Several species of finch live on the galapagos islands. they are very similar in appearance, but have adapted beaks of different sizes and shapes based on their major food source. finches with large beaks eat mainly large seeds and cacti. finches with small beaks eat mainly small seeds and insects. which of the following best explains the variety of beaks found in finches on the galapagos islands . a. evolution through natural selection can increase the species diversity of an ecosystem. b. natural selection