Jared J. Homola
Kristina M. Cammen
Caren C. Helbing
Inanc Birol
Thomas F. Schultz
Michael T. Kinnison
Cyndy Loftin
2019
<p class="chapter-para">Native species that persist in urban environments may benefit from local adaptation to novel selection factors. We used double-digest restriction-side associated DNA (RAD) sequencing to evaluate shifts in genome-wide genetic diversity and investigate the presence of parallel evolution associated with urban-specific selection factors in wood frogs (<i>Lithobates sylvaticus</i>). Our replicated paired study design involved 12 individuals from each of 4 rural and urban populations to improve our confidence that detected signals of selection are indeed associated with urbanization. Genetic diversity measures were less for urban populations; however, the effect size was small, suggesting little biological consequence. Using an<span> </span><i>F</i><sub>ST</sub><span> </span>outlier approach, we identified 37 of 8344 genotyped single nucleotide polymorphisms with consistent evidence of directional selection across replicates. A genome-wide association study analysis detected modest support for an association between environment type and 12 of the 37<span> </span><i>F</i><sub>ST</sub><span> </span>outlier loci. Discriminant analysis of principal components using the 37<span> </span><i>F</i><sub>ST</sub><span> </span>outlier loci produced correct reassignment for 87.5% of rural samples and 93.8% of urban samples. Eighteen of the 37<span> </span><i>F</i><sub>ST</sub><span> </span>outlier loci mapped to the American bullfrog (<i>Rana [Lithobates] catesbeiana</i>) genome, although none were in coding regions. This evidence of parallel evolution to urban environments provides a powerful example of the ability of urban landscapes to direct evolutionary processes.</p>
application/pdf
10.1093/jhered/esz041
en
Oxford Academic
Replicated landscape genomics identifies evidence of local adaptation to urbanization in wood frogs
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