Evolution of the human brain
Dunbar R.
© 2016 Elsevier Inc. All rights reserved. The brain is ultimately the centerpiece of neuroscience. However, the human brain does not appear fully formed out of nowhere. It is the product of a long process of evolution over many hundreds of millions of years, beginning with the first neural nets evolved by primitive invertebrates. These early neural systems were largely concerned with managing somatic processes-feeding, digestion, movement, orientation. The evolution of the vertebrate nervous system, based around a recognizable brain and a spinal cord encased in bony protecting vertebrae, marked a sea change in both efficiency and scale. The larger body size of vertebrates not only made a larger brain necessary (more somatic tissue to manage) but also provided the energetic and nutritional capacity to support a larger brain.