Darwin visited the galapagos islands several times. he observed some very unusual species. one species of bird, the finch, interested him. he observed some differences in the finches living on different islands. the finches that lived on each island had a different beak. some beaks were short some long. some beaks looked straight while others curved. darwin believed that each species of finch was related but had developed some special beak adaptations because there were different food sources on each island.