FLICKR, ERICH FERDINANDThe human genome is peppered with the DNA of extinct hominins—Neanderthals and Denisovans—as a result of interbreeding with early Homo sapiens. According to some reports, the Neanderthal and Denisovan DNA retained at specific loci, such as immune system-related genes, likely conferred adaptive advantages against infectious microorganisms. In a study published last month (November 29) in Genome Biology, researchers provide strong evidence that the Neanderthal DNA present at one such locus within the modern human genome is likely the result of positive selection.
The study authors also suggest that this Neanderthal haplotype is not unique to Neanderthals. Rather, interbreeding reintroduced the beneficial genetic variant present in early African humans that had been lost during the out-of-Africa migration and population bottleneck.
“This is an important study contributing to a growing body of work that combines population and functional genomic analyses to learn about archaic alleles,” Sriram Sankararaman, a computational biologist at the University of California, Los Angeles, who was not involved in the work, wrote in an email to The Scientist.
“This study and previous work suggests that acquiring Neanderthal and Denisovan sequences provided access to alleles that were better adapted to the novel selective pressures our ancestors experienced as they migrated Out of Africa into new geographic regions,” ...
