Fig. 2
Adaptation to biofilm selection can occur within days and produce conspicuous phenotypic differences. Populations were founded with equal ratios of Lac + (blue) and Lac- (white) ancestral genotypes that do not differ in morphology. After 5–7 days, new colony morphologies evolve and represent different biofilm-associated ecological strategies, as different beak shapes of Darwin’s finches represent distinct feeding strategies (Rainey and Travisano 1998; Poltak and Cooper 2011)