(CNN) –– Early modern humans and Neanderthals lived simultaneously in Europe and parts of Asia. In fact, they overlapped thousands of years before our archaic relatives disappeared some 40,000 years ago.
A new study of 11 teeth found at La Cotte de St. Brelade on Jersey Island in the English Channel suggests that some may have belonged to individuals of mixed race.
During this time Homo sapiens and Neanderthals met. Sometimes they even had sex and gave birth to children. The evidence is hidden in our genes, DNA analysis has shown. Most Europeans have about 2% Neanderthal DNA in their genomes because of this ancient cross.
However, relatively little direct physical evidence of these encounters and fossilized bones has been found. The skeletons found do not provide definitive evidence.
Now a new analysis of 11 teeth found in a cave on Jersey Island, in the English Channel, suggests that some of them belonged to individuals with mixed ancestors of Homo neanderthalensis and Homo sapiens.
The teeth, identified as Neanderthals, 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 was published in the journal Journal of Human Evolution This Monday. And it shows that the teeth actually came from two different individuals who lived there 48,000 years ago. Seven of the teeth had characteristics of both modern humans and Neanderthals.
Since the first stone tools were discovered in La Cotte in 1881, other discoveries followed, such as teeth. The site was first excavated in 1910 and 1911.
“We found the same unusual combinations of Neanderthals and modern human traits in the teeth of both identified Neanderthals,” 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 (of crossing) found in fossils. Although we don’t have any DNA evidence to support this yet, ”he added.
The team tried to extract DNA from the teeth to confirm whether they belonged to people with a dual Neanderthal-modern human heritage, Stringer said. Retention of DNA was “a matter of chance,” given the age of the teeth, he explained.
‘The roots of the teeth look very Neanderthal. While the neck and crowns of the teeth look much more like modern humans, ”he said.
The only other explanation, he said, is that this population was extremely geographically isolated and developed these unusual features on their teeth.
“This may be a very unusual population that has developed this combination of traits in isolation. However, at the time, due to the lower sea levels of the last Ice Age, Jersey was certainly linked to neighboring France. So isolation is unlikely, ”Stringer explained in an email.
It was surprising to find this evidence of “hybrid” individuals with the ancestors of Neanderthals and Homo sapiens in northwestern Europe, he said. This is because the earliest evidence of modern human influence in Europe has been discovered much further east. The evidence in present-day Bulgaria may date back 47,000 years. And in Iberia and the South of France 42,000 years ago.
Likewise, fossil evidence of crossing has been found further east.
The most definitive case is that of the Oasis Cave in Romania, where a 40,000-year-old jaw was excavated. It has unusual features. Genetic analysis indicated that there was 9% Neanderthal DNA, from crosses that likely occurred in the previous five generations, Stringer noted.
A 50,000-year-old bone fragment, discovered in 2018 in a Russian cave, represented the first known remains of a child with a Neanderthal mother and a father who was Denisovan. The latter is another extinct relative of modern humans believed to have lived primarily in Asia.
Teeth are especially important to archaeologists and paleoanthropologists because they are stronger than bones. The glaze is already largely mineralized and not organic, so it survives very well in the fossil record.
Jersey’s La Cotte site shows that Neanderthals used the cave for 200,000 years, the Natural History Museum said. The land layers show repeated re-occupation by different groups of Neanderthals and at least two stacks of mammoth bones.