Across
- 2. fossil age determiner
- 5. organism relation diagram
- 6. time steady evolution theory
- 7. minerals filling mold
- 11. remains with empty spaces
- 13. unstable elements breakdown
- 16. gradual species change
- 17. difference within species
- 18. organism mineral replacement
- 20. decay time by half
Down
- 1. rapid change theory
- 3. adapting survival process
- 4. older fossil dating technique
- 8. tested concepts
- 9. species disappearance
- 10. similar parts in related species
- 12. organism survival characteristic
- 14. physically similar organism groups
- 15. trace remains of organisms
- 19. collection of fossils