Biotic Regulation Overview
Here we present the first chapter of the book by Gorshkov V.G., Gorshkov V.V., Makarieva A.M. (2000) Biotic Regulation of the Environment: Key Issue of Global Change. Springer-Praxis Series in Environmental Sciences, Springer, London, 367 pp. It gives an outline of the fundamentals of the biotic regulation concept and the related scientific problems. The book in PDF format can be downloaded from here.
In 2004 we published an updated review of the concept as a paper in Ecological Complexity.
Since then the concept has been actively developed. Description of the biotic pump of atmospheric moisture has become our major advancement. It is now an inherent part and a major pillar of the biotic regulation theory.
1.1 External environment and internal milieu
1.2 Adaptation to, or regulation of, the environment?
1.3 Major inconsistencies in the genetic adaptation paradigm
1.4 Discreteness and stability of biological species
1.5 Global environment formed by the natural biota
1.6 Biotic regulation of the environment
1.7 Concepts of genetic adaptation and biotic regulation are mutually exclusive
1.8 Empirical evidence for the biotic regulation of the environment
1.9 Stability of life organisation
1.10 Mechanism of biotic regulation
1.11 Natural distribution of energy consumption over individuals of different body size
1.12 Conserving biodiversity or biotic regulation?
1.13 Biotic regulation cannot be replaced by technology
1.14 Ecological problems of humankind
This chapter presents an outline of all the problems to be covered in the book. The natural biota (i.e., flora and fauna) of Earth undisturbed by human activities regulates the environment on both local and global scales and compensates for any deviations from the optimal environmental characteristics suitable for life as a whole and humans in particular. Natural biotic regulation of the environment is based on genetic information encoded in genomes of natural biological species combined into ecological communities. When the degree of anthropogenic cultivation of the biota goes beyond the ecologically-permissible level, the remaining natural biota of Earth loses its ability to stabilise the global environment. As a result, the global environment degrades. Namely the human-induced perturbation of the natural biota rather than direct anthropogenic forcing appears to be the primary cause of the observed global change. We quantify the area that has to be occupied by natural biota unperturbed by modern industrial society in order to ensure long-term environmental stability on Earth.
1.1 External environment and internal milieu
Each organism is characterised by an internal milieu and exists in an external environment, which drastically differ from one another. Such situation is possible due to the fact that any organism has a natural envelope that protects and separates it from the external environment. Trees have bark, mammals have skin and hair, birds have feathers, living cells have special protecting membranes, etc. The internal milieu of an organism is maintained by well co-ordinated work of its internal organs. Failure of any of the internal organs leads to deterioration of the internal milieu and impairment of the general condition (health) of the individual.
Functioning of the internal organs of the organism relies on the continuous consumption of nutrients and energy from the external environment. Within the living body, organic nutrients are decomposed and further excreted from the organism together with thermal energy that is released in the course of metabolic processes. As a result, the external environment changes. Each organism is characterised by a rather narrow interval of environmental conditions where it can live (temperature, humidity, air pressure, availability of nutrients, low concentration of toxins, etc.). If the external environment is not continuously supplied with necessary nutrients and not cleared of the excreta, it soon becomes unfit for life of any organism. Thus, it is evident that in any environment species cannot exist sustainably in isolation from other species.
Life of individuals of any species is only possible provided there is correlated interaction with other species of the biota. Consequently, natural biota consists of ecological communities of species. Excreta of one species become nutrients for another and vice versa. Only then there open a theoretical possibility for the environment to remain stable. However, long-term environmental stability may be only guaranteed if functioning of all species in the community is rigidly correlated, similarly to the work of internal organs within a living body.
The statement that the natural biota may really work to stabilise the environment may seem somewhat odd to a human being. Modern humans live in artificial conditions that emerged as the main product of civilisation. Each normal human being is obliged to perform a certain amount of work. Most every-day actions of modern people are aimed at maintenance of stability of various elements of civilisation. The majority of these actions are in conflict with the inherent desires of people. This is manifested by the fact that most people would prefer to work much less than they actually do. In the modern world work takes on average six-eight hours per day. There is a constant demand imposed by trade unions on employers all over the world in order to reduce working hours. In other words, most people prefer rest to work, all other factors remaining the same.
During their free time, people act in accordance with their genetically-coded behavioural programme of positive and negative emotions. They engage in various types of social activities, enjoy sports, fishing, hiking and other types of recreation. In contrast, animals do that all the time. However, by doing so, animals in the same time perform strictly specified work on the stabilisation of the environment. Everything the animals do has a meaning and contributes to the stability of the their ecological community. One may say that people first do what they have to do, then what they wish to do, while animals do both things at the same time. This drastic difference in behaviour of humans and the rest of the biosphere sometimes precludes people from correct understanding of the observed ecological phenomena.
An ecological community taken together with its environment forms a local ecosystem. The main difference between an organism and a local ecosystem is that the latter does not have an envelope that would delineate its internal milieu (living area of all organisms of the community) from its external environment (area where there are no living beings). A partial diffusive envelope can be exemplified by lower soil horizons that separate the internal milieu of terrestrial ecological communities from the lifeless lithosphere. Concentrations of various elements in soil differ drastically from corresponding concentrations in the Earth's crust in very much the same manner as, for example, body temperature of endothermic (warm-blooded) animals differs from that of the external environment.
The scientific question whether the natural biota adapts to the external environment that changes arbitrarily due to random physical, chemical and biological processes or whether the natural biota forms and maintains its environment itself, is, as we show below, of critical importance to modern humanity.
