Footprints on Genetic Islands. The giant Galapagos tortoise once flourished on Floreana Island but was thought to have become extinct shortly after Charles Darwin made his historic voyage to the Galapagos Islands in 1835. Because these colonies remained isolated from each other, tortoises evolved into distinct species that helped inform Darwin on his theory of natural selection. It was possible that some tortoises could have cruised to neighboring Isabela Island on pirate or whaling ships.
Scientists from Yale found genetic evidence of these giant tortoises in young (~15 yr old) hybrid individuals found on Isabela Island’s Wolf Volcano indicating that the purebred parents (expected to live up to 200 years) may still alive. To do this, they analyzed fast evolving genetic markers (DNA microsatellites) from 84 hybrid tortoises and calculated that there would need to be at least 38 founders of the supposedly extinct Chelonoidis elephantopus species.
This raises the hope that this historical species may be resurrected using captive breeding programs. This is also the first time that a species may have been rediscovered by tracking genetic footprints of its hybrid offspring. All that’s left is to track their physical footprints on Isabella Island!