaptation of the Australian aborigines is not seasonal but per- manent, and apparently both genetic and anatomical.7
In human beings each of the principal arteries of the arm and lower leg — brachial, radial, ulnar, tibial, and peroneal — is ac- companied, as a rule in the same sheath, by a pair of companion veins called venae comites. At various places, particularly near elbows and other joints, neighboring arteries are connected by short blood vessels, so that under certain circumstances one can replace the other and an exchange of blood can take place. The networks formed by such connections are called anastomoses. The economy of engineering that placed the arteries and their pairs of veins together, and the emergency arrangement of con- necting arteries at anastomoses, have also provided a mechanism by which under certain circumstances heat can be transferred between the two kinds of blood vessels.
Among the Pitjendjera apparently such a transfer is made dur- ing sleep. The outgoing arterial blood warms the incoming venous blood, so that the hands and feet are cool and heat is saved. In a desert where food is scarce, heat conservation is important for survival. Why the whites tested in these experiments failed to transfer heat from arteries to veins in the same way is not known, but without doubt a program of comparative dissection could help determine the answer. Arteries are notoriously variable, and racial differences in their branching patterns have been estab- lished between Europeans and Japanese. For other populations, available data are inadequate.8
Surprisingly enough, the Australoid type of cold adaptation through insulation has been found in only one other population so far tested, the nomadic Lapps. This evidence, when added to their failure to respond to the cold-water hand test, places the Lapps far from the Mongoloid subspecies. Also, the settled village
7 Hammel, Eisner, D. H. LeMessurier, Andersen, and F. A. Milan: “Thermal and Metabolic Responses of the Australian Aborigine Exposed to Moderate Cold in Summer,” JAP, Vol. 14, No. 4 ( 1959), pp. 605-15.
8E. Loth: L’ Anthropolo gie des Parties Molles (Warsaw and Paris: Masson et Cie; 1931), PP- 348-82.
68 Evolution through Environmental Adaptation
Lapps, who are more mixed with Finns and Norwegians, show the insulative cold adaptation less than do the reindeer herders, who are less mixed. One is tempted to suspect that this type of cold adaptation was prevalent in Europe during the latter part of the Wiirm glacial epoch.
Returning to the Southern Hemisphere, where physiologists have found the world’s most striking examples of cold adaptation — among the Fuegians and Australian aborigines — we approach the Bushmen of the Kalahari Desert with some hope. The Bush- men, who are also primitive hunters and gatherers, are faced with the same alternate stresses of heat and cold that confront the Australian aborigines. These hopes have not been realized, how- ever. Three separate expeditions 9 have failed to find any differ- ences, in basal metabolism or in any other physiological attribute, between the Bushmen and the whites used as controls. This evi- dence suggests what has been suspected on other grounds, that the Bushmen have not lived in the desert very long. It also con- firms my belief that the Bushmen and the Negroes, although they share a continent, are not closely related.
Heat Adaptation
S o far, only the Negroes have been shown to possess heat adaptation. American Negores can tolerate moist heat better than American whites of the same age and economic background.1 But as far as I know this difference has not yet been demonstrated in Africa.2 American Negroes are unable to tolerate cold as well as
9 C. H. Wyndham and J. F. Morrisson: “Heat Regulation of MaSarwa” (Bush- men), Nature, Vol. 178, No. 4538 ( 1956), pp. 869-70.
Wyndham and Morrisson: “Adjustment to Cold of Bushmen in the Kalahari Desert,” JAP, Vol. 13, No. 2 (1958), pp. 219-25.
J. S. Ward, G. A. C. Bredell, and H. G. Wenzel: “Responses of Bushmen and Europeans on Exposure to Winter Night Temperatures in the Kalahari,” JAP, Vol. 15, No. 4 (i960), pp. 667-70.