1.2 Adaptation to, or regulation of, the environment?
The concept of adaptation to changing environment forms the basis of the Darwinian theory of evolution. In the first half of the 18th century, a Swedish naturalist, Karl Linnaeus, created his famous classification of biological species on the basis of morphological similarities and differences (Linnaeus, 1789). Linnaeus thought that species did not change with time. Charles Darwin analysed paleodata and the extant species to put forward the statement that similar species had a common origin in the global process of biological evolution. Darwin further assumed that evolutionary process represents continuous accumulation of hereditary changes in each individual, which is followed by natural selection of those individuals that are best adapted to the existing environment, i.e. leave in this environment the greatest number of offspring. Darwin thought that natural selection is absolutely analogous to the artificial selection that is performed by people to create new breeds of animals and sorts of plants. The primary driving force of evolution was, consequently, a spontaneous change of the environment that brought about changes in the natural selection priorities.
According to the adaptation concept, gradual accumulation of hereditary changes finally leads to the fact that individuals of a given species acquire specific traits of a new species. That continuous process is perceived as a succession of extinctions of old species and origins of new ones. Accumulation of hereditary changes may proceed along several different ways. Some species give rise to two or more new species, while others (evolutionary dead-ends) become extinct without giving rise to a new species altogether. Extinction of such species counteracts possible exponential growth of the total number of species in the biosphere. It is assumed that all those processes combine into the evolutionary pattern known from paleodata.
In the twentieth century, when the genetic nature of hereditary changes became evident, the Darwinian approach was modified to form the basis of the so-called paradigm of neo-darwinism (Dobzhansky, 1951; Mayr, 1963; Ayala and Fitch, 1997). According to that paradigm, the global environment of our planet appears to be suitable for life due to an exclusively lucky orbital position occupied by the Earth in the solar system. Within a broad corridor of physical environmental conditions that are possible given that orbital position, the natural biota of Earth is capable of adapting to practically any changes of the environment. In any case, during the nearly four billion years' period of life existence there had been no such catastrophic environmental changes to which the biota could not adapt.
Within the paradigm it is well admitted that substantial changes in the environment may be initiated by the biota itself. To these changes the biota is also able to adapt, so that a circular process entails (biotic modification of the environment → genetic adaptation to it → appearance of new species → new biotic modifications of the environment, etc.). A classic example of drastic biotic impact imposed on the environment is the transition from the oxygen-free to the present-day atmosphere, that occurred more than billion years ago and was presumably triggered by some major evolutionary changes in the biota (Cloud, 1972; Kasting, 1987).
According to the neo-darwinism paradigm, evolution and continuous genetic adaptation to changing environment are the principal properties of life in general. There are no specific environmental conditions that would be optimal for life as a whole. Any environment becomes optimal provided the biota is given sufficient time to adapt to it.
Genetic basis of the adaptation is provided by the observed genetic polymorphism (i.e., genetic non-identity of individuals in a population) and mutability (i.e., appearance of new genetic options, not found in parental lines). The most adapted individuals are, by definition, those producing the maximum number of offspring. Genetic variants imparting the highest reproductive capacity to their carriers, propagate in the population. Biosphere is composed of chaotically interacting species continuously adapting to changing environment. All the observed evolutionary changes known from paleodata are explained by continuous genetic adaptation and natural selection of individuals.
The neo-darwinistic paradigm completely excludes any possibility of biotic regulation of the environment aimed at conservation of a particular set of optimal environmental conditions. Genetic adaptation necessarily implies a rigid correlation between the new genetic information of a species and the new environment where such adaptation takes place. Genetic programme of an adapting species loses information about the former environment. As a result, genetic programme of an adapting species cannot, in principle, include a programme of actions aimed at relaxation of the environment to the initial state. Thus, genetic adaptation and long-term environmental stability are in principle incompatible, see also Section 1.7.
Within the conventional biological paradigm the observed radical change of the global environment caused by large-scale transformation of natural ecological communities into agro-, silvy- and maricultures designed to cater for the growing human needs, is often envisaged as but one of the stages of the conventional evolutionary process. Struggle with industrial pollution that acts to change the environment in an unfavourable for humans direction, is put forward as the major ecological task to be solved by humanity. The on-going cultivation of the global biota by humans and transformation of the biosphere into a global biosystem — noosphere, that solely provides for the needs of a single species, Homo sapiens, is thought to be a natural process as well.
Natural biodiversity is then treated as the genetic resource of the humankind, that can be used in the future at some advanced stage of development of biotechnology and gene engineering. It is assumed that biodiversity is a common name for such types of diversity as species diversity (i.e. the variety of the extant species in the biosphere) and intraspecific genetic variability, which serves as the necessary material basis for genetic adaptation and evolution of new species. To conserve biodiversity, people create gene banks and zoos, along with national parks that account for less than one per cent of the total Earth's surface and do not impede the free extensive as well as intensive development of the modern civilisation.
Unlimited economic growth, necessarily based on a continuous increase in rates of exploitation of biospheric resources, is envisaged as the only possibility to provide for the escalating needs of the growing global population of humans.
It may seem that some of the above conclusions, especially those concerning human strategy in the modern world, are not related to the purely biological paradigm of genetic adaptation. However, these conclusions logically follow unambiguously from that paradigm, which has been dominating the biological science during the last hundred years and has become common, at least implicitly, to most mentality patterns that proliferate in the modern world. Another possibility is that this paradigm appeared itself as a product of the European social mentality in the end of the nineteenth century, which was celebrated by a remarkable development of industry and technology and favoured the anthropocentric view of the world.
1.3 Major inconsistencies in the genetic adaptation paradigm
The outlined above paradigm of genetic adaptation is unable to provide explanations to some widespread phenomena observed in the biosphere. Among others are ecological restrictions apparently imposed on population densities of most natural species in the biosphere (Chapter 3), formation of stable ecological communities with rigid internal correlation of species (Chapters 4 and 5), approximately equal evolutionary species lifespans in different biological kingdoms (Chapter 11), etc. All these problems will be in detail discussed in the chapters to follow.
One may name, however, two major contradictions that immediately catch the eye in the genetic adaptation paradigm:
1) Why, in spite of continuous adaptation to ever-changing environment, all species retain discreteness both in space and time? In other words, why there are no transient forms between the extant as well as between the extinct species known from paleodata?
