Gene sleuths who have come up with a rough draft of the Neanderthal DNA code said on Thursday the ancient relatives of modern humans shared with us one gene for speech, but little else.

The Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and 454 Life Science Corp, a Roche company, said they have sequenced more than 60 percent of the entire Neanderthal genome.

Preliminary results confirm what the group had already suspected: that Neanderthals, humanity's closest relative, contributed very little to the gene pool of modern humans.

Neanderthals, an archaic human species that dominated Europe until the arrival of modern humans about 45,000 years ago, possessed a critical gene known to underlie speech, according to DNA evidence retrieved from two individuals excavated from El Sidron, a cave in northern Spain.

The evidence stems from analysis of a gene called FOXP2 which is associated with language. The human version of the gene differs at two critical points from the chimpanzee version, suggesting that these two changes have something to do with the fact that people can speak and chimps cannot.