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Chapter 8 of The Turning Point - Fritjof Capra (1982) |
Part 2 of 4 Parts | Web Publication by
Mountain Man Graphics, Australia - the Southern Winter of 1996
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The Systems View of Life |
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Most organisms are not only embedded in ecosystems but are complex ecosystems themselves, containing a host of smaller organisms that have considerable autonomy and yet integrate themselves harmoniously into the functioning of the whole. The smallest of these living components show an astonishing uniformity, resembling one another quite closely throughout the living world, as vividly described by Lewis Thomas.
There they are, moving about in my cytoplasm.....They are much less closely related to me than to each other and to the free-living bacteria out under the hill. They feel like strangers, but the thought comes that the same creatures, precisely the same, are out there in the cells of seagulls, and whales, and dune grass, and seaweed, and hermit crabs, and further inland in the leaves of the beech in my backyard, and in the family of skunks beneath the back fence, and even in that fly on the window. Through them, I am connected: I have close relatives, once removed, all over the place.
Although all living organisms exhibit conspicuous individuality and are relatively autonomous in their functioning, the boundaries between organism and environment are often difficult to ascertain. Some organisms can be considered alive only when they are in a certain environment; others belong to larger systems that behave more like an autonomous organism than its individual members; still other collaborate to build large structures which become ecosystems supporting hundreds of species.
In the world of microorganisms, viruses are among the most intriguing creatures, existing on the borderline between living and nonliving matter. They are only partly self-sufficient, alive only in a limited sense. Viruses are unable to function and multiply outside of living cells. They are vastly simpler than any microorganism, the simplest among them consisting of just a nucleic acid, DNA or RNA. In fact, outside of cells viruses show no apparent signs of life. They are simply chemicals, exhibiting highly complex but completely regular molecular structures. In some cases it has even been possible to take viruses apart, purify their components, and then put them back together again without destroying their capacity to function.
Although isolated virus particles are just assemblages of chemicals, they consists of chemical substances of a very special kind - the proteins and nucleic acids that are the essential constituents of living matter. In viruses these substances can be studied in isolation, and it was such studies that led molecular biologists to some of their greatest discoveries in the 1950s and 1960s. Nucleic acids are chainlike macro-molecules that carry information for self-replication and protein synthesis. When a virus enters a living cell it is able to use the cell's biochemical machinery to build new virus particles according to the instructions encoded in its DNA or RNA. A virus, therefore, is not an ordinary parasite which takes nourishment from its host to live and reproduce itself. Being essentially a chemical message, it does not provide its own metabolism, nor can it perform many other functions characteristic of living organisms. Its only function is to take over the cell's replication machinery and use it to replicate new virus particles. This activity takes place at a frantic rate. Within an hour an infected cell can produce thousands of new viruses and in many cases the cell will be destroyed in the process. Since so many virus particles are produced by a single cell, a virus infection of a multicelled organism can rapidly destroy a great number of cells and thus lead to disease. Although the structure and functioning of viruses is now well known, their basic nature still remains intriguing. Outside living cells a virus particle cannot be called a living organism; inside a cell it forms a living system together with the cell, but one of a very spcial kind. It is self-organising, but the purpose of its organization is not the stability and survival of the entire virus-cell system. Its only aim is the production of new viruses that will then go on to form living systems of this peculiar kind in the environments provided by other cells.
The special way in which viruses exploit their environment is an exception in the living world. Most organisms integrate themselves harmoniously into their surroundings, and some of them reshape their environment in such a way that it becomes an ecosystem capable supporting large numbers of animals and plants. The outstanding example of such ecosystem-building organisms are corals, which for a long time were thought to be plants but are more appropriately classified as animals. Coral polyps are tiny multicellular organisms that join to form large colonies and, as such, can grow massive skeletons of limestone. Over long periods of geological time many of these colonies have grown into huge coral reefs, which represent by far the largest structures created by living organisms on earth. These massive structures support innumerable bacteria, plants, and animals; encrustin organisms living on top of the coral framework, fishes and invertebrates hiding in its nooks and crannies, and various other creatures that cover virtually all the available space on the reef. To build these densely populated ecosystems the coral polyps function in a highly coordinated way, sharing nervous networks and reproductive capabilities to such an extent that it is often difficult to consider them individual organisms.