2) Why, in spite of uncontrollable changes of the environment, especially those due to the biotic impact, the global environmental conditions has remained within the life-compatible interval during the whole period of life existence?
We now discuss these two questions in more detail.
1.4 Discreteness and stability of biological species
The available paleodata testify for morphologic and, consequently, genetic (Jackson, 1990) constancy of all species-specific characteristics during the whole period of existence of most (at least 90%) of the species studied (Gould and Eldridge, 1993). No transient forms that would viaduct two discrete acts of speciation are observed. The classical example of gradual speciation, family Equidae, has been recently shown to be but a misinterpretation of the paleodata (MacFadden, 1993). A closer analysis showed that what had been traditionally conceived as a succession of transient forms that had finally shaped into the modern horse, often proved to be a set of discrete contemporary species, that co-existed in both space and time.
The extant species also demonstrate strict discreteness. There are neither intermediate forms between related species, nor processes of their formation being observed. Hybrid zones that are sometimes considered as a possible seeding of evolutionary process, are strongly restricted and occupy a few per cent of the biosphere at maximum (Raven and Johnson, 1988). All these facts suggest that the period of speciation (i.e., appearance and spread of a new species) takes much shorter time as compared to the average time of species existence (a few million years) (Gould and Eldridge, 1993). During the speciation 'burst' organisms undergo rapid morphologic and genetic change to remain further unchanged for the rest of the new species' existence.
One may conclude therefore that evolution of species is not a result of gradual accumulation of relatively frequent minor modifications of the hereditary programme of a species. Rather, evolutionary process is discontinuous and is due to infrequent but radical changes of the genetic programme of a species. The continuous 'daily' process of mutations that supports intraspecific genetic polymorphism bears no relation to the evolutionary process. Rather it can be conceived as random deviations from normal hereditary programme which is coded genetically in DNA molecules and is known as the species' genome. Random genetic deviations accumulate due to the mutational process and erase the genetic information of the species. The number of such deviations cannot increase infinitely, but should be limited by selection that, due to its function, may be called stabilising. In the process of stabilising selection individuals with too many genetic deviations are forced out from the population. Thus, under natural conditions genetic programme of species is prevented from decay.
However, under distorted conditions individuals with genetic defects can accumulate. Artificial selection uses this fact to create new breeds of economically important plants and animals. Unlike evolutionary changes, many of artificially created genetic changes are reversible. When placed under natural conditions, many domestic species recover their normal (wild-type) genetic programme which assures maximum competitiveness of individuals in their natural ecological niche. For example, doves (Columba livia) living free in cities have rather uniform morphology and are practically identical with wild doves, though urban doves descend from various domesticated breeds that differ drastically from one another and from the wild doves. As soon as the press of artificial selection was relaxed, the most competitive wild phenotype was restored.
In some cases when two genetically different populations of the same species live in different environmental conditions, individuals taken from one population and placed on the territory of the other appear poorly fitted to the alien environment and lose competition with aboriginal individuals. Such facts are interpreted as an important empirical evidence in favour of the existence of genetic adaptation.
However, the possibility of existence of normal and distorted environment is completely ignored in such consideration. Suppose that in the normal environment individuals of a certain species need both to swim and to walk. In one distorted environment they only need to walk, in other — only to swim. In both distorted environments individuals will lose one of the two abilities, because competitive interaction in the distorted environments will not be able to support both. Individuals that are able both to walk and to swim in the environment where swimming is the only thing needed, will have no advantage over those capable only of swimming, so the ability to swim will finally vanish. So, in the first environment individuals will only be able to walk, in the second one — only to swim. Then, after changing environment, they will die in both cases. But, evidently, their genetic differences are not an example of adaptation, i.e. acquiring new information about changed environment. On the contrary, genetic differences between the two hypothetical populations clearly represent erosion of the original genetic information, see also Section 9.8.
The above consideration may be illustrated by the example of domesticated plants and animals. Under natural conditions these plants and animals cannot compete with normal individuals of the corresponding wild species, because those hereditary properties that make them useful for humans (high productivity of milk, high degree of fat, extremely large size of edible parts of plants) prove to be disadvantageous and do not correspond to the maximum competitiveness under natural conditions.
This alternative explanation of the observed pattern relies on the notions of normal (optimal) and distorted environment, which are by definition absent from the genetic adaptation concept. The genetic adaptation concept states as an axiom that since species adapt to changing environment, any environment may become optimal and there are no favourites among possible environments. After such statement is made, the observed pattern is unambiguously interpreted as independent evidence in favour of the genetic adaptation. In reality, however, this explanation is dependent on that critical statement about environments, which in itself remains absolutely unproved. As shown above, if we replace this statement by the opposite one, the observed pattern can be consistently explained not only without involving genetic adaptation but from a opposite point of view. Thus the fact that genetically different conspecific organisms sometimes behave differently in different environments is not in itself a testimony for genetic adaptation.
On the above basis, the following explanation of the observed discreteness of species appears justified. Due to the random character of the mutation process different individuals in a population have different locations of genome sites with erased genetic information. The total amount of such sites, i.e. the total amount of erased genetic information, is limited by the stabilising selection and should be approximately equal in all competitive individuals. All the meaningful genetic information is the same in all individuals of all populations of the same species. Namely this fact determines the observed constancy of species-specific characteristics in time.
We have seen, therefore, that the available empirical data on species discreteness are inconsistent with the assumption about continuous genetic adaptation to changing environment. This suggests that there exists a certain optimal for life environment, which is maintained and controlled by the biota itself, information about the characteristics of that environment being genetically encoded in biological species and kept intact during the most time of species' existence.
