Bronze and Iron Age population movements underlie Xinjiang population history

The Xinjiang region in northwest China is a historically important geographical passage between East and West Eurasia. By sequencing 201 ancient genomes from 39 archaeological sites, we clarify the complex demographic history of this region. Bronze Age Xinjiang populations are characterized by four major ancestries related to Early Bronze Age cultures from the central and eastern Steppe, Central Asian, and Tarim Basin regions. Admixtures between Middle and Late Bronze Age Steppe cultures continued during the Late Bronze and Iron Ages, along with an inflow of East and Central Asian ancestry. Historical era populations show similar admixed and diverse ancestries as those of present-day Xinjiang populations. These results document the influence that East and West Eurasian populations have had over time in the different regions of Xinjiang. Description 5000 years of Xinjiang genetics The Xinjiang region of China is bordered by mountains and represents an important historical region. Sampling ancient genomes, Kumar et al. investigated the changes in populations of this region over time from the Bronze Age, ~5000 to 3000 years before the present (BP), covering the Iron Age, ~3000 to 2000 years BP, and into the Historical Era, ~2000 years BP. This analysis identified that older individuals represented ancestries from Steppe cultures, and that a later inflow of East and Central Asian ancestry entered the region around the end of the Bronze Age toward the beginning of the Iron Age. During the Historical Era, mixing continued but retained a core Steppe component such that populations form a genetic continuum. This retention of genetic continuity in a central population is surprising because it represents patterns more typically observed in isolated populations. Furthermore, these genetic links identify a previously unknown lineage that could potentially explain the spread of the Indo-European languages. —LMZ Modern Xinjiang populations result from Steppe ancestries mixed with waves of admixture from surrounding areas.