It has been known for some time that the Homo sapiens Non-African humans, for example, have around 2% of their DNA with Neanderthal origins. However, a new study suggests that relationships between Homo sapiens e Homo neanderthalensis may have happened much more recently than anyone realized.
Analyzing three fossils of humans, originating from the Bacho Kiro cave in Bulgaria, the researchers noted that interbreeding with Neanderthals likely occurred in the family of these individuals.
It turns out that these fossils date back between 43,000 and 42,000 years. The first humans arrived in Europe roughly 50,000 years ago, while Neanderthals became extinct in the region 40,000 years ago.
In other words, neanderthals and humans may have interbred much more frequently than previously thought. That's because researchers were able to conclude that the humans in the Bulgarian cave had ancestors 5 to 7 generations apart who were neanderthals.
From the genetic variability of other fossils, it was also concluded that the humans of Bacho Kiro probably arrived in Europe by a hitherto unknown migration, when other hominid populations were still extensively inhabiting the Middle East and the Old Continent.
The marked extinction of the Neanderthals
As said before, the H. sapiens probably interacted frequently with other species of humans who subsequently became extinct. These interactions may often have been sexual, resulting in the genetic mixing of modern humans. At other times they may have been conflictual, resulting in the death of entire tribes and the extinction of other humans.
Studies suggest, moreover, that the Homo sapiens This was because our species was probably more sociable among its groups, and had more versatile resources. This led Neanderthals and other species slowly to extinction, but not before they left their genes imprinted on our family tree.
In addition, the humans from Bacho Kiro are some of the oldest fossils of sapiens in Europe. Yet another fossil from the Czech Republic showed evidence of interbreeding with Neanderthals, making this the oldest in Europe discovered to date. The remains were discovered in 1950, but another independent study published this month showed the link to the discovery of theof Bacho Kiro.
The authors suggest that, over time, repositioning of distinct populations may have occurred on the European continent. Along with this phenomenon, genetic mixing occurred through the crossing of these populations of individuals from different species.
Articles are available in Nature and Nature Ecology & Evolution.