1.5 Global environment formed by the natural biota
The notion global environment comprises physical and chemical conditions encountered on the planet's surface and the planet's climate. A critical characteristics of the latter is the mean global surface temperature. The temperature of Earth's surface is determined by the balance of the incoming solar radiation and thermal radiation that is emitted by the planet into space. This balance is totally determined by the amount of solar radiation that is reflected by the planet back to space (the planetary albedo) and absorption of thermal radiation by the so-called greenhouse gases. At constant flux of solar radiation incident upon Earth, surface temperature can assume almost arbitrary (including life-incompatible) values depending on values of planetary albedo and greenhouse effect, see below Table 8.1, which are completely determined by inherent environmental characteristics of the planet.
Hydrosphere of Earth is sufficient for total glaciation of the Earth's surface, which corresponds to the global average surface temperature of about −100o C. On the other hand, complete evaporation of Earth's hydrosphere would lead to a catastrophic greenhouse effect with the global surface temperature rising to several hundred degrees Celsius, similar to the situation on Venus. In both cases life would be impossible. No physical barriers are known that would prevent modern climate of Earth from spontaneous transition to any of the two extreme life-incompatible stable states (Chapter 8).
Any stable state is characterised not by the absolute constancy of its characteristics, but by the absence of irreversible changes in their values. Certain non-zero fluctuations of environmental characteristics are always present in any stable state. To evaluate their importance, their values should be compared to the threshold fluctuations that undermine the system's stability and elicit irreversible changes of the initially stable state. On this basis, the most remarkable property of Earth's climate is not its variability due to succession of glacial and inter-glacial periods, volcanic activities, drift of the continents, meteorite fall etc., but the fact that in spite of all those perturbations the climate has remained suitable for life during the last four billion years. In this sense Earth's climate is indeed stable.
The observed peculiarities of the Earth's climate provide the empirical basis for the concept, where the natural biota of Earth is regarded as the only mechanism ensuring maintenance of life-compatible environmental conditions on both global and local scales, i.e. concept of the biotic regulation of the environment.
1.6 Biotic regulation of the environment
According to this concept, the main property of life is the ability of biological species to perform certain specific work aimed at maintenance of a particular set of environmental conditions favourable to the biota itself. Complex interaction of living organisms with their environment necessitates formation of internally correlated ecological communities of species. Within the community individuals of different species interact with each other in a correlated manner. Such correlation can be compared to correlated functioning of cells and organs within a multicellular organism.
Only those species that are able to perform necessary work on regulation of the environment, have a chance to persist in the biosphere and enter certain community. Such species maintain optimal population density and produce an optimal rather than maximal number of offspring. By doing so, they ensure stationary distribution of all biotic characteristics of the environment and, in particular, prevent population explosions that may lead to complete degradation of the corresponding community.
Note that such situation is often interpreted as paradoxical. It is argued that natural selection would never favour genes beneficial to community as a whole, but detrimental to the individuals possessing them (Baerlocher, 1990). In that context the property of an individual to restrict itself to producing an optimal number of progeny (instead of the maximum possible) is conceived as detrimental. However, in such consideration the question of the long-term environmental stability where individuals of a given species are to exist is completely neglected. A species unable to control its population density and tending to increase its population number infinitely would be at first prosperous, but further will inevitably undermine the ecosystem's resilience and degrade together with its environment. This gives an evolutionary advantage to those species (and, consequently, individuals) who possess a genetic control of their population density coupled to the existing environmental conditions.
To give a vivid example of the impertinence of the above objection regarding natural selection, one may rightly ask how the multicellular organism evolved from unicellular ones, if selection could not in principle favour biological objects acting for the common (instead of their own) good? There is no doubt that cells within a multicellular organism apparently function for the benefit of the organism as a whole, individual proliferation of many types of cells being strongly prohibited. When such co-ordinated interaction of cells is broken, and cells of a particular tissue begin to grow at the expense of the others (cancer), the individual becomes ill, loses competitiveness and is forced out from a population by normal individuals. Such individual further dies together with the "most prosperous" cancer cells. The answer that is in the course of evolution association of separate cells into a multicellular organism became possible due to the appearance of selection at a higher level, i.e. at the level of organisms instead of separate cells. Thus, cells that were able to suppress their own ambitions for the common good, ensured stability of the internal milieu of the organism an, by doing so, imparted to it a high competitive capacity. As a result, organisms with co-ordinated (instead of competitive) functioning of cells do dominate in the biosphere. The same is true for ecological communities with co-ordinated interaction of species within them.
The optimal number of offspring is determined by the condition of the maximum efficiency of the biotic regulation power achieved by the community. The maximum possible number of offspring is determined by the food and territory resources available at the moment. A spontaneous transition of any species to producing the maximum possible number of offspring testifies to an impaired genetic programme of that species. Such transition, similar in its effect to a cancer tumour, disintegrates normal work of the community and impairs its regulatory potential. As a result, such community loses its competitiveness and is forced out by another community where the same species retains its normal genetic programme and produces the optimum (instead of the maximum) number of offspring.
Species that work to maintain their environment stable should, apparently, prevent their genetic programme from spontaneous changes. In other words, spontaneous genetic adaptation to random fluctuations of the environment should be strongly prohibited. There should be a mechanism operating in populations of biological species that would stabilise the genetic programme of species and prevent accumulation of random genetic changes that erase meaningful genetic information of species. Thus, according to the biotic regulation concept, biological species should retain their genetic stability over geological time-scale. Species must not only be adapted to a given environment (i.e. be possible to exist within it) but also be able to perform correlated interaction with other species in the community. These restrictions explain the observed discreteness and morphological constancy of both the extinct and extant species.
The observed genetic polymorphism of individuals of natural species corresponds to random deviations from the normal genetic programme that cannot be eliminated by the stabilising selection due to the limited sensitivity of the latter (Chapters 9 and 10). Stabilising selection operates most efficiently under natural environmental conditions of a corresponding ecological niche. Under perturbed environmental conditions stabilising selection becomes weaker. This leads to increased level of genetic polymorphism in the population and accumulation of individuals with genetic deviations. When the natural environment is restored, process of stabilising selection regains its efficiency and individuals with genetic deviations are expelled from the population. As a result, the level of genetic polymorphism drops down to its initial value.
