Formed over eons by lava boiling up from the sea floor, the rocky Galapagos are inhabited by an odd assortment of plants and animals that have developed peculiar adaptations for survival; e.g., dark-skinned iguanas, able to spend more time in cold water searching for food, ``evolved into a new type of iguana—the marine iguana.'' Crisp, clear close-up photos in full color add to the appeal, but lack captions and scale. An attractive introduction to evolution and to some unusual life forms. Scientific names not given; no index. (Nonfiction. 8-10)