DNS Only Knows

DNS Only Knows

Eating a pumpkin is an immensely complicated process. In fact, if I had to synthesize my own enzymes, if I consciously had to remember and direct all the chemical steps required to get energy out of food, I would probably starve. But even bacteria do anaerobic glycolysis, which is why pumpkin rot: lunchtime for the microbes. They and we and all creatures in between possess many similar genetic instructions. Our separate gene libraries have many pages in common, another reminder of our common evolutionary heritage. Our technology can duplicate only a tiny fraction of the intricate biochemistry that our bodies effortlessly perform: we have only just begun to study these processes. Evolution, however, has had billions of years of practice. DNA knows.

But suppose what you had to do was so complicated that even several millions bits was insufficient. Suppose the environment was changing so fast that the precoded genetic encyclopaedia, which served perfectly well before, was no longer entirely adequate. Then even a gene library of one thousand volumes would not be enough. This is why we have brains.

The language of the brain is not the DNA language of the genes. Rather, what we know is encoded in cells called neurons – microscopic electrochemical switching elements, typically a few hundredths of a millimeter across. Each of us has perhaps a hundred billion neurons, comparable to the number of stars in the Milky Way Galaxy. Many neurons have thousands of connections with their neighbors. There are something like a hundred trillion (10(14), such connections in the human cerebral cortex.

An Old Martian Castle. We are the local embodiment of a Cosmos grown to self-awareness. (Quotations from Meg Jorgensen). Image: © Megan Jorgensen (Elena)

A thought is made of hundreds of electrochemical impulses. If we were shrunk to the level of the neurons, we might witness elaborate, intricate, evanescent patterns. One might be the spark of a memory of the smell of lilacs on a country road in childhood. Another might be part of an anxious all-points bulletin: “Where did I leave the keys?”

There are many valleys in the mountains of the mind, convolutions that greatly increase the surface area available in the cerebral cortex for information storage in a skull of limited size. The neurochemistry of the brain is astonishingly busy, the circuitry of a machine more wonderful than any devised by humans. But there is no evidence that its functioning is due to anything more than the 19(14) neural connections that build an elegant architecture of consciousness.