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AsianScientist (Mar. 24, 2021) – While often seen as a modern issue, it turns out that climate change drove successive waves of human migration to the Philippines over the past 50,000 years. These findings were published in the Proceedings of the National Academy of Sciences.
With over 7,000 islands at the heart of Southeast Asia, the Philippines is a key link to understanding human history within the region. Early humans are known to have inhabited these islands since at least 67,000 years ago and yet, the islands’ history of population and colonization remain poorly understood.
One prevailing theory is the “out of Taiwan” hypothesis, which holds that ocean navigators from Taiwan brought language, culture and agriculture to the Philippines as they searched for fertile land. Though several studies have attempted to map potential migration events into the archipelago, they have failed to produce conclusive results given the limited genomic dataset available.
In the country’s most expansive DNA mapping study so far, an international team of researchers from Sweden, Australia, US—and of course, the Philippines—collected 2.3 million genotypes from 1,028 people representing 115 local indigenous populations. To better explore the “out of Taiwan” hypothesis, the group also collected genome sequences from two ancient individuals dating around 8,000 years old from Liangdao Island in the Taiwan Strait.
Their results reveal that the Philippines was populated in at least five major waves, starting with the Negritos, who are distantly related to Australian and Papuan populations, followed by the Manobo, Sama, Papuan and Cordilleran groups. In contrast to the “out of Taiwan” hypothesis, the Cordillerans diverged from indigenous Taiwanese humans at least 8,000 years ago—predating the local arrival of rice paddy agriculture 2,500 years ago.
According to the authors, the Cordillerans’ migration may have been catalyzed by climate change. Specifically, the coastal plain in the ancient landmass between Taiwan and Southern China likely gradually submerged over a period of 5,000 years—prompting the group to flee to the Philippines. The Manobo and Sama groups may have migrated from Borneo into southern Philippines due to similar geographic upheavals.
Interestingly, despite over 300 years of Spanish rule, less than one percent of the individuals involved in the study traced their genetic origins from West Eurasia—suggesting the limited genetic legacy of Spanish colonization on the Philippines.
“Our findings suggest that instead of farming, climate change may have played a more important role in driving the mass movement of populations in various directions,” concluded first author Dr. Maximilian Larena, a Filipino scientist based in Uppsala University.
“[It also] debunks a view that has dominated research on human history: that language, ways of life, culture and people move together as a single unit,” added senior author Professor Mattias Jakobsson, also from Uppsala University. “New groups of people migrated to the Philippines more than seven millennia ago…it wasn’t until three thousand years later that agriculture was taken there.”
The article can be found at: Larena et al. (2021) Multiple migrations to the Philippines during the last 50,000 years.
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Source: Philippine News Agency; Photo: Stephane Bidouze/Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
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