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Thriving in the Cold: Glacial Expansion and Post-Glacial Contraction of a Temperate Terrestrial Salamander (Plethodon serratus).

Newman CE, Austin CC - PLoS ONE (2015)

Bottom Line: Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic.The Appalachian salamanders form a clade sister to all other P. serratus.Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate.

View Article: PubMed Central - PubMed

Affiliation: Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, United States of America; Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.

ABSTRACT
The dynamic geologic history of the southeastern United States has played a major role in shaping the geographic distributions of amphibians in the region. In the phylogeographic literature, the predominant pattern of distribution shifts through time of temperate species is one of contraction during glacial maxima and persistence in refugia. However, the diverse biology and ecology of amphibian species suggest that a "one-size-fits-all" model may be inappropriate. Nearly 10% of amphibian species in the region have a current distribution comprised of multiple disjunct, restricted areas that resemble the shape of Pleistocene refugia identified for other temperate taxa in the literature. Here, we apply genetics and spatially explicit climate analyses to test the hypothesis that the disjunct regions of these species ranges are climatic refugia for species that were more broadly distributed during glacial maxima. We use the salamander Plethodon serratus as a model, as its range consists of four disjunct regions in the Southeast. Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic. The Appalachian salamanders form a clade sister to all other P. serratus. Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate. These data reject the universal applicability of the glacial contraction model to temperate taxa and reiterate the importance of considering the natural history of individual species.

No MeSH data available.


Related in: MedlinePlus

Map of collection localities.Numbers correspond to map code in Table 1. Inset: Ouachita region. OK = Oklahoma; AR = Arkansas. Photograph: P. serratus, LSUMZ 98343; photo credit: C.C.A.
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pone.0130131.g001: Map of collection localities.Numbers correspond to map code in Table 1. Inset: Ouachita region. OK = Oklahoma; AR = Arkansas. Photograph: P. serratus, LSUMZ 98343; photo credit: C.C.A.

Mentions: Here, we use the terrestrial southern redback salamander, Plethodon serratus, as a case study to test the hypothesis that disjunct species ranges in the Southeast are climatic refugia for species that were more widely distributed during the LGM. Plethodon serratus is found in four isolated regions: the Ozark Mountains, the Ouachita Mountains, the Appalachian Mountains, and two parishes ( = counties) in Louisiana (Fig 1). The genus Plethodon of terrestrial woodland salamanders is the largest genus of salamanders in North America, with 55 species currently recognized and numerous cryptic species [15]. Within the eastern North American Plethodon, recent molecular studies place the P. cinereus group, of which P. serratus is a member, sister to all other eastern Plethodon [16–18]. Although intraspecific relationships of members of eastern Plethodon remain understudied (but see [19–23]), a recent survey of the mitochondrial relationships within P. serratus suggested that the systematics of this species may be more complex than indicated by current taxonomy, involving multiple genetic lineages without reciprocal monophyly of regions [24].


Thriving in the Cold: Glacial Expansion and Post-Glacial Contraction of a Temperate Terrestrial Salamander (Plethodon serratus).

Newman CE, Austin CC - PLoS ONE (2015)

Map of collection localities.Numbers correspond to map code in Table 1. Inset: Ouachita region. OK = Oklahoma; AR = Arkansas. Photograph: P. serratus, LSUMZ 98343; photo credit: C.C.A.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488858&req=5

pone.0130131.g001: Map of collection localities.Numbers correspond to map code in Table 1. Inset: Ouachita region. OK = Oklahoma; AR = Arkansas. Photograph: P. serratus, LSUMZ 98343; photo credit: C.C.A.
Mentions: Here, we use the terrestrial southern redback salamander, Plethodon serratus, as a case study to test the hypothesis that disjunct species ranges in the Southeast are climatic refugia for species that were more widely distributed during the LGM. Plethodon serratus is found in four isolated regions: the Ozark Mountains, the Ouachita Mountains, the Appalachian Mountains, and two parishes ( = counties) in Louisiana (Fig 1). The genus Plethodon of terrestrial woodland salamanders is the largest genus of salamanders in North America, with 55 species currently recognized and numerous cryptic species [15]. Within the eastern North American Plethodon, recent molecular studies place the P. cinereus group, of which P. serratus is a member, sister to all other eastern Plethodon [16–18]. Although intraspecific relationships of members of eastern Plethodon remain understudied (but see [19–23]), a recent survey of the mitochondrial relationships within P. serratus suggested that the systematics of this species may be more complex than indicated by current taxonomy, involving multiple genetic lineages without reciprocal monophyly of regions [24].

Bottom Line: Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic.The Appalachian salamanders form a clade sister to all other P. serratus.Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate.

View Article: PubMed Central - PubMed

Affiliation: Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, United States of America; Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.

ABSTRACT
The dynamic geologic history of the southeastern United States has played a major role in shaping the geographic distributions of amphibians in the region. In the phylogeographic literature, the predominant pattern of distribution shifts through time of temperate species is one of contraction during glacial maxima and persistence in refugia. However, the diverse biology and ecology of amphibian species suggest that a "one-size-fits-all" model may be inappropriate. Nearly 10% of amphibian species in the region have a current distribution comprised of multiple disjunct, restricted areas that resemble the shape of Pleistocene refugia identified for other temperate taxa in the literature. Here, we apply genetics and spatially explicit climate analyses to test the hypothesis that the disjunct regions of these species ranges are climatic refugia for species that were more broadly distributed during glacial maxima. We use the salamander Plethodon serratus as a model, as its range consists of four disjunct regions in the Southeast. Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic. The Appalachian salamanders form a clade sister to all other P. serratus. Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate. These data reject the universal applicability of the glacial contraction model to temperate taxa and reiterate the importance of considering the natural history of individual species.

No MeSH data available.


Related in: MedlinePlus