Regression of cortical area in midsagittal section on subperisoteal area () for a sample of 100 hominoid mandibles ( males and females of Pan troglodytes [t], Pongo pygmaeus [p], Gorilla gorilla [g], Homo [open circles], Hylobates lar and agilis [h]) [23]. The modern human sample (open circles) is superimposed on the hominoid regression. Human mandibles possess more bone than expected based on scaling relationships among all hominoids, based on a G-test for the random distribution of residuals above and below the regression line ().