Powerful detection of polygenic selection and environmental adaptation in US beef cattle populations
bioRxiv, (2020)DOI: 10.1101/2020.03.11.988121
Abstract
Selection can rapidly drive evolution, especially in stressful environments. We show that novel dependent variables in mixed models with large data sets identify loci responding to polygenic selection and local adaptation. Many techniques identify mutations rapidly selected to high frequencies, based on pronounced signatures in flanking sequences. However, for complex, quantitative traits, selection does not leave these intense sweeps. Instead, in polygenic selection thousands of loci undergo small allele frequency shifts, resulting in large phenotypic changes. Directional selection and local adaptation are actively changing populations; but, identifying loci underlying polygenic or environmental selection has been difficult. However, our methods identify 207 loci responding to artificial directional selection, and hundreds more with evidence of local adaptation; with the identified genes highlighting the nervous system’s central role in local adaptation. While advanced technologies increased the rate of directional selection, it has been at the expense of local adaptation, which is especially problematic in changing climates. These selection mapping approaches clarify selective forces and loci in evolutionary, model, and agricultural contexts.Competing Interest StatementThe authors have declared no competing interest.