Sequencing Bones in the Himalayas

The Himalayas is a mountain range in Asia and it separates the plains of the Indian subcontinent from the Tibetan Plateau. It includes over fifty mountains exceeding 23,600 ft in elevation. Bones of mysterious human beings are buried in a site in the Himalayan region named as "Skeleton Lake". These bones emerge from the ice during summer time and puzzle scientists about how they migrated there. Who were these individuals? A recent study published in Nature communications about the skeletons of Roopkund Lake in the Himalayan region of northern India uncovers the mystery of Mediterranean migrants in India. The genetic profiling using next generation sequencing tools explains the mystery behind those individuals. The study suggests that Roopkund Lake in Himalayan region has been visited by diverse populations over the past 1,000 years. Migrants from the Mediterranean or South Asia visited this region and died there within the last few centuries. The lake is located around 5000 meters above the sea level in India. Migration from Mediterranean region means a trip of 5000 kilometers from Greece to skeleton lake.

 

Roopkund Lake is a small body of water (~40 m in diameter) also referred as Skeleton Lake due to the remains of several hundred ancient humans scattered around its shores. Not much known about the origin of these skeletons. However, lots of speculations about these individuals, how they came here and how they died. Not much information is due to lack of systematic anthropological or archaeological scrutiny probably due to disturbed nature of the site, which is frequently affected by rockslides, and which is often visited by local pilgrims and hikers who have manipulated the skeletons and removed many of the artifacts. The unexpected results of the study involving genetic profiling of the ancient Skeleton Lake individuals have provided meaningful information about the mysterious ancient site. The investigators performed whole-genome sequencing of DNA from 38 skeletons, a huge study in terms of the history of ancient DNA analysis. Based on populations living today, these individuals fit into three distinct genetic groups. One group of 23 individuals resembled present day South Asians populations, second group consisting of one individual resembled Southeast Asian, and third group of 14 individuals have ancestry typical of the eastern Mediterranean currently centered on Greece and Crete. Besides whole genome sequencing, the researchers analyzed the samples using a series of bioarcheological analyses, including, stable isotope dietary reconstruction, radiocarbon dating, and osteological analysis. The results revealed that skeletons belong to three genetically distinct groups that were deposited during multiple events, separated in time by approximately 1000 years.  The study raises the question, how genetically unrelated individuals traveled to Roopkund Lake in Himalayan region and died only a few hundred years ago ? is still a mystery. This study highlights the power of next generation sequencing and biomolecular analyses to obtain rich information about the human story behind archaeological deposits that are so highly disturbed that traditional archaeological methods are not as informative.