How an extinct species is being revived on the Galapagos Islands

Lonesome George, the last giant tortoise of his kind from Pinta Island in the Galapagos, died in 2012, about 100 years old.

George was a type of saddleback tortoise, whose rare, peaked shells are unique to the Galapagos Islands. Those shells allow the animals to stretch their necks high, four or five feet in the air, to reach cactus leaves to eat during the Galapagos dry season.

“He was a striking individual, as [were] all members of his species," said State University of New York conservation biologist James Gibbs. Now, scientists are trying to revive the ancient species by starting a new breeding program using hybrid tortoises that have some of the same genes as George’s ancestors.

The hybrid tortoises were first identified during an expedition in 2008 to Isabela Island in the Galapagos. Scientists found tortoises living there that had the DNA both of native species and those previously found on two other islands.

“These were not just odd tortoises,” Gibbs said of the discovery. “They were transplants from other islands, and moreover, they were transplants from two islands where the tortoises are thought to have gone extinct.”

One of those islands was Lonesome George’s Pinta Island. The other was Floreana, where tortoises had been gone so long they were nearly forgotten.

"Darwin was really the last person to comment and write about them,” Gibbs said. No one really knows how the Pinta and Floreana tortoises got to their new home, Gibbs said, but one theory is that whalers or traders once collected the tortoises on their native islands, then threw them overboard near Isabela Island.

Last month, Gibbs led an expedition to that island to collect 32 of these hybrid tortoises and relocate them to a research center. Gibbs and his team, including lead geneticist Adalgisa Caccone from Yale University, will analyze the DNA of the animals to find those with the highest concentrations of Pinta and Floreana genetics.

After about a year, the research team, which is working under the Giant Tortoise Restoration Initiative, hopes to start a breeding plan to produce animals similar to those that originally lived on the two islands.