Modern humans and Neanderthals had sex across the species barrier, according to
a leading geneticist who is overseeing a project to compare their genomes.

Professor Svante Paabo, director of genetics at the renowned Max Planck
Institute for Evolutionary Anthropology in Leipzig, will shortly publish his
analysis of the entire Neanderthal genome, using DNA retrieved from fossils. He
aims to compare it with the genomes of modern humans and chimpanzees to work out
the ancestry of all three species.

Modern humans arrived in Europe from Africa about 40,000 years ago to find
Neanderthals already living there. The two species then co-existed for
10,000-12,000 years before Neanderthals died out — a fact that has caused
endless academic speculation about whether they interbred.

Paabo recently told a conference at the Cold Spring Harbor Laboratory near New
York that he was now sure the two species had had sex — but a question remained
about how "productive" it had been.

http://www.timesonline.co.uk/tol/news/science/biology_evolution/article6888874.e\
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