Across
- 1. structures – leftover body parts with little or no use
- 3. – layers of rock or soil
- 5. age – exact age in years
- 8. – trait that helps an organism survive
- 10. tree – diagram showing evolutionary relationships
- 12. – idea that sudden disasters change Earth and species
- 13. age – age compared to other rocks/fossils
- 14. structures – body parts with similar origins but different functions
- 15. evolution – unrelated species develop similar traits
- 17. characteristics – traits gained during life
- 19. structures – body parts with similar function but different origins
- 20. radiation – one species evolves into many different species
- 22. selection – organisms with helpful traits survive and reproduce more
Down
- 2. – change in species over time
- 4. selection – humans choose traits to breed
- 6. – study of embryos and development
- 7. – ability to survive and reproduce
- 9. species – species showing traits of old and new groups
- 11. – two species evolve in response to each other
- 16. – study of where organisms live
- 18. evolution – related species become more different over time
- 21. with modification – species change as they pass traits to offspring