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IS GAIA A LIVING SYSTEM?

Lane Tracy
Department of Management Systems
Ohio University
Athens, OH 45701, U.S.A.

Abstract

Gaia has been defined as a complex, self-evolving and self-regulating living system, consisting of all parts of the Earth -- the biosphere, atmosphere, oceans, soil, and rock -- acting through feedback processes to maintain homeostasis with respect to such variables as temperature, oxidation, and acidity (Lovelock, 1988). On numerous occasions the question has been raised as to whether Gaia fits the concept of living systems as developed and presented by Miller (1978). This paper investigates that question in light of the criteria specified by Miller and suggests what modifications might be necessary in order to obtain a complete fit between the theories.

Keywords: Gaia, living systems, technology, evolution

1. Introduction


James Lovelock (1995, 9) hypothesized 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, capable of maintaining the Earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts." This became known as the Gaia hypothesis. According to Lovelock and Margulis (1996) the Gaia hypothesis grew from the observation that "the Earth appeared...to be not so much a planet adorned with diverse life forms, but a planet which had been transformed by a self-evolving and self-regulating living system."

Gaia was defined as "a complex entity involving the Earth's biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet (Lovelock, 1995, 10)." Lovelock also conjectured that the collective intelligence of human beings on Earth might "constitute a Gaian nervous system and a brain which can consciously anticipate environmental changes (Lovelock, 1995, 139)."

Through much elaboration and with the collaboration of Lynn Margulis the hypothesis has evolved into the Gaia theory. For those who are familiar with the theory, the Earth has come to be perceived as "a vast living system in its own right (Lovelock & Margulis, 1996)." Other authors have also used the term living system in conjunction with Gaia (Sahtouris, 1989; Schneider & Boston, 1991). Although the term has not necessarily been used with James G. Miller's living systems theory in mind, the question has certainly arisen as to whether Gaia should be added to that theory at a level above the supranational systems (Miller, 1978). Yet Gaia, as described by Lovelock (1995, 1988) and others, seems to lack some of the defining characteristics of Miller's living systems.

The purpose of this paper is, first, to examine whether Gaia meets the criteria set forth by Miller for inclusion among the living systems. For instance, is Gaia a concrete, open system? Does Gaia maintain a steady state of negentropy? Is Gaia largely composed of organic compounds? Does Gaia "have a decider, the essential critical subsystem, causing its subsystems and components to interact" (Miller, 1978, 18)? Does Gaia possess or have access to all of the other critical subsystems, especially the reproducer, that are necessary to life? And are the subsystems "integrated together to form actively self-regulating, developing, unitary systems with purposes and goals" (Miller, 1978, 18)? The Earth is usually assumed to be the basic environment within which all living systems exist. If the Earth is itself a living system, what is its environment?

If Gaia does not meet all of these criteria, then some further questions must be considered. Should some of Miller's constraints be relaxed so that the Earth can be included among the living systems? And if Gaia is not now a living system, might it become one through further evolution, perhaps with the aid of technology? These are the questions that will be addressed in this paper.

2. Gaia and the Shared Characteristics of Living Systems

The term living systems may mean different things to different people. Thus, it is possible to claim that Gaia is a living system without having to meet the criteria proposed by Miller (1978). However, those criteria constitute by far the most rigorous definition of the term living system.

Miller arrived at the defining criteria of living systems through extensive study of the literatures of the biological and social sciences, from which it was observed that certain characteristics were invariant across levels of systems ranging from cells to societies and beyond. Furthermore, it was postulated that these system characteristics had evolved hierarchically through a "fray out" process whereby each successively higher level of living systems copied and elaborated upon the essential characteristics of the lower levels. These essential characteristics were assumed to be the minimum conditions for life to exist. Let us now look at the shared characteristics or defining criteria of living systems.

2.1 Open System

The first characteristic listed by Miller (1978, 18) is that living systems "are open systems, with significant inputs, throughputs, and outputs of various sorts of matter-energy and information." Gaia clearly meets this criterion, with inputs of various forms of radiation, dust, and meteorites; a wide variety of throughputs, especially those involving photosynthesis; and outputs of heat, various gases, radio signals, and space probes.

2.2 Steady State of Negentropy

The second characteristic is that living systems "maintain a steady state of negentropy even though entropic changes occur in them as they do everywhere else (Miller, 1978, 18)." They accomplish this feat by acquiring inputs that are higher in complexity or organization than their outputs. For example, living systems extract energy from carbohydrates or other hydrocarbons by means of a conversion process while extruding such waste products as carbon dioxide and water.

