More human than human

So the next time some sub-literate blowhard starts dribbling to you about racial purity, white superiority and the evils of race mixing, you might want to mention to him that it turns out that the only pure members of the species homo sapiens sapiens on Earth are Africans.

Early humans mated with Neanderthals, and modern human DNA was changed forever by it. New genetic evidence, announced today, proves that most humans share 1-4% of their DNA with Neanderthals. Unless you're from Africa, in which case you're Neanderthal-free. A massive, multiyear study at the Max Planck Institute compared the genomes of three Neanderthal women (reconstructed from 38,000-year-old bones) with five humans from across the world - two from Africa, one from Europe, one from China, and one from Papua, New Guinea. The results show that humans and Neanderthals did interbreed, possibly as early as 100 thousand years ago when early humans were immigrating out of Africa into Europe and Asia. This immigration pattern also helps to explain why the two human genomes from Africa have no traces of Neanderthal in them. The African population never interbred with our hominid cousins.

All those Star Trek episodes that assume that we'll cheerfully start breeding with aliens as soon as we meet them might not have been too off the mark. We've already shacked up with the only other species we ever met.