Across
- 4. When the entire population of a species dies.
- 5. Natural genetic differences that occur within a species.
- 7. When an organism's remains are preserved and replaced with minerals under very rare and specific circumstances.
- 9. When a population splits and evolves in separate directions, forming a new species.
Down
- 1. A random genetic change.
- 2. Any genetic change that makes an organism more fit.
- 3. How a species changes over time in response to its environment.
- 6. The temperature and weather patterns of an area.
- 8. An organism's ability to survive and reproduce.