Multi-layered population structure in Island Southeast Asians.

Area of Science:

• Human Population Genetics
• Archaeogenetics
• Southeast Asian Studies

Background:

• Human settlement in Southeast Asia is characterized by complex dispersal events.
• Previous genetic studies have identified major ancestry components in the region.

Purpose of the Study:

• To analyze genome-wide genotype data from diverse Mainland and Island Southeast Asian populations.
• To identify the closest living representatives of the source population for the Austronesian expansion.
• To investigate historical South Asian influences in Southeast Asia.

Main Methods:

• Genome-wide genotype data analysis of 1825 individuals from Southeast Asia.
• Analysis of autosomal data and uniparental markers.
• Comparison of genetic data with existing population structures.

Main Results:

• Confirmed previously recognized ancestry components in Southeast Asian populations.
• Identified Kankanaey Igorots as the closest living representatives of the Austronesian expansion source population.
• Detected South Asian genetic signatures in various Southeast Asian populations dating back 2,000 years.

Conclusions:

• The Kankanaey population provides crucial insights into the origins of the Austronesian expansion.
• Historical interactions and migrations have shaped the genetic landscape of Southeast Asia.
• Genetic data supports historical evidence of Indian influence in the region.