Phylogeography of the California mountain kingsnake, Lampropeltis zonata (Colubridae)

Abstract

The phylogeography of the California mountain kingsnake, Lampropeltis zonata, was studied using mitochondrial DNA sequences from specimens belonging to the seven recognized subspecies and collected throughout the range of the species. Maximum parsimony and maximum likelihood methods identified a basal split within L. zonata that corresponds to southern and northern segments of its distribution. The southern clade is composed of populations from southern California (USA) and northern Baja California, Mexico. The northern clade is divided into two subclades, a 'coastal' subclade, consisting of populations from the central coast of California and the southern Sierra Nevada Mountains of eastern California, and a 'northeastern' subclade, mainly comprised of populations north of the San Francisco Bay and from the majority of the Sierra Nevada. We suggest that past inland seaways in southwestern California and the embayment of central California constituted barriers to gene flow that resulted in the two deepest divergences within L. zonata. Throughout its evolutionary history, the northern clade apparently has undergone instances of range contraction, isolation, differentiation, and then expansion and secondary contact. Examination of colour pattern variation in 321 living and preserved specimens indicated that the two main colour pattern characters used to define the subspecies of L. zonata are so variable that they cannot be reliably used to differentiate taxonomic units within this complex, which calls into question the recognition of seven geographical races of this snake.

Molecular Phylogenetics of Western North American Frogs of the Rana boylii Species Group

“…The break observed in R. muscosa occurs between Kings Canyon National Park and a region slightly north of Yosemite National Park. This pattern is broadly congruent with genetic breaks between central and southern Sierra Nevada populations of the toad Bufo canorus (Shaffer et al, 2000), the salamander Ensatina eschscholtzii (Moritz et al, 1992), the snake Lampropeltis zonata (Rodriguez-Robles et al, 1999), and the newt Taricha torosa (Tan and Wake, 1995). Hence, there are now five species of amphibians and reptiles with a similar pattern of biogeographic fragmentation in the Sierra Nevada, suggesting that these species were influenced by a common vicariant event.…”

Mitochondrial DNA-Based Phylogeography of North American Rubber Boas, Charina bottae (Serpentes: Boidae)

“…Phylogeographic studies of Lampropeltis zonata (California mountain kingsnake) and Diadophis punctatus (ring-necked snake) in California also indicate that the most basal genetic break within these taxa corresponds to southern and northern segments of their distribution and occurs in the same general region as that of rubber boas (Rodríguez-Robles et al, 1999;Feldman, 2000). Present-day southern California was separated from regions to the north by extensive, shallow inland seaways that mostly did not recede until the Pliocene (5-1.6 mya; Dupré et al, 1991;Norris and Webb, 1990).…”

“…Present-day southern California was separated from regions to the north by extensive, shallow inland seaways that mostly did not recede until the Pliocene (5-1.6 mya; Dupré et al, 1991;Norris and Webb, 1990). These marine barriers were suggested to have played a role in the basal split of L. zonata (Rodríguez-Robles et al, 1999), and perhaps they contributed to the current population genetic structure of C. bottae and D. punctatus as well.…”

“…Although single-species studies have clearly been extremely valuable in this regard, comparative (i.e., multispecies) genetic assessments of taxa with similar distributions enable us to draw broader conclusions about regional biogeography. Recent (Barrowclough et al, 1999;Cicero, 1996;Moritz et al, 1992;Patton and Smith, 1990;Rodríguez-Robles et al, 1999;Tan and Wake, 1995;Wake, 1997) and ongoing genetic studies of various species of amphibians, mammals, reptiles, and birds from California will allow us to assess how the complicated geomorphological history of this region has interacted with demographic processes to shape the modern genetic population structure of independent lineages of terrestrial vertebrates.…”

Molecular Systematics of the Western Rattlesnake, Crotalus viridis (Viperidae), with Comments on the Utility of the D-Loop in Phylogenetic Studies of Snakes

“…Phylogeographic studies of snakes are rare, and most have used the mitochondrial genes cyt b and/or ND4 (Pook et al, 2000;Rodriguez-Robles and De Jesus-Escobar, 2000;Rodriguez-Robles et al, 1999;Zamudio and Greene, 1997). Studies of other vertebrates have often used the D-loop region because of its extreme variability (e.g., Barratt et al, 1999;Doukakis et al, 1999;Nesbo et al, 1999;Steinfartz et al, 2000;Terry et al, 2000;Vila et al, 1997).…”