Across Down 1. diagram that shows relationships between species 2. type of selection seen in dogs and other domestic 3. related species share a common animals 5. process by which evolution occurs; natural 4. had different shaped shells depending on the island 7. a model that is used to explain data and make predictions: 6. when two unrelated organisms look alike (sharks & of evolution dolphins) 10. preserved remains of ancient organisms 8. structures that are similar in different species; ex. arm 11. name of the ship Darwin traveled on, H. M.S. bones of vertebrates 15. islands that Darwin collected observations from 9. structures that have no function; ex. leg bones of 16. a characteristic that helps an organism survive whales 18. population of organisms that can interbreed I 12. change over time 19. when organisms disappear from the earth 13.proposed the theory of evolution by natural selection 20. passing of traits from parents to offspring 14. refers to the variety of living things 17. birds studied by Darwin www. biologycomer. com​