Photo: abc.net.au

A giant tortoise subspecies presumed extinct for more than 150 years is actually roaming the Galápagos Islands in the Pacific Ocean off South America today according to DNA evidence, scientists report.

They haven’t laid eyes on the Chelonoidis elephantopus. But DNA sequences taken from another Galápagos subspecies, C. becki, show they are hybrids of the presumably extinct turtle, meaning it must have been one of the living tortoises’ parents.

The scientists, who published their work in the January 10 issue of Current Biology say this is the first time an animal has been rediscovered by tracking ”genetic footprints.”

Galápagos tortoises strongly influenced Charles Darwin’s thoughts on evolution and natural selection when he visited the islands in 1835. But the C. elephantopus, which was native to Floreana island, was assumed to be extinct shortly after that.

Scientists led by Ryan Garrick from Yale University discovered the offspring on Isabela Island’s Wolf Volcano, home to about 7,000 tortoises. They say the C. elephantopus likely hopped islands on a pirate or whaling ship.

There are likely so few purebred C. elephantopus tortoises remaining that researchers would be incredibly lucky to find one. Typically, scientists dismay hybridization because it means fewer purebreds. But these direct decedents of this particular ”extinct” subspecies could still be the key to their conservation through intense targeted breeding.

Gizmodo