Main Entry: evo·lu·tion

Pronunciation: \ˌev-ə-ˈlü-shən also ˌē-və-\

Function: noun

1 : a process of change in a certain direction <tumor evolution and progression—I. J. Fidler et al>
2 a : the historical development of a biological group (as a race or species) : phylogeny b : a theory that the various types of animals and plants have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations

—evo·lu·tion·ari·ly \-shə-ˌner-ə-lē\ adverb

—evo·lu·tion·ary \-shə-ˌner-ē\ adjective