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Island Speciation

As proposed by Darwin, isolated oceanic islands like Hawaii and the Galapagos present a self-contained natural selection laboratories. These small island chains have no indigenous land-mammals, with all evidence supporting the hypothesis that oceanic islands were settled accidentally by migratory species like birds and aquatic mammals. The specialization of the finch's beak throughout the Galapagos archipelago, where food sources differ from island to island, shows natural selection at work.