| A | B |
|---|
| adaptation | a characteristic that helps an organism survive and reproduce in its environment |
| species | a group of organisms that can mate with one another to produce fertile offspring |
| evolution | the process by which populations accumulate inherited changes over time |
| fossil | the solidified remains or imprints of once-living organisms |
| fossil record | a historical sequence of life indicated by fossils found in layers of the Earth's crust |
| vestigial structures | remnants (remains) of once-useful structures ex: appendix |
| homologous stuctures | Structures that are similar, but have different functions and show a possible common ancestor |
| trait | a quality that can be passed from one generation to another |
| selective breeding | the breeding of organisms that have a certain desired trait |
| natural selection | the process by which organisms with favorable traits survive and reproduce at a higher rate then organisms without the favorable trait |
| overproduction | producing more offspring than will survive to maturity |
| genetic variation | individuals in a population are slightly different from one another due to the fact that they inherited different traits |
| struggle to survive | the natural environment does not have enough resources to support all the individuals that are born |
| successful reproduction | the organisms that are well adapted to their environment will survive and reproduce |
| mutation | a change in DNA |
| generation time | the period between the birth of one generation and the birth of the next generation |
| speciation | over time two populations become so different that they can no longer interbreed. |
