Class updates Quiz 2 - This Wednesday, May 16 Need: Scantron 882-E (big one) and note paper for short answer questions Topics: End of chapter 8, chapter 9, chapters 10, a little of chapter 11 Short answer questions and study guide are on the website. Essay 2 Questions are harder! 1
Important human fossil finds Africa * Omo Kibish, Ethiopia - earliest fossils for Homo sapiens ~200 kya Near East *Skhul and Qafzeh Caves; Israel -both sites ~130-100 kya and 120-90 kya, respectfully -30 individuals retaining some premodern human traits 2
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 reach New Guinea and Aus ~50 kya *Lake Mungo -30-25 kya according to archaeological finds 3
Competing models of AMH dispersal 1. Complete Replacement Model AMH emerge in East Africa, disperse, then replace other hominin populations 2. Regional Continuity Model AMH traits appear in multiple regions 3. Partial Replacement Model ~AMH emerge still in East Africa, dispersed, replaced and interbred with existing hominin populations 4
Current evidence relating to early modern human origins and dispersal -Newer molecular evidence of interbreeding between humans and Neandertals -Frequent migrations between the different geographically-dispersed premodern populations during Pleistocene -Modern Africans lack Neandertal genes -Earliest Homo sapiens are found in East Africa ~200 kya -Homo sapien sites in Near East date to ~100 kya 5
Origins and dispersal - Replacement Models Complete Replacement -African origin ~200 kya -dispersed and replaced Old World populations -no interbreeding with premodern H. sapiens Disconfirms the hypothesis: Newer molecular evidence of interbreeding between humans and Neandertals 6
Origins and dispersal - Regional Continuity Model 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 -gene flow prevented local populations from evolving separately 7
Origins and dispersal - Regional Continuity Model Regional Continuity Model Milford Wolpoff -Local populations in Europe, Asia, and Africa evolved from Middle Pleistocene hominins to AMH Disconfirms the hypothesis: Recent genetic data fails to confirm the multiregional models 8
Origins and dispersal - Replacement Models Partial Replacement Model Revision: 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 9
Modern human/upper paleolithic culture Upper Paleolithic ~40 kya in Europe -new tool types -new materials: bone, antler, etc -elaborate burials with grave goods Warming trend ~30 kya tundra and steppe covered Eurasia where large game was hunted 10
Modern human/upper paleolithic culture Magdalenian -spear thrower - atlatl appears Punch blade technique - standardized Burin: chisel-like tools used to modify other tools Hypothesis: more effective tools and fire usage aided in meat processing might have played a role in AMH dental reduction 11
Modern human/upper paleolithic culture -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 12
Chapter 11 -Origins and dispersal of modern humans Trend across the hominins: 2 mya = multiple hominin genera 200 kya = multiple species of Genus Homo 40 kya = multiple subspecies 0 ya = Just Homo sapiens 13
The Pleistocene Epoch 14
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? 15