Reconstructing the Human Genetic History of Mainland Southeast Asia: Insights from Genome-Wide Data from Thailand and Laos

Abstract

Thailand and Laos, located in the center of Mainland Southeast Asia (MSEA), harbor diverse ethnolinguistic groups encompassing all five language families of MSEA: Tai-Kadai (TK), Austroasiatic (AA), Sino-Tibetan (ST), Hmong-Mien (HM), and Austronesian (AN). Previous genetic studies of Thai/Lao populations have focused almost exclusively on uniparental markers and there is a paucity of genome-wide studies. We therefore generated genome-wide SNP data for 33 ethnolinguistic groups, belonging to the five MSEA language families from Thailand and Laos, and analyzed these together with data from modern Asian populations and SEA ancient samples. Overall, we find genetic structure according to language family, albeit with heterogeneity in the AA-, HM-, and ST-speaking groups, and in the hill tribes, that reflects both population interactions and genetic drift. For the TK speaking groups, we find localized genetic structure that is driven by different levels of interaction with other groups in the same geographic region. Several Thai groups exhibit admixture from South Asia, which we date to ∼600–1000 years ago, corresponding to a time of intensive international trade networks that had a major cultural impact on Thailand. An AN group from Southern Thailand shows both South Asian admixture as well as overall affinities with AA-speaking groups in the region, suggesting an impact of cultural diffusion. Overall, we provide the first detailed insights into the genetic profiles of Thai/Lao ethnolinguistic groups, which should be helpful for reconstructing human genetic history in MSEA and selecting populations for participation in ongoing whole genome sequence and biomedical studies.

Genomic Insight Into the Population Admixture History of Tungusic-Speaking Manchu People in Northeast China

“…We merged our newly genotyped data with previously published modern and ancient population data from the Affymetrix Human Origins (HO) Array dataset ( Wall and Yoshihara Caldeira Brandt, 2016 ) and the 1240K dataset from the Allen Ancient DNA Resource (AADR). 3 The included modern genome-wide SNP reference data were collected from nine language families or groups (Tungusic, Mongolic, Turkic, Sinitic, Tibeto-Burman, Austronesian, Austroasiatic, Tai-Kadai, and Hmong-Mien) in China, South Siberia, and Southeast Asia ( Patterson et al, 2012 ; Lipson et al, 2018 ; Liu et al, 2020 ; Kutanan et al, 2021 ; Wang et al, 2021a ). Ancient reference populations were also collected from China and surrounding countries ( Ning et al, 2020 ; Yang et al, 2020 ; Wang et al, 2021a ).…”

Genomic insights into the population history and biological adaptation of Southwestern Chinese Hmong-Mien people

“…Currently, HM groups mainly dwell in South China (including South -Central, Southwest, and Southeast China) (He et al, 2019;Huang et al, 2020;Xia et al, 2019;Zhang et al, 2019 ) and Vietnam, Laos and Thailand in mainland Southeast Asia (Kutanan et al, 2021;Liu et al, 2020). The history of the HM language family is obscure, which has been passed down mainly through oral legends and myths, for few written historical records exist.…”

“…The history of the HM language family is obscure, which has been passed down mainly through oral legends and myths, for few written historical records exist. Hence, linguistic, genetic and paleogenomic studies are crucial for reconstructing the demographic history of HM groups (Huang et al, 2020;Kutanan et al, 2021;Wang, T. et al, 2021;Xia et al, 2019). Wang et al successfully obtained genomic material from 31 ancient individuals from southern China (Guangxi and Fujian) ranging from ~12,000 -10,000 to 500 ya and identified HM-related ancestry represented by ~500-year-old GaoHuaHua population (Wang, T. et al, 2021).…”

Genomic Insight Into the Population Structure and Admixture History of Tai-Kadai-Speaking Sui People in Southwest China

“…The strong correlation between the population structure and linguistic classifications/geographic locations in East Asia has been reported in several genome-wide SNP-based studies (He et al, 2020;Huang et al, 2020;Kutanan et al, 2021;Wang C. C. et al, 2021). The population expansion with the extensive gene flow among populations which belong to the different linguistic classifications also drives the formation of the complex population genetic structure in East Asia (Huang et al, 2020;Liu D. et al, 2020;Kutanan et al, 2021;Wang M. et al, 2021;Wang C. C. et al, 2021;Yang et al, 2020). Yang et al (2020) recently reconstructed the genetic structure and admixture history of Neolithic ancient NEAs and SEAs, demonstrating that the population structure in East Asia had existed early in the Neolithic; the spread of the NEA-related ancestry led to more genetic homogeneity in present-day EAs than in Neolithic EAs.…”

“…The strong correlation between the population structure and linguistic classifications/geographic locations in East Asia has been reported in several genome-wide SNP-based studies (He et al, 2020;Huang et al, 2020;Kutanan et al, 2021;Wang C. C. et al, 2021). The population expansion with the extensive gene flow among populations which belong to the different linguistic classifications also drives the formation of the complex population genetic structure in East Asia (Huang et al, 2020;Liu D. et al, 2020;Kutanan et al, 2021;Wang M. et al, 2021;Wang C. C. et al, 2021;Yang et al, 2020).…”