Analysis of DNA from a thigh bone is helping solve the longstanding question of what happened to Neanderthals. Did they simply die off, were they killed by more modern humans—or did the two groups interbreed? DNA from the Neanderthal bone is so different from that of modern humans that interbreeding now appears highly unlikely, the Independent reports, making it likely that our ancestors were to blame.
“For the first time, we've built a sequence from ancient DNA that is essentially without error,” said a German scientist. Still, “we can only speculate as to what happened” to the Neanderthals, insists another investigator. Evidence indicates that only a small population of Neanderthals existed in Europe, where the bone was found, and “small populations are always more prone to extinction,” he notes. (More human evolution stories.)