Definition of evolution noun from the Oxford Advanced American Dictionary

Academic

evolution

noun
/ˌɛvəˈluʃn/
 
[uncountable]
 
1 (biology) the gradual development of plants, animals, etc. over many years as they adapt to changes in their environmentthe evolution of the human speciesDarwin's theory of evolution2 the gradual development of somethingIn politics he preferred evolution to revolution (= gradual development to sudden violent change).