the close resemblance among Darwin’s finches in plumage , calls, nests, eggs and display suggests that they have not yet had time to diverge far from one another. The only big difference is in their beaks, adapted to their different diets. It is reasonably certain that all the Galapagos finches evolved from one original colonizing form. What is unusual about them is the existence of several distinct species on the same island. In this we may have an indirect clue to haw separate species establish themselves.