| A | B |
|---|
| fossil | a trace of a long-dead organism |
| strata | layers in sedimentary rock |
| relative age | if a fossil is lower in the stratum it is older than a higher one |
| absolute age | ages put on stratum by radiological dating |
| biogeography | study of geographical distribution of fossils of living organisms |
| natural selection | organisms most suited to the environment reproduce more offspring |
| adaption | a trait that makes an individual successful in its environment |
| fitness | describes how well an organisms is matched to its environmental challenges |
| adaptive advantage | when a trait give an organism a favorable edge |
| homologous structure | organs with the same basic structure but different functions |
| analogous structure | organs with the same function but different structure |
| vestigial structure | organs that gave an ancestor an advantage but are leftovers |
| coevolution | two species change in close association to each other |
| adaptive radiation | one species evolves into many when encountering a new environment (like islands) |
| artificial selection | humans pick the traits they want from a population |
