Little is known about the mechanisms underlying the evolution of novelphenotypes and convergence.Albinism, a relativelysimple trait and aprime example of convergence, offers an outstanding opportunity tostudy both of these phenomena. Thisproposal addresses the evolution of albinism in a series of melanin pigmented species from diversephyla. For the first time, this proposal will also investigatedepigmentation in animals with dark pigments other than melanin:planaria. The combined analysis of loss of melanin and non-melaninpigmentation will provide a broad understanding about thedevelopmental and molecular trajectories underpinning the repeatedoccurrence of albinism in nature. The forces driving regression ofphenotypes have been puzzling scientists since the time of Darwin. Mypreliminary results suggest that the widespread occurrence of albinismis a result of natural selection acting on the benefits of pigmentregression for the survival of animals in dark cave.