Gaia does not seem to meet this criterion. Instead, Gaia's throughput processes tend to add complexity or organization, producing outputs that are lower in entropy (e.g., gaseous compounds and electronic signals) than its inputs. Thus, Gaia cannot restore much of its lost matter and energy. At best it can work to regulate inputs and outputs of radiation so that a steady state is maintained with respect to planetary temperature.

2.3 Template

From the moment of its origin every living system must have a template, a set of instructions for the system's structure and processes. The template may be encoded in deoxyribonucleic acid (DNA) or language (i.e., a charter). The template supplies the basic values, purposes, and goals that guide all decision making for the system. In the reproductive process the template, or part of it, is passed on to the next generation.

It can be argued that Gaia possesses a genetic template composed of all of the DNA in the world. Lovelock (1995, 1988) makes a compelling case for the theory that biological processes collectively maintain many non-equilibrium states on Earth, such as the levels of nitrogen and carbon dioxide in the atmosphere and the salinity of the seas, just as DNA-controlled processes maintain non-equilibrium states within cells, organs, and organisms. In other words, the templates of the biota provide instructions for processes that, combined, maintain steady states in the biosphere that favor life on Earth.

The template of Gaia would be dispersed among the biota, with no single individual or species retaining the entire template. Organs and organisms disperse their entire templates to their cells, but most social living systems (i.e., groups, organizations, communities, societies, and supranational systems) disperse only parts of the template to their components (Tracy, 1990). Thus, there seems to be no contradiction between living systems theory and the concept of a fragmentary, dispersed Gaian template.

Does the template of Gaia include the templates of the terrestrial social systems? The emphasis in the literature of Gaia is on the planetary collaborative effects of the biota, but Lovelock (1995) does also write about the place of human institutions in Gaian evolution. Although much has been written about the deleterious effects of man-made pollution on the health of Gaia, it would be difficult to separate these effects from such a "natural" outcome as the extinction of the dinosaurs, which died because they were unable to cope with a change in the climate. The values encoded in any template are not always the best instructions for survival in the present situation, even though they may have withstood the tests of eons. Thus, we cannot reject the templates of human institutions as components of the Gaian template simply because they sometimes seem not to reflect the best interests of Gaia. Gaia includes all living systems on Earth.

A more troubling question is whether a template existed at the origin of Gaia. Although there is some speculation that life on Earth originated from spores that came from outer space, internal evidence supports the theory that cellular life evolved through a process of endosymbiosis among proto-cellular components (Margulis, 1981). If that theory is correct, then Gaia did not arise through a reproductive process that provided a ready-made template. Rather, the template developed as life on Earth evolved. Yet such a circumstance is true of every new species of living system. Thus, the criterion should be modified for new species.

The fact that the Gaian template has evolved over time is not a problem, since the templates of all living systems are subject to change. Templates do not change as rapidly as other aspects of living systems, but templates can be modified. Overall, there appears to be substantial support for the position that Gaia possesses a template that essentially meets the requirements of living systems theory.

2.4 Organic Compounds

One criterion of living systems that Gaia clearly does not meet is that "they are largely composed of an aqueous suspension of macromolecules, proteins constructed from about 20 amino acids and other characteristic organic compounds...(Miller, 1978, 18)" Organic compounds constitute only a very small part of Gaia, and Lovelock (1988) makes it clear that Gaia is much more than the biota or the biosphere of Earth.

Some people would argue that this criterion should be dropped so that cybersystems can be included among the living systems, since some cybersystems probably meet all of the other criteria. If Gaia had been studied as a potential living system, it is possible that this criterion would have been dropped or rephrased.

2.5 Critical Subsystems

Miller (1978) identified nineteen critical subsystems that conduct essential processes for living systems. A twentieth critical subsystem, the timer, was later identified (Miller, 1990). Every living system must possess or have access to all of these critical subsystems.

2.5.1. Decider subsystem

Perhaps the most important criterion is the requirement that every living system must have a decider subsystem "which receives information inputs from all other subsystems and transmits to them information outputs that control the entire system (Miller, 1978, 67)." In making executive decisions the decider subsystem acts in accordance with the purposes and goals of the system. It is primarily the decider subsystem that enables a living system to adapt to change and to act to alter its environment. The decider is the only critical subsystem that cannot be dispersed to another system. With respect to social systems -- groups, organizations, communities, societies, and supranationals -- this means that a member or members must take on the role of leadership, making decisions according to the values of the social system (Tracy, 1994).

