The first maternal genetic study of hunter-gatherers from Vietnam

The current limitation of ancient DNA data from Vietnam led to the controversy surrounding the prehistory of people in this region. The combination of high heat and humidity damaged ancient bones that challenged the study of human evolution, especially when using DNA as study materials. So far, only 4 k years of history have been recorded despite the 65 k years of history of anatomically modern human occupations in Vietnam. Here we report, to our knowledge, the oldest mitogenomes of two hunter-gatherers from Vietnam. We extracted DNA from the femurs of two individuals aged 6.2 k cal BP from the Con Co Ngua (CCN) site in Thanh Hoa, Vietnam. This archeological site is the largest cemetery of the hunter-gatherer population in Southeast Asia (SEA) that was discovered, but their genetics have not been explored until the present. We indicated that the CCN haplotype belongs to a rare haplogroup that was not detected in any present-day Vietnamese individuals. Further matrilineal analysis on CCN mitogenomes showed a close relationship with ancient farmers and present-day populations in SEA. The mitogenomes of hunter-gatherers from Vietnam debate the "two layers" model of peopling history in SEA and provide an alternative solution for studying challenging ancient human samples from Vietnam.