July 6 (UPI) -- After analyzing ancient DNA samples, scientists now have a bit more clarity on how early humans first arrived in Southeast Asia.
For decades, scientists have disagreed on how Southeast Asia was first populated. Some researchers believed an indigenous group of hunter-gatherers, called the Hòabìnhian, developed agricultural practices on their own, some 44,000 years ago. Others argued the hunter gatherers were replaced by rice growers who migrated from what's now China.
Now, an analysis of 26 ancient DNA samples, collected from human remains in Malaysia, Thailand, the Philippines, Vietnam, Indonesia, Laos and Japan, suggests both groups are mistaken. Some of tested DNA fragments were dated to 8,000 years ago. Until now, the oldest tested samples were 4,000 years old.
The results of the genetic survey, published this week in the journal Science, suggests a link between the Hòabìnhian people and the Jomon people of prehistoric Japan.
"We put a huge amount of effort into retrieving ancient DNA from tropical Southeast Asia that could shed new light on this area of rich human genetics," Eske Willerslev, a professor at the University of Cambridge, said in a news release. "The fact that we were able to obtain 26 human genomes and shed light on the incredible genetic richness of the groups in the region today is astonishing."
The latest findings undermine the primacy of the two competing theories. The peopling of Southeast Asia was a complex process, with as many as four different ancient populations contributing to the region's genetic history.
"This is a far more complex model than previously thought," said Fernando Racimo, a geneticist at the University of Copenhagen's Natural History Museum.
Scientists hope to continue unraveling the mysteries of Southeast Asia's genetic history as more DNA samples are recovered from ancient human remains.