Conclusions
In this study on genomic adaptation of a small mammal to a pan-European
climate gradient, we have shown that both geographic population
structure and climate play important roles in explaining neutral genetic
differentiation across the bank vole range. Genetic variation among
candidate loci was mainly explained by variation in annual mean
temperature, highlighting its importance for climate adaptation in the
bank vole. We identified 74 genes that showed evidence of spatially
varying selection and whose functional annotation suggested that energy
homeostasis and response to pathogen infection are important targets of
spatially varying selection in the bank vole. We propose to further
investigate the functional significance of the identified genes, e.g.,
through common garden experiments and involving gene expression
analysis, as they represent good candidates for local adaptation. Future
studies should also look for spatial variation in physiological traits
related to energy homeostasis or the immune system to ultimately link
genetic variation, organismal physiology, and fitness traits in locally
adapted populations.