Similar patterns of coordination exist in tightly knit animal societies of higher complexity. Extreme examples are the social insects - bees, wasps, ants, termites, and others - that form colonies whose members are interdependent and in such close contact that the whole system resembles a large, multicreatured organism. Bees and ants are unable to survive in isolation, but in great numbers they act almost like the cells of a complex organism with a collective intelligence and capabilities for adaptation far superior to those of its individual members. This phenomenon of animals joining up to form larger organismic systems is not limited to insects but can also be observed in several other species, including, of course, the human species. Close coordination of activities exists not only among individuals of the same species but also among different species, and again the resulting living systems have the characteristics of single organisms. Many types of organisms that were thought to represent well-defined biological species have turned out, upon close examination, to consist of two or more different species in intimate biological association. This phenomenon, known as symbiosis, is so widespread throughout the living world that it has to be considered a central aspect of life. Symbiotic relationships are mutually advantageous to the associated partners, and they involve animals, plants, and microorganisms in almost every imaginable combination. Many of these may have formed their union in the distant past and evolved toward ever more interdependence and exquisite adaptation to one another.
Bacteria frequently live in symbiosis with other organisms in way that makes both their own lives and the lives of their hosts dependent on the symbiotic relationship. Soil bacteria, for example, alter the configurations of organic molecules so that they become usable for the energy needs of plants. To do so the bacteria incorporate themselves so intimately into the roots of the plants that the two are almost indistinguishable. Other bacteria live in symbiotic relationships in the tissues of higher organisms, especially in the intestinal tracts of animals and humans. Some of these intestinal microorganisms are highly beneficial to their hosts, contributing to their nutrition and increasing their resistance to disease.
At an even smaller scale, symbiosis takes place within the cells of higher organisms and is crucial to the organization of cellular activities. Most cells contain a number of organelles, which perform specific functions and until recently were thought to be molecular structures built by the cell. But it now appears that some organelles are organisms in their own right. The mitochondria, for example, which are often called the powerhouses of the cell because they fuel almost all cellular energy systems, contain their own genetic material and can replicate independently of the replication of the cell. They are permanent residents in all higher organisms, passed on from generation to generation and living in inmate symbiosis within each cell. Similarly, the chloroplasts of green plants which contain the chlorophyll and the apparatus for photosynthesis are independent, self-replicating inhabitants in the plant's cells.
The more one studies the living world the more one comes to realise that the tendency to associate, establish links, live inside one another and cooperate is an essential characteristic of living organisms. As Lewis Thomas has observed, "We do not have solitary beings. Every creature is, in some sense, connected to and dependent on the rest. Larger networks of organisms from ecosystems, together with various inanimate components linked to the animals, plants, and microorganisms through an intricate web of relations involving the exchange of matter and energy in continual cycles. Like individual organisms, ecosystems are self-organizing and self-regulating systems in which particular populations of organisms undergo periodic fluctuations. Because of the nonlinear nature of the pathways and interconnections within an ecosystem, any serious disturbance will not be limited to a single effect but is likely to spread thought the system and may even be amplified by its internal feedback mechanisms.
In a balanced ecosystem animals and plants live together in a combination of competition and mutual dependency. Every species has the potential of undergoing an exponential population growth but these tendencies are kept in check by various controls and interactions. When the system is disturbed, exponential "runaways" will start to appear. Some plants will turn into "weeds" and some animals into "pests," and other species will be exterminated. The balance, or health, of the whole system will be threatened. Explosive growth of this kind is not limited to ecosystems but occurs also in single organisms. Cancers and other tumours are dramatic examples of pathological growth.
Detailed study of ecosystems over the past decades has shown quite clearly that most relationships between living organisms are essentially co-operative ones, characterised by coexistence and interdependence, and symbiotic in various degrees. Although there is competition, it usually takes place within a wider context of cooperation, so that the larger system is kept in balance. Even predator-prey relationships that are destructive for the immediate prey are generally beneficient for both species. This insight is in sharp contrast to the views of the Social Darwinists, who saw life exclusively in terms of competition, struggle, and destruction. Their view of nature has helped create a philosophy that legitimates exploitation and the disastrous impact of our technology on the natural environment. But such a view has no scientific justification, because it fails to perceive the integrative and cooperative principles that are essential aspects of the ways in which living systems organise themselves at all levels.
