Researchers have shown that many genes which appeared in the Eurasian people of the modern type as a result of interbreeding with the Neanderthals, who once were present in early Homo sapiens, but were lost in the common ancestor of Eurasians, reported in Nature Ecology & Evolution. Thus, the Neanderthals tens of thousands of years served as a genetic reservoir for the archaic alleles of several genes of Homo sapiens and at some point returned their mind to whom they originally belonged. The influence of the “true Neanderthal” and newly emerging “sapientech” alleles to other genes is different.
Although Eurasia is now home to more people than in Africa, their genetic diversity below. The probable reason is that Homo sapiens went through a bottleneck when migrating from one continent to another. In Eurasia 50,000 years ago, it’s about 20 percent of the number of people of modern type, who at that time lived in Africa. As a result, many gene variants (alleles) that are typical for the species as a whole, the new continent was not hit and its residents were not represented.
However, in Eurasia, when there came the ancestors of the people of the modern type had lived other species of the genus Homo — Neanderthals and the denisovans (species status Denisova, however, is still ambiguous). Their ancestors left Africa 500,000 years ago, before the advent of Homo sapiens. Accordingly, the Neanderthals and denisovans, with whom members of our species interbred (and not time), can keep those alleles that are not inherited Eurasian sapiens due to the “bottleneck” — and when dealing with Homo sapiens could return to them of these alleles.
Researchers from Vanderbilt University led by John Capraia (John A. Capra) analyzed single-nucleotide polymorphisms (SNPS) in the DNA of modern humans, which were collected in the framework of the project “1000 genomes”. Genetics was watching, which of the polymorphisms is characteristic only of Africans, some only for Eurasians, and compared these data with what is known about the SNPS of the Neanderthals. In addition, they considered information about the manifestation of quantitative traits (those that vary in strength and are controlled by several genes, e.g. skin color), to understand how obtained from Neandertal alleles of different origin affect the expression of genes that have always been with Eurasians.