SummaryFinal 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 ModelMilford 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 hypothesisRecent genetic data ultimately fails to confirm the multiregional models
4
Complete Replacement
-African origin ~200 kya then dispersed and replaced Old World populations-no interbreeding with premodern H. sapiens
Disconfirms the hypothesisNewer 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 populationsModern Africans lack Neandertal genes - so interbreeding likely occurred AFTER AMH left Africa ~80-50 kya
5
Origins and dispersal - Replacement Models
Important fossil findsAfrica
* 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, etcCultural finds in Eurasia feature elaborate burials with grave goods
Warming trend ~30 kya resulted in tundra and steppe across Eurasia where large game was huntedIntense period of glaciation ~20 kya
8
Modern human/Upper paleolithic culture
Magdalenian-spear thrower - atlatl appearsPunch 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 artVenus figurines
-function/purpose of cave art not fully understood
Rock art also found in Africa dating ~28 kyaAlso find finely crafted bone tools dated ~80 kya
10
-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 lactaseLactase 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
Some Ch 12 - Biocultural Evolution