Asking the Provocative Question: "Who Didn't Have Sex With Neandertals?"

FoxNews also has an article on the North African evidence for Neandertal/modern hybridization. Charles Choi writes:

"The only modern populations without Neanderthal admixture are the sub-Saharan groups," said researcher Carles Lalueza-Fox, a paleogeneticist at the Institute of Evolutionary Biology at Barcelona, Spain.

The researchers say their findings do not suggest that Neanderthals entered Africa and made intimate contact with ancient North Africans. Rather, "what we are saying is that the contact took place outside Africa, likely in the Near East, and that there was a back migration into Africa of some groups that peopled North Africa, likely replacing or assimilating some ancestral populations," Lalueza-Fox told LiveScience.

If there was a back-migration into Africa then the interbreeding had to have been significant enough to establish some sort of Neandertal/modern hybrid genome that can be picked up now, some seventy to one hundred thousand years later.  These were no one-night stands.  It may lend credence to Trinkaus' arguments about Lagar Velho, in Portugal being a result of long-term interbreeding.  This may have been happening everywhere.  Somewhere, I hope Fred Smith is smiling.  

Neandertal/Modern Human Hybridization in North Africa?

That is the focus of a new paper in PLoS ONE by Sanchez and colleagues.  Using 780 thousand single nucleotide polymorphisms of 125 individuals from populations in North Africa, they write:

We found that North African populations have a significant excess of derived alleles shared with Neandertals, when compared to sub-Saharan Africans. This excess is similar to that found in non-African humans, a fact that can be interpreted as a sign of Neandertal admixture. Furthermore, the Neandertal's genetic signal is higher in populations with a local, pre-Neolithic North African ancestry. Therefore, the detected ancient admixture is not due to recent Near Eastern or European migrations. Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals.

Well, raise my rent! When we analyzed the modern human remains in the Near East using canonical variates analysis, we found that they showed more of a similarity with North African archaics than they did Neandertals and that this supported a model of a general northern migration of North Africans into the Levant between 100 and 200 thousand years ago. I will be interested to see the reaction to this from the morphologists.

Ironically, the bulk of the evidence supporting the admixture of modern humans and Neandertals has always been based on the fossil record, while the genetic evidence has traditionally been used to argue for a recent African origin. It is interesting to see all of the genetic studies that have turned the tables. There is not a specific level of admixture at which point you can say "hey, these are the same species," but the studies continue to come out suggesting that admixture was taking place wherever these two groups intermingled and that there do not seem to have been biological imperatives to mate.  They simply decided to do so.  Remember the sage words of J. Lawrence Angel: "When two groups of people meet, they may fight but they willl always mate."