AdvertisementFrom Primitive Parts, A Highly Evolved Human BrainAugust 09, 2010Jon HamiltonfacebookEmailThe dark regions of this section of a human brain are areas dense with nerve cell bodies, while the white regions are the areas where the neural fibers run, connecting one brain area to another. The structures seen in the middle are evolutionarily "older"; the wrinkly outer portions and associated white matter are more recent and differentiate us from lower mammals.