Across
- 3. Comparing body structures of different organisms to find similarities.
- 4. Layers of sedimentary rock that can hold fossils.
- 6. The study of embryos and their development.
- 8. Rock formed by layers of material pressed and cemented together.
- 10. The time it takes for half of a radioactive substance to decay.
- 11. A trait that helps an organism survive and reproduce in its environment.
- 14. The process by which remains of living things become preserved as fossils.
- 15. When closely related species become more different over time.
Down
- 1. The evolutionary history and relationships among species.
- 2. A group of organisms that can breed and produce fertile offspring.
- 3. A branching diagram showing relationships between species.
- 5. A subdivision of geological time shorter than a period.
- 7. A record of an organism’s activity, such as a footprint or burrow.
- 9. The gradual change in species over time.
- 12. Determining the exact age of a fossil or rock using radioactive decay.
- 13. The study of where organisms live and how they got there.