Recent human evolution in Evolution
Evolutionary geneticist Alan Templeton has an article in Evolution, GENETICS AND RECENT HUMAN EVOLUTION:
Starting with “mitochondrial Eve” in 1987, genetics has played an increasingly important role in studies of the last two million years of human evolution. It initially appeared that genetic data resolved the basic models of recent human evolution in favor of the “out-of-Africa replacement” hypothesis in which anatomically modern humans evolved in Africa about 150,000 years ago, started to spread throughout the world about 100,000 years ago, and subsequently drove to complete genetic extinction (replacement) all other human populations in Eurasia. Unfortunately, many of the genetic studies on recent human evolution have suffered from scientific flaws, including misrepresenting the models of recent human evolution, focusing upon hypothesis compatibility rather than hypothesis testing, committing the ecological fallacy, and failing to consider a broader array of alternative hypotheses. Once these flaws are corrected, there is actually little genetic support for the out-of-Africa replacement hypothesis. Indeed, when genetic data are used in a hypothesis-testing framework, the out-of-Africa replacement hypothesis is strongly rejected. The model of recent human evolution that emerges from a statistical hypothesis-testing framework does not correspond to any of the traditional models of human evolution, but it is compatible with fossil and archaeological data. These studies also reveal that any one gene or DNA region captures only a small part of human evolutionary history, so multilocus studies are essential. As more and more loci became available, genetics will undoubtedly offer additional insights and resolutions of human evolution.
Here is a summary of Templeton’s offering, “Out of Africa again and again.”
Related: Neandertal introgression.
Labels: Evolution
The last statement is trite. Multilocus sites have been used which support the “out of Africa” hypothesis. If you are suggesting a more “multiregional” hypothesis (the main other theory), then you might need to explain why the variation between human populations are not on the order of millions of years old. But my main point has already been stated. Perhpas more through research would have made that apparent.
“out of Africa”
note that he said “out of africa replacement.”
Templeton’s objections are reasonable, since many alternative explanations to “out of Africa replacement” are possible and were never studied. The “out of Africa replacement” explanation’s strenght is based on introspection, on self knowledge, on imagining what we would have done in the same situations. And on field observations of contemporary human behaviour in similar scenarios. The our of Africa replacement explanations hits us instintively as right, yeah, it must have happened that way. Of course, should anyone prove that it not right, I would change my opinion. Templeton is free to do it, but pointing to alternatives is not enough.