Conservation, the genetic way

It’s an awe-inspiring ceremony, as the east coast of India awaits its annual guests. They make their way through turbulent choppy seas and waddle onto the sand. But they will make it. Year after year. Unfailingly.

In arribadas or the synchronised mass nesting of the Olive Ridley Turtles, scientists believe that these magnificent amphibians return to the place of their birth to nest. But how do we know the same turtles are returning? Scientist Kartik Shanker from the Centre for Ecological Sciences, who is an authority on turtles set out to answer the question. “Given the difference in size between adults and hatchlings, long time to maturity and low survival, this was not possible to test using field techniques,” says Shanker. What eventually provided support for the theory was information Shanker and others gathered by “molecular techniques” showing population genetic structure amongst female turtles. “There’s no other way we could have derived this information,” he says.

For three years India’s expert on small cats, Shomita Mukhejee was toiling in Sariska’s arid thorn forests, mustering all the ‘field techniques’ possible to gather information on the small carnivores. “I made more headway in the lab than I did in those three years,” she says, testifying to the power of genetic techniques in conservation.

How can we possibly help creatures that are in the thick of the jungle from the confines of the lab?  It’s exactly what Uma Ramakrishnan’s job entails. She explains: “Since a genome is like a jigsaw puzzle, one can put together multiple genes which carry information.” And the information with genetics as a tool can help estimate dispersal of animals, identify sex of a species, and study a species in relation to others. Ramakrishnan also adds that the technique is of tremendous help especially in cases of monitoring elusive animals, where spotting the animal can become a task.

“DNA extracted from organic material that an individual leaves behind, such as a feather, fecal matter, blood tissue etc can be used to derive information,” she says.

Mukherjee says that genetic techniques help construct spatial maps depicting distribution of species and helps estimate the extent of connectivity between populations and determine barriers to dispersal. What does this mean? Simply that reading the genes of species (lets say the jungle cat and the leopard) one can determine if they are related.

A crucial application of genetics is in wildlife forensics that helps with the investigation of illegal trade of animal products. “Now we know that the genetic variations in leopards from north India and south India, so if a leopard skin is seized, we will be able to tell which part of the country the skin is from,” she explains.

When using genetic techniques in conservation, one needs to ask if there’s something this can tell us that other techniques can’t, says Praveen Karanth, assistant professor, Centre for Ecological Sciences, IISC. When it comes to the classification of species, genetic techniques fare much better than traditional taxonomy, he adds.

A crucial implication of genetics in conservation is the restoration of biodiversity which is believed to give species resistance against various factors, thus keeping them from extinction.

Apart from being used to delineate species, populations, and stocks to help in conservation prioritisation, genetic techniques also help in identifying individuals for population census and choosing the best specimens in captive breeding, etc.