Tracing the paths taken by human populations in prehistory is a subject of great interest to biological anthropologists and archaeologists. DNA is the key to understanding how, and when, people moved from one place to the other. The Human Genographic Project has been collecting DNA data from all over the world in order elucidate this subject, and their results so far can be seen here, after the jump.
But what about human ancestors? Can we get DNA for them? In fact, enough usable genetic material has been recovered from Neanderthal remains that researchers were able to sequence the Neanderthal genome last year. And what they found was remarkable - evidence that at some point, Neanderthal populations interbred with those composed of modern Homo sapiens sapiens.
These researchers found that somewhere between 1% and 4% of the genes in modern humans are inherited from Neanderthals. But here's the most remarkable part of their findings, in my view: only non-African populations interbred with Neanderthal groups. There are several logical conclusions to draw from this: one, that Neanderthals never encountered modern human groups in Africa in any fashion liable to promote intermingling (we can't say that they weren't there, just that the two groups didn't intermix on that continent); two, that two ostensibly different species of human not only co-existed, but managed to do so happily enough to swap a detectable amount of genetic material.
And finally, most humorously, it turns out that modern human groups from Africa have the "purest" DNA of all, if you consider that to mean that they have no genetic inheritance from older, allegedly more "primitive" human ancestors (the issue of how "primitive" Neanderthals really were is a topic for another post). I wonder what people who are biased against Africans will make of that?