Giant tortoise species thought to be extinct may still exist

Washington, Jan 10 (ANI): Researchers believe dozens of giant tortoises of a species believed extinct for 150 years may still be living at a remote location in the Galapagos Islands.

A genetic analysis conducted by Yale University researchers suggests that direct descendants of at least 38 purebred individuals of Chelonoidis elephantopus live on the volcanic slopes of the northern shore of Isabela Island - 200 miles from their ancestral home of Floreana Island, where they disappeared after being hunted by whalers.

"This is not just an academic exercise," said Gisella Caccone, senior research scientist in the Department of Ecology and Evolutionary Biology and senior author of the paper.

"If we can find these individuals, we can restore them to their island of origin. This is important as these animals are keystone species playing a crucial role in maintaining the ecological integrity of the island communities," Caccone stated.

A team of Yale researchers visiting Volcano Wolf on the northern tip of Isabela Island in 2008 took blood samples from more than 1600 tortoises and compared them to a genetic database of living and extinct tortoise species.

An analysis detected the genetic signatures of C. elephantopus in 84 Volcano Wolf tortoises, meaning one of their parents was a purebred member of the missing species.

In 30 cases breeding had taken place within the last 15 years. Since the lifespan of tortoises can exceed 100 years, there is a high probability that many purebreds are still alive, note the researchers.

"To our knowledge, this is the first report of the rediscovery of a species by way of tracking the genetic footprints left in the genomes of its hybrid offspring," said former Yale postdoctoral researcher Ryan Garrick, now assistant professor at the University of Mississipi and first author of the study.

Intensive breeding of hybrids might allow scientists to resuscitate the C. elephantopus species even if sufficient numbers of purebred tortoises cannot be found, Garrick said.

The result was published Jan. 9 in the journal Current Biology. (ANI)