Genographic Project Scientists explore the language behind DNA in Southeast Asia

Laotian Canoer

For ten years, Genographic Project scientists have explored and explained how patterns in our DNA show evidence of migration and expansion routes of our ancient ancestors across the globe. DNA has shown that humans arose in Africa some 150,000 years ago, and around 60,000 years ago humans left Africa and went east into Asia, north into Europe, and south into Australia. But new research from Genographic Project scientists in India show that eventually some of them also moved west, and brought their language with them.

Genographic Project scientists Drs. Ramasamy Pitchappan and GaneshPrasad ArunKumar from Tamil Nadu, India analyzed the Y-chromosome (paternally-inherited) DNA from more than 10,000 men from southern Asia. The findings, published in the Journal of Systematics and Evolution, showed that in the last 8,000 years humans expanded west from Southeast Asia back to India.

Lao farmer paddles along golden river at sundet. Photo by W.E. Garrett.

This previously undetected migration is evident from the frequency and diversity of a specific genetic clan, or haplogroup in that part of the world. The Genographic scientists found a much higher frequency of haplogroup O2a1 in their research than expected. “Since O2a1 is accepted as the founding lineage of Austro Asiatic languages (group of related languages from Southeast Asia), the origin and spread of this lineage gives clues on the history of these speakers and the region. Our study shows a clear decrease in age and diversity of haplogorup O2a1 from Laos to East India, suggesting an east to west spread out of Southeast Asia,” explains Dr. ArunKumar about his findings.

Dr. G. ArunKumar working in the field in eastern India. Photo courtesy of G. ArunKumar

But why did they focus on just one haplogroup, when there are hundreds of distinct haplogroups in Asia? “The Y chromosomal haplogroup O2a1 accounts for almost —> Read More