Lovelock (1995) suggests that the human species might constitute a Gaian nervous system that could anticipate environmental change and provide the necessary control. Although humans may have the potential to serve this function, particularly with the aid of information technology, there is little indication that we currently do so. Lovelock presents convincing evidence for self-regulation of some aspects of the interaction between Earth’s biota and their environment, but this is a far cry from asserting that there exists a decider system for the entire Earth system. Indeed, as we noted earlier, it is better evidence for the existence of a template. If a Gaian decider subsystem exists, its locus is unknown and it operates so slowly as to be undetectable by humans.

2.5.2. Subsystems that Gaia possesses

Living systems must also possess or have access to at least nineteen other specific critical subsystems that carry out essential processes of life, such as the input, throughput, and output of matter-energy and information. Gaia clearly possesses many of these subsystems, such as the supporter, motor, distributor, converter, producer and storage subsystems for matter-energy. Gaia also possesses a boundary subsystem, consisting of its upper atmosphere, and a timer subsystem provided by its orbit, inclination, and rotation, as well as its relationship to the moon and stars.

The subsystems for processing information are largely dispersed to individual organisms. Such dispersal of processes would not be a problem if Gaia possessed its own decider subsystem to draw the parts together. Indeed, human groups, organizations, communities, societies, and supranational systems generally disperse much of their information processing.

2.5.3. Subsystems that Gaia lacks

The critical subsystems that Gaia seems to lack, in addition to the decider, are the extruder for matter-energy and the reproducer. The extruder subsystem is needed to "transmit matter-energy out of the system in the form of products or wastes (Miller, 1978, 59)." Earth's gravity well generally prevents the extrusion of products and wastes except for a slow, random leakage of heat and gases into space. Recently Gaia has acquired the capability of extruding rocket ships and space probes, but the amount extruded thus far is minuscule.

The reproducer subsystem is the subsystem which transmits the template of a living system from one generation to the next. As Gaia appears to be a first- or single-generation entity, it neither has nor has any need for a reproducer subsystem. But that alone makes it unique and distinct from all living systems.

We should recognize, however, that many living systems do not display a reproducer subsystem in their formative stages. Reproductive capabilities and the structures needed to carry out the reproductive process often develop later than the other critical subsystems. Thus it may be that Gaia is still young and has not yet developed its reproducer subsystem.

2.6 Purposes and Goals

The behavior of every living system and its subsystems is regulated by a set of values. The values of a living system are originally defined in the template of the system, although they may later be modified by experience. It is these values, the purposes and goals of the system, that guide its decision-making processes.

Purposes relate to internal states of the system. A purpose is the preferred steady-state value for a specific system variable, such as the level of oxygen in the blood. In the examples of Gaian self regulation cited by Lovelock and Margulis (1996) the purposes are steady states of temperature, oxygen content, acidity, salinity, and so forth that are conducive to the flourishing of the biota on Earth. Yet these are also the purposes or goals of various living components of Gaia.

Goals are preferred external steady states or relationships with the environment. It is not clear that Gaia itself has any goals. The regulatory actions on the atmosphere and seas cited by Lovelock (1995, 1988) are in accord with the goals of the biota, but with the purposes of Gaia. Although Gaia could be said to have goals such as maintaining steady radiation from the sun and avoiding collision with large asteroids, those goals reside only in the imagination of human beings. Furthermore, Gaia has no way of pursuing such goals. In general Gaia lacks means of acting purposefully on its environment.

The results of pursuing the goals of Gaia's living systems may be beneficial to nonbiological components such as the atmosphere, but it is difficult to see how we could judge the benefits except as they affect the biota. Does it make any difference to the rocks how much oxygen and nitrogen and carbon dioxide there is in the atmosphere? Although the biota may actively regulate the Gaian components and subsystems toward the purposes and goals of the biota, that is not the same as working toward purposes and goals of Gaia as a whole.

If Gaia is a living system, it must have its own purposes and goals which are distinct from those of its components. Yet the Gaian template consists of the templates of all living systems on Earth, and the purposes of Gaia are the goals of the components. Thus, there is apparently no way to isolate the purposes and goals of Gaia from those of its living components.

2.7 Environment

The final criterion supplied by Miller is that living systems can exist only in an Earth-like environment that maintains a narrow range of such variables as temperature, air pressure, hydration, oxygen content of the atmosphere and the seas, and intensity of radiation. For Gaia these variables apply to the system, itself, rather than its environment. The environment of Gaia is the solar system.

