SIZE AND SHAPE VARIATION IN A LESSER ANTILLEAN ANOLE, ANOLIS-OCULATUS(SAURIA, IGUANIDAE) IN RELATION TO HABITAT

The anole fauna of the Lesser Antilles is depauperate in relation to t hat of the Greater Antilles, where complex communities characterized b y adaptive specialization and convergent structure are present. Much o f this adaptation is the result of changes in body size and shape, pro bably as a result of interspecific competition. Here we present data o n variation in size and shape within a solitary Lesser Antillean speci es occupying an ecologically heterogenous island, and test the hypothe sis that natural selection for varying environmental conditions is the cause of this variation. Univariate (analysis of variance), bivariate (analysis of covariance) and multivariate (multiple-group principal c omponent analysis, canonical variate analysis) analysis showed that th ere is considerable geographic variation in size and shape within Anol is oculatus on Dominica. Partial Mantel tests rejected the null hypoth esis of no association between size and shape and environmental variat ion. The possible proximate and evolutionary mechanisms responsible fo r these patterns are discussed. Despite these overall associations, a considerable amount of variation in shape appears to be unrelated to e nvironmental variation. (C) 1997 The Linnean Soceity of London.