| A | B |
|---|
| evolution | changes in an organism over a long period of time |
| adaptation | a special feature in an organism which helps it survive in its environment |
| fossil | any evidence of ancient life |
| natural selection | the process which results in evolution, which involves traits which increase the chances that an organism will survive and reproduce successfully |
| vestigial structure | body part which is a remnant of a more important structure in the past. |
| selective breeding | breeding of individual plants or animals which have desired traits |
| mutation | changes in a gene |
| variation | different forms of a trait in a species, range of differences between individuals |
| mold | fossil imprint |
| cast | fossil formed when minerals deposit and harden in the mold left by a disintegrating organism |
| fossil record | a historical sequence of life |
| species | group of similar organisms which can mate with each other and produce fertile offspring |
| trait | distinguishing qualities in an organism |
| generation time | period between the birth of one generation and the birth of the next one |
| speciation | the separation of two populations over time which results in each one becoming so genetically different that they can no longer interbreed |
