| A | B |
|---|
| amber | hardened tree sap |
| extinct | species that is no longer found alive |
| fossil | remains or traces of once-living organism |
| geologic time scale | record of earth's history based upon types of organisms that lived at different times |
| era | largest division og geologic time |
| relative age | age of something compared with the age of something else |
| adaptation | trait that helps an organism survive in its environment |
| evolution | process by wich organisms change over time |
| mutation | change in a gene |
| natural selection | survival of offspring that have favorable traits |
| variation | differences in traits among individuals of a species |
| anthropology | science that deals with the study of human beings |
