From the very beginning of human existence one thing has always been constant and that is movement. Humans just like animals tend to move about a lot. They rarely stay in one particular region for so long. Its either they travel to other places to visit, for work purposes or to settle down. Migration is quite high in the human populace. Asia being the most populous continent on planet earth has a huge variation in ethnicity, language and gene make up of its population and the constant movement of people in and out of that region has made it complicated to trace the origin of the diversity in that region.

Thailand is a region in Asia and is at the center of Mainland Southeast Asia (MSEA). It occupies a strategic position being that it is at the crossroad of ancient migration path between North and East Asia and Island Southeast Asia therefore would have people carrying the genes of ancestral migrants, yet extensive research on the genetics of the population has not been done on this region. Genetic substructure may exist within the Thai population since given its geographical location it must have been flooded with migrants from different parts of Asia particularly Southern Asia and so would have substantial gene flow. The earliest archeological evidence of humans in MSEA was obtained in southern Thailand and DNA analysis of this specimen showed close relationship with the present day Semang population in Peninsula Malaysia. Studies have also shown that it’s likely that the first population of significance in the MSEA were established by Austric agriculturist people, the ancestors of Austroasiatic and Austronesians who may have originated in Southern China. The Tai people migrated from Southern China into Northern Thailand more recently and they have established settlements in Thailand alongside the indigenous Austric and eventually the Tai became dominant and established control over Northern Thailand.

Large scale study of the genetic variation of the population of Thailand has not been carried out. So to better our understanding of the Mainland Southeast Asia ( MSEA) and the Thai population genetics, a study was carried out and result of that study showed that the Thai population is genetically distinct from other Asian population, but there is evidence of shared ancestry supporting the known origin and historical migration patterns across MSEA. The study also clarified the Thai population structure, revealing four major subpopulations. A major ancestry is common among these four subpopulations which probably are the evidence of Austric ancestors who originally settled across most of MSEA.

N.B: Tai refers to the group that have migrated from Southern China while Thai refers to the people presently living in Thailand.

Read the technical details at DOI: 10.1371/journal.pone.0079522

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