2. Modern Homo Sapiens Regional-Continuity Model (Milford Wolpoff, UMich)
Humans evolved more or less simultaneously across the entire Old World from several ancestral populations.
Rapid-Replacement Model (Chris Stringer, NHM London)
Humans evolved only once--in Africa from H. heidelbergensis ancestors--and then migrated throughout the Old World,
replacing their archaic predecessors. Also called the “Out of Africa” and “Killer Ape” hypothesis.

3. There used to be several species of Homo
- eventually gave rise to Homo erectus
- about 1.8 millions yr ago ( may be older)
- originated in East Africa
- migrated extensively
- Indonesia (Java man), China ( Peking Man)
  - compared to other Homo species
- larger brain
- flatter face, prominent brow ridges
- height and walking similar to modern humans
- tooth wear patterns - indicate meat eating
- active users of tools
- tool use evidence is present in the Australopithecus lines
- first evidence of extensive tool use Homo habilis
- contemporary of H. erectus

4. Homo erectus Homo sapiens

5. With large brains, migration and tool use
Homo erectus was quite successful
- lived as families in cave communities as recently as 35,000 yr ago
- hunter gatherer society - males /female pairing
- most primates have harems
- co-existed for some time with Homo sapiens
Homo sapiens
Two main theories on their origin
1. Out of Africa hypothesis
2. Multi regional hypothesis

6. Out of Africa hypothesis
- H. erectus moved out of Africa
- population that remained behind evolved and gave rise to Homo sapiens
- from this single source, Homo sapiens migrated outward and displaced the H. erectus population
- this hypothesis predicts
- only one speciation event occurred in a restricted African population
- all humans should show a high degree of relatedness

7. Support for Out of Africa
- African populations have more diversity in DNA than non-African population
- mitochondrial DNA analysis indicates a common African ancestor
- calculation indicates origin about 200,000 yr ago

8. Multi regional hypothesis
Homo sapiens evolved out of an interbreeding network of H. erectus that had migrated through out much of the world
- fossil record shows a gradual transition from archaic to modern human taking place at multiple sites outside of Africa.
Proposal - H erectus becomes gradually transformed into H. sapiens rather than being replaced by it.

9. What happened to Neandertals?
H. neanderthalensis coexisted with H. sapiens for at least 20,000 years, perhaps as long as 60,000 years
What happened?
Neandertals interbred with H. sapiens?
Neandertals were killed off by H. sapiens?
H. sapiens drove Neandertals into extinction by competition?