Abstract
Because of limited availability of ancient genomes, the genetic history of prehistoric Inner Asian hunter-gatherers remains incomplete, especially for eastern Kazakhstan where the Eurasian Steppe meets mountain forests of Inner Asia. Here we report genome-wide data of two Early Neolithic (EN) hunter-gatherers and 19 Middle-Late Bronze Age (MLBA) pastoralists, from the site of Koken in the Upper Irtysh River region in eastern Kazakhstan. We find that the two EN individuals differed in their genetic profiles and yet were second-degree relatives. They were genetically most similar to subsequent Neolithic individuals in the Irtysh region, while contemporaneous hunter-gatherers from the Tobol-Ishim and Upper Ob River regions had distinct genetic profiles, likely influenced by riverine geography. The Koken MLBA individuals were genetically similar to other MLBA steppe pastoralists, while genetic outliers provide evidence of two distinct trajectories of admixture with local hunter-gatherer populations. These findings illuminate the dynamic population structure of Inner Asian hunter-gatherers and their genetic legacy in subsequent pastoralist populations.