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

Rachael Y. Dudaniec, Stephen F. Spear, John S. Richardson, Andrew Storfer

Research output: Contribution to journalArticle

26 Citations (Scopus)
19 Downloads (Pure)

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 (Dicamptodon tenebrosus) 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 D. tenebrosus 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.

Original languageEnglish
Article numbere36769
Pages (from-to)1-12
Number of pages12
JournalPLoS ONE
Volume7
Issue number5
DOIs
Publication statusPublished - 10 May 2012
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2012. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Fingerprint Dive into the research topics of 'Current and historical drivers of landscape genetic structure differ in core and peripheral salamander populations'. Together they form a unique fingerprint.

  • Cite this