From the journal Material For Thought, issue number 9

© 1990 Far West Editions

 

Organic life is a totally improbable affair

Gaia

James Lovelock

Oxford: Oxford University Press, 1979

 

The biosphere, that extraordinary and fragile living membrane sur­rounding the earth, owes its existence solely to a fortuitous set of condi­tions that happen to be favorable for life, conditions such as the presence—within the atmosphere, in the oceans, and on the land—of chem­ical elements in precisely the most beneficial ratio, together with an accept­able level of temperature and humidity, and a balanced condition of acidity in the soil and salinity in the oceans—to name only a few of the most im­portant. All of these factors are so poised in relation to each other that they have never strayed outside the narrow range of values indispensable to the support of life.

Such is the conventional view, a view that includes the mechanism of random mutation, by means of which life has adapted to planetary condi­tions as each evolved its separate way; as such, this view has never been seriously challenged.

For Dr. James Lovelock, this conventional view has proved less than adequate in the face of evidence that has steadily mounted, particularly in recent years as a result of space probes—evidence so anomalous and con­tradictory that he felt impelled to search for an alternative scientific frame­work that would account for these seemingly conflicting data by proposing a view in which life, far from being passive in relation to “outside” influ­ences, actively defines the material conditions needed for its survival and makes sure that they do not stray beyond precise limits.

This quest for a more comprehensive perspective grew out of a project that Lovelock undertook for NASA in the early sixties to devise a method for life detection on the planet Mars by means of atmospheric analysis. Using the earth as a model, and its atmosphere as a reference, he put to himself the question: Was there anything singular about the earth’s atmo­sphere that would lead one to suspect the existence of life?

Based on his examination of atmospheric studies, Lovelock’s response to his own question was simple arid direct: The earth’s atmosphere is a totally improbable affair. It defies simple description and, as attempts at long- range weather forecasting have shown, there is no consistent model of the atmosphere that can be used for the purpose of prediction.

How are we to account for the fact that within the earth’s atmosphere a most remarkable level of chemical disequilibrium is sustained? For example, if chemical thermodynamics alone mattered, then all of the oxygen and most of the nitrogen in the atmosphere should have ended up in the sea as nitrates.

Using our planet as a model, we examined the extent to which simple knowledge of the chemical composition of the earth’s atmosphere ... could provide evidence of life. Our results con­vinced us that the only feasible explanation of the earth’s highly improbable atmosphere was that it was being manipulated on a day to day basis and that the manipulator was life itself. . . Take for example the simultaneous presence of methane and oxygen in our atmosphere ... the quantities of both these gases required to maintain the constancy of the Earth’s extraordinary mixture was improbable on a biological basis by at least 100 or­ders of magnitude.

Pursuing this line of study still further, Lovelock gradually developed his hypothesis

that the entire range of living matter on Earth, from whales to viruses, and from oaks to algae, could be regarded as consti­tuting a single living entity.... By now a planet-sized entity, albeit hypothetical, had been born, with properties that could_ not have been predicted from the sum of its parts. It needed a name. William Golding ... recommended that this creature be called GAIA, after the Greek earth goddess.

Lovelock draws upon an ever-increasing body of data in support of Gaia. For example, he cites the crucially significant role of ammonia in control­ling the level of acidity in the soil. And later he calls attention to the process whereby sulfur—one of the essential constituents of living cells—is ex­tracted from sulfate ions in the sea through the agency of certain kinds of algae and seaweed. In this process it is converted into the gas dimethyl sul­fide, thus making it easily transportable via atmospheric winds over land surfaces where, in its water-soluble form, it is absorbed by plants.

Impressive as the marshalling of this kind of evidence is, by itself it could not have unfolded into so far-reaching an hypothesis as Gaia. A subsidiary idea was necessary—an idea with force enough to act as a catalyst and broad enough to provide a matrix suggesting order and coherence within an otherwise bewildering array of information.

It is startling therefore that in order to account for phenomena occurring on the grand scale of the biosphere itself Lovelock should have borrowed from the field of physiology of the human body. At one point he advises us that if we seek to discover whether there is indeed a biological process for regulating planetary conditions favorable for life, that we would do well to bear in mind the words of the distinguished physiologist Walter B. Cannon:

The coordinated physiological processes which maintain most of the steady states in the organism are so complex and so peculiar to living beings—involving, as they may, the brain and nerves, the heart, lungs, kidneys and spleen, all working cooperative­ly—that I have suggested a special designation for these states, homeostasis.

Appearing and reappearing throughout the pages of Gaia as a connecting thread, this concept of homeostasis enables Lovelock to confront his data in a most novel way.

We shall see if the Gaia hypothesis accounts for the strange com­position of our atmosphere by examining it in much the same way that a physiologist might examine the contents of the blood to see what function it serves in maintaining the living creature of which it is a part.

He then goes on to remind us that questions having to do with blood— for example: How is its pH kept constant? or: How is its temperature regu­lated around its set point?—would seem irrelevant, never needing to be asked at all, if the blood were simply an inert environment (as the atmo­sphere is currently regarded).

This parallelism with the self-contained circulatory system of blood within the human organism becomes for Lovelock a special kind of view­ing lens.

Within the context of a self-regulating biosphere actively main­taining its gaseous environment at an optimum for life, it is ap­propriate to ask what is the function of a gas such as methane. It is no more illogical than asking what is the function of glucose or of insulin in the blood ... In a non-Gaian context, the question would be condemned as circular or meaningless, which may be why it has never been asked before.

