摘要：The debate on the origin of East Asian is taking down by the molecular anthropological studies of the various populations in and around East Asia. Some previous studies revealed that most of the Y chromosome lineages of East Asian came from the South. However, the Southeast Asian populations which supposed to be the ancestral populations of East Asian lack for investigations. Therefore, the entrance of East Asian and the formation process of the unique genetic structure have never been studied. Here we present the Y chromosome data of 1652 individuals from 47 populations of Mon-Khmer and Hmong-Mien ethnic groups, which are the aborigines of Southeast Asia and extending area in East Asia. The most frequent haplogroup of the two ethnic groups is O2a*-M95, but is not ethnic specific. Haplogroup O3a4-M7 can only be found in these two ethnic groups, indicating the closest relationship between these two groups. The STR network of O3a4 displayed a layered expansion structure, with the Mon-Khmer haplotypes in the central and the Hmong-Mien haplotypes in the outer layer, the Lolo-Burman haplotypes in the margin. The layered structure was resulted from the slow and even migration of early modern human from Southeast Asia to East Asia by a “Jungle Filter” effect which includes many small bottle-neck effects. The age of O3a4 was estimated to around 27 thousand years, and the migration event was earlier than 16 thousand years ago during the last Ice Age. The unique genetic structure of East Asian might also be resulted from the “Jungle Filter” effect
关键词：Jungle Filter effect; origin of East Asian; Y chromosome haplogroup O3a4; network analysis