Evolutionary transitions to new species may only occur provided that the species ability to stabilise the environment is conserved. The mechanism providing for appearance of such species is that of competitive interaction of ecological communities. New species that are not able to correlate with the others to keep the environment stable, change adversely the competitive capacity of their communities. As a result, communities patronising such species, are forced out by other communities, where all species (both evolutionary old and new) perform correlated interaction.
Over larger time-scales (of the order of billion years) evolutionary process may be accompanied by considerable environmental changes. The transition of environment from one favourable for life state to another is brought about by the restructuring of the biota itself. In other words, during the long-term evolutionary process there may be formed new communities of species that are more competitive than the old ones and for which quite another environment may become optimal. Such communities force out the previously dominating ones and transform the former environment into a favourable for themselves state to maintain it further unchanged over another billion of years. Such large-scale evolutionary change may be exemplified by the widely cited transition from the oxygen free atmosphere to the present-day one. This is believed to be due to the appearance of photosynthesising organisms that both produced oxygen and used it for breathing. Communities with photosynthesis appeared to be more competitive than those composed of anaerobic organisms, the result being the major restructuring of the biosphere as a whole. Note, however, that during that large-scale evolutionary process the environment had all the time remained under control of the biota, be that biota composed of either evolutionary new (photosynthesising) or old (anaerobic) organisms.
Thus, long-term environmental changes in the biosphere are explained by the fact that, despite the universal biochemical character of life, different types of environment appear to be optimal for different types of organisation of living beings. The inherent ability of life to control its environment being conserved, evolutionary changes of dominant organisms in the biosphere may lead to even significant environmental modifications at no risk of spontaneous adverse changes of the environment that could threaten the existence of life as a whole. As far as these modifications are due to the fact that the newly-arisen biota appears to be more competitive than the old one, these modifications are inherently irreversible.
1.7 Concepts of genetic adaptation and biotic regulation are mutually exclusive
We have so far considered two possible hereditary patterns of reactions of living beings to environmental changes.
According to the biotic regulation concept, any deviation from the optimal state of the environment necessarily elicits a correlated reaction of all species of the community directed at compensation of that deviation. In other words, any random fluctuations of the environment are counteracted by a biotically-driven negative feedback, so that the favourable for life optimal environment is maintained in a stable state.
Note that the very existence of an optimal environment implies a correlation between morphological and behavioural properties of living beings on the one hand, and characteristics of their optimal environment on the other hand. Such correlation may be called adaptedness or adaption. The ability of leaves to absorb solar radiation; the ability of roots to take in water solutions of nutrients from soil; the ability of animals to run, swim, fly and climb the trees; the ability of endothermic animals to keep constant body temperature using feather and hair etc. are but a few examples of how the organisms are adapted to their optimal environment. Such adaption (sometimes called also adaptation) is a hereditary property of the organisms, characterising the state of their correlation with the environment.
According the concept of genetic adaptation briefly outlined in Section 1.2, individuals of any species genetically adapt to the changing environment. The new environment becomes optimal to those organisms that have adapted to it, their genetic programme being accordingly altered. Individuals of certain species adapt to the presence of individuals of other species in very much the same manner as they adapt to abiotic environmental conditions. As a result, a concordant co-existence of species emerges. Such reaction of the biota to environmental perturbations corresponds to the process of genetic adaptation to changing environment.
It should be emphasised that the process of genetic adaptation consists in a directional change of the genetic programme of a species, the ultimate goal being to ensure correlation of the genetically modified species with a new arbitrary environment. This process is opposed to the state of genetic adaption to the specific optimal environment, that is kept constant by the biota.
These two reactions to environmental changes — biotic regulation and genetic adaptation — are incompatible in that sense that only one of them is actually realised. Individuals of biological species may either change the environment to the initial optimal state, or change themselves genetically adapting to the new environment. There is not any compromise between the two possibilities.
If the biotic regulation strategy is realised, biological species should retain unchanged the information about characteristics of the optimal environment. This information, being genetically encoded into species, governs their work on maintenance of the optimal environment. Thus, biological species cannot change genetically when adapting to a new environment. Otherwise the information about how to maintain the optimal environment will be lost.
If the natural biota as a whole follows the strategy of genetic adaptation, no biotic regulation of the environment is possible. Biotic regulation is not a random coincidence of properties of randomly co-existing species, but a complex genetic programme of correlated interaction of individuals of different species within the community. This programme is aimed at maintenance of a specific environment optimal for the whole community. The complexity of such programme by far exceeds the complexity of the genetic programme of a single species, that ensures stable internal milieu of organisms through correlated interactions of various types of cells. During genetic adaptation to a changing environment species change their genetic programme and the new environment becomes optimal for those who survive best, i.e. produces the maximum number of progeny. It is highly improbable that those who produce the maximum progeny will randomly invent a new programme of regulation of a new environment. Such situation can be compared to a hypothetical case when cell lines from different tissues of a single organism are selected in vitro for a sufficiently long period of time for their ability to reproduce at the maximum possible rate. It is evident that genetically modified cells would then be no longer able to function in an organism without disintegrating its internal milieu.
Another argument against co-existence of the processes of genetic adaptation and biotic regulation is that when you are able to regulate the environment keeping it at a certain optimum, you have no need to change genetically. Also, when you are able to adapt to any environment, there is no need to spend efforts to regulate something. Thus we conclude that biotic regulation and genetic adaptation are mutually exclusive.
Which of the two strategies dominates in the natural biota is to be determined from the available empirical data that allow unambiguous interpretation. As shown above (see also Chapters 9, 10 and 11), the available data on species discreteness and physical instability of the Earth's climate testify in favour of the biotic regulation concept.
1.8 Empirical evidence for the biotic regulation of the environment
There is direct evidence suggesting that the global environment of Earth is formed and maintained by the natural biota. We list these arguments below.
