Across
- 1. Non-functional features fully developed and functioning in earlier species but serve little or no present purpose for an organism.
- 5. The disappearance of a species from Earth.
- 7. Biological structures having similar or corresponding functions but not from the same evolutionary origin.
- 8. When species are reproductively isolated from others due to differences in behavior.
- 9. The process in which two or more populations of an ancestral species accumulate independent genetic changes (mutations) through time.
- 12. Change over time /a change in a population's gene pool.
- 13. Describes how reproductively successful an organism is in its environment.
- 14. Changes in DNA.
- 15. The physical separation of populations of organisms from one another due to geographical barriers.
- 16. The process by which traits that improve an organism's chances for survival and reproduction are passed on more frequently to future generations than those that do not.
- 17. The continued existence of organisms which are best adapted to their environment, with the extinction of others.
- 19. The process by which a new species are generated.
- 20. A sequence of DNA that codes for a particular trait.
Down
- 2. A reproductive barrier which prevents interbreeding between distinct but closely related species due to differences in the timing of mating receptivity, activity, or fertility.
- 3. An organ, system, or body part that shares a common ancestry in multiple organisms.
- 4. A type of prezygotic barrier, where no fertilization occurs and thus reproduction does not occur.
- 6. Process of selection conducted under human direction.
- 10. The separation of groups of organisms as a result of changes in their ecology or in the environment in which they live.
- 11. Biological evolution that occurs by chance.
- 18. A heritable trait that increases an individual's fitness is called an adaptation.