Inland-coastal bifurcation of southern East Asians revealed by Hmong-Mien genomic history

ABSTRACT The early history of the Hmong-Mien language family and its speakers is elusive. A good variety of Hmong-Mien-speaking groups distribute in Central China. Here, we report 903 high-resolution Y-chromosomal, 624 full-sequencing mitochondrial, and 415 autosomal samples from 20 populations in Central China, mainly Húnán Province. We identify an autosomal component which is commonly seen in all the Hmong-Mien-speaking populations, with nearly unmixed composition in Pahng. In contrast, Hmong and Mien respectively demonstrate additional genomic affinity to Tibeto-Burman and Kra-Dai speakers. We also discover two prevalent uniparental lineages of Hmong-Mien speakers. Y-chromosomal haplogroup O2a2a1b1a1b-N5 diverged ∼2,330 years before present (BP), approximately coinciding with the estimated time of Proto-Hmong-Mien (∼2,500 BP), whereas mitochondrial haplogroup B5a1c1a significantly correlates with Pahng and Mien. All the evidence indicates a founding population substantially contributing to present-day Hmong-Mien speakers. Consistent with the two distinct routes of agricultural expansion from southern China, this Hmong-Mien founding ancestry is phylogenetically closer to the founding ancestry of Neolithic Mainland Southeast Asians and present-day isolated Austroasiatic-speaking populations than Austronesians. The spatial and temporal distribution of the southern East Asian lineage is also compatible with the scenario of out-of-southern-China farming dispersal. Thus, our finding reveals an inland-coastal genetic discrepancy related to the farming pioneers in southern China and supports an inland southern China origin of an ancestral meta-population contributing to both Hmong-Mien and Austroasiatic speakers.