With dozens of high-powered human evolution specialists roaming the AAAS meeting, it's only natural that the hallway buzz focused on the rough draft Neandertal genome sequence announced Thursday. But might that DNA actually have come from a modern human bone? That controversial possibility was raised by Milford Wolpoff of the University of Michigan, Ann Arbor, one of the most vocal proponents of the notion that Neandertals and modern humans shared genes. The bone, sequenced by Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, was found in Vindija Cave in Croatia, a well-known Neandertal site. But the little chunk of bone that yielded DNA is so incomplete that anatomists can't say whether it's from a Neandertal or a modern human. And at 38,000 years old, it could have been either, said Wolpoff. The bone is "young enough for a late Neandertal or a modern human, or a mix," he said.
Pääbo relied on genomics to identify the bone: As he and colleagues
reported this summer in Cell, they sequenced the mitochondrial genome
and found that it matched the DNA from other bones that are clearly
Neandertal. And the mitochondrial DNA (mtDNA) was distinct from that of
living people. So they proceeded to sequence the much more difficult
nuclear genome. But Wolpoff isn't buying the mtDNA comparison, saying
that mtDNA from a 38,000-year-old modern human also wouldn't match that
of living people. The true comparison, he said, would be to show that
the Neandertal mtDNA differs from the DNA of modern humans of the same
age.
At a reception later, I caught up with another Neandertal expert, Chris Stringer of the Natural History Museum in London. He and Wolpoff are old adversaries on the question of whether Neandertals were a distinct species. "Yes, it's theoretically possible that a 38,000-year-old bone is modern human," he said. But he pointed out that researchers first identified the distinctive Neandertal mtDNA from bones that everyone agrees are those of Neandertals. "I think we can lay this [question] to rest," he said.
And even Wolpoff, although unabashedly clinging to his minority view, approved of Pääbo's sequence, saying that whatever the bone is, having its DNA will move science forward. "It's a really cool piece of work, and it's terrific that it's done."
--Elizabeth Culotta
At a reception later, I caught up with another Neandertal expert, Chris Stringer of the Natural History Museum in London. He and Wolpoff are old adversaries on the question of whether Neandertals were a distinct species. "Yes, it's theoretically possible that a 38,000-year-old bone is modern human," he said. But he pointed out that researchers first identified the distinctive Neandertal mtDNA from bones that everyone agrees are those of Neandertals. "I think we can lay this [question] to rest," he said.
And even Wolpoff, although unabashedly clinging to his minority view, approved of Pääbo's sequence, saying that whatever the bone is, having its DNA will move science forward. "It's a really cool piece of work, and it's terrific that it's done."
--Elizabeth Culotta
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