Across
- 2. The division of the Earth's history into a series of named units.
- 3. Process by which unrelated organisms independently evolve similarities when adapting to similar environments
- 5. An evolutionary pattern in which many species evolve from a single ancestral species
- 7. English natural scientist who formulated a theory of evolution by natural selection (1809-1882)
- 8. Formation of new species
- 10. Ability of an organism to survive and reproduce in its environment
- 13. A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
- 14. Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
- 15. Diagram that shows the evolutionary relationships among a group of organisms
- 16. principle that all living things were derived from common ancestors
- 17. members of each species compete regularly to obtain food, living space, and other necessities of life
- 19. A trait that helps an organism survive and reproduce
- 20. Structures in different species that are similar because of common ancestry.
Down
- 1. scientists who study fossils
- 4. mutations
- 6. theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms
- 9. Process by which two species evolve in response to changes in each other
- 11. Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection
- 12. Change over time
- 18. A term that typically describes a species that no longer has any known living individuals.