Microgeographic variation in Anolis oculatus, on the island of Dominica, West Indies

Abstract

The current study provides a quantitative description of the pattern of geographic variation in three morphological character systems of Anolis oculatus, on the ecologically diverse island of Dominica. Causal relationships were investigated by comparing observed patterns of variation to hypothesised patterns (derived from six ecological variables), using Mantel tests, partial correlations and canonical correlations. The similarity between generalised morphological and ecological matrices was highly significant. Partial correlations indicated which of the ecological factors had the most significant influence on individual characters, while canonical correlations showed that characters formed constellations which were influenced by constellations of ecological factors. This analysis also illustrates the incongruence of patterns of variation which result from ecogenetic adaptation. The conventional subspecific categories cannot adequately reflect this variation and consequently, in such cases, the use of subspecies is inappropriate. Copyright © 1991, Wiley Blackwell. All rights reserved