See fast_boot and plot.wrightscape functions in code. Gape size
See fast_boot and plot.wrightscape functions in code Jaw Protrusion
Figures show strong evidence for the relax of constraint hypothesis, as the strength of selection (alpha parameters) appears to have substantially weakened in both morphological traits in the parrotfish clade relative to the wrasses clade. The wrasses show strong preference for OU model with substantial stabilizing selection, while the Parrotfish estimate almost zero stabilizing selection (Brownian model, clear phylogenetic signal).
Note that while the theta and sigma parameters can be accurately estimated in the wrasses, the model places little confidence on the reconstructed values of these parameters in the smaller Parrotfish clade, even though alpha seems well-defined in both clades.