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Biogeography and Climatic Niche Evolution in the Eastern Red-backed Salamander (Plethodon cinereus)

Radomski, Thomas P.,
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1473718749599987

Abstract Details

2017, Master of Science (MS), Ohio University, Biological Sciences (Arts and Sciences).
Phylogenetic niche conservatism (PNC) is the retention of ancestral ecological characteristics among related species, more so than would be expected by a simple Brownian motion process. PNC may be important in explaining biodiversity gradients, species’ ranges, and species formation, but an ecological cause for PNC has been challenging to identify. One hypothesis is that PNC occurs when ecological opportunity (exposure to new, accessible niche space) is lacking. Ecological opportunity may be unavailable when habitats are ecologically saturated, but conversely, the availability of depauperate environments may provide opportunity. Because eastern Plethodon salamanders are characterized by strong PNC, studying a species within Plethodon characterized by niche lability may elucidate why PNC occurs. I investigated the biogeography of the Eastern Red-backed Salamander (Plethodon cinereus) and tested the hypothesis that the climatic niche of P. cinereus diverged when glacial retreat made competitor-free habitats available. I addressed this hypothesis by sampling 202 individuals from 107 populations throughout the range of P. cinereus, and I analyzed molecular sequences for three mitochondrial and three nuclear loci, totaling 4,686 base pairs. A time-calibrated phylogeny was inferred with the Bayesian phylogenetic program BEAST. Among intraspecific clades, I tested for climatic niche divergence and compared rates of evolution using climatic data. I found that three different clades invaded areas north of the last glacial maximum (LGM), with one clade occupying most of the range beyond the LGM. Niche models and rates of climatic niche evolution were compared between clades. Consistent with the ecological opportunity hypothesis, I found that the rate of climatic niche evolution was significantly greater for populations that colonized areas north of the LGM. This study provides an ecological explanation for PNC and its converse, niche lability, by examining the climatic niche in a phylogeographic context.
Shawn Kuchta (Advisor)
Morris Molly (Committee Member)
White Matthew (Committee Member)
90 p.
Biology; Ecology
niche conservatism; ecological opportunity; biogeography; phylogenetics; rates of evolution; Plethodon cinereus

Recommended Citations

Citations

  • Radomski, , T. P. (2017). Biogeography and Climatic Niche Evolution in the Eastern Red-backed Salamander (Plethodon cinereus) [Master's thesis, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1473718749599987

    APA Style (7th edition)

  • Radomski, , Thomas. Biogeography and Climatic Niche Evolution in the Eastern Red-backed Salamander (Plethodon cinereus). 2017. Ohio University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1473718749599987.

    MLA Style (8th edition)

  • Radomski, , Thomas. "Biogeography and Climatic Niche Evolution in the Eastern Red-backed Salamander (Plethodon cinereus)." Master's thesis, Ohio University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1473718749599987

    Chicago Manual of Style (17th edition)

ohiou1473718749599987
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This open access ETD is published by Ohio University and OhioLINK.