Figure 1.

Radical amino acid changes in selected sites across the cetacean phylogeny. Parallel amino acid substitutions occurred in three selected genes (ACE, AGT, and SLC14A2) shown on the right of the figure. The selected genes and their corresponding parallel amino acid substitutions in cetaceans are marked with different colors, i.e., ACE (red), AGT (blue), SLC14A2 (green), and AQP2 (purple). Selected sites identified using site models and branch-site models are indicated separately by vertical lines and circles, respectively. For each amino acid position, the parallel amino acid is labeled on the right of the corresponding terminal branches, while a, d, and f in parentheses indicate the internal branches where the parallel changes occurred. Terrestrial mammals were used as outgroups including cetartiodactyls, carnivores, rodents, and primates.