When farmers migrated to southeast Asia
By analyzing genome-wide DNA from the remains of ancient Southeast Asian individuals, scientists have shed new light on the past 4,000 years of genetic history from the region. Their analysis helps reveal potential migration events that may have led to the region’s rich cultural and linguistic diversity observed today. Southeast Asia has a complex history of human occupation, yet studying this history through genetics has remained a challenge because, for one, its humid and tropical environment presents unfavorable conditions for DNA preservation. As such, hypotheses based on archaeological findings – predicting the human origins of cultural shifts (like the use of tools and pottery) brought on by the introduction of farming, for example – remain unresolved by genetic studies.
Here, Mark Lipson, David Reich and colleagues obtained DNA data of 18 ancient Southeast Asian individuals from the Neolithic period to the Iron Age (4,100 to 1,700 years ago), found in modern-day Vietnam, Myanmar, Thailand and Cambodia. With additional support from archaeological and linguistic data, the researchers identified two major waves of genetic mixture indicative of specific migration events. The first wave, occurring during the Neolithic period, consisted of early farmer migrants from South China who mixed with local Southeast Asian hunter-gatherers. A couple thousand years afterwards, during the Bronze Age, an additional “pulse” of genes flowed from China to Southeast Asia, reflecting another influx of farmers, the researchers say. Interestingly, the pattern of human movement in Southeast Asia parallels that observed in Europe, where ancient DNA studies have also revealed genetic mixture associated with transitions in agricultural culture.