Anthropology: the Origin and Dispersal of Modern Humans

1. Explain the complete replacement model, the partial replacement model, and the regional continuity model. The replacement model of Christopher Stringer and Peter Andrews proposes that modern humans evolved from archaic humans 200,000-150,000 years ago only in Africa and then some of them migrated into the rest of the Old World replacing all of the Neandertals and other late archaic humans beginning around 60,000-40,000 years ago. If this interpretation of the fossil record is correct, all people today share a relatively modern African ancestry. All other lines of humans that had descended from Homo erectus presumably became extinct. From this view, the regional anatomical differences that we now see among humans are recent developments–evolving mostly in the last 40,000 years. This hypothesis is also referred to as the “out of Africa”, “Noah’s ark”, and “African replacement” model.

The regional continuity model advocated by Milford Wolpoff proposes that modern humans evolved more or less simultaneously in all major regions of the Old World from local archaic humans. For example, modern Chinese are seen as having evolved from Chinese archaic humans and ultimately from Chinese Homo erectus. This would mean that the Chinese and some other peoples in the Old World have great antiquity in place. Supporters of this model believe that the ultimate common ancestor of all modern people was an early Homo erectus in Africa who lived at least 1.8 million years ago. It is further suggested that since then there was sufficient gene flow between Europe, Africa, and Asia to prevent long-term reproductive isolation and the subsequent evolution of distinct regional species. It is argued that intermittent contact between people of these distant areas would have kept the human line a single species at any one time. However, regional varieties, or subspecies, of humans are expected to have existed.

Proposed by Gunter Brauer, University of Hamburg, this idea also starts with the idea that Homo sapiens evolved in Africa and migrated into both Europe
and Asia. However, Mr. Brauer believes that there was some interbreeding, to a small extent with local populations. The result being that old groups were replaced with genetically different populations which evolved into modern Homo sapiens of the world today. In short, a gradual replacement of the old with the new. Ch 12 : Human Variation and Adaptation

1. How do environmental factors influence our interpretation of race. Environmental factors such as global warming may expand the range of tropical diseases. The spread of diseases is associated with encountering people; this include crossing borders and penetrating remote areas. The increasingly large human population leads to overcrowding, unsanitary conditions and the spread of communicable disease. Human variation is the result of adaptations to environmental conditions.

Ch 13: the anthropological perspective on the human life course 1. Do you think that natural selection operates on human behaviors such as parenting and aggression. I think that natural selection does operate on human behaviors such has survival of the fittest. In the real world its every man for himself and along the way you have to adapt to your surroundings. For example I didn’t grow up in a good neighborhood; however, my parents were always positive enough to me and my brothers that there is a light at the end of the tunnel. So we never got into any type of gangs or drugs, we simply took what my parents said and implemented on our daily lives. Even though we grew up poor we never felt aggression or depressed about what we had. We just took what we had and thanked the lord.

Ch 14: lessons from the past, lessons for the future
1. How is human culture related to environmental degradation and overpopulation