iNDICA NEWS BUREAU-
Researchers have gleaned new insights into India’s evolutionary history after conducting the largest genome study of its kind.
Scientists analyzed more than 2,700 modern Indian genomes from 17 states, including DNA from individuals from most geographic regions, speakers of all major languages, tribal and caste groups.
The findings trace one of India’s three primary ancestral lineages, the ancient Iranian farmers, to agriculturalists from Sarazm in present-day Tajikistan. The study also highlighted the remarkable genetic diversity stemming from Neanderthals and Denisovans, our closest extinct human relatives, within the Indian gene pool.
A crucial discovery is that the genetic mosaic of contemporary Indians largely originates from a singular, significant migration wave from Africa to India approximately 50,000 years ago. This insight was detailed in a preprint paper released on February 20 on the bioRxiv database.
Elise Kerdoncuff, the study’s lead author and a population geneticist at the University of California, Berkeley, emphasized the importance of including South Asian populations in genomic research. Such studies not only shed light on India’s past but also enrich our understanding of human history at large.
Despite India’s vast population of over 1.4 billion and its rich heritage of over 4,500 distinct anthropological groups, Indian genomes have been notably absent in genomic research, which has historically favored European ancestries.
To address this gap, the study’s authors delved into the genetic data of participants from the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia (LASI-DAD), all aged over 60, who provided blood samples for analysis.
The research reaffirmed that Indian ancestry is derived from three main groups – ancient Iranian farmers, Eurasian Steppe pastoralists, and South Asian hunter-gatherers. While the migration patterns of the latter two were known, the origins and arrival of ancient Iranian farmer DNA in India remained a mystery until now.
Analyses revealed that the Iranian-related DNA in Indians dates back to the early Neolithic era, specifically from individuals in Sarazm. Furthermore, Indians, like most non-Africans, inherit 1-2% of their DNA from Neanderthals and Denisovans, with Indian genomes exhibiting nearly 90% of all Neanderthal genes found in humans outside Africa.
Contrary to earlier archaeological theories, the study suggests that the main genetic influx in India aligns with a single migration event from Africa 50,000 years ago, rather than predating the Toba volcanic eruption circa 74,000 years ago.
The research opens up new inquiries, particularly about the inhabitants of India 50,000 years ago and whether the ranges of Neanderthals and Denisovans extended to South Asia. Priya Moorjani, co-senior study author and assistant professor at UCB, anticipates that future interdisciplinary collaborations will further unravel the intricate narrative of our evolutionary heritage.
