| Two forms of iguanas lived in the islands. Each type
had affinities with the common South American green iguana, yet they had
adapted so profoundly to different ecologic niches in the islands that
they had evolved into separate genera. Conolophus, adept at living on
the arid islands and feeding on the sharp-spined Opuntia cactus became
the land iguana, while Amblyrhynchus, with its flattened tail for
swimming, its strong claws for hauling itself out on the water, and its
blunt, shortened snout for scraping algae off of rocks, became the
marine iguana. Moreover, many islands developed their own races of these
unusual lizards.
Charles Darwin and the Galapagos Islands |
