Fig. 7. Phylogeny, head size and force production in Odontomachus. Head sizes are species means, scaled to 2 mm bar. Bar graph shows force production predicted by independent-contrast model (blue bars), species mean data (maroon bars), and star-phylogeny model (beige bars) for each species studied. Forces calculated from actual species means differed from head width-based predictions from phylogenetically corrected models by an absolute mean value of 12%, and from the uncorrected models by 11%. Predictions derived from uncorrected (star-phylogeny) and phylogeny-corrected models differed by an average of 3%.