Despite the ontogenetic allometric size effects that explain much ofphyletic variation in brain components, the residuals of somestructures indicates that mosaic brain evolution was an importantfactor in hominid evolution, and that reorganization of the hominidbrain may have occurred as early as 3+ MY. Finlay et al.'sallometric technique masks residual variation around allometrictrends, and the patterns of residuals relevant tospecies-specific departures from strict allometric trends.