This talk will discuss reconstructing the evolution of cortical geometry of the human brain and its link to function, behavior and ecology. A joint geometric representation of the cerebral cortices of ninety living species forms the basis of reconstructing ancestral shapes and tracing the evolutionary history of localised cortical expansions, modal segregation of brain function. We will discuss their association to behaviour and cognition, as individual cortical regions follow different sequences of area increase during evolutionary adaptations to dynamic socio-ecological niches. Anatomical correlates of this sequence of events are still observable in living species, and relate to their current behaviour and ecology. A decomposition of the evolutionary history of the shape of the human cortical surface into spatially and temporally conscribed components yields interpretable functional associations, and new evidence relating to the tethering hypothesis.