[Mechanisms for making neocortical diversity--insights from evolutionary developmental biology]

The cerebral cortex is one of the most intricate structures in the vertebrate brain, and enormous expansion in size and complexity are conspicuous features in the mammalian cortex. Although how the cerebral cortex evolved from ancestor brains still remains elusive, recent advances of developmental neurobiology shed light on the molecular mechanisms underlying cortical development, and also provide novel insights into the origin of the mammalian cerebral cortex. Here I introduce classical concepts and modern theories on the process for making morphological and functional diversity of the cerebral cortex. In this review, we especially focus on possible mechanism that provide 1) morphological diversity of the amniotes' cortex, 2) expansion of the mammalian neocortical areas, and 3) advancement of human cognitive abilities, based on accumulating knowledge of the comparative brain anatomy, molecular neurobiology, anthropology and cognitive archaeology.