Genome-Wide Screens for Molecular Convergent Evolution in Mammals

Abstract

Convergent evolution can occur at both the phenotypic and molecular level. Of particular interest are cases of convergent molecular changes that underlie convergent phenotypic changes, as they highlight the genomic differences that underlie phenotypic adaptations and can inform us on why evolution has repeatedly chosen the same solution in lineages that have evolved independently. Many approaches to identify convergent molecular evolution have focused on candidate genes with known functions as well as lineages with known convergent phenotypes. The growing amount of genomic sequence data makes it now possible to systematically detect molecular convergence genome-wide. Here, we highlight the advantages and drawbacks of using genomic screens to identify molecular convergence. We present our method to detect convergent substitutions between any pair of lineages in a genome-wide manner, ways of enriching for convergence that are more likely to affect protein function, and present novel cases of convergence in echolocating mammals. Our results suggest that genomic screens have the potential to generate new hypotheses of associations between molecular convergence and phenotypic convergence. Together with experimental assays to test for functional convergence, this will contribute to revealing the genomic changes that underlie convergent phenotypic changes.