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Origin of Modern Humans

Scientists have attempted to explain the origin of modern humans using models. Outline and critique the arguments presented in the “Multiregional”, “Assimilation”, and “Replacement” Models of modern human origins; referring to evidence from fossil finds and dates; genetics; and the archaeological record.

Multiregional Model (aka Regional Continuity)

Summary:
“Lumper”
Predict regional lineages of Homo sapiens
Ancient Homo sapiens ancestry; 1.7 mya
Gene flow makes us one species; multiregional origin
Repeated migration; “Out of Asia”
Regional Homo erectus characteristic in local Homo sapiens (ancestor descendent, Asia) Neandertals interbred with anatomically modern humans (AMH)
Major proponent: Milford Wolpoff

Local populations in Europe, Asia, and Africa continued their indigenous evolutionary development from premodern forms to AMH Modern Homo sapiens did not exclusively originate in Africa
Through gene flow and natural selection, local populations would not have evolved independently of each other and such mixing would prevent speciation between the regional lineages and maintained human beings as a single though polytypic species That is, all hominins following Homo erectus are classified as Homo sapiens

*Recent data suggest that this model is not longer useful for telling us anything about origins of modern humans

Complete Replacement Model

Summary:
“Splitter”
Predict Homo sapiens fossils first came from Africa
Recent Homo sapiens ancestry; 200 kya
Speciation event -> new species -> Homo sapiens; localised origins Replaced indigenous hominins; “Out of Africa”
Regional overlap of Homo erectus and archaic Homo sapiens
Neandertals did not interbreed with humans
Major proponent: Chris Stringer

AMH first evolved in Africa and only later dispersed to rest of the world, where they then replaced existing hominins AMH arose within last 200,000 years, then migrating to Asia and Europe, completely...
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