Ancient DNA reveals Europeans had sex with Neanderthals

According to a study, there is a surprising genetic unity between the earliest known Europeans and contemporary Europeans.

This finding suggests that a complex network of sexual exchange may have existed across Europe over the past 50,000 years, and also helps to pinpoint when humans interbred with Neanderthals, the closest extinct relatives of modern humans.

The scientists analysed DNA from the left shinbone of a skeleton known as K14 which was excavated in 1954.

K14 is one of the oldest fossils of a European modern human - a man who lived between 36,200 and 38,700 years ago in Kostenki in western Russia, LiveScience reported.

The researchers sequenced K14's genome and found that contemporary Europeans shared genetic continuity with ancient Europeans.

"Virtually all the major genetic components you find in contemporary Europeans are present among the earliest Europeans," said lead study author Eske Willerslev, an evolutionary biologist at the University of Copenhagen in Denmark.

For millennia, Europe may have been home to a so-called "metapopulation" of modern humans - a group of distinct, separate populations that regularly mixed, grew and fragmented. The genetic contributions of the early Eurasians to modern European populations may not have arrived through a few distinct migrations from Asia to Europe, but instead through gene flow in various directions, the authors noted.

The modern human ancestors of contemporary Eurasians are believed to have left Africa about 50,000 to 60,000 years ago, but how these early Eurasians contributed to the modern European gene pool remains unclear.