HOW Neanderthal are you? That question sounds vaguely insulting. But unless you are African, or of recent African ancestry, the answer is likely to be 1-3%.

Though Homo sapiens is the only type of human around at the moment, that was not true until recently. Sixty thousand years ago, when modern humans first left Africa, they encountered other species of humanity, such as Neanderthals (imagined above, in an artist’s interpretation), in Europe and Asia. In some cases, they interbred with them. The genetic traces of those encounters remain in modern human genomes. And two studies, one just published in Nature, and one in Science, have now looked in detail at this miscegenation, and tried to understand its consequences.
The Nature study, conducted by Sriram Sankararaman of Harvard Medical School and his colleagues, looked at the genomes of 1,004 living people of European and Asian descent and compared them with Neanderthal DNA from a 50,000-year-old toe bone found in a Siberian cave, and also with the genomes of 176 west Africans. This latter group, Dr Sankararaman assumed, could have little Neanderthal DNA in them because Neanderthals, as far as can be determined from the fossil record, lived only in Europe and western Asia. Continue reading