Brain enlargement and dental reduction were not linked in hominin evolution

Significance The evolution of the brain and of posterior teeth seem to follow parallel trends in hominins. Larger brain size is associated with reduced premolars and molars, but this association is not observed in all hominin species. We have evaluated this association in a quantitative way by measuring lineage-specific rates of dental and cerebral evolution in the different branches of the hominin evolutionary tree. Our results show that different species evolved at different rates and that brain evolution in early Homo was faster than dental evolution. This result points to different ecological and behavioral factors influencing the evolution of hominin teeth and brains.