Are modern humans the hybrid children of early humans and Neanderthals? For over a decade, scientists have wondered what exactly happened to the Neanderthals, low-tech hominids who populated Western Europe, when homo sapiens arrived on the scene from Africa and Asia with sophisticated weaponry and the rudiments of symbolic art. Homo sapiens arrived in Europe roughly 45,000 years ago, and co-existed with Neanderthals for what scientists estimate could have been anywhere from 1000 to 10,000 years. Some remains seem to indicate that the two groups shared the same caves, and might have traded with each other. But what else did they share?
Though we can't be sure what their everyday interactions were like, scientists now have one more piece of evidence that homo sapiens and Neanderthals weren't mixing their DNA.
A group of Italian researchers published a new study today in PLoS One comparing the DNA from early human bones from about 28,000 years ago with DNA Neanderthal bones. What's cool about the new study is that the early human bones are quite recently discovered, and therefore very unlikely to have been contaminated by DNA from humans who have handled them.
The researchers sequenced DNA from these bones, testing to see if there was significant overlap with Neanderthal DNA, which would indicate that homo sapiens' DNA had been changed by interbreeding with Neanderthals. Many anthropologists have long believed that the two species interbred because there are a few ancient skulls whose morphology seems to be a perfect blend of human and Neanderthal.
But tests of the fossilized DNA revealed no matches. The early human DNA from the Italian researchers' sample looked very much like modern DNA, not like Neanderthal DNA. So it looks like humans weren't getting busy with Neanderthals after all. Or if they were, they didn't have a lot of babies.
28,000 Year Old Cro Magnon Sequence [PLoS One]