Population structure of side blotched lizards (Uta Stansburiana) displaying adaptive dorsal coloration

We investigated adaptive dorsal coloration of Uta stansburiana (Side\ud Blotched Lizard) living on the Cima Lava Field in San Bernardino County,\ud California. We take an experimental approach to ensure that substrate matching\ud is not a plastic trait in this species. We then test a candidate gene, melanocortin-\ud 1 receptor ( Mc1r), to see if it is correlated with dorsal color differences between\ud light and dark individuals. We also use mitochondrial loci (ND4 and cytb) in\ud combination with Mc1r to investigate the population structure of this system by\ud means of phylogenetic and population genetic analyses. Results suggest that\ud substrate matching is not a plastic trait in this species; however variation in Mc1r\ud is not associated with observed color differences. We also find an extraordinarily\ud high amount of genetic variability in our sample, suggesting a very large\ud population size. Pairwise mismatch analysis and Tajima???s D tests are consistent\ud with a recent population expansion. Furthermore, we find genetic differentiation\ud among sub localities, suggesting that abiotic barriers are inhibiting gene flow