Genetic structure of a 2,500-year-old human population in China and its spatiotemporal changes

To examine temporal changes in population genetic structure, we compared th e mitochondrial DNA (mtDNA) sequences of three populations that lived in th e same location, Linzi, China, in different periods: 2,500 years ago (the S pring-Autumn era), 2,000 years ago (the Han era), and the present day. Two indices were used to compare the genetic differences: the frequency distrib utions of the radiating haplotype groups and the genetic distances among th e populations. The results indicate that the genetic backgrounds of the thr ee populations are distinct from each other. Inconsistent with the geograph ical distribution, the 2,500-year-old Linzi population showed greater genet ic similarity to present-day European populations than to present-day east Asian populations. The 2,000-year-old Linzi population had features that we re intermediate between the present-day European/2,500-year-old Linzi popul ations and the present-day east Asian populations. These relationships sugg est the occurrence of drastic spatiotemporal changes in the genetic structu re of Chinese people during the past 2,500 years.