Y chromosomes from south to north in East Eurasia

I am continuing my Y-STR boycott, but I have to note that the paper uses the "evolutionary rate", and hence its age estimates are wrong. A great range of ages can be supported when one uses Y-STRs, because of their poor qualities, but, as a first step the 19ky estimate should be downsized to about 6ky.

I know next to nothing about Tibeto-Burman languages, but, apparently the age estimate for Proto-Han and Proto-Tibeto-Burman unity is... 6ky. I would wager that we have here, one more piece of evidence for Y-chromosome-language correlation, and not at all events of glacial antiquity.

Table 1 contains the haplogroup frequencies:

The clustering analysis is instructive:

Indo-Aryan/Dravidian are the clear outgroup, due to their possessing a set of West Eurasian/South Asian haplogroups largely lacking in Southeast Asia. Altaic and Austronesian is slightly closer to the main group, probably due to a different set of haplogroups. Not surprisingly, Austroasiatic speakers who are native to Southeast Asia are closer to Sino-Tibetans, while the latter category emerges naturally, joining Han with Tibeto-Burman.

PLoS ONE 6(8): e24282. doi:10.1371/journal.pone.0024282

Human Migration through Bottlenecks from Southeast Asia into East Asia during Last Glacial Maximum Revealed by Y Chromosomes

Xiaoyun Cai et al.

Molecular anthropological studies of the populations in and around East Asia have resulted in the discovery that most of the Y-chromosome lineages of East Asians came from Southeast Asia. However, very few Southeast Asian populations had been investigated, and therefore, little was known about the purported migrations from Southeast Asia into East Asia and their roles in shaping the genetic structure of East Asian populations. Here, we present the Y-chromosome data from 1,652 individuals belonging to 47 Mon-Khmer (MK) and Hmong-Mien (HM) speaking populations that are distributed primarily across Southeast Asia and extend into East Asia. Haplogroup O3a3b-M7, which appears mainly in MK and HM, indicates a strong tie between the two groups. The short tandem repeat network of O3a3b-M7 displayed a hierarchical expansion structure (annual ring shape), with MK haplotypes being located at the original point, and the HM and the Tibeto-Burman haplotypes distributed further away from core of the network. Moreover, the East Asian dominant haplogroup O3a3c1-M117 shows a network structure similar to that of O3a3b-M7. These patterns indicate an early unidirectional diffusion from Southeast Asia into East Asia, which might have resulted from the genetic drift of East Asian ancestors carrying these two haplogroups through many small bottle-necks formed by the complicated landscape between Southeast Asia and East Asia. The ages of O3a3b-M7 and O3a3c1-M117 were estimated to be approximately 19 thousand years, followed by the emergence of the ancestors of HM lineages out of MK and the unidirectional northward migrations into East Asia.

Link

Tai and Mon-Khmer of northern Thailand

BMC Genetics 2011, 12:56doi:10.1186/1471-2156-12-56

Genetic structure of the Mon-Khmer speaking groups and their affinity to the neighbouring Tai populations in Northern Thailand

Wibhu Kutanan et al.

Background
The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure.

Results
A large fraction of genetic variation is observed within populations (about 80% and 90 % for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2 %) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern.

Conclusions
The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them.

Link