Brain folding
The neocortex is the part of the brain that enables us to speak, dream, or think. The underlying mechanism that led to the expansion of this brain region during evolution, however, is not yet understood. A research team headed by Wieland Huttner, director at the Max Planck Institute of Molecular Cell Biology and Genetics, now reports an important finding that paves the way for further research on brain evolution: The researchers analyzed the gyrencephaly index, indicating the degree of cortical folding, of 100 mammalian brains and identified a threshold value that separates mammalian species into two distinct groups: Those above the threshold have highly folded brains, whereas those below it have only slightly folded or unfolded brains. The research team also found that differences in cortical folding did not evolve linearly across species.