The 13 species of finches that live in the galápagos islands evolved from a single common ancestor. although they may not seem to be all that different from one another, distinct species living on the same island generally keep to themselves and don’t interbreed. finches tend to discriminate between members of their own species and those of a closely related species based on song and appearance. only male finches sing, learning their song from their father. each species' song is distinctive. what, most likely, keeps the finch species separate?