Pittayawat Pittayaporn

Genetic and linguistic correlation of the Kra–Dai-speaking groups in Thailand

The Kra–Dai linguistic family includes Thai and Lao as well as a great number of languages spoken by ethnic minorities in Southeast Asia. In Thailand, a dozen of other Kra–Dai languages are spoken in addition to Thai, the national language. The genetic structure of the Kra–Dai-speaking populations in Thailand has been studied extensively using uniparentally inherited markers. To extend this line of genetic investigation, this study used 15 autosomal microsatellites of 500 individuals from 11 populations, belonging to nine Kra–Dai ethnicities, namely, the Kaleung, Phu Thai, Saek, Nyo, Lao Isan, Yuan, Black Tai, Phuan and Lue. These ethnolinguistic groups are dispersed in three different geographic regions of Thailand, that is, Northern, Northeastern and Central. The results show a very low average of pairwised Fst (0.0099), as well as no population substructure based on STRUCTURE analysis, indicating genetic homogeneity within the Kra–Dai-speaking group, possibly owing to shared linguistic ancestry. The Mantel test, an analysis of molecular variance, and the approximate Bayesian computation procedure employed to evaluate potential factors for driving genetic diversity revealed that language is the predominant factor affecting genetic variations, whereas geography is not. The result of distance-based clustering analyses and spatial analysis of molecular variance revealed genetic distinctions of some populations, reflecting the effects of genetic drift and gene flow on allele frequency within populations, in concordance with the result of R-matrix regression. The genetic and linguistic affiliations of the contemporary Kra–Dai-speaking groups are consistent with each other despite certain deviation due to various evolutionary factors that may have occurred during their migrations and resettlements.

Admixed origin of the Kayah (Red Karen) in Northern Thailand revealed by biparental and paternal markers.

This study analyzes the autosomal short tandem repeats (STRs) variation and the presence of Y chromosomal haplogroups from 44 individuals of the Kayah or Red Karen (KA) in Northern Thailand. The results based on autosomal STRs indicated that the KA exhibited closer genetic relatedness to populations from adjacent regions in Southeast Asia (SEA) than populations from Northeast Asia (NEA) and Tibet. Moreover, an admixed origin of the KA forming three population groups was observed: NEA, Southern China, and Northern Thailand. The NEA populations made a minor genetic contribution to the KA, while the rest came from populations speaking Sino‐Tibetan (ST) languages from Southern China and Tai–Kadai (TK) speaking groups from Northern Thailand. The presence of six paternal haplogroups, composed of dual haplogroups prevalent in NEA (NO, N, and D1) and SEA (O2 and O3) as well as the intermediate genetic position of the KA between the SEA and NEA also indicated an admixed origin of male KA lineages. Our genetic results thus agree with findings in linguistics that Karenic languages are ST languages that became heavily influenced by TK during their southward spread. A result of the Mongol invasions during the 13th century A.D. is one possible explanation for genetic contribution of NEA to the KA.

New insights from Thailand into the maternal genetic history of Mainland Southeast Asia

Tai-Kadai (TK) is one of the major language families in Mainland Southeast Asia (MSEA), with a concentration in the area of Thailand and Laos. Our previous study of 1234 mtDNA genome sequences supported a demic diffusion scenario in the spread of TK languages from southern China to Laos as well as northern and northeastern Thailand. Here we add an additional 560 mtDNA genomes from 22 groups, with a focus on the TK-speaking central Thai people and the Sino-Tibetan speaking Karen. We find extensive diversity, including 62 haplogroups not reported previously from this region. Demic diffusion is still a preferable scenario for central Thais, emphasizing the expansion of TK people through MSEA, although there is also some support for gene flow between central Thai and native Austroasiatic speaking Mon and Khmer. We also tested competing models concerning the genetic relationships of groups from the major MSEA languages, and found support for an ancestral relationship of TK and Austronesian-speaking groups.

Laryngeal contrasts in the Tai dialect of Cao Bằng

The Tai dialect spoken in Cao Bằng province, Vietnam, is at an intermediate stage between tonal register split and the accompanying transphonologization of a voicing contrast into a dual-register tone system. While the initial sonorants have completely lost their historical voicing distinction and developed a six-way tonal contrast, the obstruent series still preserves the original voicing contrast, leaving the tonal split incomplete. This paper presents the first acoustic study of tones and onsets in Cao Bằng Tai. Although f0, VOT, and voice quality were all found to play a role in the system of laryngeal contrasts, the three speakers considered varied in terms of the patterns of acoustic cues used to distinguish between onset types, particularly the breathy voiced onset / /. From the diachronic perspective, our findings may help to explain why the reflex of modal pre-voiced stops (*b) can be either aspirated or unaspirated voiceless stops.