EVOLUTIONARY CONSEQUENCES OF ECOLOGICAL RELEASE IN CARIBBEAN ANOLIS LIZARDS

On the large islands of the Greater Antilles, multi-species communitie s of Anolis lizards are composed of species specialized to use particu lar habitats; similar sets of specialized species have evolved indepen dently on each island. We studied species of anoles found on small Car ibbean islands. Because these islands contain at most only one other s pecies of anole, we predicted that species on these islands should not be as specialized as Greater Antillean species; rather, they might be expected to exhibit a generalized morphology and a greater breadth of habitat use. Our findings, however, do not confirm these predictions. Lesser Antillean species do not exhibit greater breadth of habitat us e than Greater Antillean species, nor do they exhibit a generalized mo rphology. Most species are ecologically and morphologically similar to specialized trunk-crown anoles of the Greater Antilles, although some species exhibit morphologies unlike those seen in Greater Antillean s pecies. Among descendants-of specialized Greater Antillean species occ urring on one or two-species islands, most descendants of trunk-crown species have diverged relatively little, whereas several descendants o f trunk-ground anoles have diverged considerably. Consequently, eve pr opose that ancestral species in the Greater Antilles may have been tru nk-crown anoles. (C) 1997 The Linnean Society of London.