Indians descended from two ancestral populations: Study

A new research has revealed that nearly all Indians carry genomic contributions from two distinct ancestral populations. Following this ancient mixture, many groups experienced periods of genetic isolation from each other for thousands of years.

The study, which has medical implications for people of Indian descent, was done by scientists at the Hyderabad-based Centre for Cellular and Molecular Biology (CCMB) together with US researchers at Harvard Medical School, the Harvard School of Public Health and the Broad Institute of Harvard and MIT.

The results of the study were disclosed to the media here on Thursday by CCMB director Veena K Patnaik, its former director Lalji Singh and scientist K Thangaraj.

The study revealed that many groups in modern India descended from a small number of founding individuals, and have since been genetically isolated from other groups. In scientific parlance, this is called a ‘founder event’.

According to Thangaraj, this also has important medical implications. “The widespread history of founder events helps explain why incidence of genetic diseases among Indians is different from the rest of the world,” he said.

To find out the genetic variability across the Indian subcontinent, the research team analysed more than 500,000 genetic markers across the genomes of 132 individuals from 25 diverse groups spread across 13 states.

The genomic analyses revealed that different Indian groups have inherited 40 to 80 percent of their ancestry from a population that is now called ancestral north Indians, who are related to western Eurasians, and the rest from the ancestral south Indians, who are not related to any group outside India.