Researchers at Yale University said the analysis suggests direct descendants of Chelonoidis elephantopus may be living on the volcanic slopes of Isabela Island, 200 miles from their ancestral home of Floreana Island, where they seemed to disappear after being hunted by whalers in the 19th century.
DNA evidence suggests purebred Floreana tortoises must be living on Isabela Island among a population of its native Chelonoidis becki species, they said.
Testing of 1,600 tortoises on Isabela Island found at least 84 animals that were the direct offspring of supposedly extinct Floreana Island tortoises.
"This is not just an academic exercise," Gisella Caccone of Yale's Department of Ecology and Evolutionary Biology said in a university release Monday. "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."
Researchers say it's doubtful C. elephantopus reached Isabela Island on its own, and theorize the tortoises were taken as food from Floreana and were either thrown overboard by whalers or left on shore at Isabela.