Unit 4, part B

7. Heritable trait that increases an individual fitness
10. two populations are separated by geographic barriers such as rivers, mountains, or bodies of water
12. change over time
13. Biological evolution that occurs by chance
14. How reproductively successful an organism is in its environment
16. Disappearance of a species from earth
17. changes in DNA
19. Human direction
21. Process by which traits that improve an organism chances for survival and reproduction

1. physical incompatibility between reproductive organs of two organisms
2. two or more populations of an ancestral species accumulate independent genetic changes through time
3. type of reproductive isolation mechanism among sexual organisms
4. the contained existense of organism are best adapted to their environment
5. sequence of DNA that codes for a particular trait
6. mismatches in mating traits
8. features of different species that are similar in function but not necessarily in structure
9. separation of groups of organisms as a result of changes in their ecology or in the environment in which they livE
11. similar physical features in organisms that share a common ancestor, but the features serve completely different functions
15. preserved remains, impression, or trace of any once-living thing from a past geological age
18. formation of new and distinct species in the course of evolution
20. various cells, tissues, and organs in a body which no longer serve a functioN