The formation of proto-austronesians: insights from a revised phylogeography of the paternal founder lineage.

OBJECTIVES: Previous studies suggested that the Y-chromosome haplogroups O2-N6-B451-AM01756 and O1a-M119 are two founder lineages of proto-Austronesians at about five thousand years ago. The objective of this study was to investigate the formation of proto-Austronesians from the perspective of the paternal gene pool. MATERIALS AND METHODS: In this study, we developed a highly evised phylogenetic tree with age estimates for haplogroup O2-N6 and early branches of O1a-M119 (M110, F1036, and F819). In addition, we also explored the geographical distribution of eight sub-branches of O2-N6 and O1a-M119, and spatial autocorrelation analysis was conducted for each sub-branch. RESULTS: The paternal lineage combination of proto-Austronesians is a small subset of a diverse gene pool of populations from the mainland of East Asia. The distribution map and results of the spatial autocorrelation analysis suggested that the eastern coastal region of northern China is likely the source of lineage O2-N6 while the coastal region of southeastern China is likely the diffusion center of early branches of O1a-M119. We developed an evolutionary diagram for Austronesians and their ancestors in the past 18,000 years. DISCUSSION: We proposed that the millet farming community in North China is the common ancestor group of the Austronesians and the Han people, while the diverse ancient people in the southeast coastal areas of East Asia form the common ancestor group of the Austronesians and the East Asian mainland population. The demographic history of multiple ancestral groups of the most recent common ancestor group itself in the more ancient period is helpful to understand the deep roots of the genetic components and cultural traditions of Austronesians.

Post-last glacial maximum expansion of Y-chromosome haplogroup C2a-L1373 in northern Asia and its implications for the origin of Native Americans.

OBJECTIVES: Subbranches of Y-chromosome haplogroup C2a-L1373 are founding paternal lineages in northern Asia and Native American populations. Our objective was to investigate C2a-L1373 differentiation in northern Asia and its implications for Native American origins. MATERIALS AND METHODS: Sequences of rare subbranches (n = 43) and ancient individuals (n = 37) of C2a-L1373 (including P39 and MPB373), were used to construct phylogenetic trees with age estimation by BEAST software. RESULTS: C2a-L1373 expanded rapidly approximately 17.7,000-14.3,000 years ago (kya) after the last glacial maximum (LGM), generating numerous sublineages which became founding paternal lineages of modern northern Asian and Native American populations (C2a-P39 and C2a-MPB373). The divergence pattern supports possible initiation of differentiation in low latitude regions of northern Asia and northward diffusion after the LGM. There is a substantial gap between the divergence times of C2a-MPB373 (approximately 22.4 or 17.7 kya) and C2a-P39 (approximately 14.3 kya), indicating two possible migration waves. DISCUSSION: We discussed the decreasing time interval of "Beringian standstill" (2.5 ky or smaller) and its reduced significance. We also discussed the multiple possibilities for the peopling of the Americas: the "Long-term Beringian standstill model," the "Short-term Beringian standstill model," and the "Multiple waves of migration model." Our results support the argument from ancient DNA analyses that the direct ancestor group of Native Americans is an admixture of "Ancient Northern Siberians" and Paleolithic communities from the Amur region, which appeared during the post-LGM era, rather than ancient populations in greater Beringia, or an adjacent region, before the LGM.

Paternal origin of Tungusic-speaking populations: Insights from the updated phylogenetic tree of Y-chromosome haplogroup C2a-M86.

OBJECTIVES: Haplogroup C2a-M48 is the predominant paternal lineage of Tungusic-speaking populations, one of the largest population groups in Siberia. Up until now, the origins and dispersal of Tungusic-speaking populations have remained unclear. In this study, the demographic history of Tungusic-speaking populations was explored using the phylogenetic analysis of haplogroup C2a-M86, the major subbranch of C2a-M48. MATERIALS AND METHODS: In total, 18 newly generated Y chromosome sequences from C2a-M48 males and 20 previously available Y-chromosome sequences from this haplogroup were analyzed. A highly revised phylogenetic tree of haplogroup C2a-M86 with age estimates was reconstructed. Frequencies of this lineage in the literature were collected and a comprehensive analysis of this lineage in 13 022 individuals from 245 populations in Eurasia was performed. RESULTS: The distribution map of C2a-M48 indicated the most probable area of origin and diffusion route of this paternal lineage in North Eurasia. Most C2a-M86 samples from Tungusic-speaking populations belonged to the sublineage C2a-F5484, which emerged about 3300 years ago. We identified six unique sublineages corresponding to the Manchu, Evenks, Evens, Oroqen, and Daurpopulations; these sublineages diverged gradually over the past 1900 years. Notably, we observed a clear north-south dichotomous structure for sublineages derived from C2a-F5484, consistent with the internal north-south divergence of Tungusic languages and ethnic groups. CONCLUSIONS: We identified the important founding paternal haplogroup, C2a-F5484, for Tungusic-speaking populations as well as numerous unique subgroups of this haplogroup. We propose that the timeframe for the divergence of C2a-F5484 corresponds with the early differentiation of ancestral Tungusic-speaking populations.

Phylogenetic analysis of the Y-chromosome haplogroup C2b-F1067, a dominant paternal lineage in Eastern Eurasia.

Human Y-chromosome haplogroup C2b-F1067 is one of the dominant paternal lineages of populations in Eastern Eurasia. In order to explore the origin, diversification, and expansion of this haplogroup, we generated 206 new Y-chromosome sequences from C2b-F1067 males and coanalyzed 220 Y-chromosome sequences of this haplogroup. BEAST software was used to reconstruct a revised phylogenetic tree of haplogroup C2b-F1067 with age estimates. The revised phylogeny of C2b-F1067 included 155 sublineages, 1986 non-private variants, and >6000 private variants. The age estimation suggested that the initial splitting of C2b-F1067 happened at about 32.8 thousand years ago (kya) and the major sublineages of this haplgroup experienced continuous expansion in the most recent 10,000 years. We identified numerous sublineages that were nearly specific for Korean, Mongolian, Chinese, and other ethnic minorities in China. In particular, we evaluated the candidate-specific lineage for the Dayan Khan family and the Confucius family, the descendants of the ruling family of the Chinese Shang dynasty. These findings suggest that ancient populations with varied C2b-F1067 sublineages played an important role during the formation of most modern populations in Eastern Eurasia, and thus eventually became the founding paternal lineages of these populations.

[Gene frequency of 12 characters in 5 nationalities in inner mongolia].

The gene frequency of 12 characters was reported in Ewenki, Oroqen, Daur, Mongol and Han nationalities in Inner Mongolia, and compared among these nationalities. The result indicated that the difference of Mongoloid fold among nationalities was significant, followed by the Folding tongue, while the difference of Handedness and Nasal profile was relatively insignificant.