phil. trans. r. soc. b 2010 walker 3265 6

7/29/2019 Phil. Trans. R. Soc. B 2010 Walker 3265 6

1/3

, published 20 September 2010, doi: 10.1098/rstb.2010.01793652010Phil. Trans. R. Soc. BAlan Walker and Chris StringerThe first four million years of human evolution

Supplementary data

mlhttp://rstb.royalsocietypublishing.org/content/suppl/2010/09/30/365.1556.3265.DC1.ht

"Audio supplement"

Subject collections

(589 articles)evolution

Articles on similar topics can be found in the following collections

Email alerting servicehereright-hand corner of the article or click

Receive free email alerts when new articles cite this article - sign up in the box at the top

http://rstb.royalsocietypublishing.org/subscriptionsgo to:Phil. Trans. R. Soc. BTo subscribe to

on March 6, 2013rstb.royalsocietypublishing.orgDownloaded from
http://rstb.royalsocietypublishing.org/content/suppl/2010/09/30/365.1556.3265.DC1.htmlhttp://rstb.royalsocietypublishing.org/content/suppl/2010/09/30/365.1556.3265.DC1.htmlhttp://rstb.royalsocietypublishing.org/cgi/collection/evolutionhttp://rstb.royalsocietypublishing.org/cgi/collection/evolutionhttp://rstb.royalsocietypublishing.org/cgi/alerts/ctalert?alertType=citedby&addAlert=cited_by&saveAlert=no&cited_by_criteria_resid=royptb;365/1556/3265&return_type=article&return_url=http://rstb.royalsocietypublishing.org/content/365/1556/3265.full.pdfhttp://rstb.royalsocietypublishing.org/cgi/alerts/ctalert?alertType=citedby&addAlert=cited_by&saveAlert=no&cited_by_criteria_resid=royptb;365/1556/3265&return_type=article&return_url=http://rstb.royalsocietypublishing.org/content/365/1556/3265.full.pdfhttp://rstb.royalsocietypublishing.org/cgi/alerts/ctalert?alertType=citedby&addAlert=cited_by&saveAlert=no&cited_by_criteria_resid=royptb;365/1556/3265&return_type=article&return_url=http://rstb.royalsocietypublishing.org/content/365/1556/3265.full.pdfhttp://rstb.royalsocietypublishing.org/subscriptionshttp://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/subscriptionshttp://rstb.royalsocietypublishing.org/cgi/alerts/ctalert?alertType=citedby&addAlert=cited_by&saveAlert=no&cited_by_criteria_resid=royptb;365/1556/3265&return_type=article&return_url=http://rstb.royalsocietypublishing.org/content/365/1556/3265.full.pdfhttp://rstb.royalsocietypublishing.org/cgi/collection/evolutionhttp://rstb.royalsocietypublishing.org/content/suppl/2010/09/30/365.1556.3265.DC1.html


2/3

Introduction

The first four million years of human

evolution

In one of the last paragraphs of The origin of species

(1859), Darwin famously suggested that Much lightwill be thrown on the origin of man and his history.

When he published The descent of man 12 yearslater, there was still no fossil evidence of our earliestevolutionary history, and nothing at all from theAfrican continent. Yet our close biological relationshipto the great apes, and especially the African apes, the

gorilla (Gorilla gorilla) and chimpanzees, had longbeen recognized, even by scientists who were ignorant

of, or unsympathetic to, evolutionary thinking.Nevertheless, when we remember his cautious natureand the continuing powerful opposition to his ideas,it still required fortitude for Darwin to venture It istherefore probable that Africa was formerly inhabitedby extinct apes closely allied to the gorilla and chim-panzee; and as these two species are now mans

nearest allies, it is somewhat more probable that ourearly progenitors lived on the African continent thanelsewhere. In explaining why the fossil evidence ofour origins was slow to appear, he propheticallystated Nor should it be forgotten that those regionswhich are the most likely to afford remains connectingman with some extinct ape-like creature, have not as

yet been searched by geologists. In fact it was totake another 50 years before such fossil evidencebegan to emerge in Africa itself, and Darwin would

have been amazed by the remarkable evidence whichhas accumulated since then concerning the earlieststages of human evolution.

Spectacular discoveries of early members of thehuman lineage, including nearly complete skeletons

and dozens of other 6 to 2 Ma fossils have beenmade in the last 1020 years. Single complete skel-

etons are much more useful analytically thanseparate parts of many individuals, yet until recently,few had been found from the period before 2 Ma.Even Australopithecus, discovered in South Africain 1924, and published and named in 1925, is stillrelatively incompletely known. For instance, thefamous Lucy skeleton from Ethiopia is only about

20 per cent intact. But new and more complete earlyhominin skeletons from different parts of the Africancontinent now promise to give us a much morecomplete picture of the early phases in the history ofthe human lineage.

