The Wire Staff 
New Delhi: A new research study revealed the presence of rich diversity of genes from Neanderthals and their close evolutionary cousins, the Denisovans in Indian genomes. It is a surprising revelation as no fossils of these ancient human relatives have been found in India.
As per a report published in Science, the study carried out by University of California, Berkeley population geneticist Priya Moorjani and her colleagues by sequencing more than 2700 modern Indian genomes revealed that most Indians are a mixture of three ancestral populations: hunter-gatherers who lived in the region for tens of thousands of years, farmers with Iranian ancestry who arrived between 4700 and 3000 B.C.E. and herders from the central Eurasian steppe region who came sometime after 3000 B.C.E., perhaps between 1900 and 1500 B.C.E.
Interestingly, the scientists found that modern individuals sampled derive 1% to 2% of their ancestry from Neanderthals and their close cousins, the Denisovans which is on par with Europeans and Indians collectively carry a stunning variety of these archaic genes compared with other worldwide populations, Science reported.
As per this study — assumed to be the largest ever modern whole-genome analysis from South Asia, published as a preprint last month on bioRxiv — about 90% of all known Neanderthal genes that have made their way into human populations turned up in the 2700 Indian genomes. It is about 50% more than what was recovered in a similar study of Neanderthal DNA in Icelanders that analysed more than 27,000 genomes.
Moorjani speculated that “ancient humans might have encountered and mated with a relatively large, genetically diverse population of our archaic cousins living on the subcontinent — although no fossils of those archaic cousins have been found,” Science reported. According to another assumption by scientists, there is a possibility that different segments of Neanderthal DNA is preserved better in India’s vast geography and close kin-marrying traditions compared to other places.
“To find out more about the identity of the Iranian-related farmers who entered the region thousands of years ago, the researchers analyzed previously extracted ancient DNA from groups with Iranian ancestry who predated the genetic pulse into India. They then played out simulations to see whose genes best matched the patterns seen in present-day Indians. The best fit came from farmers from an ancient agricultural center called Sarazm in the northwest of what today is Tajikistan. Farmers here grew wheat and barley and kept cattle, and traded extensively throughout Eurasia,” Science reported.
Population geneticist Kelsey Witt of Clemson University told Science that this research was important as India had largely been ignored in global population geneticist Kelsey Witt of Clemson University. “We’re learning a lot about populations that we didn’t know much about,” Witt said.