6.0 - A Definition of Life

Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

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

"A hen is only an egg’s way of making another egg."
-- Samuel Butler, in Life and Habit (1877)

"Life is more a matter of relationships and organization than of material."
-- Dr. Manfred Clynes (1960)⁹²

"The tumult of the time disconsolate
To inarticulate murmurs dies away
While the eternal ages watch and wait."
-- Henry Wadsworth Longfellow (1807-1882)

In earlier chapters we considered the astronomical environment which extraterrestrial lifeforms must cope with. Other galaxies, stars, and countless planets appear amenable, if not perfectly hospitable, to life.

Since no ETs have been detected outside the Earth to date, it might be argued that any statements regarding the ubiquity of life in the universe must necessarily be pure speculation. But this is not so. We have the incredibly good fortune to be alive at the first moment in history when this tantalizing question can be approached with rigor and in some detail.²⁰ Not only can we draw certain tentative conclusions regarding the existence of extrasolar planetary systems, but we may also seriously discuss whether or not other worlds will possess environs which permit, encourage, or demand the emergence of life.

It is probably true that a good many planets are merely dead bodies of rock washed by sterile seas.⁹³⁹ Much depends on whether life originates quickly and regularly given suitable conditions, or if it requires an event so improbable that evolution in any reasonable time is scarcely possible on any world.

The study of the origin of life, called "abiogenesis" by many researchers in the field, is highly relevant to xenology and xenologists. By determining the conditions that existed on the primitive Earth, and by duplicating them in the laboratory, scientists can attempt to recreate events that must have occurred on this planet billions of years ago. Should these experiments indicate that the fundamental chemical building blocks of life are easy to generate -- perhaps even inevitable under the proper circumstances -- then we might well be justified in concluding that biology is a fairly widespread phenomenon among the many worlds of the Milky Way.

Studies in abiogenesis give some clues as to the universality of those processes which lead to the emergence of life. Of course, any rigorous discussion must include a good working definition of the subject of discourse. When we say we are searching for "life," what do we really mean? The traditional wisdom that "if it wiggles, it’s alive" is insufficient to deal with exotic lifeforms which may have little in common with organisms on Earth.⁵⁰

We must also remain sensitive to yet another aspect of the problem of the origin of life. We 180-centimeter-high lifeforms with mere 70-year lifespans all too easily lose sight of the broader perspective we need to appreciate the vastness of space and time. This "chauvinism of scale" is simple to identify but almost impossible to overcome.

In one sense, life is both abundant and ubiquitous on Earth. The live weight of microscopic organisms in an acre of soil to the plow depth of 18 cm has been estimated as more than two tons.* But viewed from a slightly different perspective, life fades into obscurity. The entire Earth weighs 6 × 10²⁴ kg, the whole atmosphere only 5 × 10¹⁸ kg. The total mass of the biosphere is no more than 10¹⁶ kg, about 0.2% as much as air or 0.0000002% of the entire planet. The mighty works of man and nature are a kind of biological rust, clinging doggedly to the surface of a small world.²⁰

So even in terms of mere planetary spatial frames, biology is only an impurity, a trace constituent of the cosmos.

Perhaps an even more relevant problem of scale is what might be called "temporal chauvinism." Man tends to think in terms of timescales commensurate with his own puny lifespan. But if we are to comprehend the meaning and the magnitude of evolutionary processes that lead to the origin and development of life, it becomes necessary to overcome temporal chauvinism. Centuries are of little concern in this arena -- it is only the millions and billions of years that count.

Events which seem unfathomable in the usual time frame become more sensible on geological timescales. Indeed, it appears that the key to evolution is time. As one scientist puts it, "in two billion years the impossible becomes the inevitable."⁷⁰²

A proper sense of the passage of time enables us to firmly grasp, not only the origin of life and the evolution of intelligence in the universe, but also such seemingly diverse topics as comparative culturology, technology gaps and alien thought processes, suboptic communications lag times, and the mechanics of galactic colonization.

* This includes 900 kg of molds, 450 kg of bacteria, 450 kg of branching unicellular organisms (Actinomycetes), 100 kg of protozoa, 50 kg of algae, and 50 kg of yeasts. Viruses are present in great numbers, but their mass is insignificant.³⁸