The lizard genus Uta comprises nine currently recognized species with the center of diversity occurring on islands in the Gulf of California and Pacific Ocean. The molecular evolution of the side-blotched lizards is analyzed using 1132 base pairs of mitochondrial DNA sequence from the cytochrome b and cytochrome oxidase III genes. Samples come from 98 'individuals from 50 islands in the Gulf of California and Pacific Ocean and 48 adjacent populations from Baja California Sur, Baja California, California, New Mexico, and Sonora. All currently recognized species are represented. Both maximum parsimony and maximum likelihood were used to reconstruct phylogenetic relationships. This study is intended to expand on the analysis of Upton and Murphy (1997) who used 21 individuals representing five of the nine species. The deep divergence discovered by Upton and Murphy (1997) for the two geographically proximate haplotype clades in central Baja California is supported in this analysis. In Upton and Murphy (1997), the two haplotype groups contained samples located approximately 70 km apart in central Baja California; this distribution gap is narrowed to 10 km. The narrowing of the geographical gap between these deeply diverged haplotype clades and their geographical concordance is strong evidence of a cryptic species boundary. This deep substructuring is compared with the many geographically concordant haploclades nested higher in the tree. In addition, a number of insular populations are placed in a basal position with respect to their potential mainland source populations. This is counter-intuitive to the general notion that island populations are derived from current mainland populations. Due to their more restricted area and smaller effective population size, insular populations are also expected to evolve faster. Instead, this analysis has found that there has been enough evolution and extinction within the ancestors of mainland populations that they are now more closely related to each other, while many of the insular populations have preserved enough of their ancestral genetic sequence to remain in basal positions within the genetic tree. Lastly, the taxonomy of Uta is reevaluated in light of its molecular evolution.
Ronald L. Carter
L. Lee Grismer
H. Paul Buchheim
William K. Hayes
Garry P. Larson
Doctor of Philosophy (PhD)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Molecular Biology; Base Sequence; Likelihood Functions; Classification; Lizards.
Loma Linda University Libraries
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Hollingsworth, Bradford Damion, "The Molecular Systematics of the Side-blotched Lizards (IGUANIA: PHRYNOSOMATIDAE: UTA)" (1999). Loma Linda University Electronic Theses, Dissertations & Projects. 602.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives