Unit 4 Part B Vocab

6. Structures that have no apparent function and appear to be residual parts from a past ancestor.
7. Describes how reproductively successful an organism is in its environment.
12. A heritable trait that increases an individual’s fitness.
13. A sequence of DNA that codes for particular traits.
14. Organisms that are best suited to survive and reproduce offspring.
15. Occurs when two populations differ in their periods of activity or reproductive cycles.
17. A change in a population’s gene pool over time.
18. A physical incompatibility between reproductive organs of two organisms.
20. Biological evolution that occurs by chance.
21. Occurs when mismatched in mating traits prevent mating between two species/populations.

1. Similar physical features in organisms that share a common ancestor, but the features serve completely diff ent functions.
2. When two populations are separated by geographic barriers such as rivers, mountains, or bodies of water.
3. Features of different species that are similar in function but nit necessarily in structure and which do not derive from a common ancestral feature.
4. When all members of a species die out.
5. The process of selection conducted under human direction.
8. The separation of groups of organisms as a result of changes in their ecology or in the environment in which they live.
9. The process in which two or more population s of an ancestral species accumulate independent genetic changes through time.
10. Changes in DNA.
11. The preserved remains of organisms who’s bodies were preserved in sediment, such as sand and mud, under ancient seas, lakes, and rivers.
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.
19. The process by which new species are generated.