CHENNAI:The extinction of a species can be predicted by studying its genetic diversity, says Dr Uma Ramakrishnan who studies the decline in tiger population in India. Speaking on Sunday at Science at the Sabha, an annual event organised by the Institute of Mathematical Sciences (IMSc), she said though tigers in India had a reasonable genetic diversity, they faced a number of other problems.

We found out that a poor genetic diversity was not causing the depletion of the species but that several other problems were contributing to it, said Uma. The higher the internal genetic diversity within a species, the higher its survival chance, as having more genes would also translate to having more ecologically adapted versions of the same genes of that species.

We have over 2,500 tigers living in different parts of India. But what we found out is, the average number of tigers living in a national park is only 19, she said. Having small isolated groups of tigers that are geographically widespread would lead to a wide genetic diversity, but lowering of diversity within each of these patches.

Multiple problems led to the present situation in India. For a species to survive, it must live in a large area in large numbers and must stay connected with genetically variant members of the same species for breeding. The tiger habitat was spread all across Asia before colonial rule. Now, its population is confined to patches in South Asia and mostly in India, says Uma.

One thing we observed from the data is that the growth of urban areas is directly proportional to the depletion of forest land. This means that we further reduce the habitat of these mammals, causing intense fragmentation, said Uma, adding that this would worsen the problems of inbreeding.

Although I worked extensively with tigers, the same problems haunt all dying species. One important solution to prevent fragmentation while still promoting development is to ensure that wildlife corridors must not be encroached upon, she told Express on the sidelines of the main event. She added that historical data showed that the chances of extinction of big animals, such as mammoths, were more.

Other speakers included Yashwant Gupta, who spoke of star-gazing and touring the universe through an astronomical medium; S Krishnaswamy, who spoke about the basics of molecular particles; and Amritanshu Prasad who triggered the minds of young children by speaking about coding and encrypting.

Read more:
Predicting extinction via genetics - The New Indian Express