Patrilineal perspective on the Austronesian diffusion in Mainland Southeast Asia

Area of Science:

• Population Genetics
• Human Migration Studies
• Austronesian Dispersal

Background:

• The Cham people are major Austronesian speakers in Mainland Southeast Asia (MSEA).
• Understanding Cham population history offers insights into Austronesian diffusion patterns.
• Previous studies have not fully elucidated the genetic origins and admixture of the Cham population.

Purpose of the Study:

• To reconstruct the population history and genetic origins of the Cham people.
• To investigate the genetic admixture between Austronesian immigrants and local MSEA populations.
• To explore the role of male-mediated dispersals in shaping the Cham gene pool.

Main Methods:

• Analysis of non-recombining Y chromosome (Y-DNA) markers in 177 males from four MSEA populations (Cham, Kinh, Lao, Thai).
• Integration of published mitochondrial DNA (mtDNA) data for comprehensive population analysis.
• Comparative analysis of Y-DNA and mtDNA patterns to identify genetic influences and admixture.

Main Results:

• Cham people exhibit genetic admixture, with origins involving Austronesian immigrants and local MSEA populations.
• Y chromosome and mtDNA patterns show discordance, with some Y-DNA lineages prevalent in South Asians.
• Cham are generally identified as an indigenous Southeast Asian population with complex genetic origins.

Conclusions:

• The origin of the Cham population is a result of admixture between Island Southeast Asian (ISEA) Austronesian migrants and local MSEA groups.
• Male-mediated dispersals, potentially through religion and trade, significantly influenced the Cham patrilineal gene pool.
• Further research into specific Y-DNA lineages can illuminate historical migration and interaction patterns in MSEA.