1 P. T. Baker: “Racial Differences in Heat Tolerance,” AJPA, Vol. 16 (1958), pp. 287-305.
T. Adams and B. G. Covino: “Racial Variations to a Standardized Cold Stress,” JAP, Vol. 12, No. 1 (1957), pp. 9-12.
2 A study conducted in West Africa by N. A. Barnicot yielded negative re- sults, possibly because he apparently failed to allow for differences in height.
The Significance of Adaptation to Heat and Cold 69
American whites; this is true even when the individuals of both races who are tested have the same amount of subcutaneous fat.3 This final observation indicates that the difference in thermal adaptation between Negroes and European Caucasoids is not due to insulation alone. Probably a whole complex of physiological processes is involved, particularly those concerned with the depo- sition of melanin in the skin by the action of three hormones.4
The Significance of Adaptation to Heat and Cold
Several conclusions can be drawn from this review of human adaptation to heat and cold. One is that the subspecies of man as defined in Chapter 1 tend to sort themselves out on this basis. The Mongoloids are the most distinctive in thermal adaptation as in so many other features, and the Negroes stand at the opposite ex- treme.
A second is that because these adaptations are both genetic and linked to climate they may have been acquired by the several subspecies of Homo erectns at the time of their dispersal into different environmental regions.
A third conclusion is suggested by the Alakaluf study. It indi- cates that ill-clad human beings carrying fire and the crudest of tools (the Alakaluf cutting tool was a quahaug shell) could have entered North America over the Bering Strait at any time when the sea level was low enough to permit passage. At such times, with the flow of arctic water cut off and the Japanese current swinging along the southern shoreline, the climate could have been no colder than it is in modern Tierra del Fuego.
The two kinds of cold adaptation recently discovered allow
weight, and bodily components between the Negroes and Europeans tested. N. A. Bamicot: “Climatic Factors in the Evolution of Human Populations,” CSHS, Vol. 24 (i959), PP- 115-29.
3 Baker: “American Negro-White Differences in Thermal Insulative Aspects of Body Fat,” HB, Vol. 31 (1958), pp. 287-305.
4 Melanin is deposited by the combined action of one hormone from the pineal gland and two from the pituitary. The melanocytes in which the pigment is formed have their embryonic origin in nerve cells. Thus, skin pigment is basically a neuroendocrinological product. A. B. Lerner: “Hormones and Skin Color,” SA, Vol. 205, No. 1 (1961), pp. 98-108.
7° Evolution through Environmental Adaptation
human beings to live at temperatures near the freezing point with little or no environmental protection when out of doors, but they would not allow anyone, however well adapted genetically, to hunt out of doors in the winter temperatures found today in Lap- land and Greenland without a combination of good clothing and good housing, both made with good tools by skilled hands di- rected by a fully evolved modern brain. As far as the fossil record tells us, only Homo sapiens has ever lived in such climates.
Adaptation to Altitude
And as far as we know only Homo sapiens has ever lived at altitudes of over 10,000 feet. Only two plateaus of this height which are large enough to be human breeding grounds exist. They are Tibet and the Andean altiplano. Both are inhabited by Mongoloids. Careful physiological and anthropometric work has shown that the Andean Indians have large chests, large lungs, large hearts, and blood that contains a high ratio of red corpuscles. Although each red corpuscle carries less oxygen than it would at sea level, the total amount of oxygen borne by the blood far ex- ceeds that supplied by the arteries of outsiders who have moved into the highlands. Such outsiders may survive, but they have difficulty reproducing because the mother cannot transfer enough oxygen to her embryo to ensure its live birth.5 That is one reason why the highlands of Ecuador, Peru, and Bolivia are still Indian country four and a half centuries after Pizarro. As far as I have been able to determine, the adaptation of Tibetans to high alti- tudes has not yet been studied.
On the opposite extreme, Negroes, whose blood carries the sick- ling trait polymorphically ( Ss ) and bears with it even less oxygen than that of Caucasoids, may be seen along the Andean coast but not on the plateau. In the Himalayan region the clinal zone be- tween Mongoloids and all others is extremely steep, and in some places it is only a few miles wide.
