It is pretty much a well known fact now that non-African people outside of Africa have anywhere from 1% to 3% or more Neanderthal DNA in them. It’s also known that between 35-45 kya as modern humans were spreading through Europe the Neanderthals began to disappear. What is less known is the some researchers believe that 40 kya some modern human genomes may have had much more Neanderthal DNA perhaps to the tune of at least twice as much.
I myself contend that some people have much more Neanderthal DNA in them and that their ancestors had even more Neanderthal DNA in their genes and that is why today we can see some people who have clearly Neanderthal features.
In 2015 a report appeared in the journal Nature concerning DNA recovered from a 40 kyr human bone unearthed in Romania that contained between 6% and 9% Neanderthal DNA. Some of that DNA was found in three large chromosome segments and what this suggests is that this individual had a Neanderthal ancestor only 4 to 6 generations back! This bone found in Romania is CLEAR EVIDENCE that Neanderthals were interbreeding with modern humans in Europe 35-45 kya with resulting hybrids being born!
The Romanian bone is a jawbone dated at about 40 kyr. The jawbone is known as the “Oase Individual” due to the location in Romania of the cave in which it was found. The cave is known as Oase and also as Pestera. David Reich of the Harvard Medical School was senior author of the paper. He and his team sequenced DNA from the jawbone that was found in 2002. He noted that the skeletal remains showed morphological features that strongly suggested it was a Neanderthal-Modern Human hybrid. In addition to finding this discovery Reich and his team also found DNA evidence of an EARLIER HYBRIDIZATION between Neanderthals and modern humans!
Of course, this was not the first time such evidence for interbreeding of these two hominin species has been found and I’m sure it won’t be the last. DNA evidence for such hybridizastion has also been found in the Levant, specifically Israel. So it just wasn’t solely in Europe that Neanderthals and modern humans were interbreeding but it was also in the Levant and even elsewhere! What Reich and his team concluded was that as modern humans moved through historically Neanderthal territory they interbred with them “multiple times.” In other words this was not just a one or two time event but it appears to have happened frequently and widely!
In fact, researchers have several skeletal remains that have morphological traces of shared ancestry between modern humans and Neanderthals. As DNA techniques improve I’m sure we will find more and more genetic evidence for interbreeding between these two species and that we will also find that the truth is Neanderthals didn’t magically disappear or go extinct at all. I believe they were “assimilated” for lack of a better word by modern humans! Further, I am sure this will also turn out to be the case with other ancient human ancestors such as Homo erectus and Heidelbergensis et. al.!! And, this will transform our perception of human evolution proving that hybridization was the reason for the “disappearance” of these various species and NOT a matter of one species going extinct as a new species emerged. As I’ve noted before the NORM appears to have been SEVERAL ancient human species COEXISTING at the same time for various periods of time. I’m sure further research will only add more support to this notion and then we will be forced to look at our own modern-day species. I do not believe we are the exception! I do believe that there are still different species of humans running around today in our midst! We are NOT all the same, frankly!