As Thomas has emphasised, even in cases where there have to be winners and losers the transaction is not necessarily a combat. For example, when two individuals of a certain species of corals find themselves in place where there is room for only one, the smaller of the two will always disintegrate, and it will do so by means of its own autonomous mechanisms: "he is not thrown out, not outgamed, not outgunned; he simply chooses to bow out." Excessive aggression, competition, and destructive behaviour are predominant only in the human species and have to be dealt with in terms of cultural values rather than being "explained" pseudoscientifically as inherently natural phenomena.
Many aspects of the relationships between organisms and their environment can be described very coherently with the help of the systems concept of stratified order, which has been touched upon earlier. The tendency of living systems to form multileveled structures whose levels differ in their complexity is all-pervasive throughout nature and has to be seen as a basic principle of self-organization. At each level of complexity we encounter systems that are integrated, self-organising wholes consisting of smaller parts and, at the same time, acting as parts of larger wholes. For example, the human organism contains organ systems composed of several organs, each organ being made up of tissues and each tissue made up of cells. The relations between these systems levels can be represented by a "systems tree".
As in a real tree, there are interconnections and interdependencies between all systems levels; each level interacts and communicates with its total environment. The trunk of the systems tree indicates that the individual organism is connected to larger social and ecological systems, which in turn have the same tree structure.
At each level the system under consideration may constitute an individual organism. A cell may be part of a tissue by may also be a microorganism which is part of an ecosystem, and very often it is impossible to draw a clear-cut distinction between these descriptions. Every sub-system is a relatively autonomous organism while also being a component of a larger organism; it is a "holon," in Arthur Koestler's term, manifesting both the independent properties of wholes and the dependent properties of parts. Thus the pervasiveness or order in the universe takes on a new meaning; order at one systems level is the consequence of self-organization at a larger level.
From an evolutionary point of view it is easy to understand why stratified, or multileveled, systems are so widespread in nature. They evolve much more rapidly and have much better chances of survival than nonstratified systems, because in cases of severe disturbances they can decompose into their various subsystems without being completely destroyed. Nonstratified systems, on the other hand, would totally disintegrate and would have to start evolving again from scratch. Since living systems encounter many disturbances during their long history of evolution, nature has sensibly favoured those which exhibit stratified order. As a matter of fact, there seem to be no records of survival of any others. The multileveled structure of living organisms, like any other biological structure, is a visible manifestation of the underlying processes of self-organization. At each level there is a dynamic balance between self-assertive and integrative tendencies, and all holons act as interfaces and relay stations between systems levels. Systems theorists sometimes call this pattern of organization hierachical, but that word may be rather misleading for the stratified order observed in nature. The word "hierachy" referred originally to the government of the Church. Like all human hierachies, this ruling body was organised into a number of ranks according to levels of power, each rank being subordinate to one at the level above it. In the past the stratified order of nature has often been misinterpreted to justify authoritarian social and political structures.
To avoid confusion we may reserve the term "hierachy" for those fairly rigid systems of domination and control in which orders are transmitted from the top down. The traditional symbol for these structures has been the pyramid. By contrast, most living systems exhibit multileveled patterns of organization characterised by many intricate and nonlinear pathways along which signals of information and transaction propagate between all levels, ascending as well as descending. That is why I have turned the pyramid around and transformed it into a tree, a more appropriate symbol for the ecological nature of stratification in living systems. As a real tree takes its nourishment through both its roots and its leaves, so the power in a systems tree flows in both directions, with neither end dominating the other and all levels interacting in interdependent harmony to support the functioning of the whole.
The important aspect of the stratified order in nature is not the transfer of control but rather the organization of complexity. The various systems levels are stable levels of differing complexities, and this makes it possible to use different descriptions for each level. However, as Weiss has point out, any "level" under consideration is really the level of the observer's attention; The new insight of subatomic physics also seems to hold for the study of living matter; the observed patterns of matter are reflections of patterns of mind.
The concept of stratified order also provides the proper perspective on the phenomenon of death. We have seen that self-renewal - the breaking down and building up of structures in continual cycles - is an essential aspect of living systems. But the structures that are continually being replaced are themselves living organisms. From their point of view the self-renewal of the larger system is their own cycle of birth and death. Birth and death, therefore, now appear as a central aspect of self- organization, the very essence of life. Indeed, all living things around us renew themselves all the time. "If you stand in a meadow," Thomas writes, "at the edge of a hillside and look around carefully, almost everything you can catch sight of is in the process of dying." But for every organism that dies another one is born. Death, then, is not the opposite of life but an essential aspect of it.