The fact that adaptations favoring or counteracting excesses of oxygen in the blood stream cannot be demonstrated in fossil man
5 Newman: “Man and the Heights,” Nil, Vol. 67, No. 1 (1958), pp. 9-19.
Adaptation to Altitude yi
does not mean that they did not exist, because such adaptations are found only in perishable fluids and tissues.
In this chapter we have surveyed the principles of geography as they may be applied to the distribution of animals and the de- velopment of species and subspecies. We have situated the sub- species of man in their ancient homes, and examined the evidence for climatic adaptation in fossil and living men. We have found that human subspecies differ considerably in climatic adaptation, which has played a part in the ability of human beings to invade and inhabit regions too cold or too dry for other primates. The historic distribution of races, in fact, may partly be explained on the basis of these adaptations.
But we have found no extreme forms of adaptation comparable to those of desert rodents that live without drinking water, or of polar bears that sleep naked on ice floes. The principal adapta- tions of human beings to climate are technological. Skill at tech- nology’ and particularly the inventive genius that makes technical advances possible, requires the possession of a top-grade brain, which our ancestors began to acquire long ago, and which is still useful in an increasingly technological society.
« &
EC 3 K
EVOLUTION THROUGH SOCIAL ADAPTATION
Leadership , Communication, and Brain Growth
top-grade brain is needed not only to master, by technical means, cold, drought, and other environmental difficul- ties beyond the physiological capacities of the human body, but also to manage human relations skillfully. Natural selection in favor of this second kind of skill has been a prime factor in hu- man phyletic evolution — the rise of a more intelligent species from one that is more primitive intellectually. In this chapter I shall try to show how this kind of natural selection may have operated.
I am particularly concerned with the surviving societies of primitive hunters and gatherers because they serve, to a certain extent, as a window into the distant past, but more advanced systems should not be neglected since all societies are governed by the same natural rules.
In all the historic societies whose structural details are well known, the greatest tangible rewards have rarely gone to the geniuses of technology or to outstandingly skilled craftsmen, how- ever important their work has been for the preservation of human life and to social evolution. The men who have reaped the highest rewards are the geniuses, artists, and skilled craftsmen whose ma- terial is not clay, flint, or metal, but other people. They are the “operators,” the artificers of human relations. The leader who can keep the peace among his followers, organize his men for war, regulate the distribution of food and other wealth in such a way
73
Leadership, Communication, and Brain Growth
that everyone will be taken care of, particularly himself — such a man is well paid. He lives in the finest structure, be it hut or palace, eats the best food, and in many societies has the most women. Whatever genes he has that others lack have a better than average chance to multiply in the local pool.
Also well rewarded in esteem, if not in material goods, is the priest, shaman, or medicine man whose artistry allays fears and eases people individually and as groups over the emotional hurdles of crisis and trouble. In many societies his personality is an odd one. As he ministers to both sexes, he is sometimes celibate. What makes him an artist does not necessarily give him more women than the others; a society in which everyone is a shaman would soon fall to pieces. A few of his special genes in the pool will go a long way. Like popes, he can pass on his heritage through nephews.
Under the umbrella of law and order, ritual sanction, and emo- tional security that both chief and shaman spread, the craftsman can do his work, and every man can get food for his family. As there must be leaders, there must also be followers — men and women who can live together under guidance without disruptive quarreling. During the long stretch of human evolutionary history the sizes and complexities of groups have grown, and the ability of group members to live together peacefully, while presenting a united front against outsiders, has been of great importance for survival. In many structurally simple societies the troublemaker is killed one dark night by his fellows, or driven away, and so the genes which may have contributed to his antisocial behavior are thus, in a sense, fished out of the pool. Social adaptation, which is the capacity for living together in groups, has been as influential in human evolution, if not more so, as environmental adaptation through technology. But the relative importance of these two facets of adaptation is hard to evaluate as they are parts of a single picture.
