The surest way to grasp complexity in the brain, as in any other biological system, is to think of it as an engineering problem. What are the broad principles needed to create a brain from scratch? Whether contrived by advance planning or by blind natural selection, the key features of architecture can be expected to be very broadly predictable. Researchers in biomechanics have discovered time and again that organic structures evolved by natural selection conform to high levels of efficiency when judged by engineering criteria. And at a more microscopic level, biochemists marvel at the exactitude and power of the enzyme molecules controlling the actions of the cells. Like the mills of God, the processes of evolution grind slowly — yet, as the poet said, they grind exceeding fine.
Edward O. Wilson, Consilience