| A | B |
|---|
| species | A distinct population of organisms that have the same basic structure and can interbreed to produce fertile offspring |
| speciation | The evolutionary process by which new species form |
| natural selection | Process by which the organisms best suited to their environment survive and reproduce |
| population | All the members of a species that live in an area |
| extinct | When all members of a species die |
| directional selection | Occurs when individuals near both ends of a frequency distribution are better adapted than those in the middle |
| disruptive selection | Occurs when individuals near both ends of a frequency distribution are better adapted than those in the middle |
| stabilizing selection | Occurs when the individuals at the middle of the frequency distribution are fittest for the environment |
