Meeting Abstract

37.9  Tuesday, Jan. 5  Fine Scale Phylogeography of Sceloporus occidentalis) in the Transverse Ranges of California Reveals Coincidence with Geological Complexity ARCHIE, James W*; QUIJANO, Marc Oliver; California State Univ., Long Beach jarchie@csulb.edu

The Transverse and South Coastal Ranges of California have undergone complex geological changes affecting resident taxa. The Transverse Santa Inez Range originated from a 90° crustal rotation of a crustal block that resulted in uplift. Crust folding and uplift along strike-slip faults occurred further inland forming South Coast Ranges. The eastern extension of the transverse ranges are part of a continental margin region that experienced drift associated with two different fault systems. This resulted in at least four distinct geological regions associated with distinct phylogeographic breaks in different taxonomic groups although samples were inadequate to associate phylogeographic complexity with the full complexity of the geologic history. We sampled western fence lizards (Sceloporus occidentalis) from 150 populations along the Transverse and Coastal Ranges and adjacent Los Angeles Basin. Individuals were sequenced for 1550bp of mtDNA. Phylogenetic and nested clade analyses were carried out. Nearly all sequences were distinct (<1% identical); maximum differences were >7%. Five major clades were identified: 1) LA Basin + San Diego, 2) Ridge Basin + Sierra Pelona, 3) South Coast Ranges north of Cuyama River drainage, 4) Western Transverse Ranges south of Cuyama River drainage, and 5) Pine + Topatopa Mountains. A Great Basin clade was most closely related to the northeastern South Coast Range. Additional geographic structure is present at a finer scale within nested clades. The distribution of clades coincides with major fault blocks and geological regions resulting from geological processes that began during the Miocene era and completed in the Holocene. Only some of these have been identified in previous studies.