Bipedalism, canine tooth reduction, and obligatory tool use

Bipedalism in the earliest hominid specimens is always accompanied by the reduction of projecting canine teeth. Body size is smaller than chimpanzees or humans, but molar teeth are markedly larger. Use of a pointed stick for defensive purposes on the one hand, and digging for USOs on the other, may be why bipedalism was selected for. Passing such learned behavior to the next generation may have played a role in selecting for language.