Under the name of "Lua": Revisiting Genetic Heterogeneity and Population Ancestry of Austroasiatic speakers in Northern Thailand Through Genomic Analysis

Abstract

Austroasiatic (AA)-speaking populations in northern Thailand are of significant interest due to their status as indigenous descendants and their location at the crossroads of AA prehistoric distribution across Southern China, the Indian Subcontinent, and Mainland Southeast Asia. However, the complexity of ethnic identification can result in inaccuracies regarding the origin and migration history of these populations. To address this, we conducted a genome-wide SNP analysis on 89 individuals from two Lavue- and three Lwa-endonym populations and combined them with previously published data to elucidate the genetic diversity and clustering of AA groups in northern Thailand. Our findings align with linguistic classifications, revealing distinct genetic structure among the three branches of the Mon-Khmer subfamily within the AA family: Monic, Khmuic, and Palaungic. Although the term "Lua" ethnicity is used confusingly to identify ethnic groups belonging to both Khmuic and Palaungic branches, our genomic data clarifies that the Khmuic-speaking Lua living on the eastern side of the region show genetic differentiation from the Palaungic-speaking Lavue and Lwa populations living on the western side. Within the Palaungic branch, the Dara-ang population stands out as genetically distinct, reflecting remnants of ancient ancestry. The Lavue populations, mainly inhabiting mountainous areas, exhibit a genetic makeup unique to the AA family, with a close genetic relationship to the Karenic subgroup of the ST family. Conversely, the Lwa and Blang populations, residing in lowland river valleys, display genetic signatures resulting from admixture with Tai-Kadai-speaking ethnic groups. Author summaryIn the past, many Austroasiatic speakers in northern Thailand concealed their identity due to perceptions of inferiority compared to the majority Tai-Kadai-speaking group in the region. However, attitudes have shifted in the modern era, with a greater appreciation for ethnic diversity and the unique aspects of different valuable cultures. This scenario provides an opportunity for us to use genetic insights to untangle the complexities of ethnic identification among these indigenous inhabitants of Mainland Southeast Asia. Through our genetic analysis, we aimed to shed light on the ancestry and diversity of the Austroasiatic people in northern Thailand, often collectively referred to as "Lua" or "Lawa", which is an exonym (a name of the ethnic group created by another group of people) commonly used in prior scientific reports. Our findings clearly indicate genetic distinctions among the Lua, Lavue, and Lwa ethnic groups. The intricate interplay of genetics, cultural heritage, and historical influences has shaped these ethnic communities. Our study underscores the importance of accurate ethnic classifications, emphasizing the use of self-identified endonyms, names created and used by the ethnic group themselves. This approach respects the Austroasiatic communities in northern Thailand and acknowledges their significant contributions to advancing our understanding of genetic anthropology.