Pleistocene Homo sapiens from Middle Awash Ethiopia Tim D White Berhane Asfaw David DeGusta Henry Gilbert Gary D Richards Gen Suwa F Clark H ID: 37235
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andfacialportionswererestored.Apartialdentitioncomprisesbothleftdeciduousmolarsaswellasuneruptedfullyformedcanineandpremolarcrowns,anda®rstmolarwithwearfacets.Onthebasisofmodernhumanstandards,weestimatetheindividual'sageatdeathas6±7years.ThecraniumismorphologicallycompatiblewiththeHertoadults.Itsvaultispentagonalinposteriorpro®le,andthefaceshowsaclearcaninefossaandstrongmalarincisura.Thesupraorbitalsarepoorlydeveloped,withpronouncedvertical-ityandfrontalbossing.Aswiththeadults,theHertochildexhibitsacharactercomplexthatisdistinctlyunlikethatofNeanderthalsTheHertocraniaarethusnotNeanderthals.TheyexhibitnoneofthenotablyderivedfeaturesthatarecommontothoseEurasianspecimensattributedtoaNeanderthallineagerepresentedbyamultitudeoffossilsofsuccessiveages,andculminatinginthe`classic'Neanderthals.TheHertohominidsarecontemporaneouswithobviousantecedentsofthe`classic'Neanderthals,butdonotresemblethem.TheHertohominidsalsohavederivedcharactersnotseeninHomoerectusandinotherapparentlyolderAfricanspecimenssuchasBodo,SaldanhaandKabwe,andsocannotbeassignedtothosegroups. Figure1TheHertoBOU-VP-16/1adultcraniuminlateral,frontal,three-quarter,posterior,superiorandinferiorviews.Scalebar,1cm. letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature743 WhenBOU-VP-16/1iscomparedmetricallywithalargeglobalsampleofmodernhumancrania(Figs3and4),similaritiesanddifferencesareapparent.ThelargeoverallsizeofBOU-VP-16/1standsout,aspectsofwhicharedescribedabove.Apartfromitsexceptionallygreatanterior±posteriorlength,thecraniumexhibitslargevaultdimensionstogetherwithadeep,tallandbroadface.However,theorbitandcheekbonedimensionsaresmaller,andfacialprojectionanteriortothezygomaticisrelativelyweak.Thesemetricaspectscontributetothecomparativelymoderngestaltoftheface(contrary,forexample,toNeanderthalsorKabwe).BOU-VP-16/1ismetricallyindistinguishablefromanatomicallymodernHomosapiens(AMHS)initshighcranialvaultandrelativelylargefrontalandparietalsagittaldimensionsasexpressedintheirsize-standardizedvariables(bygeometricmeansof50variables).MetricindicesofneurocranialglobularityandfacialretractionhavebeenproposedasdiagnosticcriteriaforAMHS.Theformerindexisestimatedat0.54inBOU-VP-16/1,withintherangesuggestedtobecharacteristicofAMHS.Hereagain,though,theBOU-VP-16/1parietalbonetendstobelesscurved,theoccipitaldistinctly¯exed,andsupraorbitalsprojectinganteriorly,attestingtoitsretentionofarchaicmorphology.Amongtheglobalsampleofmodernhumans,theHertocrania,bothmetricallyandnon-metrically,lackanyderivedaf®nitywithmodernAfricancraniaorwithanyothermoderngroup,con®rmingearliersuggestions.Instead,theclosestapproximationsamongmodernindividualstotheoverallmorphology,sizeandfacialrobusticityarefoundinsomeAustralianandOceanicindividuals,althoughthesearealsoclearlydistinctfromtheHertohominids. Figure2TheHertoBOU-VP-16/5child'scraniuminfrontal,lateral,posterior,three-quarter,superiorandinferiorviews.Scalebar,1cm. letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature