Evolutionary differentiation of bimaculatus group anoles based on analyses of mtDNA and microsatellite data

The bimaculatus group of anoles inhabit the northern Lesser Antilles, as far south as Dominica. This study uses 1005 base pairs (bp) of mitochondrial DNA sequence data from two genes, cytochrome b (521 bp) and cytochrome oxidase subunit I (484 bp) to reconstruct phylogenetic relationships between species and populations of anoles from all islands banks. Allele frequency data from nuclear microsatellite loci are also analysed to assess their utility in uncovering historical relationships and provide independent corroboration for the mtDNA tree. Although the number of microsatellite loci used (six) was relatively small, some essential elements of the mitochondrial DNA phylogeny were recovered successfully. Anoles from Terre de Haut, Les Saintes, previously described as a subspecies of Anolis marmoratus, are shown to be more closely related to A. oculatus and their elevation to a full species, A. terraealtae, is supported. An island colonisation sequence inferred from the phylogeny shows a general pattern of North-to South colonisation. However, the Saban anole, A. sabanus, is shown to be derived from A. marmoratus populations from western Basse Terre following a longer-range, south to north translocation. (C) 2004 Elsevier Inc. All rights reserved.