Objectives: Three different hypotheses proposed via the controversial evidence from cultural, anthropological, and uniparental genetic analyses, respectively, stated that Tanka people probably originated from Han Chinese, ancient Baiyue tribe, or the admixture of them. Therefore, the genetic origin and admixture history of the Tanka people, an isolated "Gypsies in water" in the coastal region of Southeast China, are needed to be genetically clarified using genome-wide SNP data.
Materials and methods: To elucidate the genetic origin of the Southeast Tanka people and explore their genetic relationship with surrounding indigenous Tai-Kadai (TK), Hmong-Mien (HM), and Austronesian (AN) people and Neolithic-to-historic ancients from the Yellow River Basin (YRB) and Fujian, we conducted a large-scale population genomic study among 1498 modern and ancient Eurasians, in which 73 Tanka and 4 Han people were first reported here. Both allele-shared and haplotype-based statistical methods were used here, including PCA, ADMIXTURE, f-statistics, ALDER, qpGraph/TreeMix and qpAdm/qpWave, ChromoPainter, and fineSTRUCTURE. Results: We found a specific genetic cline in PCA plots and detected the Tankaspecific homogeneous ancestry in model-based ADMIXTURE, suggesting differentiated demographic history between Tanka and surrounding Hans. Formal tests based on sharing allele patterns showed a close relationship between Tanka people and Han Chinese, but the Tanka population harbored more southern indigenous East Asian ancestry related to AA/HM/TK people compared with southern Hans. Besides, Guanglin He, Yunhe Zhang, and Lan-Hai Wei contributed equally to this work.