Figure 4.

Pruned subtree of CslF clade and codeml branch-site tests. Branch lengths are proportional to substitutions per site. Postduplication branches with sites that codeml has identified as under significant positive selection are colored blue. Green branches indicate a sustained shift in selection pressure across all branches after a major gene duplication. Predicted gene duplication events are annotated as red dots. ω denotes dN:dS values. The overall dN:dS for the CslF clade is 0.17 (Fig. 3).