Across
- 2. Difference in a physical trait
- 7. Organisms that have a backbone
- 8. Selection in which a species could change by breeding it for certain traits
- 9. Naturalist who cruised around the world in the HMS Beagle
- 12. Many species in an environment
- 13. Structures that have no function
- 14. Structures from different species that are similar
- 17. Structures that perform a similar function but are not similar
- 19. Study of the geographic distribution of organisms
- 20. ancestry Species descended from one species
Down
- 1. Allows organisms to survive much better
- 3. Preserved remains of organisms
- 4. Idea that a species changes into a new species
- 5. Group of organisms that can produce fertile offspring
- 6. Study of embryos
- 10. Common relative a species descended from
- 11. Change in a species over time
- 15. Idea that a species changes over time
- 16. Proposed that traits modify over an organism's lifetime
- 18. Selection explains how evolution can occur