Izu Islands - Ecology

Ecology

A chain of volcanic islands, the Izu Archipelago are oceanic islands that formed relatively recently (within a few million years) without any previous connection to mainland Japan. In contrast to isolated Pacific islands, such as Hawaii and the Galápagos, the Izu Islands are located near the mainland and have thus been frequently colonized by various species by overseas dispersal from the mainland or from adjacent islands. This make them interesting for the studies of ecological and evolutionary processes.

Campanula (Bellflower) colonized the entire archipelago in a single event. Similarly, the Euhadra snails, endemic to Japan, populated the islands in a single event and all individuals on inhabited islands possess an identical haplotype. The Apodemus mice, on the other hand, colonized the islands from the mainland in two independent events.