Across
- 3. his essay made Darwin understand evolution
- 6. could wipe out almost a whole local population
- 8. one of the factors that affect natural selection
- 9. Darwin identified_____ factors that affect natural selection
- 10. Darwin couldn't figure out evolution's_____
Down
- 1. Darwin studied them if they are produced by artificial selection
- 2. members of a_____differ from one another
- 4. species produce more____than can survive
- 5. Darwin bred them if they had fan-tails
- 7. the process of which individuals that are better adapt to their environment are most likely to survive