A giant tortoise species presumed extinct for more than 150 years is actually roaming the Galápagos islands today according to DNA evidence, scientists report.
They haven't actually laid eyes on the Chelonoidis elephantopus. But DNA sequences taken from another Galápagos species, C. becki, show they are hybrids of the presumably extinct species, meaning it must have been one of the living turtles' parents. The scientists, who published their work in the January 10th issue of Current Biology say this is the first time a species 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 hybridisation because it means fewer purebreds. But these direct decedents of this particular "extinct" species could still be the key to their conservation through intense targeted breeding.
Galápagos turtles are incredible: they can weigh almost 900 pounds, grow to nearly six feet, and live for more than 100 years. But many of the 13 remaining species are endangered. Lonesome George is 100 years old and considered by researchers to be the last of his species and likely the rarest creature in the world. Personally I can't look at his picture without getting a little misty. That face! So it's extremely exciting that a species thought to have been lost forever is still alive. George might still be alone as a species, but he may be a little less lonely than we thought. [Current Biology]