| A | B |
|---|
| adaptation | hereditary characteristic that helps and organism survive in its environment |
| species | group of organisms that can mate with one another and produce fertile offspring |
| evolution | process by which populations accumulate inherited changes over time |
| fossil | solidified remains or imprints of once living organisms |
| fossil record | historical sequence of life indicated by fossils |
| vestigial structure | remnant of a once useful anatomical structure |
| trait | distinguishing qualities that can be passed from one generation to another |
| selective breeding | breeding of organisms aht have a certain desired trait |
| natural selection | process by which organisms with favorable traits survive |
| generation time | ther period between the birth of one generation and the birth of the next generation |
| speciation | the process by which two populations of the same species become so different they can no longer interbreed |
| mutation | changes in the bases of an organism's DNA |
