Figure 2.

Codon-based models of evolution (ω = d_N/d_S models). (a) TSGs with the signature of positive selection in different branches of the cetacean tree of life. (b) For the branch model, we found that the distribution of the ω values estimated between groups is significantly different (D = 0.32764, p-value < 2.2 × 10−6). The height of the curves is relative to the number of genes with the observed ω values and the dotted lines represent the mean value for cetaceans (orange) and the outgroup (grey). (Online version in colour.)