| A | B |
|---|
| law of use & disuse | Lamark's theory: the more an animal uses a particular part of it's body, the stronger & better developed it will become |
| the inheritance of aquired characteristics | Lamark's theory: characteristics developed by an organism through use & disuse can be passed on to its offspring |
| natural selection | organisms with favorable variations would be better able to survive and to reproduce than organisms with unfavorable variations |
| variations | differences |
| adaptation | any kind of inherited trait that improves an organism's chance of survival and reproduction in a given environment |
| speciation | the formation of a new species |
| gradualism | Darwin's theory: new species arise through gradual changes in characteristics, thus evolution occurs slowly over millions of years |
| punctuated equilibrium | a theory of evolution stating that a species remains the same for a long time and then evolves rapidly during a short time interval |
| synthetic theory of evolution | evolution happens to populations, not to individuals; a change in allele frequency within a population over time |
| population genetics | the study of the changes in the genetic makeup of populations |
| gene pool | total of all the alleles present in a population |
| genetic recombination | formation of new combinations of alleles during sexual reproduction |
| genetic drift | a change in a gene pool of a small population that is brought about by chance |
| genetic equilibrium | the condition in which allele frequencies do not change from one generation to the next |
| Hardy-Weinberg law | the principle that sexual reproduction alone does not affect allele frequencies in a population |
| camouflage | adaptation: organism blends in with environment |
| warning coloration | adaptation: the colors make the animals easier to see but, the organism is unpleasant to eat, so the predator avoids eating the organism |
| mimicry | one organism is protected from its enemies by its resemblance to another species |
| directional selection | type of natural selection: an extreme phenotype becomes a favorable adaptation-this type of selection usually operates when the environment changes or when species migrate |
| stabilization selelciton | type of natural selection: the average phenotype is favorable, and extreme phenotypes are unfavorable to survival |
| disruptive selection | type of natural selection: rare type of natural selection in which two opposite phenotypes are favorable adaptations |
| geographic isolation | occurs when a population is divided by a natural barrier such as a mountain, desert, river, body of water, etc. |
| reproductive isolation | the loss of the ability to interbreed by two isolated groups |
| adaptive radiation | the process by which a species evolves into a number of different speices, each occupying a new environment |
| convergent evolution | natural selection that causes unrelated species to resemble one another |
| coevolution | when two or more species evolve in response to each other through cooperative or competative adaptations |
| symbiosis | relationship in which two different organisms live in close association with each other to benefit at least one of them |
