Ancient Indian DNA has shown that there are traces of genes of Neanderthals, who lived mostly in Europe, and Denisovans, who lived in Southeast Asia, indicating the complex admix of populations over millions of years of evolution, said Director of Centre for DNA Fingerprinting and Diagnostics (CDFD) K. Thangaraj on Monday.
Genetic and archaeological evidence showed that the modern humans have overlapped with Neanderthal and Denisovan populations for a period, and also interbred as was indicated from a cave in Siberia leaving a small amount of genetic material from 3% to 0.5 %, respectively, from the distant ancestors with people of Africa being exceptions, he explained.
Dr. Thangaraj was delivering a popular science lecture on ‘Who are we? Mystery revealed by the ancient DNA’ to celebrate the Nobel Prize for Physiology/Medicine 2022 to Swedish scientist Svante Paabo, who not only sequenced the Neanderthal genome but also discovered the previously unknown species of Denisovans more than a decade ago.
Dr. Paabo also found that the gene transfer had occurred from these extinct species to modern humans following the out of Africa migration around 70,000 years ago. “It is for the first time that the Nobel has been given to evolutionary genetics,” pointed out the director, who has been collaborating with the eminent scientist and his team in research projects.
Ancient DNA is sourced from the jaw bone or from any bone including tooth. It is ground into powder and mitochondria DNA is sequenced to contrast with the reference sequence. There has been a divergent period between Neanderthals and Denisovans around 500,000 years ago as was discovered by Dr Paabo and his team.
The first ancient human hybrid of 50% father and 50% mother between Neanderthals and Denisovans was found in 2018 which connected the missing link in the origin of humans. The latest study this year had shown that Neanderthals knew how live as a society and genes from it have led to increase of neurons in the brain and developing frontal lobe, perhaps making the modern human more intelligent, said Dr. Thangaraj.
Modern Europeans lineage can be traced to three ancestral populations – indigenous hunter gathers, middle east farmers who migrated 7,500 years ago and north Eurasians but they are not direct ancestors from Neanderthals. Indians, of course, can trace their lineage to admix of Ancestral South Indians (ASI) – originating from Africa through the southern sea route to south India and later to Andamans about 65,000 years ago and Ancestral North Indians (ANI) moving from Africa northward through land route to Europe and into North India.
They gave rise new populations and later ASI and ANI admixed giving rise to newer populations as exemplified in the skin colour among other evidences. About 2,000-4,000 years ago the endogamous marriages of marrying with communities took vogue. “ASI and ANI are the two founding populations of India though every single population is unique, we have genetic affinities”, added the director.
Published - November 22, 2022 12:13 am IST
