The ω values of FGF5 genes in distinct evolutionary lineages of cetaceans and other mammals using a phylogenetic tree derived from Chen et al. , Gatesy et al. , and Zhou et al. ,. Branches a-h relate to those shown in Table 3. The ω values of individual branches shown are based on the free-ratio model. In some cases, zero synonymous substitutions produced an ω value of infinity (n.a.). The estimated numbers of nonsynonymous and synonymous changes are shown in parentheses. The ω values of branches a, b, and c (marked with different colors) were estimated using the two-ratio models.