TheHertocraniaarelikewisedistinctfromPleistocenerepresenta-tivesofAMHSinsomeofthefeaturesoutlinedabove.Insupra-orbitalmorphologyandoccipitalconstructionandrobusticity,BOU-VP-16/1isdistinguishedfromthelaterKlasiesandQafzehspecimensoftenidenti®edastheearliestAMHS.OtherAfricanfossilcraniathatarepossiblytemporallyintermediatebetweentheearlyforms(suchasBodoandKabwethe`earlyarchaicH.sapiensofBra12,13)andAMHSexhibitconsiderablemorphologicaldiversity.Theaf®nitiesofthesespecimens(suchasNgaloba,Omo2,EliyeSpringsandJebelIrhoudthe`latearchaicH.sapiens'of)haveproveddif®culttoassess.However,regardlessoftheparticularrelationshipsbetweenthesespecimens,thegeneralevolutionarypositionoftheHertosampleisclear.ThemorphologyoftheHertocraniafallsbetweenthemoreprimitivemorphologyoftheearlierAfricanspecimens(suchasBodoandKabwe)andthemorederivedmorphologyoflaterAMHS(suchasKlasiesandQafzeh).TheHertocraniaareintermediate,metricallyandnon-metrically,inanAfricanseriesspanningabout600,000±100,000yearsago,althoughtheyarenottheonlysuchintermediatesintheseries.Theysampleapopulationthatisonthevergeofanatomicalmodernitybutnotyetfullymodern(Fig.4).Thisconclusionissupportedbycomparativeanatomical,metricandcladisticconsiderations,andhasprofoundevolutionaryandtaxonomicimplications.SomegeneticstudieshaveconcludedthatpopulationswhosecontributionsquantitativelydominatethemodernhumangenepoolwerelocatedinMiddlePleistoceneAfrica.However,fossilcon®rmationofthesepredictionshasbeenlacking.ThishaspromptedsometoassertthatthesparseAfricanrecorddidnotfalsifythe`multiregional'evolutionofAMHSinEuropeandtheFarEast15±17.TheHertocraniafailtocon®rmsuch`multiregional'speculationandconformmorecloselytomostmolecularpredic-.Theyadddirectfossilevidenceabouttheanatomyofthepopulationsancestraltomodernhumans.ThemanymorphologicalfeaturessharedbytheHertocraniaandAMHS,totheexclusionofpenecontemporanousNeanderthals,provideadditionalfossildataexcludingNeanderthalsfromasigni®cantcontributiontotheancestryofmodernhumans.TheHertohominids,althoughclarifyingevolutionaryquestions,raisetaxonomicissues.Widelyscattered,oftenpoorlydated,andmorphologicallydiverseMiddleandUpperPleistocenehominidcraniafromtheeasternhemispherehavebeenassignedtovarioustaxa.Inadditiontothedif®cultiesinherentinpartitioninglineages,severaloftheavailablespeciesnamesarebasedoninadequatetypespecimens(suchasH.heidelbergensis,Schoetensack,1908;H.helmei,Dreyer,1935;andH.njarasensis,ReckandKohl-Larsen,1936).BecausetheHertohominidsaremorphologicallyjustbeyondtherangeofvariationseeninAMHS,andbecausetheydifferfromallotherknownfossilhominids,werecognizethemhereHomosapiensidaltu,anewpalaeosubspeciesofHomosapiensMethods).Theavailableevidencefromcomparativeanatomy,multivariateanalysisandcladisticconsiderationssuggeststhatH.rhodesiensis'(BodoandKabwe)wasultimatelyancestraltoH.sapiensidaltu,whichinturnwasancestraltoHomosapiensTheMiddleAwashvalleyofEthiopiahasnowyieldedasuccessionofhominidsspanningthepast6millionyears21±26Withinthisstudyarea,andwithinthegenusHomo,thereexistsachronologicallyorderedsuccessionofincreasinglyderivedhominids:fromDaka(1.0millionyearsago)toBodo(500,000yearsago)toHerto(155,000yearsago).Whenconsideredwiththeevidencefromothersites,this