- There is a constant, though small, net influx of inorganic carbon entering the biosphere due to filtration from the Earth's mantle. In a billion years such flux could increase the atmospheric CO2 concentration by a factor of ten thousand (!) as compared to its modern value. (For comparison, at present humanity is seriously concerned by a 30% increase in the atmospheric CO2.) This would increase the average global surface temperature by several hundred degrees Celsius. The fact that the global surface temperature has remained suitable for life during four billion years suggests that the atmospheric concentration of carbon dioxide retained its order of magnitude during that period (i.e., it did not change more than tenfold in either direction). One may therefore conclude that a compensating mechanism should be operating removing the excessive inorganic carbon from the atmosphere. Such a mechanism is indeed discovered. It is the biotic depositing of inactive organic carbon in sediments. As follows from the paleodata, the biotic sedimentation compensates the net emission of inorganic carbon very precisely. As soon as a random precise coincidence of two independent fluxes appears improbable, this fact points unambiguously to the biotic regulation mechanism operating in the biosphere (see Section 5.4 for more details).
- Molar ratios of certain important inorganic nutrients dissolved in the ocean coincide with stoichiometric ratios of those elements observed in biochemical reactions of synthesis and destruction of organic matter by the oceanic biota. This is an indication that oceanic concentrations of nutrients are formed and maintained by the oceanic biota itself (Redfield, 1958; Chen et al., 1996, see Section 6.1 for more details).
- River run-off is equal to the amount of water that evaporates from the oceanic surface but precipitates on land. The observed global river run-off is three times lower than precipitation on land. It means that two-thirds of the precipitated water evaporates from land, and only one third is brought from the ocean. Most of the water that evaporates from land comes from the vegetation cover. Plants spend the most part of the absorbed power of solar radiation on transpiration. Thus, the precipitation regime on land is also under biotic control (see Section 6.6 for more details).
- The atmospheric CO2 concentration coincides with the average global concentration of the dissolved CO2 in the surface oceanic layer (CO2 solubility equals unity at 15oC) and is three times lower than the CO2 concentration at oceanic depths. Such difference is maintained by the biological pump. Diffusion of inorganic carbon from the depths to the surface is compensated by photosynthesis of organic carbon at the surface and its sinking down to depth where it is decomposed by heterotrophic organisms. Thus the oceanic biota maintains atmospheric CO2 concentration four times lower than it would have been in the absence of the biota (see Section 6.1 for more details).
Note that arbitrary changes of marine ecosystems as a result of their possible cultivation by humans may lead to disintegration of the biological pump which is ensured by strictly specified correlated interactions of synthesisers and reducers in natural marine communities. As a result of world-wide cultivation of the oceanic biota, atmospheric concentration of CO2 would increase by a factor of four bringing about catastrophic greenhouse effect and, possibly, other adverse environmental changes that at present are difficult even to be outlined. Thus large-scale cultivation of marine ecosystems presents a major threat to the long-term stability of the environment of Earth. Those optimists who plan to feed the growing population of humans by marine products are in fact preparing a global ecological catastrophe. The same statement holds true for people that plan to introduce large-scale perturbations into marine systems in order to increase their productivity and make them to absorb carbon from the atmosphere (see, e.g., (Martin et al., 1990) for discussion of such a possibility and Section 6.1 for more details). The effect of breaking the harmonic balance of the nonperturbed biota of the ocean1 is likely not only to be the opposite to what is naively expected, but catastrophic in its irremediability. 1[The oceanic biota as a whole may be considered nonperturbed due to the fact that people consume only a small part of its primary production in contrast to the situation with terrestrial ecosystems.]
- The available data on changes of oxygen and carbon content in the atmosphere indicate that the nonperturbed biota of the ocean absorbs excessive atmospheric CO2 and thus partially compensates anthropogenic carbon emissions at a rate comparable to that of fossil fuel burning. The terrestrial biota substantially perturbed by anthropogenic activities has lost its stabilising ability and at present adds to the anthropogenic perturbation of the environment (see Section 6.3 for more details).
- Any external perturbation of forest communities (fire, windfall, cutting) brings about biological processes of recovery known as succession. Direct observations show that in the course of succession the community changes various parameters of its environment (pH, humidity, light and temperature regimes, etc.) by orders of magnitude. When the initial stationary stable state is recovered, the forest community is able to further maintain its own environment unchanged for infinitely long periods of time in the absence of large-scale external perturbations. This provides unambiguous evidence for biotic regulation in the forest ecosystems (see Sections 6.7 and 6.8 for more details).
1.9 Stability of life organisation
Let us now discuss major properties of life that enable living beings to combine into ecological communities capable of maintaining long-term environmental stability (see Chapter 2 for detailed coverage of this issue).
Any living organism represents a super-organised internally correlated system that exists due to the external fluxes energy. The level of organisation (complexity) of living beings by far exceeds that of physical fluxes of energy used by life. This means that no living object will ever arise spontaneously in any fluxes of external energy. This also means that the external fluxes of energy are unable to support the level of organisation of living objects for a long time. Due to this fact all living objects inevitably decay in spite of the constant presence of external energy fluxes. The decay of living objects is manifested as a decreasing level of their organisation that tends to physical equilibrium with the inanimate environment. This process ends with death of the organism well before that physical equilibrium is reached. Note that the ability to reproduce, inherent to biological objects, does not help to maintain the long-term stability of organisation of living beings, because such ability is itself subject to decay.
To maintain the level of organisation achieved in the course of evolution life has invented the mechanism of selection that we everywhere below call stabilising, in accordingly with its function. This way of maintaining stability is unique to life and is never encountered in the inanimate nature. It consists in the following. All biological species necessarily exist in the form of populations, i.e., sets of non-correlated individuals with approximately the same physiologically meaningful hereditary programme. Within a population, individuals compete with each other in an aggressive manner. This means that competitive interaction does not depend on the availability/unavailability of resources like food, territory, etc., but is an inherent property of living individuals.
