Did you know that our DNA only differs from chimpanzees by 2%. That is right. We share 98% of our DNA with those furry things that swing from trees, eat bananas and screech. So what is it exactly that makes us human and keeps them being chimps?
Scientists, as part of the human genome project, identified specifically which genes are different. Turns out one of them is the regulatory gene that determines how many neurons humans can make and when the process stops.
Human neurons are basically identical those of chimpanzee neurons and even those of a marine snail. Hard to believe, isn’t it? The big difference is in the total number of neurons each ends up making. Humans end up having about 100 billion neurons. Yes, billion. Chimpanzees stop a little earlier so that they have brains about one-third the size of ours.
Each neuron makes thousands of connections. This leads to the possibility of a staggering amount of neural circuits, a ten followed by a million zeros. This huge number allows the human brain to be so complex and to be capable of performing such a vast array of mental functions and behaviors.
This also explains how the brain is capable of massive change through neuroplasticity. Before the discovery and acceptance of neuroplasticity (the ability of the brain to physically change itself and it's function based on a person’s experiences and behaviors) it was pretty much believed the only way the brain could change its structure was through the long, painstakingly slow process of evolution.
Plasticity offers a new way for the brain to change and evolve other than genetic mutation. For example, when a person learns to read, it changes the biological structure of their brain. Reading is taught to the next generation and, subsequently changes their brain and so on.
However, this process of learning not only changes the brain circuits in one area of the brain, but also many modules that are connected to the ones actually used in reading are changed. Plastic change tends to “flow” through the brain. When areas of the brain are linked together in a new way by a new activity, the brain modules involved are changed by the interaction. This creates synergy and a new whole which has greater capabilities than it’s individual parts is formed.
This may explain how our hunter-gatherer brain and more cognitive-cerebral brain work together to make us “civilized.” Becoming civilized is basically a process of learning to restrain or channel brute predatory and dominance instincts into acceptable expressions such as contact sports, board and computer games, art and literature.
The basic instincts are still there, for instance, when a fan yells “Kill him!” at a football game. Yet, when the instinct to stalk prey is linked up to an activity with rules and acceptable behaviors, the neuronal networks are also linked and temper each other.
Civilization is a series of processes where the hunter-gatherer brain teaches itself to rewire itself. Because the plastic brain can always allow brain functions that have come together to separate, regression is always possible. Civilization is always, at most, only one generation deep.