Lampropeltis getula complex
In a pair of papers Pyron and Burbrink (2009a,b) controversially proposed splitting what has long been regarded as a large, transcontinental, polytypic species (Lampropeltis getula) into five separate evolutionary species, based almost entirely on mitochondrial DNA (mtDNA) sequencing techniques and equally tenuous ecological niche modeling. We have noted that the editors of the Center for North American Herpetology (CNAH) names list have enthusiastically embraced these highly counterintuitive taxonomic changes and will doubtless adopt this classification in the next print edition of their “standardized” list. Additionally, given that the second author of these papers has continuously served as a member of the snake taxonomy subcommittee of the SSAR et al. names list, we feel it likely that this proposal will also be adopted by that body despite the controversy surrounding it. We at SWCHR, however, continue to feel that taxonomic changes based solely on mtDNA should be regarded skeptically until/unless those conclusions are also supported by data from alternative methods (e.g., multivariate analysis of morphological characters, etc.) While our questions regarding these papers are too numerous to list here, our reluctance appears to be borne out by recent advances in nuclear DNA analysis that thus far tend to indicate significant discordances between phylogenetic trees generated by nuclear methods versus those employing mtDNA only (e.g., Leache 2010). It is becoming increasingly apparent that nuclear clades – to the extent that they are determined correctly – are more representative of the true evolutionary history of an organism. Thus, in the absence of additional support from morphological and/or nuclear studies, we are choosing to disregard the Pyron and Burbrink proposal and retain the “traditional” arrangement of Lampropeltis getula. In the words of the late Carl Sagan, “extraordinary claims require extraordinary proof.” Pyron and Burbrink have made extraordinary claims regarding L. getula, but in our view have yet to provide extraordinary – or at least convincing – proof.
Leaché, Adam D. 2010. Species trees for spiny lizards (Genus Sceloporus): Identifying points of concordance and conflict between nuclear and mitochondrial data. Molecular Phylogenetics and Evolution. 54: pp. 162-171.
Pyron, R. Alexander and Frank T. Burbrink. 2009a. Lineage diversification in a widespread species: roles for niche divergence and conservatism in the Common Kingsnake, Lampropeltis getula. Molecular Ecology. 18: pp. 3443–3457.
Pyron, R. Alexander & Frank T. Burbrink. 2009b. Systematics of the Common Kingsnake (Lampropeltis getula: Serpentes: Colubridae) and the burden of heritage in taxonomy. Zootaxa. (2241): pp. 22-32.
1 Mar 2010
SWCHR Committee on Common and Scientific Names
Tom Lott, Committee Chair
Riley J. Campbell
Gerald Keown (ex officio member)
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