[puhngk-choo-ey-shuh-nl-iz-uh
m] 
| theory of, Biology. a hypothesis holding that the evolution of species proceeds in a characteristic pattern of relative stability for long periods of time interspersed with much shorter periods during which many species become extinct and new species emerge. Also called punctuationalism. Compare gradualism (def. 3). |
punctuated equilibrium (pŭngk'ch -ā'tĭd) Pronunciation Key
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. |