Like the organic compounds criterion, the environmental criterion might reasonably be relaxed if we wish to include Gaia among the living systems. After all, the environment of the existing living systems also includes such extraterrestrial variables as intensity of solar radiation, range of tides, and size of rocks falling out of the sky. But Gaia does not meet the criterion as currently stated.

2.8 Summary of Criteria for Living Systems

Table 1 summarizes the major shared characteristics of living systems and compares them with the characteristics of Gaia. From this summary it is clear that Gaia does not meet some of the living systems criteria as they were originally stated. Specifically, Gaia (1) only partially maintains a steady state of negentropy, (2) is only to a small degree composed of organic compounds, (3) lacks a decider subsystem of its own, (4) lacks reproducer and extruder subsystems, (5) has no goals or means of acting on its environment, and (6) can exist in a non-Earth-like environment.

It has been suggested that the criteria of organic compounds and Earth-like environment could be relaxed without doing violence to the existing concept of living systems. The failure to meet other requirements, including possession of a decider subsystem, control of reproducer and extruder subsystems, and maintenance of steady states of negentropy, is more problematical. Earth’s biota might collectively meet these criteria, but Gaia as a whole does not. Gaia appears to be an example of a quasi-living system, behaving like a living system but lacking some of the essential characteristics (Tracy, 1995).

Living System Characteristic Gaia Characteristics
Open system Open system
Maintains steady state of negentropy Maintains steady state of planetary temperature
Possesses a template, composed of DNA or a charter, from the moment of origin Has evolved a template consisting of the templates of all component living systems
Largely composed of organic compounds Organic compounds comprise only a small part of the whole
Has a decider subsystem which receives information inputs from all other subsystems and transmits to them information that controls the entire system Lacks a central decider subsystem, although humans might potentially fulfill that function as they do for many social systems
Possesses or has access to nineteen other critical subsystems: Reproducer; boundary; ingestor, storage, extruder, motor, and supporter for matter-energy; input transducer, internal transducer, channel and net, decoder, associator, memory, encoder, output timer for information Possesses or has access to the following critical subsystems: Boundary; ingestor, distributor, converter, producer, storage, and supporter for matter-energy; input transducer, channel and net, decoder, associator, encoder, output transducer, and timer for information; Lacks the transducer, and reproducer and extruder subsystems
Acts in accordance with purposes and goals that are initially estabilished in the template but may later be modified Acts in accordance with purposes that are the goals of its component systems. Has no established goals or means of acting on its environment
Can exist only in an Earth-like environment Can (does) exist in a non-Earth-like environment

Table 1. Comparison of Characteristics of Living Systems and of Gaia

3. Should the Criteria Be Rewritten to Include Gaia?

Literature on the Gaia hypothesis was not extant at the time of Miller’s study. Thus, we may reasonably ask whether Gaia might have been included as a level of living systems if the literature on Gaia had been available at the time and, if so, whether the criteria would have remained the same.

The literature on Gaia is not extensive. Based on what we know now, however, if that literature were included in the search for shared characteristics of living systems, the criteria for living systems would be quite different and the list of shared characteristics would be shorter. The criteria for a living system would not include maintaining a steady state of negentropy, having a template from the moment of origin, being composed largely of organic compounds, having its own decider subsystem, possessing or having access to extruder and reproducer subsystems, or existing in an Earth-like environment. Furthermore, it would not be required that a living system have goals or be able to act on its environment. The remaining criteria would consist of being an open system, maintaining a steady state of temperature, having or evolving a template, containing organic compounds, possessing or having access to seventeen critical subsystems (but not the decider, reproducer, or extruder subsystems), existing in a solar system, and having purposes.

Do these criteria really correspond to what we think of as living systems? The answer to that question is subjective, of course. Many people think that including social systems as living systems is too broad an interpretation of the word "living." Yet probably most would agree that there is more to living systems than the reduced list of criteria given above. Thus, inclusion of Gaia as a living system leads to a set of criteria that seems inadequate to describe the common core of the life phenomenon.

4. Might Gaia Evolve into a Living System?

The continuing development of technology opens up scenarios of the future in which the Earth might indeed become a self-regulating system of the sort defined as a living system. For instance, continued advances in weaponry, communications, information processing, and transportation technologies may lead to creation of a world government that can make decisions for the whole Earth.

