| A | B |
|---|
| biogenesis | theory that all living things come from other living things |
| spontaneous generation | theory that living things can come from nonliving things |
| radioactive decay | the release of particles or radiant energy by the unstable nuclei of some isotopes |
| half-life | the length of time it takes for one-half of any size isotope to decay |
| fossil | trace of a long-dead organism |
| relative age | age comparison with other fossils |
| absolute age | age in years |
| biogeography | the study of geographical distribution fo fossils and of living organisms |
| evolution | an orderly succession of changes |
| acquired trait | trait that is determined by the environment, not by genes |
| natural selection | process by which organisms best suited to their environment reproduce more successfully than other organisms |
| adapt | to change genetically over generations to become more suitd to the environment |
| coevolution | the change of two or more species in close association with each other |
| population genetics | the study of evolution from a genetic point of view |
| immigration | movement of individuals into a population |
| emmigration | movement of individuals out of a population |
