The most famous reptiles in the Galápagos Islands are, of course, the giant Galápagos tortoises, after whom the islands came to be named ("Galápagos" is the Spanish word for "tortoise"). These remarkable animals can live for more than 150 years.
The most interesting reptiles, however, are the marine iguanas. These black iguanas, which Darwin branded "a hideous-looking creature, of a dirty black colour, stupid and sluggish in its movements," are believed to have evolved from land iguanas that perhaps reached the Galápagos Islands by clinging to floating vegetation from South America. Although the marine iguanas evolved to feed on algae in the sea, they never became comfortable in the water. Darwin observed:
[W]hen frightened it will not enter the water. [I]t is easy to drive these lizards down to any little point overhanging the sea, where they will sooner allow a person to catch them by the tail than jump into the water. . . . One day I carried one to a deep pool left by the retiring tide, and threw it in several times as far as I was able. It invariably returned in a direct line to the spot where I stood. . . . I several times caught this same lizard, by driving it down to a point, and though possessed of such perfect powers of diving and swimming, nothing could induce it to enter the water; and so often as I threw it in, it returned in the manner above described. Perhaps this singular piece of apparent stupidity may be accounted for by the circumstance that this reptile has no enemy whatsoever on shore, whereas at sea it must often fall a prey to the numerous sharks.
On the island of North Seymour, evolution has now come full circle. In recent years, marine iguanas have been observed for the first time feeding on land (perhaps to keep naturalists like Charles Darwin from throwing them in the water). Although typically black, during the breeding season male marine iguanas sport red patches on their skin. Also pictured here is a smaller, but colorful lava lizard.