Figure3Univariatecomparisons,byanatomicalregionanddimension,ofBOU-VP-16/1withQafzeh6,Kabwe,LaFerrassie,andmodern(recent)humanmales.AllcomparativedataarefromHowellsonoriginalspecimens.ThelistedmeansarethegrandmeansofthemalesamplemeansfortheskeletalpopulationsstudiedbyHowells.ThemeasurementabbreviationsareasperHowells,andarealsode®nedintheSupplementaryInformation.Symbols:multiplicationsigns,Herto;diamonds,Qafzeh;plussigns,Kabwe;opencircles,LaFerrassie1;®lledcircles,meansformodernhumans;greybars,rangeformodernhumans.Ht,height. letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature745 Figure4a,ComparativeanalysisoftheHertoBOU-VP-16/1adultcranium.,Fromlefttoright,inanteriorandlateralviews,Bodo(TheNationalMuseumofEthiopia,AddisAbaba),Kabwe(TheNaturalHistoryMuseum,London),HertoBOU-VP-16/1(boxed),Qafzeh9(TheRockefellerMuseum,Jerusalem),and,insetbelow,theLaFerrassieNeanderthal(MuseedeL'Homme,Paris),alltothesamescale,withapproximatetimeline.,Plotof®rsttwoprincipalcomponentscores,withthepositionofHertoBOU-VP-16/1givenbythefossilsymbolmarked`x'.Homoerectus,includesKNM-ER3733andKNM-ER3883(openstars),andSangiran,NgandongandZhoukoudiancrania(plussigns).`Neanderthals'(Amud,Atapuerca,Gibraltar,LaFerrassie,LaChapelle,LaQuina,MonteCirceo,Petralona,Saccopastore,Shanidar,SteinheimandTabuncrania)areshownbycircledletterN,Omo2andKabweby®lledstars,andfossilAMHS(Qafzeh6,9,Skhul5,Cro-MagnonandPredmostõ3crania)by®lledcircles.Populationmeansof28malemodernhumansamples(shownbyopencircles)weretakenfromHowellsandincludedintheprincipal-componentsanalysis(PCA).Thiswasdonetoshowtheplotpositionofmodernhumansandthedegreeofinter-populationvariation.Theovals(lineandshade)representthe1s.d.dispersionareasofthefossilAMHSsample,theNeanderthalsample,theAsianH.erectussample,andthemodernhumanpopulationmeans.Themeasurementsusedforthisanalysisarethoseofthecranialvault(GOL,NOL,XCB,XFB,AUB,ASB,FRCandPAC;seeSupplementaryInformationformeaningsofabbreviations).Therawmeasurementswerestandardizedforsizebythegeometricmeanofalleightvariables.PCAwasperformedonthesize-standardizedvariablessoastodescribeshape.Thelimitednumberofmeasurementsisanecessarylimitationwhenincludingfossilspecimens.Thisgraphthusillustratesthepheneticaf®nitiesasre¯ectedinalimitedpartoftheanatomy.ThecomparativedataarefromArsuagaetal.andHowells,Plotofthe®rstthreeprincipalcomponentsofthecompleteHowellsdatasetof3,024modern(recent)humanindividuals,plusHertoBOU-VP-16/1(thefossilsymbolmarked`x').Theprincipalcomponentsweregeneratedfromthenatural-log-transformeddata.ThisandotherresultsofmultivariateanalysesdemonstratethepheneticdistinctivenessoftheHertohominidsrelativetomodernhumancrania.However,®nerdetailsoftherelativepositionofHertohominidsinmultidimensionalmorphometricspacearedif®culttointerpretbecauseofthenecessaryinclusionofestimatedmeasurements.ThemeasurementsusedaregivenintheSupplementaryInformation. letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature