In the latest volley of what may seem like effectively tittering gossip by staid scientists, Richard G. Klein of Stanford University writes in the current issue of Science that Neanderthals and modern humans never mixed in substantial numbers; when the Neanderthals in Europe died out, so did their genes. “The Neanderthals may thus be regarded as a fascinating, but extinct, side branch of humanity,” Klein writes in the journal Science. This conclusion is at odds with other evidence such as a possible hybrid human-Neandertal child found in Portugal which is perhaps the most convincing. Modern mitochondrial DNA studies from Neanderthal fossils suggest that the modern humans and the Neanderthals had a common ancestor about 500,000 years ago. Klein notes such studies do not support the notion that there was interbreeding after modern humans evolved in Africa and invaded Neanderthal habitats in Europe starting about 45,000 years ago.

So did they do it, or didn’t they? Other scientists think the question remains open. University of Utah anthropologist Henry Harpending is unconvinced of either Klein’s arguments or theories that there was interbreeding between Neanderthals and modern humans. “Right now, there’s no compelling evidence for either point of view,” he said.