Across
- 5. the descendants differ from their ancestors
- 7. allows an organism to better survive
- 8. natural disasters that have happened
- 10. study of fossils
- 12. processes that change uniformly
- 15. slow changes over a long period of time
- 16. similar structures in different organisms
Down
- 1. a measure of the ability to survive
- 2. organisms that are closely related
- 3. humans change a species
- 4. study of organism distribution
- 6. individuals who inherited traits
- 9. similar functions but not in origin
- 11. structures that no longer have a function
- 13. traces of organisms from the past
- 14. different physical traits from individuals