showsthatmodernhumanmorphologyemergedinAfricalongbeforetheNeanderthalsvanishedfromEurasia.MethodsOrderPrimatesL.,1758SuborderAnthropoideaMivart,1864SuperfamilyHominoideaGray,1825FamilyHominidaeGray,1825Homosapiensidaltusubsp.nov.Etymology.Thesubspeciesname`idaltu'istakenfromtheAfarlanguage.Itmeans`elder'.Holotype.BOU-VP-16/1(Fig.1),anadultcraniumwithpartialdentition.HolotypeandreferredmaterialarehousedattheNationalMuseumofEthiopia,AddisAbaba.HolotypefromBouriVertebratePaleontologyLocality16(BOU-VP16);differentiallycorrectedGPScoordinates:10Nand40Referredmaterial.BOU-VP-16/2cranialfragments;BOU-VP-16/3parietalfragment;BOU-VP-16/4parietalfragment;BOU-VP-16/5child'scranium;BOU-VP-16/6R.uppermolar;BOU-VP-16/7parietalfragment,BOU-VP-16/18parietalfragments;BOU-VP-16/42upperpremolar,BOU-VP-16/43parietalfragment.Stratigraphyandage.BouriFormation,UpperHertoMember.DatedbyArtobetween160,000and154,000yearsago(ref.6).Diagnosis.Onthelimitedavailableevidence,asubspeciesofHomosapiensdistinguishedfromHoloceneanatomicallymodernhumans(Homosapienssapiens)bygreatercraniofacialrobusticity,greateranterior±posteriorcraniallength,andlargeglenoid-to-occlusalplanedistance.HomosapiensidaltuisdistinguishedfromtheholotypeofHomorhodesiensis(Woodward,1921)byalargercranialcapacity,amoreverticalfrontalwithsmallerface,andmoremarkedmidfacialtopography(forexample,caninefossa).WeconsidertheholotypesH.helmeiandH.njarasensistoofragmentaryforappropriatecomparisons.Received21November2002;accepted14April2003;doi:10.1038/nature01669. 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boratoired'Anthropologie,Facultedecine,SecteurNord,Blvd.PierreDramart,13916MarseilleCedex20,FranceTheUniversityMuseum,TheUniversityofTokyo,Hongo,Bunkyo-ku,Tokyo113-0033,JapanHyogoMuseumofNatureandHumanActivities,Yayoigaoka,Sanda669-1546,JapanBerkeleyGeochronologyCenter,2455RidgeRoad,Berkeley,California94709,CNRSUMR6046,UniversitedePoitiers,FranceRiftValleyResearchService,P.O.Box5717,AddisAbaba,Ethiopia...............................................................................................................................Clarifyingthegeographic,environmentalandbehaviouralcon-textsinwhichtheemergenceofanatomicallymodernoccurredhasproveddif®cult,particularlybecauseAfricalackedadequategeochronological,palaeontologicalandarchae-ologicalevidence.ThediscoveryofanatomicallymodernfossilsatHerto,Ethiopia,changesthis.HerewereportonstratigraphicallyassociatedLateMiddlePleistoceneartefactsandfossilsfrom¯uvialandlakemarginsandstonesoftheUpperHertoMemberoftheBouriFormation,MiddleAwash,AfarRift,Ethiopia.Thefossilsandartefactsaredatedbetween160,000and154,000yearsagobypreciseagedeterminationsusingtheArmethod.ThearchaeologicalassemblagescontainelementsofbothAcheuleanandMiddleStoneAgetechnocom- letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature747 HomosapiensMiddleAwash,EthiopiaTimD.White,BerhaneAsfaw,DavidDeGusta,HenryGilbertGaryD.Richards,GenSuwa&F.ClarkHowellDepartmentofIntegrativeBiologyandLaboratoryforHumanEvolutionaryStudies,MuseumofVertebrateZoology,UniversityofCalifornia,Berkeley,California94720-3160,USARiftValleyResearchService,P.O.Box5717,AddisAbaba,EthiopiaLaboratoryforHumanEvolutionaryStudies,MuseumofVertebrateZoology,UniversityofCalifornia,Berkeley,California94720-3160,USATheUniversityMuseum,TheUniversityofTokyo,Hongo,Bunkyo-ku,Tokyo,113-0033,Japan...............................................................................................................................TheoriginofanatomicallymodernHomosapiens letterstonatureNATURE|VOL423|12JUNE2003|www.nature.com/nature © 2 00 3 Nature Publishing Group