Question

How did Darwin explain the existence of different varieties of finches on the Galapagos Islands?

Answer 1

Darwin observed that the finches are evolved due to the difference in their habitat. Consistent environmental differences in different habitats on different islands in the Galapagos, as well as the availability of different foods sources (seeds, cactus, insects, and fruit) promotes directional selection on resident finches for optimal beak morphology that maximizes survival under local conditions. This process has produced more than a dozen distinct species of finches, all unique to the archipelago.