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Title: Climate variables explain neutral and adaptive variation within salmonid metapopulations: the importance of replication in landscape genetics
Abstract

Understanding how environmental variation influences population genetic structure is important for conservation management because it can reveal how human stressors influence population connectivity, genetic diversity and persistence. We used riverscape genetics modelling to assess whether climatic and habitat variables were related to neutral and adaptive patterns of genetic differentiation (population‐specific and pairwiseFST) within five metapopulations (79 populations, 4583 individuals) of steelhead trout (Oncorhynchus mykiss) in the Columbia River Basin,USA. Using 151 putatively neutral and 29 candidate adaptiveSNPloci, we found that climate‐related variables (winter precipitation, summer maximum temperature, winter highest 5% flow events and summer mean flow) best explained neutral and adaptive patterns of genetic differentiation within metapopulations, suggesting that climatic variation likely influences both demography (neutral variation) and local adaptation (adaptive variation). However, we did not observe consistent relationships between climate variables andFSTacross all metapopulations, underscoring the need for replication when extrapolating results from one scale to another (e.g. basin‐wide to the metapopulation scale). Sensitivity analysis (leave‐one‐population‐out) revealed consistent relationships between climate variables andFSTwithinthree metapopulations; however, these patterns were not consistent in two metapopulations likely due to small sample sizes (= 10). These results provide correlative evidence that climatic variation has shaped the genetic structure of steelhead populations and highlight the need for replication and sensitivity analyses in land and riverscape genetics.

 
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PAR ID:
10266244
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Molecular Ecology
Volume:
25
Issue:
3
ISSN:
0962-1083
Page Range / eLocation ID:
p. 689-705
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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