Both these categories of adaptation depend primarily on an ancient revolution in communication made possible by the inven- tion of speech. Like tool-making and the use of fire, speech, we know, was a human invention. It must be learned, not quickly like some of the semi-instinctive habit patterns of other mammals
74 Evolution through Social Adaptation
but slowly and with great effort, and it requires the co-ordination, within the brain, of several different organs that are not used in concert by any other primate. If speech did not have to be learned, the peoples of the world would not speak hundreds of different languages; they would all make the same noises, like sea gulls.1
Before speech could be invented, the ancestral primate or- ganism had to undergo certain anatomical changes.2 These involve the following organs of speech (and, of course, their nerves): the diaphragm, which expels the air from the lungs; the larynx, which contains the so-called vocal chords and their controlling muscles; the pharynx, which is essentially the valve that opens and shuts the intersection of the air and food passages of the throat, both below and above the meeting point; and the muscles that control the movements of the jaws, lips, tongue, and soft palate.
The principal change was in the pharynx. In primates that walk on all fours, the air tube is continuous from pharynx to nasal passages except when the animal is swallowing or crying out; it takes effort to expel breath through the mouth. In man the valve of the pharynx is habitually open, and breath will come out of the mouth whenever the lips are open and the lungs are exhaling, unless an effort is made to block its passage with the tongue.
The cause of this change was, apparently, the assumption of the erect posture by our ancestors. DuBrul has shown by a series of dissections of the heads and necks of tree shrews, lemurs, tarsiers, Old World monkeys, and apes that the opening of the pharynx in man was only the last step in a series of changes caused by an increasing postural shift from the horizontal to the vertical plane. In the most primitive primates the air passages form almost a straight line from lungs to lips. In man they are
1 For a thorough discussion of the origin of speech and its role in cultural evolution, see:
A. I. Hallowell: “Self, Society, and Culture,” in S. Tax: Evolution After Dar- win (University of Chicago Press; i960), pp. 309—71.
C. F. Hockett: “The Origin of Speech,” SA, Vol. 203, No. 3 ( i960), pp. 88-96.
2E. L. DuBrul: Evolution of the Speech Apparatus (Springfield, 111.: Charles C Thomas; 1958); and “Structural Evidence in the Brain for a Theory of the Evo- lution of Behavior,” PBM, Vol. 1, No. 4 (i960), pp. 40-57.
Leadership, Communication, and Brain Growth 75
bent, in the pharyngeal section, into a 45 0 angle. It was this bending that opened the valve.
Once the pharynx was open, air was free to move between larynx and lips, whether the flap of the soft palate had closed off the nasal passages or left them open. Now it was possible to utter a wide variety of sounds, the formation of which depended on a combination of many factors: the degree of tension of the vocal cords, which could either be tightened so as to vibrate and thus
Dots = breathing tube Solid = feeding tube
Fig. 2 The Speech Organs of Pri- mates. A. Lemur rufifrons. The soft palate overlaps the epiglottis, and the corniculate cartilage of the pharynx is hooked to hold its grip over the rear rim of the palatal additus. Air pas- sages are normally open and food passages closed except in swallowing. B. Homo sapiens. The larynx has slid far down the neck. Both the front and rear valves are normally open, permit- ting free air to flow into the oral cav- ity, while the back flap of the soft palate can close off the nasal passages in speaking. ( Drawings after DuBrul, 1958.)
emit voiced sounds, or left slack so as to permit the formation of unvoiced sounds which, if continuous, became whispering; the opening and closing of the nasal passages, which produce nasal sounds if left open; the positions taken by the tongue and lips; and the sequences of all these elements in the formation of words. The number of possible sounds is nearly infinite, but the
7 6 Evolution through Social Adaptation
number used in any one language is limited by the number that can be easily recognized.
To be understood, language must be heard, both by the speaker and by the person addressed. The vocal vibrations of speech pass into the outer environment and return to the brain through the ears. If successful communication is achieved, they also hit the eardrums of a second person, whose answers strike the eardrums of the originator of the conversation.