Contemporary attempts to make global decisions generally lack means of consistent implementation. Furthermore, they tend to focus on the maintenance or retrieval of conditions that favor human beings or the human-friendly biota of the Earth, not Gaia as a whole. The Kyoto accords on pollution, for instance, were aimed at purposes and goals defined by human environmental needs. Cockroaches or cacti might have an entirely different set of priorities. If preservation of the environment somehow aids other components of Gaia, that aid is an incidental byproduct of the decision-making process.

A world government could focus on the good of the planet, but there is no assurance it would do so. Yet consider a world government dominated by computers, specifically programmed to appraise and balance the purposes and goals of all biotic and non-biotic components of Gaia. Such a government might have both the values and the integrative capability that would permit it to serve as a proper decider subsystem for Gaia. It might also develop a set of Gaian values that are distinct from the collective values of the component systems.

Technology could also provide means for Gaia to act upon its environment and enable it to do a better job of maintaining a steady state of negentropy. Space technology could mine the asteroids to replace metals and gases that have become depleted, place mirrors in space to capture more sunlight, repel marauding comets and asteroids, and in general obtain greater control over inputs and outputs. Such technology would help to overcome the current problem that Gaia’s inputs are limited to collection of whatever happens to be aimed at Earth or falls within its gravitational field, with no capability of actively seeking inputs.

Technology might also alleviate the problem of the lack of an extruder subsystem. For instance, it has been proposed that electromagnetic guns could be constructed to rid Earth of pollutants such as atomic wastes. Excess population might be exported to other worlds by means of technology not yet developed.

As a living system Gaia would be lonely. Space technology could eventually provide a means of reproduction for Gaia. Perhaps Mars, Venus, or a Jovian moon could be terraformed to provide a platform for a Gaia-like system. The technology of space travel might eventually enable the replication of Earth’s biota all over the galaxy, either by sending actual samples or by transmitting the templates from which the biota could be reconstructed elsewhere.

5. Gaia, Sustainability, and Technology

The concepts of Gaia and sustainability are often inaccurately lumped together in the same ecological bag. Current ecological thinking about sustainability of the Earth seems to focus on preservation of the status quo or restoration of conditions that obtained before the Industrial Revolution reared its ugly head. Advanced technology is seen as a destroyer of the status quo rather than as a means of obtaining greater control of the system or its environment. If Gaia were already a full-fledged living system, that viewpoint might make sense. But Gaia is not a living system and never will be, unless it is allowed to evolve further.

Lovelock (1995) does not reject advanced technology. Indeed, he regards human development of technology as an integral part of Gaian evolution. Some technological advances, such as we have seen recently in communications, actually reduce the drain on Gaian resources. Lovelock sees more danger in certain types of low-level technology, particularly as applied to delicate areas such as the tropics and the continental shelves.

Perhaps we do not yet have the right technology to develop the potential of Gaia. Perhaps evolution of Gaia lies in development of the technologies of bioengineering or sociobiology, for instance, instead of or in addition to the technologies of information, cybernetics, and space. Yet restriction of technological development in order to "preserve" Gaia will instead hamper its evolution into a full-fledged living system. A true understanding of what Gaia is and might be calls for rethinking our positions about sustainability and technology. We need to be more selective in our thinking about which technologies are destructive and which are necessary for the maintenance, actualization, and propagation of Gaia as a living system.

6. References

Lovelock, J. 1988. The Ages of Gaia. New York: Norton.

Lovelock, J. 1995. Gaia: A New Look at Life on Earth. Oxford: Oxford University Press. First published in 1979.

Lovelock, J. and Margulis, L. 1996. The Gaia Hypothesis. Website: http://magna.com.au/~prfbrown/gaia"

Margulis, L. 1981. Symbiosis in Cell Evolution. San Francisco: W. H. Freeman.

Miller, J. G. 1978. Living Systems. New York: McGraw-Hill.

Miller, J. L. 1990. "The Timer," Behavioral Science Vol. 35:164-196.

Sahtouris, E. 1989. Gaia: The Human Journey from Chaos to Cosmos. New York: Pocket Books.

Schneider, S. and Boston, P. 1991. Scientists on Gaia. Cambridge, MA: MIT Press.

Tracy, L. 1990. "Template Dispersal in Living Systems," Proceedings of the 33rd Annual Meeting of the International Society for the Systems Sciences, Vol. 2:962-967.

Tracy, L. 1994. Leading the Living Organization. Westport, CT: Quorum Books.

Tracy, L. 1995. "Molecular Approach to Living Systems," Systems Research Vol. 12:123-131.