What evidence is there that the 15 species of finch all evolved from one common ancestor? DNA analysis shows that their DNA is almost identical with only minor changes. Scientists have been studying...

What evidence is there that the 15 species of finch all evolved from one common ancestor? DNA analysis shows that their DNA is almost identical with only minor changes. Scientists have been studying them since Darwin in 1835 and have watched them evolve. Observation of all 15 species shows that they look incredibly similar, with minor changes to beak size and shape. These 15 species are found nowhere else in the world, and the islands are located close enough to the mainland for birds to migrate.