Answer to Question #149983 in Evolution for Brightness

Question

There are two popular theories currently debated concerning the origins of
hominids. Name the two theories and expatiate (supportive arguments) on the
out of Africa theory.

Answer 1

There are two key theories have been put forward to explain the evolution of hominids. These are the Multiregional Continuity Theory and Replacement Theory.

Replacement Theory (also known as the Out of Africa model) says that hominids first evolved in Africa and then spread out from it after 100,000 years ago, replacing the Archaic populations that they encountered from Europe to China. The evidence for Replacement is pretty good and based on multiple, independent lines of evidence:

1. In the fossil record, most physical anthropologists don’t see the ancient, regional variations that the Continuity model demands.

2. In the fossil record, archaic skeleton traits disappear rapidly after the introduction of AMHss. In Europe, for example, only 10,000 years after AMHss appears, the Neanderthals go extinct after 170,000 years of Neanderthal survival in Europe.

3. Archaic tool types disappear rapidly and are replaced with AMHss tool types.

4. Symbolism first appears in Africa and spreads, also replacing the distinctly nonsymbolic archaeological traces of Archaic life.

5. Genetic studies show that modern populations outside Africa are very similar to one another, indicating that everyone outside Africa emerged from the continent (and then diverged into regional groups) relatively recently.

6. Studies show that humans carry very little Neanderthal DNA, if any, so even if Neanderthals and AMHss did interbreed, it didn’t matter in the long run.