Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization
© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.
Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm
Life is a process by which relatively unorganized environmental components are made more organized. That is to say, life is a building up-process, although to organize also means to cut down the possibilities. But certainly a basic characteristic of all lifeforms is that they are highly organized.2214
What do we mean by "organization"? The concept may be viewed in terms of what Sneath has called "complex interrelatedness."64
Interrelatedness means simply that all parts of the pattern are related to and somehow affect all other parts. Each component reacts to changes in its surroundings so as to preserve internal integrity and minimize the effects of any disturbances. This damping action is the principle of homeostasis, common among biological systems. Of course, biochemical homeostasis can be preserved only within certain critical tolerance limits. Death will rapidly overtake any system which is subject to stresses it cannot tolerate.
Complexity is the other facet of organization.64,1643 "Complex" is used here in its normal sense, as opposed to "simple." Candle flames have a great deal of interrelatedness, yet they lack complexity and hence "organization" as well. Conversely, a lump of granite is highly complex, but because it lacks interrelatedness it cannot be considered "organized" in the sense of having life.
Dr. Sneath cites a most useful example of the role of complexity. If complexity is defined as the amount of information needed to completely characterize a system, the perplexing case of the growing crystal is greatly simplified. We might describe a small cube of rock salt as follows: "A simple-cubic Bravais crystal lattice structure with spacing of 2.82 × 10-8 cm, consisting of alternating sodium and chlorine atoms, containing a total of 1020 atoms of each kind." This requires only a few lines of print, and is complete.
On the other hand, living things are typically characterized by enormously more complicated descriptions. Life systems possess order on a scale far smaller than the macroscopic. Unlike the monotonous repetitiveness of the salt crystal, even the simplest bacterium needs some 103-104 different enzymes, each with a unique sequence of perhaps a hundred or so amino acids.64,630 This is real complexity. On the microscopic level, life might best be characterized as a highly "aperiodic crystal."2213,2364
The key to life may well be information itself. The living world is built from the stuff of the nonliving world, different only in its complexity and organization. Organisms find it possible to actually store and replicate the information that specifies their organization.
Yet it is purely capricious to set some arbitrary level of complexity as the threshold of life.1717 A frozen amoeba, for example, has an amazingly detailed and intricate structure without being alive -- it has only the potential for life. Organization, as we shall see presently, is a most useful parameter for assessing the intensity or efficiency of life. However, it is more reasonable to base our definition on the fundamental processes and functions displayed uniquely by living systems.
Last updated on 6 December 2008