Molecular genetic analysis of remains of a 2,000-year-old human populationin China - and its relevance for the origin of the modern Japanese population

We extracted DNA from the human remains excavated from the Yixi site (simil ar to 2,000 years before the present) in the Shandong peninsula of China an d, through PCR amplification, determined nucleotide sequences of their mito chondrial D-loop regions. Nucleotide diversity of the ancient Yixi people w as similar to those of modern populations. Modern humans in Asia and the ci rcum-Pacific region are divided into six radiation groups, on the basis of the phylogenetic network constructed by means of 414 mtDNA types from 1,298 individuals. We compared the ancient Yixi people with the modern Asian and the circum-Pacific populations, using two indices: frequency distribution of the radiation groups and genetic distances among populations, Both revea led that the closest genetic relatedness is between the ancient Yixi people and the modern Taiwan Han Chinese. The Yixi people show closer genetic aff inity with Mongolians, mainland Japanese, and Koreans than with Ainu and Ry ukyu Japanese and less genetic resemblance with Jomon people and Yayoi peop le, their predecessors and contemporaries, respectively, in ancient Japan.