origin and dispersal of modern humans

1. Origin and Dispersal of Modern Humans Homo sapiens sapiens

2. Homo sapiens sapiens Members of early Homo sapiens sapiens are our direct kin. They were much like us skeletally, genetically, and (most likely) behaviorally. They were the first hominids that we can confidently refer to as �fully human.�

3. Modern Homo sapiens evolved in Africa around 150 k.y.a. and then dispersed to the rest of the Old World and Australia and then later into the Americas. These first modern humans are clearly the descendents of the previously discussed pre-modern humans. The primary questions that need to be addressed are: When did modern humans first appear? Where did the transition take place? What was the pace of the evolutionary change? How did the dispersal of modern humans to other areas of the world take place?

4. Theories of Human Origins Complete Replacement Model Regional Continuity Model Partial Replacement Model

5. The Complete Replacement Model (Recent African Evolution) Developed by Christopher Stringer and Peter Andrews, this model proposes that anatomically modern populations arose in Africa about 200 k.y.a., dispersed from Africa, replacing pre-modern populations in Asia and Europe. This model assumes that the origin of modern humans was a speciation event, so there could be no modern human/pre-modern human admixture.

6. Stringer argues that even if interbreeding could have taken place, very little actually occurred. The mtDNA analyses of recent human populations that tend to support this model have met with criticism for their methods and conclusions. Analyses of the Y chromosome indicate humans are much less genetically variable than other primates, thus supporting the replacement hypothesis. Also, ancient mtDNA studies (of Neandertals) support the replacement scenario.

7. The Regional Continuity Model (Multiregional Evolution) This model, defended by Milford Wolpoff and others, proposes that pre-modern forms throughout the Old World evolved into modern humans. The earliest modern H. sapiens did not arise exclusively in Africa, as postulated by the complete replacement model. Gene flow between geographically widespread populations prevented speciation.

8. Partial Replacement Model Proposed by G�nter Br�uer of the University of Hamburg. Postulates the earliest dates for African modern Homo sapiens at over 100,000 y.a.

9. Initial dispersal of H. sapiens sapiens from South Africa was influenced by environmental conditions. Moving into Eurasia, modern humans hybridized with resident groups, eventually replacing them. The disappearance of archaic humans was due to both hybridization and replacement.

10. Early Modern Homo sapiens Discoveries from Africa and the Near East

11. Early Modern Homo sapiens Discoveries From Africa and the Near East

12. Time Line of Homosapiens sapiens Discoveries

13. Early Modern Homo sapiens Discoveries - Europe, Asia, Australia

14. Early Modern Homo sapiens Discoveries - Europe, Asia, Australia

15. Cro Magnon

16. Skuhl 5

17. Technology and Art in the Upper Paleolithic In Europe, the Upper Paleolithic began about 40 k.y.a. and this cultural period is divided into 5 different industries: Chatelperronian Aurignacian Gravettian Solutrean Magdalenian

18. Cultural Periods of the European Upper Paleolithic

19. Starting about 30 k.y.a., there was a warming trend that produced tundra and steppe throughout much of Eurasia, creating a �hunter�s paradise� of plentiful large game. The Upper Paleolithic people became very successful, and this period saw the highest human population densities up to that time in Europe and perhaps Africa. Cultural innovations in Eurasia such as warmer, better-fitting sewn clothing allowed Upper Paleolithic peoples to occupy eastern Europe and northern Asia for the first time. The warming trend ended about 20 k.y.a. as the last, most intense period of glaciation began.

20. Upper Paleolithic Tools

21. Upper Paleolithic Tools

22. The Upper Paleolithic is distinguished by the appearance of new tool types as well as the increased use of materials such as bone, antler, and ivory. The spear thrower, or atlatl, as well as barbed harpoons appear during the Magdalenian. The punch blade technique provided abundant standardized blades that were fashioned into a variety of tools such as burins and borers. C. Loring Brace suggests that the reduction of tooth size and the decreased protrusion of the face reflect an increase in the use of technology for food production.

24. Upper Paleolithic Tools

25. The Punchblade Technique A large core is selected. The top portion is removed by use of a hammerstone.

26. The Punchblade Technique The objective is to create a flat surface called a striking platform.

27. The Punchblade Technique The core is struck by use of a hammer and punch (made of bone or antler) to remove the long narrow flakes (called blades).

28. The Punchblade Technique The blades can also be removed by pressure flaking.

29. The Punchblade Technique The result is the production of highly consistent sharp blades. They can be used, as is, as knives; or can be modified to make a variety of other tools.

30. Upper Paleolithic Stone Tool Efficiency