350 years ago William Harvey was the first to state that the hearts main purpose was to circulate blood throughout the body. This was in direct contrast to the rest of the world that was in the thought process that the heart was the center for emotions and love while the brain was the main area for circulation. This revelation led to what we now know as evolutionary psychology or the theory of cognitive structure for the survival of the person.
The theory goes that the human body is nothing more than a mass of systems that work together in unison to survive. The evolution came into play as we were being formed, when the body is made to be a collection of different resources for the rest of the body to use at will. This also speaks to the central nervous system, more specifically the brain. This theory contends that the brain is not one organ but a collection of many systems that have evolved over time to become a mass processor for the information that we take in.
Again it goes back to the natural selection debate at this point where it states that the body is functionally responsible for its own survival because it is acting as several organisms that are designed...