资源描述：
《The Story of Human Origins》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、…fromsosimpleabeginningendlessformsmostbeautifulandmostwonderfulhavebeenandarebeing,evolved.(p.460,TheOriginofSpecies,1859/1979)Chapter2TheStoryofHumanOriginsLetususethislastsentenceofCharlesDarwin’sOriginofSpeciestostartourdiscussionabouttheoriginofhumankind.This
2、chapterissonamedbecauseboththepaleoanthropologicalandgeneticliteratureinwhichhumanoriginsaretracedcontainasmanydifferentinterpretationsas,ifnotmorethan,facts.Thejourneyofhumanoriginismanyastorywhichalsodependsonthestoryteller.Thehumanoriginstorypresentedherewillbe
3、organizedintothreeparts.Ifirstpresentfossilrecordstodocumenttheexistingevidenceaboutourhumanodyssey.Thisispart1.Iwillthenpresentthetwomajorinterpretationsofthesedata,namely,themultiregionalhypothesis,whichiscontainedinpart2,andthereplacementortheOutofAfricatheoryi
4、npart3.Part1:FossilsandDates,andTheirFindersandDatersThefactthatweandalltheorganismsonearthstartedfromasinglecellbillionsofyearsagomakesitdifficulttofindastartingpointtonarratethehistoryofhumanevolution.Sinceweoftensay(correctly)thatmancomesfromape,letusstartwitha
5、pewhicharosefromOldWorldmonkeys33to24millionyearsago.Thefossilmonkey,Aegyptopithecus,whichhadapelikefeatureswasfirstfoundinEgypt.OtherfossilsfoundineasternAfricaanddatedtobe23to15millionyearsagowereconsideredancestraltomanandAfricanapes.Howevertherewerefewfossilre
6、cordsforAfricanapesfrom6to13.5millionyearsago.About12to15millionyearsago,thelivingapesbrokeintotwogroupsthatarereferredtoasAfricanapeandAsianape.TheAfricanapegroupincludesgorilla,chimpanzees,andman.TheAsianapegroupincludesgibbonsandtheorangutan.Asshowninthefigure,
7、theclosestrelativeofhumanbeingischimpanzee.Thus,theapefromwhichmaniscommonlysaidtocomefromrefersspecificallytochimpanzee.Whendidhominidsbreakoutfromchimpanzee?Foralongtimeitwasthoughttobe15to16millionsyearsago.RecentadvancesinmolecularclockandDNAresearchhavenowspe
8、cifiedthesplittingdatetobebetween5and8millionyearsago.Itisalsoknown,andwithmorecertainty,thatthesplitbetweenhumansandchimpanzeeismorerecentthanthesplitb
