人类进化1：混沌初开

Wheredidwecomefrom?Whatmakesushuman?Anexplosionofrecentdiscoveriesshedslightonthesequestions,andNOVA'scomprehensive,three-partspecial,"BecomingHuman,"examineswhatthelatestscientificresearchrevealsaboutourhominidrelatives.Part1,"FirstSteps,"examinesthefactorsthatcausedustosplitfromtheothergreatapes.Theprogramexploresthefossilof"Selam,"alsoknownas"Lucy'sChild."PaleoanthropologistZerayAlemsegedspentfiveyearscarefullyexcavatingthesandstone-embeddedfossil.NOVA'scamerasaretheretocapturetheunveilingoftheface,spine,andshoulderbladesofthis3.3million-year-oldfossilchild.AndNOVAtakesviewers"insidetheskull"toshowhowourancestors'brainshadbeguntochangefromthoseoftheapes.Whydidleapsinhumanevolutiontakeplace?"FirstSteps"exploresaprovocative"bigidea"thatsharpswingsofclimatewereakeyfactor.