Prehistoric human migration between Sundaland and South Asia was driven by sea-level rise

Rapid sea-level rise between the Last Glacial Maximum (LGM) and the mid-Holocene transformed the Southeast Asian coastal landscape, but the impact on human demography remains unclear. Here, we create a paleogeographic map, focusing on sea-level changes during the period spanning the LGM to the present-day and infer the human population history in Southeast and South Asia using 763 high-coverage whole-genome sequencing datasets from 59 ethnic groups. We show that sea-level rise, in particular meltwater pulses 1 A (MWP1A, similar to 14,500-14,000 years ago) and 1B (MWP1B, similar to 11,500-11,000 years ago), reduced land area by over 50% since the LGM, resulting in segregation of local human populations. Following periods of rapid sea-level rises, population pressure drove the migration of Malaysian Negritos into South Asia. Integrated paleogeographic and population genomic analysis demonstrates the earliest documented instance of forced human migration driven by sea-level rise.

Automated summary

By creating a paleogeographic map and analyzing whole-genome sequencing data, this study investigates the impact of sea-level rise on human demography in Southeast and South Asia. The results show that sea-level rise reduced land area and led to the segregation of local populations. Population pressure driven by rapid sea-level rises forced the migration of Malaysian Negritos into South Asia. This research provides the earliest documented evidence of forced human migration caused by sea-level rise.