• The Lampropeltis calligaster complex is composed of three species occupying distinct ecological niches in North America.
• Speciation in the Eastern Nearctic is associated with ecological processes occurring near the Mississippi River.
• Divergence occurred in the late Pliocene or early Pleistocene and was likely ecological rather than allopatric.
• Two of the three species delimited are likely imperiled by urbanization and climate change.
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.
Keywords: Ecological speciation; Statistical phylogeography; Biodiversity; Environmental niche modeling; Snakes; Conservation
|Fig. 1. (A) Approximate range of each species of Yellow-bellied Kingsnake and sampling distribution for the Prairie Kingsnake, Lampropeltis calligaster (Brown, B), Mole Kingsnake, Lampropeltis rhombomaculata, (Green, C) and South Florida Mole Kingsnake Lampropeltis occipitolineata (Purple, D) and dated species tree. Ranges are estimated based on Ernst and Ernst (2003) and Conant and Collins (1998) as well as environmental niche models produced in this study. South Florida species L. occipitolineata diverged from the Eastern clade L. rhombomaculata $0.88 MYA, posterior probability 0.797. An older split between the western group L. calligaster from the two eastern groups occurred $1.56 MYA. Posterior probability values are displayed to the left of each node. |
Photograph B courtesy of Donald Shepard, C Kenneth Krysko and D Kevin Enge. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) DOI: 10.1016/j.ympev.2016.09.006
A.D. McKelvy and F.T. Burbrink. 2017. Ecological Divergence in the Yellow-bellied Kingsnake (Lampropeltis calligaster) at Two North American Biodiversity Hotspots. Molecular Phylogenetics and Evolution. 106; 61–72. DOI: 10.1016/j.ympev.2016.09.006
Common US snake actually three different species http://phy.so/394888790 @physorg_com