Neanderthals died out because of sex, not war

Regardless of how they communicated, their encounters led to reproduction between the two species. How this happened remains a mystery.

Was the crossing a success?

Whether the crossing was a success depends on the breeding pair. There is no evidence of Homo sapiens genetics in late Neanderthal genomes from 40-60,000 years ago.

Even though we know that our species was crossed with Neanderthals, the genes we have in us today are not the result of the interactions that Homo sapiens maintained when they left Africa.

Another interesting finding – the lack of mitochondrial DNA, which is inherited by females, points to the evidence that only male Neanderthals and female Homo sapiens were able to mate.

“We don’t know if the apparent one-way gene flow is because it just didn’t happen, that the breeding happened but wasn’t successful, or if the Neanderthal genomes we have are not representative. As more Neanderthal genomes are sequenced, we should be able to to see if any nuclear DNA from Homo sapiens has been passed on to Neanderthals and to show if this idea is correct,” Stringer added.

Study Summary:

There is some evidence that the Neanderthal and Homo sapiens lineages began to diverge about 600,000 years ago and after that time developed largely separately in Eurasia and Africa. About 60,000 years ago, H. sapiens began a significant emergence from Africa that would lead to an almost worldwide distribution 10,000 years ago. However, recent research on fossils from Apidima Cave (Greece) suggests that there was an earlier distribution of our species reaching Europe more than 200,000 years ago, which is consistent with data from ancient DNA suggesting gene flow between early H. neanderthalensis and H. sapiens lineages in the later Middle Pleistocene time span. Additional range extensions from H. sapiens are suggested based on West Asian evidence from before 100,000 years ago, and from China, Sumatra, and Australia before the 60,000-year date. Until recently, there were few other signs of H. sapiens presence in Europe prior to the Aurignacian expansion that began about 41,000 years ago. However, new data from sites such as Zlatý k?? (Czech Republic), Bacho Kiro Cave (Bulgaria), Grotta del Cavallo (Italy), and Grotte Mandrin (France) indicate pre-Aurignacian ranges that may have juxtaposed H. sapiens populations with the persistent Neanderthals. While some of these populations may be related to later Indos, others appear to represent now extinct genera of H. sapiens. It is now known from a growing body of genetic data that this coexistence of H. neanderthalensis and H. sapiens was accompanied by periods of crosses between the two species. It is suggested here that continued inclusion of Neanderthals in H. sapiens groups could be one of the factors that led to the demise of Neanderthals.