Thank you Gordon Wilson for your contribution to this amazingly informational book, Galapagos Islands.
Galápagos tortoises are more closely related to African hinge-back tortoises. This finding suggests that the most recent mainland ancestor of the Galápagos tortoises may have hailed from Africa, not South America.
The Phoenicians (or some other ancient mariners) may have brought the first tortoises. They are low-maintenance food aboard ships because they can live long periods without food or water. In fact, the Galápagos tortoises were often used this way in the 19th century by whaling ships.