co·ev·o·lu·tion (kō'ěv-ə-lōō'shən, -ē-və-) n. The evolution of two or more interdependent species, each adapting to changes in the other. It occurs, for example, between predators and prey and between insects and the flowers that they pollinate. co'ev·o·lu'tion·ar·y adj., co'e·volve' (-ĭ-vŏlv') v.