punctuated equilibrium (pŭngk'ch-ā'tĭd) The theory that new species evolve suddenly over relatively short periods of time (a few hundred to a thousand years), followed by longer periods in which little genetic change occurs. Punctuated equilibrium is a revision of Darwin's theory that evolution takes place at a slow, constant rate over millions of years. Compare gradualism. See Note at evolution. |
The theory that new species evolve suddenly over brief periods of time, followed by longer periods during which there is no genetic change. Punctuated equilibrium is a revision of Darwin's theory of evolution. (Compare gradualism and catastrophism.)