Speech requires the neural co-ordination, in the brain stem and cortex, of many organs and sets of muscles, all of which, being located near the brain, enter it independently, as do the auditory nerves, rather than through the spinal cord. Their co-ordination in the brain was different neurologically from that of the hands and eyes needed for tool-making. Also, it was acquired later than the hand-eye combination that brachiation (swinging from limb to limb) called for: an ape has to see where he is going, in order to place his hand, or he will fall.3
Therefore, speech was probably invented after tool-making. Tools made hunting possible, and the social requirements of a group of hunters made speech necessary. Speech is also a pre- requisite to thinking, because we think in words. He who thinks can plan ahead, and he who plans ahead can learn to deal with other human beings.
During the course of human evolution, in different parts of the world, the brains of successive fossil men grew larger as time went on, until the present brain sizes, typical of the living races of man, were reached. Undoubtedly, talking and thinking influ- enced these increases, which occurred as more and more had to be learned. Evolutionary increases in brain size have not been confined to man. The fossil record shows comparable changes in many other kinds of animals. What is unusual about man is not that his brain grew, but that it grew as much as it did.4 By and
3 The other primates lack the extensive pharyngeal plexus needed for speech which is found in man. J. M. Sprague: “The Innervation of the Pharynx in the Rhesus Monkey and the Formation of the Pharyngeal Plexus in Primates,” AR, Vol. 9°, No. 3 (1944), PP- 197-208.
4 For the problem of brain size vs. body size in animals, see:
B. Rensch: “The Relation Between the Evolution of Central Nervous Func-
Leadership, Communication, and Brain Growth 77
large, in response to the needs of communication, the growth of the human brain may be considered primarily a social adapta- tion and, in addition, an example of evolution through succession.
This increase in brain size probably started with the erect posture. In any evolutionary line of mammals any entirely new kind of locomotion must be learned. Baby seals, for example, must be taught to swim, and baby birds must be pushed out of their nests before they will fly. Each of us, as a baby, must be taught to walk, or we would go on all fours. Learning a new method of locomotion fosters, and indeed requires, a concomitant increase in intelligence and, by the same token, in brain size. An animal bright enough to learn to walk erect might also be bright enough to begin making tools, and so on to hunting and speech.
But brain growth has disadvantages that had to be outweighed by the greater advantages of an increasing intelligence. In the fossil record of our zoological family, brain size increased only gradually; our brain is an expensive organ that grew as man be- came increasingly able to support it. The brain requires a large skull that must be carried about by the bones, tendons, and muscles of the neck, trunk, and legs. Being very sensitive to changes in temperature, it must be kept warm in cold weather and cool in hot weather. Only the visceral organs, which are much better insulated by the body mass, require such a narrow thermal range. As the brain lies close to the surface of the head, its large size taxes the body’s capacity for maintaining thermal equilib- rium.
It is also a gluttonous organ, requiring an even blood flow ranging from about 765 cc. a minute when at rest to about 1300 cc. a minute when hard at work. At rest it monopolizes about 12 per cent of the body’s blood supply, although it comprises only about
tions and the Body Size of Animals,” in J. Huxley, ed.: Evolution as a Process (London: Allen & Unwin; 1954), pp. 181-200.
H. J. Jerison: “Brain to Body Size Ratios and the Evolution of Intelligence,” Science, Vol. 121, No. 3144 ( 1955), pp. 447-9.
Rensch: “Trends Towards Progress of Brains and Sense Organs,” CSHS, Vol. 24 ( 1959), pp. 291-303.
For the functioning of the brain, particularly in speech, see W. Penfield and L. Roberts: Speech and Brain Mechanisms (Princeton: Princeton University Press; 1959).
