This study investigated the phylogenetic relationships and biogeographic history of West Indian geckos belonging to the genus Sphaerodactylus through an analysis of protein variation. Two techniques were used: sequential starch gel electrophoresis of 15 slow‐evolving loci and microcomplement fixation of albumin. The relationships obtained were used to revise the classification of this genus. Two major groups (subsections) occur in the West Indies. The sputator subsection, centred in the Greater Antilles, is composed of three series: cinereus, sputator and argus. The fantasticus subsection, restricted to the Lesser Antilles, includes only the fantasticus series. Three antibodies (argus, asterulus and copei) were used to investigate albumin evolution and estimate times of divergence within Sphaerodactylus. Using the albumin clock calibration derived from other groups, the West Indian Sphaerodactylus had diverged from other sphaerodactylines by approximately 27 million years before present (mybp). Therefore, fragmentation of the Proto‐Antilles (60 mybp) apparently did not play a role in the group's evolution. The present distribution of West Indian Sphaerodactylus resulted from dispersal. Hispaniola probably was the centre of Sphaerodactylus diversity and the source of colonists for other islands. Certain features of Sphaerodactylus ecology and physiology make them likely candidates for dispersal. In contrast to the West Indian species of Anolis and Eleutherodactylus, few exampies of morphological convergence are found in Sphaerodactylus. Allopatric speciation, perhaps due to climatic changes in the Pliocene and Pleistocene, is suggested as the primary mechanism of species formation in West Indian Sphaerodactylus.
We present an initial evaluation of relationships among a diverse sample of 215 species of snakes (8% of the world snake fauna) representing nine of the 16 commonly‐recognized families. Allelic variation at four slow‐evolving. protein‐coding loci, detected by starch‐gel electrophoresis, was found to be informative for estimating relationships among these species at several levels. The numerous alleles detected at these loci [Arp‐2 (42 alleles). Ltlh‐2 (43), Mdh‐1 (29), Pgm (Z)] provided unexpected clarity in partitioning these taxa. Most congeneric species and several closely‐related genera have the same allele at all four loci or differ at only a single locus. At thc other extreme are those species with three or four unique alleles; these taxa cannot be placed in this analysis. Species sharing two or three distinctive alleles are those most clearly separated into clades. Typhlopids, pythonids, viperids, and elapids were resolved into individual clades. whereas bods were separated into boincs and erycines, and colubrids appeared as scveral distinct clades (colubrines, natricines, psammophines, homalopsines, and xenodontines). Viperids were recognized as a major division containing three separate clades: Asian and American crotalines. Pabearctic and Oriental viperines, and Ethiopian causines. The typhlopids were found to be the basal clade, with the North American erycine boid Chrrrino and the West Indian woodsnakes Tropidophi, Y near the base. A number of species and some small clades were not allocated because of uninformative (common, unique, or conflicting) alleles. Of the 21 S species examined, five to eight appear to have been misplaced in the analysis of these electrophoretic data.
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