Figure 4

Comparisons of synonymous divergence. Synonymous divergence (dS) between 3 pairs of species estimated from the 3' boundary region and the remaining exonic region (center + 5' boundary), indicated by open and shaded bars, respectively. dS was estimated from the concatenated sequences of the same 24 orthologous pairs of ASEs that were identified in all five species pairs. Error bars represent standard errors estimated by the bootstrap method of 500 replications. No statistically significant difference between the two regions was observed in any of the species pairs.