| A | B |
|---|
| species | a group of organisms that can breed and produce fertile offspring |
| variation | a difference between members of the same population |
| adaptation | inherited characteristic that increases an organisms chance for survival |
| evolution | change in a species over time |
| natural selection | process by which individuals tha are better suited to their environment survive and reproduce most successfully |
| punctuated equilibrium | pattern of evolution in which long stable periods are interrupted by brief periods of rapid change |
| gradualism | a theory about the rate of evolution is consistant over time |
| speciation | formation of a new species |
| divergent evolution | process by which once related organisms evolve independently |
| convergent evolution | process by which unrelated oranisms independently evolve similarities when adapting to an environment |
| coevolution | process by which two species evolve in response to changes in each other |
| adaptive radiation | process by which a single species evolves into severl different species |
| gene pool | the combined genetic information of all the members of a population |
| allele frequencies | how often an allele is represented in a gene pool |
| genetic equilibrium | a situation in which allele frequencies remain constant |
| genetic drift | random change in allele frequencies that occurs in small poplulations |
| directional selection | a form of natural selection in which the entire distribution curve moves as a result of the organisms at one end of the curve are more adapted to the environment |
| disruptive selection | form of natural selection in which a single curve splits into two curves |
| fossil | preserved remains or evidence of an ancient organism |
| homologous structures | structures tha have different mature forms in different organisms but developl from the same embryonic tissues |
| analogous structures | structures shared by different species tha is similar in function but not inherited from a common ancestor |
| vestigial structures | parts in an organism that serve no useful function |
| DNA fingerprint | analysis of sections of DNA that have little or no known function, but vary widely from one individual to another, in order to identify individuals |
| mass extinction | period of some catastrophic event resulting in the loss of a significan number of species |
| endosymbiosis | theory that eukaryotic orgainisms formed from a symbiosis among several different prokaryotic organisms |
| carbon dating | the process of detetermining the age of a substance by using carbon isotope content |
| Miller Urey experiment | simple inorganic compounds were exposed to extreme environments in a closed system resulting in complex organic compounds |
| common descent | the principle that all living things have a common ancestor |
| descent with modification | principle that each living speices has descended, with changes, from other species over time |
| artificial selection | selection by humans for breeding of useful traits from the natural variation among different organisms |
