Pink Noise - Leonid Korogodski [46]
Revolution is the singularity aspect of evolution.
THE SCIENCE OF COMPLEXITY IS STILL IN ITS INFANCY, developing a new scientific methodology. Ilya Prigogine was awarded the 1977 Nobel Prize in Chemistry for his discovery of spontaneous self-organization in systems far from equilibrium. Until his death, he was the President of the International Academy of Science. Despite that, his work is relatively unknown outside the scientific circles. Some of the related evolutionary paradigms are well accepted by mainstream science, like Neural Darwinism, for example. Some are still being ignored, like Plasma Universe. (Both are drawn upon in Pink Noise.)
For a brief description of epicycles (and their modern counterparts), see Galaxies in Plasma Lab on pages 145–146.
The opposition to this view can be found in the stubborn hold on scientists that the universe must have the quality of elegant simplicity, that a beautiful theory just must be true. But the ancient Greeks too believed that the orbits of planets simply had to be perfect circles—ending with the devilishly, artificially complex system of Ptolemaic epicycles.
There is a beauty in the universe, but not the beauty of a simple perfect form. The beauty of the natural complexity—the beauty of a tree, not of a polyhedron.
BRAIN AND EVOLUTION
IN 1972, GERALD EDELMAN (B. 1929) RECEIVED THE NOBEL Prize in Physiology or Medicine for his discovery of somatic selection in the immune system of mammals. It was his answer to the question of how our bodies manage to produce so many different antibodies, each geared against a particular invader.
Previously, it had been thought that the blueprints of all antibodies were encoded somewhere and were activated during an infection. But the number of all possible infectious agents that our species has encountered in the past and may yet encounter in the future is so staggering that this assumption strained credulity. Moreover, different people produced very different antibodies in response to the same invader.
Gerald Edelman showed that the immune system works by the evolutionary principle. While any other cell in the body carries the same genes, certain immune cells are an exception to the rule. Their genetic composition allows variation. When a new infectious agent is encountered, the immune system’s engine guns itself into a frenzy, busily trying different combinations of immune cells’ genes, until a fit is made.
This architecture allows a quick response to any invader that may ever be encountered. In only a few days, evolution does what may have taken rational design decades to accomplish.
BUT EDELMAN DIDN’T REST ON HIS LAURELS. HE PROPOSED that the brain too works by the evolutionary principle. This was the birth of the Neural Darwinism paradigm in neuroscience.
Evolution manifests itself in the brain in several ways. Firstly, as far as its structure is encoded in the genes, the brain is a product of the evolution of the species—natural selection.
A neuron that has failed to make any connection commits suicide by a mechanics called apoptosis.
Secondly, in a growing organism, neurons compete to make connections between each other. Again we see how evolution is superior to rational design. Instead of pre-programming a specific rigid structure, neural evolution allows the competition to self-optimize the connectivity pattern. This developmental selection ensures that even identical twins or clones would never have identical brains. Yet the randomness is not allowed to run amok; the general, high-level structure of the brain is kept intact—a sort of combination of “free market” and control, honed to perfection over the eons of evolution.
Thirdly, in a functioning brain, neurons compete for a chance to fire; that is, to send signals to other neurons. There are two kinds of neurons in the brain: excitatory and inhibitory. When an excitatory neuron sends a signal to another, it encourages the target to fire in turn, whereas an inhibitory neuron tries to silence its target (whether or not either succeeds