Higher Levels of Neanderthal Ancestry in East Asians than in Europeans

Abstract

Neanderthals were a group of archaic hominins that occupied most of Europe and parts of Western Asia from ∼30,000 to 300,000 years ago (KYA). They coexisted with modern humans during part of this time. Previous genetic analyses that compared a draft sequence of the Neanderthal genome with genomes of several modern humans concluded that Neanderthals made a small (1–4%) contribution to the gene pools of all non-African populations. This observation was consistent with a single episode of admixture from Neanderthals into the ancestors of all non-Africans when the two groups coexisted in the Middle East 50–80 KYA. We examined the relationship between Neanderthals and modern humans in greater detail by applying two complementary methods to the published draft Neanderthal genome and an expanded set of high-coverage modern human genome sequences. We find that, consistent with the recent finding of Meyer et al. (2012), Neanderthals contributed more DNA to modern East Asians than to modern Europeans. Furthermore we find that the Maasai of East Africa have a small but significant fraction of Neanderthal DNA. Because our analysis is of several genomic samples from each modern human population considered, we are able to document the extent of variation in Neanderthal ancestry within and among populations. Our results combined with those previously published show that a more complex model of admixture between Neanderthals and modern humans is necessary to account for the different levels of Neanderthal ancestry among human populations. In particular, at least some Neanderthal–modern human admixture must postdate the separation of the ancestors of modern European and modern East Asian populations.

Early history of Neanderthals and Denisovans

“…All DNA than Europeans (12,14,(17)(18)(19)(20)(21). This view may be an artifact of ascertainment bias (17) or of the biases documented by Rogers and Bohlender (10).…”

Demographic Events and Evolutionary Forces Shaping European Genetic Diversity

“…Schematic map of Europe showing the major migrations events that may have influenced modern-day European genetic diversity. The map shows (1) the initial colonization of Europe approximately 40,000 years ago from the Middle East (blue arrows), (2) the contraction of humans into four major refugia during the LGM approximately 18,000 years ago followed by the subsequent recolonization of Europe (green arrows), (3) the movement of Neolithic famers approximately 10,000 years ago from the Fertile Crescent (red arrows), (4) various barbarian migrations into the Roman Empire during the migration period of 400-800 CE (dashed yellow arrows), and (5) (Wall et al 2013).…”

Ancient DNA and human history

“…Comparison of the Vindija Neanderthal genome with a larger number of present-day human genomes revealed the surprising fact that the genetic similarity of East Asians to Neanderthals is slightly but significantly greater than the similarity of Europeans to Neanderthals (10,34). This pattern is the opposite of what was expected on purely paleoanthropological grounds, as no Neanderthal fossils have been identified in East Asia, and only a few have been found in West and Central Asia.…”