78
Evolution through Social Adaptation
2 per cent of the body’s bulk. It burns up a correspondingly great amount of oxygen and sugar, which have to be fed to it con- stantly.5
If the brain is an expensive superstructure for an adult to carry around, it is even more of a burden for infants and children, who have to be protected and fed longer than the young of other ani- mals. At birth it has already reached 24 per cent of its adult mass, whereas the whole infant body is only 5 per cent of its adult body weight. At the age of three, the brain has attained 82 per cent of the adult weight and the body only 10 per cent. When the child is ten years old, shortly before puberty, the brain has attained 95 per cent of its adult volume, and from there on it gains very slowly and very little, whereas the body grows rapidly.6
In order to justify its carrying charges, any oversized and over- fed organ has to have a selective advantage in the reproductive life of the animal burdened with it, or its frequency will be kept down by natural selection. This has been shown many times in studies of other animals, the most conspicuous example, perhaps, being that of antler size in the deer family. Putting it very simply, there must have been a point in human history at which brains came to be more effective than brawn in acquiring women. Other- wise the brain sizes of various lines of fossil men would not have increased during the Pleistocene. Just how the brainier men won out is not known, except through analogy with living peoples. Clever planning, self-control at the right moments, persuasive talking, the exercise of leadership through language — these are obvious possibilities.
The importance of brain size in relation to more complex social behavior is suggested by comparisons with certain animals. Of all the mammals, only the whales have larger and more complex brains than man. The porpoise Tursiops truncatus, which is a small and very bright species of whale, has a very complex brain one third larger than ours, and a highly developed social life. In
5 C. F. Schmidt: The Cerebral Circulation in Health and Disease (Springfield, 111.: Charles C Thomas; 1950).
6J. H. Scott: “The Growth of the Human Face,” PRSM, Vol. 47, No. 2 (1954), PP- 91-100.
79
On the Antiquity of a Human Type of Society
it can be observed clear dominance relationships, and also al- truism. Care, anxiety, and friendship between individuals have been seen in the behavior of porpoises (as well as in that of chimpanzees and some other primates).7 Furthermore, the por- poises have possibly the most elaborate system of vocal com- munication of all the nonhuman mammals.
On the Antiquity of a Human Type of Society: the Beginning of Hunting
Before we can assume that the progressive increases in brain size seen in the fossil record constituted, at least in part, an adap- tation to the requirements of living together in a human society, we must establish the antiquity of our basic social system, which consists of a number of families living together and sharing food. We can never do this absolutely — social structure is not a material object that can be fossilized — but we can try to zero in on the point at which it may have begun by following several lines of evidence, including archaeological sequences, comparative ani- mal behavior, and the social systems of living primitive peoples. Let us begin with archaeology.
As previously stated, we may assume that the sharing of food must certainly, because of the nature of the beasts eaten, have begun with hunting, if indeed it had not already been practiced earlier among food gatherers. We can gain some idea of when hunting began by examining the camping sites at which fossil men, or other manlike primates, lived, or at least made their tools and ate.
The two oldest seem to be Bed I at Olduvai Gorge, Tanganyika,8 and Tell Ubeidiya in the Middle Jordan Valley just south of Lake
7 A. F. McBride: “Meet Mr. Porpoise,” NH, Vol. 45, No. 1 (1940), pp. 16-29.
McBride and D. O. Hebb: “Behavior of the Captive Bottle-nose Dolphin
Tursiops truncatus,” JCPP, Vol. 41, No. 2 ( 1948), pp. 111-23.
W. R. Thompson: “Social Behavior,” in A. Roe and G. G. Simpson: Behavior and Evolution (New Haven: Yale University Press; 1958), pp. 291-310.
8 L. S. B Leakey: “A New Fossil Skull from Olduvai,” Nature, Vol. 184, No. 4685, pp. 491-3; and “Recent Discoveries at Olduvai Gorge,” Nature, Vol. 188, No. 4755, pp. 1050-2.
80 Evolution through Social Adaptation
Tiberias in Israel.9 Both are Lower Pleistocene, and both were discovered in 1959. The Olduvai camp contained a fossil manlike primate which its finder, L. S. B. Leakey, named Z injanthropus, and a second one, the so-called Olduvai child, both of which will be described in Chapter 7. What is important here is that crude stone implements as well as bones which showed signs of being the remains of animals eaten on the spot were scattered there. The tools were sharp enough to enable the hominid who used