Researchers have several different theories on why ancients became extinct. Although some believe that Neanderthals were killed off by humans, a new report suggests it was more complicated than that. It appears that Homo neanderthalensis may have mated with our ancestors, which led to their eventual demise.

According to a new research by German scientists, Neanderthals interbred with early humans on a regular basis. This is evident in the genetic analysis of three different fossilized remains. The remains belonged to a Neanderthal, an early human as well as a modern human. Interestingly, it revealed that interbreeding may have been the true cause of the extinction of Homo neanderthalensis.

Neanderthals possibly mated themselves into extinction.

Svante Paabo is a professor of evolutionary genetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. He stated that Neanderthals kept interbreeding with humans to the point that their own species was eventually wiped out.

“It means they were incorporated, which is why we see so many of their genes living on in modern Europeans,” he said. “If we look at a few thousand genomes we can pick out 15,000 Neanderthal genes — so at least half their genome is walking around in people today.”

A different report also revealed that the Neanderthal genes are still present in the modern population. The study suggests that people with Neanderthal genes are likely to have skulls similarly shaped to Neanderthals.

A Neanderthal exhibit at the Natural History Museum in London.

Neanderthals roamed the Earth between 430,000 to 450,000 years ago and were wide-spread across Eurasia until the arrival of modern humans. The introduction of the new species is believed to have affected our ancient cousins to the point that it caused their extinction 40,000 years ago.

There is still much to be learned about Neanderthals. Further research could reveal if we are truly evolved from the ancient species and whether their genetic influence still affects us today.