In the course of competitive interaction non-competitive individuals (i.e. those with impaired hereditary programme) are forced out from the population, even though such individuals may remain quite viable. The vacancies appearing in the population are filled by the progeny of normal individuals. As a result, the population sustains its status of a set of equally competitive individuals with the initial high level of organisation. It is natural to call such mechanism of maintaining stability for stabilising selection, though in biological textbooks this term usually refers to stabilisation of the phenotype (i.e., morphological and behavioural properties of individuals), rather than to stabilisation of the genetic hereditary programme as a whole (which, naturally, includes stabilisation of the phenotype as well).
For stabilising selection to operate, individuals within the population should not be correlated with each other, so that exclusion of any individual from the population should not affect the well-being of the others. If individuals form an internally correlated association (e.g. a family of animals), elimination of any of its members would impair the correlated organisation of the association in very much the same manner as ablation of a certain organ would impair the correlated functioning of the organism. Thus, maintenance of internal correlation of associations of individuals may be only ensured by stabilising selection operating at a higher level than individuals, namely in a population of associations with competitive interaction between them.
Internally correlated associations of biological objects are encountered at all levels of life organisation, e.g. association of cells in a multicellular organism, association of social insects in structures like bee-hives and ant-hills, and, finally, association of individuals of different species in ecological communities. Similarly to other levels of organisation, internal correlation of species within an ecological community can only be maintained due to competitive interaction of homologous communities within a non-correlated set of communities. A population of homologous (uniform) communities together with their environment is known as ecosystem. One can speak about forest ecosystem, coral reef ecosystem, etc.
Internal correlation of human societies is also maintained in the same manner. Sociality (i.e. the ability of humans to form a stable sustainable society) is a complex hereditary species-specific property genetically encoded into the Homo sapiens species. It may be only maintained in the course of competitive interaction of different societies (countries). Thus, if the global population of people were united into a single globally correlated society (this may be done by forming a culturally uniform global nation), the ability of sociality would undergo genetic decay and finally would be lost.
The aggressive mode of competitive interaction inherent to biological objects at any level of organisation explains the incessant political and economical competition between different countries, which often have tragic consequences and at present may even threaten the very existence of humankind (e.g., nuclear arms race). Here two points need to be stressed. Firstly, even though competitive interactions of nations is the only mechanism that prevents sociality of humans from genetic decay, the process of genetic decay, as we show in Section 9.2, is a very slow one and takes very long periods of time. Thus, if we humans weakened the intensity of the present-day international confrontations for several decades or even hundred and thousand of years, that would not threaten our hereditary genetic programme with regard to sociality, but would only help to establish a more secure world for all people. Secondly, as far as the ability to compete is inherent to any living being including humans, it is useless to try to suppress it altogether. The only thing that can be really done is to enhance peaceful forms of competitive interaction at the expense of political and economical confrontations, which actually present the most danger to the fragile balance of the modern world. This may be done by imparting increasing importance to such forms of peaceful international competition as sports championships, musical festivals, scientific achievements, etc.
1.10 Mechanism of biotic regulation
To regulate the environment, ecological communities use processes of synthesis (production) and decomposition (destruction) of organic matter. In the absence of external physical fluxes of biogens to and from the local ecosystem, their concentrations inside the local ecosystem will only remain stable if biological synthesis of organic matter is precisely compensated by biological destruction. Thus, in the absence of external perturbations communities tend to maintain close biochemical cycles of all biogens not to disturb the optimal characteristics of the environment.
If external physical fluxes of certain biogens are smaller than biological productivity (and, consequently, destructivity) of the community, the latter is able to form and easily maintain concentrations of these biogens inside the local ecosystem at a level that can differ significantly from that in the external milieu. For example, concentrations of various elements in soil differ drastically from corresponding concentrations in the Earth's crust or the atmosphere. It means that in natural ecosystems the rate of physical and chemical degradation of soil (soil erosion) is substantially lower than the rate of the compensating process of soil recovery performed by ecological communities. In a situation when physical fluxes of biogens are negligible compared to biotic ones, even a single ecological community is able to maintain concentrations of these biogens at the optimal level in the local ecosystem.
In many cases external fluxes of biogens are considerably larger than community's productivity. For example, physical mixing in the atmosphere and ocean is so large that it is not possible to discriminate between the biotic and abiotic environment. In such a situation optimal concentrations of biogens can be only maintained by a large number of uniform biological communities occupying large territories of Earth's surface. Such biogens, for example atmospheric CO2, may be called globally regulated. The process of their regulation is organised as follows.
If the external concentration of a certain globally regulated biogen differs from the community's optimum, the community activates processes aimed at compensation of that difference. Direction and rates of these processes are the same in communities of equal competitiveness. Compensating processes can be based on increasing productivity as compared to destructivity, or vice versa. For example, if the global atmospheric concentration of CO2 exceeds the community's optimum, the community can try to decrease the internal CO2 concentration of the local ecosystem depositing excessive CO2 in organic form. This will induce a physical influx of CO2 into the local ecosystem.
If such minor local change gives the community advantage, i.e. it makes it more competitive, such community can force out other communities that cannot perform such change. As a result, there appears a large set of communities all ensuring the same flux. Thus there will be a global flux of CO2 to biota until the global atmospheric CO2 concentration equals the community's optimum. The excessive atmospheric CO2 will be removed from the atmosphere and deposited in organic form in humus or other organic stores. So, small relative changes of concentration of biogens performed by local communities may lead to large absolute changes in global environment (see Section 5.6 for more details).
Internal correlation of individuals inside an ecological community is characterised by a certain radius, i.e. it becomes weaker with distance and dies out at a certain critical value of it. In other words, biological communities as all other internally correlated biological objects (e.g. bodies of living organisms) are characterised by finite size. This property of ecological communities follows from the necessity to form populations consisting of a large number of communities in order to support their stability. Thus, a single community cannot occupy a very large territory. However, due to the absence of visible boundaries delimiting the adjacent communities, the characteristic size of ecological communities is difficult to evaluate directly. Visible boundaries are only observed in the simplest communities encountered in the biosphere — epilithic lichens (see the book cover). Lichen community consists of only two species, an alga (synthesiser) and a fungus (reducer). Individuals of both species are so tightly correlated that lichens are formally classified as species. The picture on the book cover shows different communities of Lecidea spp.. that are delimited from each other by visible boundaries.
