Invited Seminar at CES on 6 May 2025 at 3:00 pm titled "Discovery of a 4,400-year-old ancestral lineage in a Dravidian-speaking tribe." by Dr. Ranajit Das from IIsc, Bangalore

Share this story on

Facebook icon Twitter icon
Topic: 
Discovery of a 4,400-year-old ancestral lineage in a Dravidian-speaking tribe.
Speaker: 
Dr. Ranajit Das, IIsc, Bangalore
Date & Time: 
6 May 2025 - 3:00pm
Event Type: 
Invited Seminar
Venue: 
CES Seminar Hall, 3rd Floor, Biological Sciences Building
Coffee/Tea: 
Before the talk
Abstract:

Recent genetic research has shown that the present-day population of the Indian subcontinent derives its ancestry from at least three major sources: early agriculturalists from the Iranian plateau, pastoralist groups originating in the Pontic-Caspian steppe, and ancient hunter-gatherers with affinities to the Andamanese. The current genetic landscape of India represents a cline resulting from admixture among these sources. However, with growing availability of ancient and modern genome sequences and advanced population structure analyses, a more nuanced picture of ancestry is beginning to take shape.
In this study, we focus on Dravidian-speaking populations and propose the existence of a fourth ancestral component. This component appears to have diverged from the basal Middle Eastern lineage that contributed to the Iranian agriculturalist ancestry. Supported by the Elamo-Dravidian hypothesis and linguistic phylogenies within the Dravidian language family, our genetic findings suggest a coherent link between language and ancestry.
Our analyses identify this unique ancestry—termed ‘Proto-Dravidian’—within the Koraga tribe, suggesting its emergence around the early period of the Indus Valley Civilization. This ancestry is genetically distinct from the previously described sources and is estimated to have originated at least 4,400 years ago in the region stretching between the Iranian plateau and the Indus Valley. The presence of this component across contemporary Indian populations, with the exception of some tribal groups, underscores its enduring influence.
This discovery highlights the critical role of fine-scale, population-specific studies in reconstructing ancestral histories. It also calls for carefully designed sampling strategies in genomic biobanking to avoid oversimplified models of ancestry. Moving forward, an interdisciplinary approach will be essential to unravel the complexities of human population history in South Asia.

Speaker Bio: 
Dr. Ranajit is a human geneticist interested in population and quantitative genetics, genetic epidemiology and biostatistics. He did his Bachelors in Zoology from the prestigious Presidency College, Kolkata, followed by a Masters in Biotechnology from University of Calcutta, Kolkata. He then did a Masters in Zoology from Southern Illinois University Carbondale, followed by his PhD in Biological Sciences from Duquesne University, Pittsburgh, Pennsylvania. His PhD thesis focused on deciphering the molecular evolution of hominoid Primates. After his PhD, he did his Postdoctoral research in University of Sheffield, England. He then joined Manipal Academy of Higher Education (MAHE), Manipal and worked as an Assistant Professor for four years. Since 2019, he has been working as an Assistant Professor in Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore. His lab is interested in integrating both theoretical (mathematical and statistical modeling) and bioinformatic approaches. The overarching goal of their research is to use population genetic and quantitative genetic measures to answer key questions pertaining to reconstruction of population history, deciphering origin and migration history of various human populations using their genomic information and deducing ancestry informative genetic markers (AIMs) that highlight ethnicity specific variation in allele frequencies to aid in genomic healthcare, biomedical and forensic studies. They also develop AIMs panels for critically endangered non-human populations to facilitate their management and conservation. Further, his research group aims to uncover individual and population specific variation in multifactorial disorders including but not limited to COVID-19, cancers, neuropsychological and cardiovascular diseases. They envision that the knowledge regarding our ancestral origin and population history can help to identify genetic regulators of key complex traits, such as aging and longevity, as well as aid in improving the conventional approach in biomedicine and healthcare on delineating underlying pathomechanisms and therapeutics for complex multifactorial diseases, such as COVID-19.