Scientists create genetic blueprint of Neanderthal

An international team Thursday said it has completed a draft of the genome (or genetic blueprint) of Neanderthals, which shows that our extinct cousins made "very little, if any" contribution to human genes.

Team chief Svante Pääbo of Germany's Max Planck Institute for Evolutionary Anthropology in Leipzig described the work as a 63% complete gene map. This genome was stitched together from fossil DNA samples taken from four Neanderthals found in Europe.

Neanderthals occupied Europe from about 800,000 to 30,000 years ago. Scholars have long argued over their extinction, and their relationship to people.

"We still have lots of gaps, but we also now have a good overview of the (Neanderthal) genome," said Pääbo, in a webcast from Germany. The announcement previews a presentation scheduled for Sunday at the annual meeting of the American Association for the Advancement of Science in Chicago. "We see this as a tool for future biologists (looking for) what's really unique to modern humans."

"I think it is spectacular, to get something out of bones 40,000 years old, absolutely stunning," says anthropological geneticist Henry Harpending of the University of Utah, author of The 10,000 Year Explosion: How Civilization Accelerated Human Evolution.



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The Neanderthals, "represent the last diverging branch on the bush of human evolution," said Max Planck's Jean-Jaques Hublin, who spoke at the briefing. "Study of Neanderthals tells us what made modern humans really modern."

The results suggest that the primitive human ancestors of Neanderthals and modern humans separated, to Europe and Africa respectively, about 800,000 years ago and that Neanderthals became genetically distinct from that common ancestor only about 300,000 years ago. The genes of Neanderthals and modern humans are more closely related than chimps and humans, Pääbo says, but Neanderthal genes differ 50% more than the differences between the most distantly-related humans. The researchers have sampled Neanderthal bones for DNA since 1997. Only last year did researchers produce a gene map of Neanderthal "mitochondrial" DNA, genes found outside the center of cells. The draft genome of "nuclear" DNA found in the center of cells required mapping 3.7 million gene elements to find:

• Humans and Neanderthals share a speech gene, but not a gene that regulates brain size in humans.

• A "tiny" possibility of interbreeding between humans and Neanderthals, although European genes lean slightly closer, in a statistical sense, to the extinct race; researchers think that may signify trace contamination of their samples with lab researchers' DNA.

• Uniformity suggesting the Neanderthals, like modern humans, arose from a small population.

Paleontologist Christopher Stringer of the Natural History Museum in London, says the genome suggests "while interbreeding was probably possible, it may have occurred only rarely, with trivial impact on modern humans"

The draft genome relied on state-of-the-art gene sequencing machines and techniques, including the radioactive tagging of verified Neanderthal genes, to produce results only a decade after the completion of a draft human genome. The researchers relied on a 37,000 year-old thigh bone found in Croatia, as well as 43,000-year-old from El Sidron, Spain, a 41,000 year-old-bone from Germany and a 70,000-year-old bone from Mezmaiskaya Cave in the Caucasus. They hope to have a 100% complete Neanderthal gene map within three years.

Gene maps of extinct creatures, such as the woolly mammoth and cave bear, have served as tune-ups for the Neanderthal effort in recent years. But Pääbo threw water on the question of whether the genome would enable cloning of Neanderthals. "I would say starting with just DNA, it is and will remain impossible. But we can all speculate as much as we like."