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Self-Regulation and Explosive Growth Teilhard spoke of three processes in the evolution of the universe: differentiation, whereby given forms continuously develop and test out variations in an effort to produce an improvement; individuation, whereby there is produced a self-regulating interiority, and communion, whereby individuals come together to form cooperative groups functioning at a higher level. Consideration of the second of these, individuation, leads to some striking conclusions. The process of individuation, like the other two, is considered to be taking place at all levels of evolution, from inorganic minerals to human beings. Of course, the level of interiority which is produced is quite different between, for example, a simple plant and a human being. The interiority of a plant is seen in its ability to keep its different kinds of cells doing their own specific work, carrying out photosynthesis, forming seeds for reproduction, among many others. These essential functions are directed not from outside but from within the plant itself. The ability to carry out these functions indicates a certain level of consciousness. For a human being, of course, the interiority is wider and deeper. Besides the plant and animal functions, we have the capacity for self reflection, creativity, and conscious choice. Our ability to create a culture for ourselves has shifted the cutting edge of evolution from the biological, genetic sphere, which is much too slow for the present needs of the earth, to a consciously manipulated culture. We might say, with Teilhard, that in the enlightened human being the evolution of consciousness will have reached its ultimate peak. Closely related to the notion of interiority is the capacity for self regulation, a process called homeostasis by biologists, and based on negative feedback. The term feedback comes from electronic engineering and refers to a circuit in which the output signal is continuously sampled and a small portion of it “fed back” (combined with) the input signal, but with the sign reversed (hence negative). As a result, when the output becomes higher than desired (the set point), the negative feedback brings it down. On the other hand, if the output drifts low, the feedback (now positive because of the change of sign) brings it back up. A familiar example is the thermostat in a home heating system. The thermostat continuously monitors the deviation of the measured temperature from the set point and turns the furnace on and off accordingly. Here the set point is under full control of the person who sets the thermostat. Perhaps the most familiar example of a natural homeostatic system is the process whereby our body temperature is maintained at approximately 98.7 degrees F. The process of converting food calories into body energy actually produces more heat than we need to stay warm, even at rest. Regulation of body temperature, therefore, involves several cooling mechanisms: perspiration, increased water content in exhalation, and more blood flow into surface capillaries. Being a warm-blooded animal, then, means being capable of varying these cooling mechanisms whenever the temperature moves outside the normal range. What is often not appreciated is that negative feedback often operates within a restricted range. In the case of body temperature, for example, if body temperature for some reason rises above a certain point, around 107 degrees or so, the feedback switches to positive. In other words, the cooling mechanisms become more and more reduced as the temperature increases, causing an explosive rise in temperature which proves fatal. A similar mechanism operates in the other direction in hypothermia, without such a sharp transition, in which cooling down gradually produces life-threatening additional cooling. It is striking that many and widespread systems of negative feedback are found in living organisms and in ecosystems. In nature, the set point is not manipulated by the organisms themselves, but is established automatically by environmental conditions. Negative feedback can be seen in populations within an ecosystem. In a simplified version of a balanced ecosystem, the population of rabbits is just sufficient to sustain the population of hawks. When the number of hawks increases, the insufficient supply of rabbits eventually reduces the population of hawks through starvation and other mechanisms, and soon balance is restored. Similarly, an increase in vegetation may increase the number of rabbits, which increases the number of hawks, which subsequently reduces the number of rabbits. But suppose it is not a balanced ecosystem? Suppose a species is not limited by available resources? Such, of course, is the situation of the human population. Here, positive feedback comes into play, and one can expect a population explosion, exactly what we are currently experiencing. With human beings, fortunately, our control over our culture shows us a way out. We need not reproduce by reflex as do lower organisms. We can structure our society to introduce intangible controls, including such things as improving the status of women and fostering economic development, to replace the more primitive force of starvation. Over the 4.5-billion-year lifetime of our planet, our life support systems have evolved into a complex web of interacting living and inorganic factors. The built-in homeostatic mechanisms have for the most part protected against gross instability. With the coming of human beings, beginning even with primitive agricultural and settled communities, the earth has had to adjust to the stress. In the last two centuries, the stress has increased dramatically, but our old reliable self-regulation has generally limited the damage. With the coming of global warming, there is a significant increase in the risk. Some negative feedback loops still limit the harmful effect. Increased carbon dioxide in the air, for example, drives increased dissolution of carbon dioxide into the oceans, thus mitigating the full effect. On the other hand, we are coming closer to the point where positive feedback loops will come into play. The polar ice caps and glaciers reflect sunlight, for example, tending to keep the earth cooler. As the earth warms, more ice melts and exposes rocks which absorb sunlight rather than reflect it and thus add further to the warming and the melting. A vicious cycle. The
most important kind of negative feedback is a kind of spiritual one. As we
human beings come to understand and take to heart the suffering of our
planet, we will be moved to use our creativity to
devise effective measures and to strengthen our determination to put them in
place. Such is the vision of Teilhard. And so we may hope. Dom Roberti |