A Neanderthal who's been given a shave and a new suit

Neanderthal DNA

The project was finally generating useful results -- essentially, long lists of A's, T's, G's, and C's -- when one of the members of Paabo's ream, David Reich, a geneticist at Harvard Medical School, noticed something odd. The Neanderthal sequences were, as expected, very similar to human sequences. But they were more similar to some humans than others. Specially, European and Asians shared more DNA with Neanderthals and did Africans. "We tried to make this result go away," Rich told me. "We thought, 'This must be wrong' "

Many members of Paabo's en.wikipedia.org/wiki/Svante_P%C3%A4%C3%A4bo team suspected that the Eurasian bias was a sign of contamination. At various points, the samples had been handled by Europeans and Asians; perhaps these people had got their DNA mixed in with the Neanderthas'. Several tests were run to assess their possibility. The results were all negative. "We kept seeing this pattern, and the more data we got, the more statistically overwhelming it became," Rich said. Gradually, the other team members started to come around. In a paper published in Science in May 2010, they introuced what Paabo has come to refer to as the "leaky replacement" hypothesis. (The paper was later voted the journal's outstanding article of the year, and the team received a twenty-five-thousand dollar prize). Before modern humans'replaced" the Neanderthals, they had sex with them. The liaisons produced children, who helped to populate Europe, Asia and the New World. ~ Page 246 / 247