As discussed in one of the first contributions to thisvolume, molecular estimates of the divergence time

between humans and chimpanzees presently convergeon approximately 57 Ma, although we two are oldenough to remember the pre-molecular days, whenthe supposed uniqueness of humans seemed to requirea time-span 23 times those figures to account for theevolution of special features like bipedalism and high

encephalization. But now, fossils of putative humanlineage members have been reported from approxi-mately 6 Ma deposits in Chad and Kenya, and fossilsof the genus Ardipithecus from approximately 4.4 Masediments in Ethiopia include about 40 per cent of acomplete skeleton. Views differ on the relationshipof these forms to each other, and to the succeedingand better-known genus Australopithecus. Several

skeletons of the latter have been found in the lastfew years. These include an adult from Sterkfonteincave, South Africa, not yet certainly dated, anotheradult from 3.8 Ma deposits in Woranso-Mille,Ethiopia, a 3.3 Ma childs skeleton from Dikika,Ethiopia and four partial skeletons from MalapaCave, South Africa, dated to about 1.9 Ma. Dozensof other less complete hominin fossils from approxi-

mately 6 to 2 Ma have been found, as well as theseskeletons.

Our meeting was timed to coincide with the doublecelebration of Darwins 200th birthday and the 150thanniversary of the publication of The Origin of Species,and to take the first opportunity to bring together asmuch as possible of the rich, newly published data

concerning the earliest-known members of thehuman lineage. Through the generosity of the partici-pants, our hope that detailed images and casts of thenew material would be brought together for the firsttime during the meeting was amply met, although inthe event only one of us could be there to see theoutcome.

The meeting was also planned to showcase theinterdisciplinary nature of palaeoanthropology, by

highlighting the new methods that have been devel-oped to extract behavioural and life historyinformation from fossils. These included computermodelling of locomotor capabilities, finite elementmodelling of stresses in bone, laser scanning compari-sons of joint surfaces, quantification of semicircularcanal morphology and its relationship to headmotion, isotope analysis of teeth for dietary and cli-

mate reconstruction, confocal microscopy andtexture analysis of tooth wear to indicate diet, andreconstruction of life history parameters from

One contribution of 14 to a Discussion Meeting Issue The first fourmillion years of human evolution.

Phil. Trans. R. Soc. B (2010) 365, 32653266

doi:10.1098/rstb.2010.0179

3265 This journal is # 2010 The Royal Society

http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/


3/3

incremental lines in tooth enamel and dentine. Theanalytical sessions highlighted what could be accom-

plished by the careful reconstruction, study andanalysis of the new fossils.

By concentrating on the early part of the record ofhuman evolution, the meeting was also able to docu-ment the essential ecological, behavioural, andmorphological stages that underpinned the subsequentemergence of the genus Homo. Field workers reported

on studies of the behaviour of wild chimpanzees aspossible models for early hominin behaviour, and onthe geological and environmental setting of the fossils,as well as their anatomy and preservation. Context forthe discoveries was provided by colleagues who, forexample, used tephrostratigraphy, argonargon radio-metric dating, faunal and floral analysis, GIS satelliteimagery and taphonomy.

Our hope was to bring about a new understand-ing of early hominin evolution by bringing togetherthe newest fossils and the latest analytical methods,and we think the meeting at least helped progresstowards that ambitious goal. But the meeting alsoprovided the first opportunity to present many ofthe newest discoveries to scientific and public audi-

ences alike. A memorable conference dinner wasaccompanied by a display of replicas of spectacular

new material such as the just-published Ardipithecusskeleton, and the reconstructed Sahelanthropus

cranium.In the event, we have not been able to publish all of

the contributions made at the meeting, and this unfor-tunately included a description of the very completeaustralopithecine skeleton from Sterkfontein men-tioned earlier. Nevertheless we feel that The first fourmillion years of human evolution was an appropriate

measure of how much progress the field of palaeoan-thropology (a term unknown 150 years ago) hasmade in meeting Charles Darwins expectations. Wewould like to thank all the staff of the Royal Societywho worked on the planning and running of the meet-ing, and the editorial team who has worked so hard tobring this volume to fruition.

Alan Walker1

Chris Stringer2,* June 2010

1Anthropology & Biology, Penn State University,

University Park, PA 16802, USA2

Dept of Palaeontology, The Natural History Museum,

London SW7 5BD, UK*Author for correspondence ([email protected]).

3266 A. Walker & C. Stringer Introduction

Phil. Trans. R. Soc. B (2010)

mailto:[email protected]://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/http://rstb.royalsocietypublishing.org/mailto:[email protected]

phil. trans. r. soc. b 2010 walker 3265 6

Documents