A  Neanderthal Specimen
A girl looks through the replica of a Neanderthal skull displayed in the new Neanderthal Museum in Krapina, Croatia. A finger bone found in Siberia seems to show that there was a third type of humans inhabiting the Earth at the same time, called Denisovans. REUTERS

Genetic researchers at the University of Montreal seem to have confirmed that non-Africans interbred with Neanderthals thousands of years ago.

Damian Labuda of the University of Montreal Department of Pediatrics and the CHU Sainte-Justine Research Center said that his team’s findings determined that some of the human X chromosome originates in Neanderthals and is found only in people outside Africa.

This confirms recent findings suggesting that the two populations interbred, says Labuda. In addition, because our methods were totally independent of Neanderthal material, we can also conclude that previous results were not influenced by contaminating artifacts.

Labuda thinks this interbreeding occurred somewhere in the Middle East.

According to scientific research, Neanderthals departed Africa about 400,000 to 800,000 years ago, and subsequently evolved in lands that now comprise France, Spain, Germany and Russia. They are believed to have died out (or absorbed into the modern human population) about 30,000 years ago.

Meanwhile, early modern humans are estimated to have left Africa some 80,000 to 50,000 years ago.

About a decade ago, Labuda and his researchers identified a DNA called a haplotype in the human X chromosome with mysterious origins. Last year, when the Neanderthal genome was sequenced last year, the Labuda team compared 6,000 chromosomes from around the world with the Neanderthal haplotype. They determined that the Neanderthal sequence was found in people across much of the world, excluding Africa.

There is little doubt that this haplotype is present because of mating with our ancestors and Neanderthals. This is a very nice result, and further analysis may help determine more details, said Dr. Nick Patterson, of the Broad Institute of MIT and Harvard University.

Also, David Reich, a Harvard Medical School geneticist, told media: Dr. Labuda and his colleagues were the first to identify a genetic variation in non-Africans that was likely to have come from an archaic population. This was done entirely without the Neanderthal genome sequence, but in light of the Neanderthal sequence, it is now clear that they were absolutely right!