From time to time, these GEITP pages focus on the evolution of modern human, including the Great Diaspora (i.e. several waves of Homo sapiens originating in southeast Africa and migrating to Asia and Europe, along with some ‘back-migrations’). As humans moved to a new ecological niche, the new environment (plants, food, weather) affected their genomes; hence, gene-environment interactions. The topic of the attached article comprises the ~10 million ethnic Mongolians that currently inhabit a wide geographical range — which includes present-day Mongolia, northern China, southern Russia, and other neighboring countries. It has been suggested that the first permanent settlers of North America had migrated from Mongolia perhaps 24,000-22,000 years ago (when the warming climate, at that time, had decreased the amount of ice to allow passage).
Mongolians also played a pivotal role in shaping the culture and genetic make-up of modern Eurasia through rapid expansion of the Mongolian Empire around 1,000 years ago. Genghis Khan and his successors spread the Mongolian Empire across Asia and Eastern Europe in the 13th century (yes, there was a lot of ‘admixture’ hanky-panky going on), controlling the largest contiguous empire (16% of Earth’s total land-mass) in the history of the world (the attached article shows a nice map of this). Whereas the historical aspects of the Mongolian Empire are well documented, little is known about the genetic architecture (refers to the underlying genetic basis of a each and every trait and its variational properties due to segration of each gene’s alleles) within today’s Mongolian populations, nor is it known how those populations have influenced (or have been influenced by) the genetics of other peoples from the region and the world.
Authors [see attached article] generated a new genetic variation reference panel by whole-genome sequencing (WGS) of 175 ethnic Mongolians — representing six tribes. The catalogued variation in the panel shows strong population stratification (refers to differences in allelic frequencies between a study population, and a control population, due to systematic differences in ancestry — rather than association of genes with disease) among these tribes, which is correlated with the diverse demographic histories in the region. Incorporating these results with the 1000 Genomes Project panel identifies derived alleles that are shared between Finns and Mongolians/Siberians, suggesting that substantial gene flow between northern Eurasian populations has occurred in the past ~1200 years. Furthermore, authors point out that North, East, and Southeast Asian populations are more aligned with each other — than these groups are with South Asian and Oceanian populations.
Nat Genet Dec 2o18; 50: 1696–1704