Although death is a central aspect of life, not all organisms die. Simple one- celled organism, such as bacteria and amoebae, reproduce by cell division and in doing so simply live on in their progeny. The bacteria around today are essentially the same that populated the earth billions of years ago, but they have branched into innumerable organisms. This kind of life without death was the only kind of life for the first two- thirds of evolutionary history. During that immense time span there is no ageing and no death, but there was not much variety either - no higher life forms and no self- awareness. Then, about a billion years ago, the evolution of life went through an extraordinary acceleration and produced a great variety of forms. To do so, "life had to invent sex and death," as Leonard Shlain put it. "Without sex there could be no variety, without death no individuality." From then on higher organisms would age and die and individuals would pair their chromosomes in sexual reproduction, thus generating enormous genetic variety which made evolution proceed several thousand times faster.
Stratified systems evolved along with these higher life forms, systems that renew themselves at all levels and thus maintain ongoing cycles of birth and death for all organisms throughout the tree structure. And beings in the living world. Since we too are born and are bound to die, does this mean that we are parts of larger systems that continually renew themselves? Indeed, this seems to be the case. Like all other living creatures we belong to ecosystems and we also form our own social systems. Finally, at an even larger level, there is the biosphere, the ecosystem of the entire planet, upon which our survival is utterly dependent. We do not usually consider these larger systems as individual organisms like plants, animals, or people, but a new scientific hypothesis does just that at the largest accesible level. Detailed studies of the ways in which the biosphere seems to regulate the chemical composition of the air, the temperature on the surface of the earth, and many other aspects of the planetary environment have led the chemist James Lovelock and the microbiologist Lynn Margulis to suggest that these phenomena can be understood only if the planet as a whole is regarded as a single living organism. Recognising that their hypothesis represents a renaissance of a powerful ancient myth, the two scientists have called it the Gaia hypothesis, after the Greek goddess of the earth.
Awareness of the earth as alive, which played an important role in our cultural past, was dramatically revived when astronauts were able, for the first time in human history, to look at our planet from outer space. Their perception of the planet in all its shining beauty - a blue and white globe floating in the deep darkness of space - moved them deeply and, as many of them have since declared, was a profound spiritual experience that forever changed their relationship to the earth. The magnificent photographs of the "Whole Earth" which these astronauts brought back became a powerful new symbol for the ecology movement and may well be the most significant result of the whole space program.
What the astronauts, and countless men and women on earth before them, realised intuitively is now being confirmed by scientific investigations, as described in great detail in Lovelock's book. The planet is not only teeming with life but seems to be a living being in its own right. All the living matter on earth, together with the atmosphere, oceans, and soil, forms a complex system that has all the characteristic patterns of self-organization. It persists in a remarkable state of chemical and thermodynamic nonequilibrium and is able, through a huge variety of processes, to regulate the planetary environment so that optimal conditions for the evolution of life are maintained.
For example, the climate on earth has never been totally unfavourable for life since living forms first appeared, about four billion years ago. During that long period of time the radiation from the sun increased by at least percent. If the earth were simply a solid inanimate object, its surface temperature would follow the sun's energy output, which means that the whole earth would have been a frozen sphere for more than a billion years. We know from geological records that such adverse conditions never existed. The planet maintained a fairly constant surface temperature throughout the evolution of life, much as a human organism maintains a constant body temperature in spite of varying environmental conditions.
Similar patterns of self-regulation can be observed for other environmental properties, such as the chemical composition of the atmosphere, the salt content of the oceans, and the distribution of trace elements among plants and animals. All these are regulated by intricate cooperative networks that exhibit the properties of self-organising systems. The earth, then, is a living system; it functions not just like an organism but actually seems to be an organism - Gaia, a living planetary being. Her properties and activities cannot be predicted from the sum of hr parts; every one of her tissues is linked to every other tissue and all of them are mutually interdependent; her many pathways of communication are highly complex and nonlinear; her form has evolved over billions of years and continues to evolve. These observations were made within a scientific context, but they go far beyond science. Like many other aspects of the new paradigm, they reflect a profound ecological awareness that is ultimately spiritual.
Intro | Part1 | Part2 | Part3 | Part4 | Index | ||||||
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The Systems View of LifeChapter 8 of The Turning Point
by Fritjof Capra (1982) | |||||||||||
Web Publication by
Mountain Man Graphics, Australia - the Southern Winter of 1996
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