Ch 11 Modern Homo sapiens 1
Summary Final redtape Modern human morphology Origins and dispersal Important fossil finds Modern human/upper paleolithic culture 2
Modern humans - morphology and overview Anatomically modern human = AMH *Continued evolutionary trends: bipedalism, tool manufacturing, dental reduction, brain size 3
Origins and dispersal - Regional Continuity Model Question: Why is there uniform morphology across populations? Regional Continuity Model Milford Wolpoff -Local populations in Europe, Asia, and Africa evolved from Middle Pleistocene hominins to AMH Confirms the hypothesis -Frequent migrations between the different geographically-dispersed premodern populations during Pleistocene SO: gene flow prevented local populations from evolving separately Disconfirms the hypothesis Recent genetic data ultimately fails to confirm the multiregional models 4
Origins and dispersal - Replacement Models Complete Replacement -African origin ~200 kya then dispersed and replaced Old World populations -no interbreeding with premodern H. sapiens Disconfirms the hypothesis Newer molecular evidence of interbreeding between humans and Neandertals Partial Replacement Model(s) SO: revise to partial replacement - AMH emerged in Africa and then interbred with premodern humans in the various regions Confirms the hypothesis -African origins but 1-4% interbreeding between AMH and premodern populations Modern Africans lack Neandertal genes - so interbreeding likely occurred AFTER AMH left Africa ~80-50 kya 5
Important fossil finds Africa * Omo Kibish, Ethiopia - earliest fossils for Homo sapiens radiometrically dated ~195 kya * Herto, Ethiopia ~160-154 kya based on cranial morphology (nearly identical to modern cranial morphology) Fossil finds used to argue for AMH originating in Africa Near East * Skhul and Qafzeh Caves; Israel -both sites ~130-100 kya and 120-90 kya, respectfully with the remains of 30 individuals retaining some premodern human traits Note: Tabun site has Neandertal dated ~120 kya which adds some support to the area being a place where AMH and Neandertal interbred 6
Important fossil finds Asia * Zhoukoudian Caves again -AMH dated ~27 kya Oceania -All Australians descending from participants of a single migratory event ~50 kya -AMH inhabited areas around New Guinea and Aus ~50 kya * Lake Mungo - 30-25 kya according to archaeological finds 7
Modern human/upper paleolithic culture Upper Paleolithic ~40 kya in Europe -emergence of new tool types made of materials like bone, antler, etc Cultural finds in Eurasia feature elaborate burials with grave goods Warming trend ~30 kya resulted in tundra and steppe across Eurasia where large game was hunted Intense period of glaciation ~20 kya 8
Modern human/upper paleolithic culture Magdalenian -spear thrower - atlatl appears Punch blade technique standardized blades for various usages - burins and borers Hypothesis: more effective tools and usage of fire aided in meat processing might have played a role in AMH dental reduction 9
Modern human/upper paleolithic culture -emergence of cave paintings in W Europe and portable art Venus figurines -function/purpose of cave art not fully understood Rock art also found in Africa dating ~28 kya Also find finely crafted bone tools dated ~80 kya 10
Some Ch 12 - Biocultural Evolution -human evolution makes sense only in a cultural context Sickle-cell trait - adopting slash-and-burn agriculture resulted in humans living closer to/in mosquito breeding areas -so HbS became more frequent in the population -interacted with DDT Lactose intolerance - produce less of the enzyme lactase Lactase persistence - European groups sharing descent from Middle Eastern populations who were pastoralists ^-Cultural dependence on milke increased the frequency of lactose tolerance in populations via natural selection Examples that we're still evolving? 11