Patterns of Local Adaptation in the Northern Leopard Frog (Rana pipiens) From a Region Undergoing Rapid Climate and Land-Use Change.

Preservation of local adaptation is a key goal for conservation of populations, and, within the current era of profound environmental change, characterization of local adaptation is necessary to assess the potential resilience of populations to future environmental conditions. In this study, we attempted to characterize patterns of putative, locally adaptive genetic diversity in the northern leopard frog (Rana pipiens) from an area of the Prairie Pothole Region in North Dakota profoundly impacted by climate and land-use change. Using a dataset of 25,587 SNPs obtained using RAD-seq, we characterized population structure, finding similar patterns of isolation by distance and high gene flow as found in previous studies of the region. We considered environmental variables related to climate and several agrochemicals, including nitrates and four commonly applied pesticides, and tested for effects on both neutral and putatively adaptive genetic structure. Genotype by environment analyses identified 388 candidate loci under selection. A large majority of these loci were associated with climatic factors, seemingly mainly driven by differences in breeding-season precipitation regimes across our study area.