Lineage diversification in a widespread species: roles for niche divergence and conservatism in the common kingsnake, Lampropeltis getula

Abstract

Niche conservatism and niche divergence are both important ecological mechanisms associated with promoting allopatric speciation across geographical barriers. However, the potential for variable responses in widely distributed organisms has not been fully investigated. For allopatric sister lineages, three patterns for the interaction of ecological niche preference and geographical barriers are possible: (i) niche conservatism at a physical barrier; (ii) niche divergence at a physical barrier; and (iii) niche divergence in the absence of a physical barrier. We test for the presence of these patterns in a transcontinentally distributed snake species, the common kingsnake (Lampropeltis getula), to determine the relative frequency of niche conservatism or divergence in a single species complex inhabiting multiple distinct ecoregions. We infer the phylogeographic structure of the kingsnake using a range-wide data set sampled for the mitochondrial gene cytochrome b. We use coalescent simulation methods to test for the presence of structured lineage formation vs. fragmentation of a widespread ancestor. Finally, we use statistical techniques for creating and evaluating ecological niche models to test for conservatism of ecological niche preferences. Significant geographical structure is present in the kingsnake, for which coalescent tests indicate structured population division. Surprisingly, we find evidence for all three patterns of conservatism and divergence. This suggests that ecological niche preferences may be labile on recent phylogenetic timescales, and that lineage formation in widespread species can result from an interaction between inertial tendencies of niche conservatism and natural selection on populations in ecologically divergent habitats.

Snakes on an island: independent introductions have different potentials for invasion

“…Kingsnakes consist of a number of closely related species, and are native to North America (Pyron and Burbrink 2009). Whilst other snake species are notorious as destructive invaders-for example, boa constrictors in Conzumel Island and brown tree snakes in Guamaside from this current case in Gran Canaria, kingsnakes have yet to be reported as invasive outside of their native North American range (David Steen, pers.…”

Niche conservatism in Gynandropaa frogs on the southeastern Qinghai-Tibetan Plateau

“…Longer-term events, on the other hand, such as differentiation across phylogenies, show a tendency for a breakdown in conservatism811. Overall, the relative importance of niche conservatism versus niche divergence for influencing lineage diversification in taxa crossing heterogeneous habitats and putative geographical barriers remains poorly understood8111213.…”

Geographic Distribution and Niche Divergence of Two Stinkbugs,Parastrachia japonensisandParastrachia nagaensis

“…It is widely accepted that ecology plays an important role in speciation (Rice et al 2003; Rissler and Apodaca 2007; Pyron and Burbrink 2009). Generally, the speciation event takes place in geographic dimensions and may not be accompanied by ecological innovation (Peterson et al 1999; Pyron and Burbrink 2009; McCormack et al 2010; Peterson 2011).…”

“…Generally, the speciation event takes place in geographic dimensions and may not be accompanied by ecological innovation (Peterson et al 1999; Pyron and Burbrink 2009; McCormack et al 2010; Peterson 2011). When populations enter into a new environment, however, the ecological niche of a species might diverge to adapt to the novel environment, and subsequent natural selection might promote this process and facilitate speciation (Graham et al 2004; Wiens and Graham 2005; Sánchez-Fernández et al 2011).…”