title: Ecological divergence in the yellow-bellied kingsnake (Lampropeltis calligaster) at two North American biodiversity hotspots.
abstract: Several biogeographic barriers in the Eastern Nearctic appear to reduce gene flow among populations of many species in predictable ways, however these patterns used to infer process of divergence may be deceiving if alternative modes of diversification are not considered. By using a multilocus statistical phylogeographic approach to examine diversity within a North American snake, Lampropeltis calligaster, we find that mode and timing of speciation near the Mississippi River embayment and peninsular Florida, two main biodiversity hotspots in eastern North America, challenge previously held notions of strict vicariance as the causal factor behind patterns of divergence seen among taxa at these locations. We found three species inhabiting distinct ecological niches with divergences dating to the mid- and early-Pleistocene with subsequently stable or increasing effective population sizes, further supporting the idea that the Pleistocene was an important driver of diversification in North America. Our results lead to a revised hypothesis that ecological divergence has occurred in this group across environments associated with the Mississippi River and at the Florida peninsula. Importantly, in their western distributions, we show that species divergence is associated with the ecological transition from distinct forested habitats to grasslands, rather than the nearby Mississippi River, a barrier often implicated for many other organisms. Additionally, we stress the importance of examining each delimited lineage with respect to conservation, since ecological niche models suggest that by the end of the century changes in climate may negatively alter habitat suitability and, barring adaptation, substantially reduce the suitable range of two of the three species we identified.
authors.affiliation: Department of Biology, The Graduate School and Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA; Department of Biology, 6S-143, College of Staten Island, 2800 Victory Boulevard, Staten Island, NY 10314, USA. Electronic address: Smoochy@SnakeEvolution.org.
authors.forename: A D
authors.initials: AD
authors.lastname: McKelvy
authors.affiliation: Department of Herpetology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.
authors.forename: F T
authors.initials: FT
authors.lastname: Burbrink
mesh_terms: D000818:Animals; D044822:Biodiversity; D017812:Colubridae / Q000145:classification* / Q000235:genetics; D045303:Cytochromes b / Q000145:classification / Q000235:genetics; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism; D017753:Ecosystem; D051456:Gene Flow; D010802:Phylogeny; D058974:Phylogeography; D011156:Population Density; D017422:Sequence Analysis, DNA; D014481:United States
chemical_list: D004247:DNA; D045303:Cytochromes b
keywords: Biodiversity; Conservation; Ecological speciation; Environmental niche modeling; Snakes; Statistical phylogeography