A Dynamic 6,000-Year Genetic History of Eurasia’s Eastern Steppe

The Eastern Eurasian Steppe was home to historic empires of nomadic pastoralists, including the Xiongnu and the Mongols. However, little is known about the region’s population history. Here, we reveal its dynamic genetic history by analyzing new genome-wide data for 214 ancient individuals spanning 6,000 years. We identify a pastoralist expansion into Mongolia ca. 3000 BCE, and by the Late Bronze Age, Mongolian populations were biogeographically structured into three distinct groups, all practicing dairy pastoralism regardless of ancestry. The Xiongnu emerged from the mixing of these populations and those from surrounding regions. By comparison, the Mongols exhibit much higher eastern Eurasian ancestry, resembling present-day Mongolic-speaking populations. Our results illuminate the complex interplay between genetic, sociopolitical, and cultural changes on the Eastern Steppe. [Display omitted] •Genome-wide analysis of 214 ancient individuals from Mongolia and the Baikal region•Three genetically distinct dairy pastoralist groups in Late Bronze Age Mongolia•Xiongnu nomadic empire formed through mixing of distinct local and distant groups•No selection on the lactase persistence alleles despite 5,000 years of dairy culture Ancient DNA from over 200 individuals inhabiting the Eastern Eurasian Steppe during the Bronze Age provides insights into the population history of the Mongols and Xiongnu.