Fig. 2

(A) Phylogenetic tree of the toothed whale species included in this study, according to McGowen et al. (2020) [40]. Test branches are color-coded according to each environmental category/hypothesis: river = purple (H2a, H2b, H2c), oceanic = orange (H3), coastal/estuarine (H4) = blue; background branches are marked in gray. The five branches of coastal dolphins evolving under positive selection according to aBSREL are highlighted with blue rectangles. (B) Robust Positively Selected Sites (PSS) for the genes CDH23, TMC1, and prestin, using branch-site and site approaches, with the amino acid changes that were identified in the corresponding foreground branch. Rows in Fig. 2B report the PSS that correspond to the lineages at the same level in Fig. 2A. (C) Summary of the selective regime found for each gene. Circles represent each environmental category (colored as in F2A), while stars denote evolutionary hypotheses: light grey for all extant toothed whales (H1b) and dark grey for ancestral toothed whales (H1a)