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Current and historical drivers of landscape genetic structure differ in core and peripheral salamander populations

Dudaniec, Rachael LU ; Spear, Stephen F.; Richardson, John S. and Storfer, Andrew (2012) In PLoS ONE 7. p.36769-36769
Abstract
With predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. To address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (<italic>Dicamptodon tenebrosus</italic>) in two core regions (Washington State, United States) versus the species' northern peripheral region (British Columbia, Canada) where the species is listed as threatened. Coalescent-based demographic simulations were consistent with a pattern of post-glacial range expansion, with both... (More)
With predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. To address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (<italic>Dicamptodon tenebrosus</italic>) in two core regions (Washington State, United States) versus the species' northern peripheral region (British Columbia, Canada) where the species is listed as threatened. Coalescent-based demographic simulations were consistent with a pattern of post-glacial range expansion, with both ancestral and current estimates of effective population size being much larger within the core region relative to the periphery. However, contrary to predictions of recent human-induced population decline in the less genetically diverse peripheral region, there was no genetic signature of population size change. Effects of current demographic processes on genetic structure were evident using a resistance-based landscape genetics approach. Among core populations, genetic structure was best explained by length of the growing season and isolation by resistance (i.e. a ‘flat’ landscape), but at the periphery, topography (slope and elevation) had the greatest influence on genetic structure. Although reduced genetic variation at the range periphery of <italic>D. tenebrosus</italic> appears to be largely the result of biogeographical history rather than recent impacts, our analyses suggest that inherent landscape features act to alter dispersal pathways uniquely in different parts of the species' geographic range, with implications for habitat management. (Less)
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author
publishing date
type
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published
subject
in
PLoS ONE
volume
7
pages
36769 - 36769
publisher
Public Library of Science
external identifiers
  • scopus:84861012518
ISSN
1932-6203
DOI
10.1371/journal.pone.0036769
language
English
LU publication?
no
id
7a5e8e3b-ab88-4579-9eb7-56c7f471cbe4 (old id 3738462)
date added to LUP
2013-05-23 14:22:05
date last changed
2017-10-22 04:17:10
@article{7a5e8e3b-ab88-4579-9eb7-56c7f471cbe4,
  abstract     = {With predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. To address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (&lt;italic&gt;Dicamptodon tenebrosus&lt;/italic&gt;) in two core regions (Washington State, United States) versus the species' northern peripheral region (British Columbia, Canada) where the species is listed as threatened. Coalescent-based demographic simulations were consistent with a pattern of post-glacial range expansion, with both ancestral and current estimates of effective population size being much larger within the core region relative to the periphery. However, contrary to predictions of recent human-induced population decline in the less genetically diverse peripheral region, there was no genetic signature of population size change. Effects of current demographic processes on genetic structure were evident using a resistance-based landscape genetics approach. Among core populations, genetic structure was best explained by length of the growing season and isolation by resistance (i.e. a ‘flat’ landscape), but at the periphery, topography (slope and elevation) had the greatest influence on genetic structure. Although reduced genetic variation at the range periphery of &lt;italic&gt;D. tenebrosus&lt;/italic&gt; appears to be largely the result of biogeographical history rather than recent impacts, our analyses suggest that inherent landscape features act to alter dispersal pathways uniquely in different parts of the species' geographic range, with implications for habitat management.},
  author       = {Dudaniec, Rachael and Spear, Stephen F. and Richardson, John S. and Storfer, Andrew},
  issn         = {1932-6203},
  language     = {eng},
  pages        = {36769--36769},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {Current and historical drivers of landscape genetic structure differ in core and peripheral salamander populations},
  url          = {http://dx.doi.org/10.1371/journal.pone.0036769},
  volume       = {7},
  year         = {2012},
}