Solving a 100-year-old controversy
TWO competing theories about the human occupation of South-East Asia have been debunked by groundbreaking analysis of ancient DNA extracted from 8,000 year-old skeletons.
One theory believed indigenous Hòabìnhian hunter-gatherers populated South-East Asia from 44,000 years ago who later adopted agricultural practices independently, without e input from early farmers from East Asia. Another theory – the “two-layer model” favours the view that migrating rice farmers from what is now China replaced the indigenous Hòabìnhian hunter-gatherers
Monash University Malaysia Jeffrey Cheah School of Medicine and Health Sciences human geneticists, Prof Dr Maude E Phipps and Dr Farhang Aghakhanian were part of an international group of academics who collaborated on this new research, recently published in Science, one of the world’s top academic journal.
Led by Prof Eske Willerslev, who holds positions both at St John’s College, University of Cambridge and the University of Copenhagen, the study found neither theory completely accurate – present-day South-East Asian populations derive ancestry from at least four ancient populations.
DNA samples from human skeletal remains from Malaysia, Thailand, the Philippines, Vietnam, Indonesia, Laos and Japan dating back as far as 8,000 years ago were extracted for the study.
The samples also included DNA from Hòabìnhian hunter-gatherers and a Jomon from Japan – a scientific first, which revealed a long suspected genetic link between the two populations. In total, 26 ancient human genome sequences were studied and compared with modern DNA samples from people living in South-East Asia today including Jehai, the last of the huntergatherer indigenous group in Malaysia.
The pioneering research is particularly impressive because the heat and humidity of South-East Asia makes it one of the most difficult environments for DNA preservation.
Prof Willersley explained, “We put a huge amount of effort into retrieving ancient DNA from tropical South-East Asia that could shed new light on this area of rich human genetics.
“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 human occupation history of South-East Asia remains heavily debated. Dr Fernando Racimo
The Centre for GeoGenetics in the Natural History Museum of Denmark of the University of Copenhagen PhD student and one of the lead authors on the paper, Hugh McColl said, “By sequencing 26 ancient human genomes, we have shown neither interpretation fits the complexity of SouthEast Asian history. Our results help resolve one of the long-standing controversies in South-East Asian prehistory.”
The Centre for GeoGenetics in the Natural History Museum of the University of Copenhagen assistant professor and the other lead author, Dr Fernando Racimo said, “The human occupation history of SouthEast Asia remains heavily debated. Our research found that present-day South-East Asian populations derive ancestry from at least four ancient populations – a far more complex model than previously thought.”
Some of the samples used were from The Duckworth Collection, University of Cambridge, one of the world's largest repositories of human remains.
One of the lead authors from the Centre for GeoGenetics in the Natural History Museum of the University of Copenhagen and the National Museum of Natural History, Ecoanthropology and Ethnobiology, Musee de l'Homme, Paris, Dr Fabrice Demeter said, “Of particular importance to the study was Pha Faen, an 8,000 year old Hòabinhian skeleton found in a cave in Laos sampled in collaboration with Department of Heritage, Ministry of Information, Culture and Tourism, Vientiane, Laos. This sample, along with the Gua Cha from Malaysia anchors the study deeper in the past than has previously been possible.”
Other Malaysian researchers were Universiti Sains Malaysia archaeologists, Prof Datuk Dr Mohd Mokhtar Saidin and Shaiful Shahidan.
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