Prehistoric teeth hint at Stone Age sex with Neanderthals

A new study of 11 teeth, found at La Cotte de St. Brelade on the island of Jersey in the English Channel, suggests that some could have belonged to individuals that had mixed ancestry.

(CNN)Early modern humans and Neanderthals lived in Europe and parts of Asia at the same time -- overlapping for several thousands of years before our archaic relatives disappeared around 40,000 years ago.

During this time, Homo sapiens and Neanderthals encountered each other and sometimes had sex and gave birth to children. The evidence is buried within our genes, DNA analysis has shown, with most Europeans having around 2% Neanderthal DNA in their genomes from this ancient interbreeding.
Neanderthals and early modern humans living in Europe and parts of Asia overlapped for several thousand years.
However, there has been relatively little direct physical evidence of these encounters and fossilized bones. Skeletons that have been found haven't offered definitive proof.
    Now, a new analysis of 11 teeth found in a cave in Jersey, an island in the English Channel, has suggested that some of them could have belonged to individuals that had mixed Homo neanderthalensis and Homo sapiens ancestry.
      The teeth, identified as being Neanderthal, were found when the site, known as La Cotte de St. Brelade, was first excavated in 1910 and 1911. A new analysis of the teeth, published in the Journal of Human Evolution on Monday, has shown that the choppers actually came from two different individuals who lived there 48,000 years ago. Seven of the teeth had both modern human and Neanderthal traits.
        Since the first stone tools were discovered at La Cotte in 1881,  other discoveries, such as the teeth, have followed. The site was was first excavated in 1910 and 1911.
        "We find the same unusual combinations of Neanderthal and modern human traits in the teeth of both identified Neanderthal individuals," said study author Chris Stringer, research leader in human origins and professor at the Natural History Museum in London.
        "We consider this the strongest direct evidence yet (of interbreeding) found in fossils, although we don't yet have DNA evidence to back this up," he said.
          The team was trying to recover DNA from the teeth to confirm whether the teeth belonged to individuals with dual Neanderthal-modern human heritage, Stringer said. Preservation of DNA was a "matter of chance," given the age of the teeth, he explained.
          "The tooth roots look very Neanderthal, whereas the neck and crowns of the teeth look much more like those of modern humans," he said.
          The only other explanation, he said, was that this population was extremely geographically isolated and evolved these unusual traits in their teeth.
          It "might be that this (is) a highly unusual population that developed this combination of traits in isolation - however at this time, because of the lower sea levels of th