Cambridge researchers have contributed to an international study of human genetic diversity and ancestry in 54 indigenous populations across six continents. The study, published this week in Science, clarifies the genetic relationships between human populations around the world, including shared ancestry from ancient interbreeding with extinct relatives of Homo sapiens.
The study, which analysed the whole genome sequences of 929 individuals, found that although genetic differences between these populations reflect their geographical, cultural and linguistic diversity, there are also many patterns shared across continents which reveal both ancient and recent connections between them. The data are released without restriction to benefit future research in human evolution and genetics worldwide.
Researchers from the Genetics Department in Cambridge, Dr Ruoyun Hui and Dr Aylwyn Scally, investigated the evidence of interbreeding between the ancestors of modern humans and extinct human lineages such as Neanderthals and Denisovans, which occurred 40-60 thousand years ago. Previous studies showed that people outside Africa derive around 3% of their ancestry from Neanderthals, and the new analysis found that this interbreeding involved several Neanderthal individuals, but probably all from a single relatively small population. By contrast there appear to have been multiple separate episodes of interbreeding with Denisovans (another now-extinct group related to Neanderthals), resulting in varying patterns of Denisovan ancestry amongst present-day Asians.
https://science.sciencemag.org/content/367/6484/eaay5012.full