Abstract:
We investigated species boundaries and phylogenetic relationships in the Sceloporus variabilis group, using multilocus isozyme characters. Fortyone genetic markers were screened in a sample of 238 lizards freom 47 localities, representing eight ingroup species. Thirtyfour loci were variable within or between taxa, Morphologically welldefined species (S. chrysostictus, S., cozumelae, and S. parvus) were strongly and unambiguously differentiated genetically. Within S. variabilis, S. v.maramoralus, highelevation populations of S. v. variabilis (freom Hidalgo, Queretaro and San Luis Potosi), lowelevation populations of S., v. variabilis, and S. v. olloporus, were each recognized as full species. Lowelevation populations of S. v. variabilis were only slightly divergent freom S. v. teapensis and were retained as conspecific, Two different methods of parsimony analysis recovered trees with the following structure: (S., parvus (S. chrysostictus (S., cozumelae + S. variabilis speciesgroup))), A freEQPARS analysis recovered a different topology.