And further on:

Just as important for Gaia as for all living systems, is the regula­tion of chemical composition. Salinity control, for example, may be a key Gaian regulatory function. If its details are as intricate and complex as those of that amazing organ the kidney, then our quest will be a long one. We now know that the kidney, like the brain, is an information processing organ. To achieve its aim of regulating the salinity of our blood, it purposefully segregates individual atoms ... This recent new knowledge was not easily found and it may be even more difficult to unravel a system for the global regulation of salinity and chemostasis.

It is easy to imagine oneself taking hold of this idea and assessing it; re­garding it, for example, as simply a culminating stage of ecological thought which has finally elected to take on the entire planet as its arena of consideration. To picture Gaia in that way, however—as simply an en­larged ecosystem—drastically reduces its scale of ramification.

Nor can Lovelock’s proposal be so casually set aside as it is, for example, in Theodore Roszak’s Person/Planet, wherein the author states:

GAIA, as Lovelock and Epton use the concept is really a charm­ing metaphor. . . . It is striking, that when modern ecology searches for a way to think, it gropes its way back to that classic act of personification, Mother Earth.

Thus is Gaia relegated to the level of an intriguing anthropological meta­phor.

It is tempting to react with disapproval toward the patronizing attitude expressed in such words. But in so reacting we overlook the built-in psy­chological resistance—that all of us have—to any idea which demands a fundamental revision of our ordinary way of thinking—a revision that cer­tainly challenges the serious investigator of biospheric phenomena with a paradigm of quite another order of magnitude, in the domain not only of space but of thought. Gaia places us in a mode of thinking that gives rise to a whole other species of question that would never occur to us otherwise to ask. Lovelock speaks directly on this aspect of Gaia in regard to the marine alga laminaria when he says:

If GAIA does indeed exist, then there are associations of species which cooperate to perform some essential regulatory function. The thyroid gland present in all mammals and most vertebrates harvests the meager supplies of iodine from the internal bodily environment and converts them into iodine bearing hormones which regulate our metabolism and without which we cannot live.

Is it possible, Lovelock asks, that laminaria may perform a similar func­tion but on a planetary scale?

There is a latent power of thought that resides within this idea of Gaia which reminds us that we are not isolated entities who happen to exist on the surface of this planet, but creatures who function—together with all other life forms—in accordance with planetary needs that transcend our ordinary view of terrestrial phenomena.

It would appear that Lovelock is fully cognizant of this larger scale when he says that possibly

... the destiny of mankind is to become tamed so that the fierce and destructive forces of tribalism and nationalism are fused into a compelling urge to belong to the commonwealth of all crea­tures which constitute Gaia.

Yet, what comes across to the reader may well be more an emotional appeal than a challenge to move to a different scale of thinking. It is inter­esting in this regard to compare, for example, the following passage from The Biosphere, by V. I. Vernadsky, which first appeared in Russian in 1926 and in French in 1929:

The outer layer of the earth must therefore not be considered as a region of matter alone, but also as a region of energy and a source of transformation of the planet. Cosmic forces from out­side in large measure shape the face of the earth, and as a result the biosphere differs historically from other parts of the planet. The role it plays is altogether extraordinary.

The biosphere is at least as much a creation of the sun as a result of terrestrial processes. Ancient religious institutions that con­sidered terrestrial creatures, especially man, to be children of the sun, were far nearer the truth than is thought by those who see earthly beings simply as ephemeral creations arising from blind and accidental interplay of matter and forces. Creatures on earth are the fruit of a long and complicated process, and are an essen­tial part of a harmonious cosmic mechanism in which it is known that fixed laws apply and chance does not exist.

Thus, long before the Gaia hypothesis appeared, Vernadsky, starting from experiments in geochemistry, also envisioned the land surface and liv­ing matter, together with the atmosphere and hydrosphere, collectively as a giant self-contained system exhibiting the properties of a single living entity. And, like Lovelock, he also remained scrupulously faithful to the canons of scientific empiricism in developing his thesis. But there the sim­ilarity ends.

In the cosmic purposefulness evoked by the extraordinary work of this Russian scientist—so little known except in his native Russia, where he was acknowledged during his lifetime (1863-1945) as one of the great scientific pioneers of the twentieth century—man’s notion of himself is even more seriously challenged than it is in Gaia.

Within the cosmic interplay of forces, Vernadsky sees the biosphere as an energy-gathering instrument whereby not only solar energy but all forms of cosmic energy are being constantly transformed.

The biosphere may be regarded as a region of transformers that convert cosmic radiations into active energy in electrical, chemi­cal, mechanical, thermal, and other forms. Radiations from all stars enter the biosphere, but we catch and perceive only an in­significant part of the total; this comes almost exclusively from the sun. The existence of radiation originating in the most dis­tant regions of the cosmos cannot be doubted.

There is something evocative about these passages from Vernadsky, an echo of ancient teachings in which the whole created universe is regarded as a living network of purposes within which everything has its organic place and function.

Not the least important question to emerge from the researches of both Vernadsky and Lovelock is whether man significantly acts upon the bio­sphere or whether he is inescapably subject to its laws. It is not an either-or question; but certainly there is an increasing sense of urgency to learn what are these laws that govern the process of energy exchanges ceaselessly at work—in “the most distant reaches of the cosmos,” the sun, the biosphere, and within that remarkable tendril of life called man.