Across
- 2. structures that are similar in form
- 3. "leftover" structure
- 4. remains of dead organisms preserved in rock
- 6. characteristic that improves fitness
- 8. change over time
Down
- 1. combining genes during sexual reproduction
- 3. differences between individuals in a species
- 4. organism's ability to survive and reproduce
- 5. change in DNA
- 7. section of DNA that codes for a trait