SPECIES LIMITS, PHYLOGENETIC-RELATIONSHIPS, AND ORIGINS OF VIVIPARITYIN THE SCALARIS COMPLEX OF THE LIZARD GENUS SCELOPORUS (PHRYNOSOMATIDAE, SAURIA)

We electrophoretically assayed 32 gene loci in the Sceloporus scalaris complex. We sampled 208 animals from 22 localities representing the f ollowing: Sceloporus aeneus (12 localities), S. bicanthalis (five loca lities), S. chaneyi (one locality), S. goldmani (one locality), and S. scalaris samcolemani (two localities), and we used Sceloporus parvus and S. variabilis as outgroups. Of the 32 gene loci, 11 were uninforma tive, 10 were polymorphic both within and among species, and 11 were p olymorphic among species but monomorphic within species. Thirteen diag nostic loci, plus two morphological characteristics (number of canthal scales and male belly patterns) and the type of parity mode present, define a total of eight genetically and/or morphologically distinct in group units. Cladistic analysis of these markers suggests at least two separate origins of viviparity within the complex (based on the most parsimonious trees from the cladistic analysis), as well as the possib ility of reproductively bimodal groups within the complex. A phylogene tic hypothesis of the complex is presented.