The Ami and Yami aborigines of Taiwan and their genetic relationship to East Asian and Pacific populations.

This article reports on the genetic characteristics of the Ami and Yami, two aboriginal populations of Taiwan. Y-SNP and mtDNA markers as well as autosomal SNPs were utilized to investigate the phylogenetic relationships to groups from MSEA (mainland Southeast Asia), ISEA (island Southeast Asia), and Oceania. Both the Ami and Yami have limited genetic diversity, with the Yami having even less diversity than the Ami. The partitioning of populations within the PCA plots based on autosomal SNPs, the profile constitution observed in the structure analyses demonstrating similar composition among specific populations, the average IBD (identical by descent) tract length gradients, the average total length of genome share among the populations, and the outgroup f3 results all indicate genetic affinities among populations that trace a geographical arc from Taiwan south into the Philippine Archipelago, Borneo, Indonesia, and Melanesia. Conversely, a more distant kinship between the Ami/Yami and MSEA based on all the markers examined, the total mtDNA sequences as well as the admixture f3 and f4 analyses argue against strong genetic contribution from MSEA to the Austronesian dispersal. The sharing of long IBD tracts, total genome length, and the large number of segments in common between the Ami/Yami and the Society Archipelago populations East Polynesia standout considering they are located about 10,700 km apart.