Refining the genetic structure and admixture history of Hmong-Mien populations.

Background: Recent studies have shed light on the unique linguistic and genetic characteristics of Hmong-Mien speakers. However, the underlying genetic structure and admixture events that shape their genetic diversity remain inadequately elucidated.

Results: Here, we co-analyzed newly generated genome-wide data from 164 individuals in Guizhou Province with published data from geographically proximate HM speakers using both allele frequency-based and haplotype-based methods. We unveiled fine-scale genetic substructure within HM speakers in southwest China, emphasizing distinct genetic differentiation between the Miao and Yao branches. Notably, Guangxi GaoHuaHua individuals showed close affiliation with the Yao branch, indicating a divergence time predating approximately 500 years ago. Besides, southwestern HM speakers exhibited an admixture pattern of indigenous Hmong and BaikuYao-like ancestry with minor contributions from neighboring populations like Tai-Kadai and Sino-Tibetan speakers in recent history. We finally identified the dominant paternal and diverse maternal lineages of HM speakers, implying a rich genetic tapestry and intricate historical migrations.

Conclusions: Our study provided new insights into the genetic formation and admixture events that significantly shaped the genomic diversity of present-day HM speakers in southwest China.