Low connectivity between sympatric populations of sunfish ecotypes suggests ecological opportunity contributes to diversification

Ecological opportunities, such as access to a novel habitat or the extirpation of a key competitor, can lead to adaptive divergence by exposing populations to diversifying selection. Typically, effects of ecological opportunity on adaptive divergence are inferred from macroevolutionary patterns rather than tested in populations undergoing contemporary divergence. This limits our insight on how ecological conditions contribute to adaptive...