Neanderthals are not entirely gone. Their DNA lives on within us, but more in some people than others. People of European ancestry are much more likely to have inherited a bundle of Neanderthal variants in their genome as compared to those of Asian or African descent.
The genes responsible for the breakdown of lipids (fats, fat soluble vitamins and sterols among others) are particularly likely to come from Neanderthals – presumably because they were good at it, and offspring with these genes were likely to benefit. Dr Philipp Khaitovich of the Max Plank Institute of Evolutionary Anthropology compared genes in this area from 11 human populations with varying ancestry to those from the Neanderthal genome, sequenced in last December.
Adapted to cold climates, Neanderthals overlapped with modern humans for long periods in Europe before being wiped out, and it appears interbreeding occurred. This has resulted in a substantially higher number of Neanderthal sequences in the DNA of people of European than African descent.
With a range that extended well into the Middle East and Central Asia the presence of Neanderthal genes in Asian populations is more intriguing. Khaitovich's paper in Nature.html reports, “While the genome-wide frequency of Neanderthal-like sites is approximately constant across all contemporary out-of-Africa populations, genes involved in lipid catabolism contain more than threefold excess of such sites in contemporary humans of European descent.”
"These sequences show signs of recent positive selection,” Khaitovich says. He found that the Neanderthal variants appear to be associated with changes in lipid concentration and the expression of metabolic enzymes in the brains of people of European origin. "We don't know what these lipid concentration changes do to the brain, but the fact that Neanderthal variants might have changed our brain composition has interesting implications," says Khaitovich.
In three African populations Neanderthal genes were vanishingly rare, and in the lipid processing area accounted for 2% of genes. Five European and three Asian populations had very similar rates of overall Neanderthal genes in the study – around 6% of those sampled, although more extensive studies have estimated 1-4%. However, in the lipid cluster this reached 20% for Europeans (and higher still for a sample from Spain, where Neanderthals are believe to have made their last stand) while being a third of that in the Japanese and northern and southern Chinese groups studied. The researchers note that large areas of the globe are missing from their study.
Stand by for racist groups claiming European superiority based on greater frequency of Neanderthal lipid processing genes, and DNA testing to find the most “pure bred” Neanderthal individuals.