Evolution of the Prefrontal Cortex in the Hominins

Abstract

When body weight is taken into account, there was a rapid expansion of the brain during the evolution of the hominins, with the greatest increase occurring from around 400,000 years ago. After this time there is evidence of the bulging of the frontal lobe indicating the further expansion of the prefrontal (PF) cortex. Many selection pressures could have influenced these changes, but all of them involve a change in environment. This could occur via climatic change, via changes in the ecosystem, by migration, or by changes in the cultural environment. The cultural environment includes technology such as stone tool making, cooperation in hunting, and the improvements in communication that this required. The adaptation to new environments requires the solution of new problems, and this was aided by the ability of the PF cortex to support rapid transfer from one problem to another.