The formation of modern Japanese is one of the hottest topics in anthropology, archaeology, linguistics, and genetics in East Asia. In 1991, Hanihara Kazuro put forward the most prevailing “dual structure model”. According to model, the modern Japanese are the result of an admixture between the Jomon and Yayoi populations who have successively migrated to Japan from the Asian continent, and who have given rise to Jomon and Yayoi culture respectively. How the Jomon culture shifts to the Yayoi culture remains a controversial issue among scientific community.　 

The Ph.D. candidate PENG Mincheng supervised by academician ZHANG Yaping from Kunming Institute of Zoology, Chinese Academy of Sciences attempted to address the issue using genetic approach. Based on the notion that mtDNA genome variation is a good predictor of population size in humans, PENG applied Bayesian Skyline Plot (BSP) with a dataset based on 952 Japanese mitochondrial DNA (mtDNA) genomes to reconstruct the prehistoric demographics of Japanese.

The results suggested that a rapid population expansion event happened about 5, 000 years ago conforming to the middle period of the Jomon culture, which acted as a major force in shaping current maternal pool of Japanese. The study supported a model for population dynamics in Japan in which the prehistoric population growth initiated in the Middle Jomon Period experienced a smooth and swift transition from Jomon to Yayoi, and then continued through the Yayoi Period. The main findings have been published in PLoS ONE(http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021509).