Meeting Abstract
Adaptive radiations are considered a special case of evolutionary diversification in which a clade displays exceptional ecological and phenotypic diversity. A common feature uniting studies of adaptive radiation is that the ecology-phenotype connection has been almost exclusively described in terms of morphology. For example, the adaptive radiation of Caribbean anoles is known for the evolution of distinct ‘ecomorphs’, which are so-named based on the tight association between structural habitat use and morphological traits in these lizards. Despite all of the disproportionate attention that morphological traits have received, it has been well-recognized that physiological evolution along environmental gradients is also a key aspect of the adaptive radiation of anoles. For example, Caribbean anoles have evolved to exploit distinct thermal and hydric microhabitats, and also have diversified along elevational gradients. Here, we compare morphological and physiological evolution in anoles from the Caribbean island of Hispaniola. We discover that physiological diversity is high in Hispaniolan anoles and contributes to within-ecomorph phenotypic divergence. Nonetheless, patterns of physiological and morphological evolution are distinct, such that ecomorphs do not cluster together in physiological trait space. We propose that the exceptional diversity of Caribbean anoles may be driven by the combined influence of physiological and morphological evolution, and that physiological divergence along environmental gradients are an equally important, though less appreciated, aspect of adaptive radiation.