Indirect estimates show that ecological communities never exceed several tens of meters in size (Section 3.5). In a non-perturbed forest large trees are likely to perform the function of the community centre, around which the other community components (bacteria, fungi, small invertebrates) are tightly combined.
Such consideration renders "homeless" large animals (reptiles, birds, mammals) in that sense that they apparently do not belong to any particular ecological community due to the small size of the latter as compared to the feeding territories and home ranges of most animals. Rather, large animals may be regarded as a certain component of the environment, which is regulated by the communities in the same manner as the concentrations of globally regulated biogens. Large animals are encountered in the overwhelming majority of ecosystems, which indicates that their presence in the community contributes to the competitive capacity of the latter (see Sections 4.5 and 6.7 for discussion of ecological functions of large animals). Correlated interaction of large animals with other species in the community mostly consists in a correct choice of food and a strictly-specified share of consumption allocated to large animals within the community. Community is able to control the share of consumption of every particular species of large animals via optimisation of their population density. If the population density of a given species of large animals deviates from the optimum, ecological community may react to that by changing environmental conditions favourable for that species. For example, when too many large herbivores are present, the community may reduce production of edible parts of plants and at the same time increase production of poisonous mushrooms or thorny parts of plants. As a result, the average time spent by a large animal in that community will be reduced and, accordingly, their birth rate and death rate will be affected as well. All normal communities proceed with such impact until the population density of large animals relaxes to its initial value optimal for all normal communities.
1.11 Natural distribution of energy consumption over individuals of different body size
The complex programme of biotic regulation, genetically encoded into natural biological species, comprises information about peculiarities of functioning and optimal population densities of species, that uniquely determine the amount of energy consumed by individuals of a particular species.
Figure 1.1 gives distribution of consumption of the primary production of plants over heterotrophs of different body sizes. This distribution is based on published data for different natural terrestrial ecosystems and is universal for all ecological communities of the terrestrial biota. Notice that the most part of primary production (more than 90%) is consumed by the smallest organisms, mostly bacteria and fungi. One may say that bacteria and fungi together with photosynthesising plants constitute the core of any ecological community. Medium-sized organisms, invertebrates mostly, consume less than 10% of the primary production leaving less than one per cent of it to be consumed by large vertebrates.
Fig. 1.1. Share of consumption of the net primary production allocated to heterotrophic individuals (bacteria, fungi, animals) of different body size in natural terrestrial ecosystems (Gorshkov, 1981). The solid curve gives the universal distribution found in all nonperturbed terrestrial ecosystems. The area enveloped by the solid curve is equal to unity. Numbers in percent give the relative input of different parts of the histogram. The dashed line describes violation of the natural distribution caused by the present-day anthropogenic perturbation of the biosphere. Area under the anthropogenic peak (7%) corresponds to food of humans, cattle fodder and anthropogenic consumption of wood (Gorshkov, 1995).
The observed distribution of energy consumption is not random. It is arranged in such a way that the smallest absolute amount of energy is to be consumed by the largest organisms that are characterised by the largest relative fluctuations of consumption. Large animals consume plant production by confiscation of substantial amounts of biomass accumulated in leaves, branches, trunks of living trees etc. This inevitably leads to sharp fluctuations of a community's biomass. In other words, environmental impact of a single large animal is very substantial and sometimes can even lead to complete degradation of the community on a local scale. To prevent such situations on a larger scale, population densities of large animals are kept low in natural communities, so that the cumulative energy consumption of large animals and its absolute fluctuations appear to be small.
Each bacterial cell consumes but a tiny part of the net primary production, the total flux of consumption being ensured by a huge population of bacteria. Relative fluctuations of consumption of the smallest organisms appear to be very low due to the operation of the law of great numbers (see Section 3.5 for more details). The smallest organisms are therefore allocated the largest absolute part of consumption (more than 90%, Figure 1.1). Such distribution allows the community to keep absolute fluctuations of consumption introduced by any species below the natural level of fluctuations of plant productivity. Thus the distribution in Figure 1.1 corresponds to the maximum possible stability of the community's organisation.
Each organism is characterised by a strictly specified set of internal organs and a strictly specified distribution of fluxes of nutrients and energy going through different organs. Similarly, each community is characterised by 1) a strictly specified species composition and 2) a strictly specified distribution of fluxes of matter and energy going through different species in the community.
Each biological species is characterised by its hereditary genetic information. Random changes of genetic information of natural species as well as violation of the natural distribution of energy fluxes in the community disintegrates the internal community structure, reduces its regulatory potential and, consequently, elicits unfavourable environmental changes. Evidently, most environmental risks are associated with reduction of energy fluxes ensuring functioning of the dominant species of the community — plants, bacteria and fungi. Disturbance of these community components has an immediate adverse impact on the environmental quality. In contrast, even complete elimination of species of large animals affects the community's well-being only after a lapse of time.
Significant danger is also associated with increase in population density of large animals, when their consumption goes beyond the limits prescribed by the natural distribution (Figure 1.1). Such an increase occurs at the expense of the smaller-sized species that perform the largest amount of work on regulation of the environment. The fact that distribution presented in Figure 1.1 is universal for all terrestrial ecosystems suggests that communities where large animals are allowed to dominate energetically, lose their ability to regulate the environment and cannot compete with normal communities where the share of energy consumption by large animals is limited. Thus, biotic regulation of the environment on a global scale corresponds to the condition when biosphere as a whole conforms to the natural energy distribution represented in Figure 1.1. It means, in particular, that large mammals altogether may consume not more than one per cent of the net primary production of the global biota.
Natural ecological communities are completely destroyed on territories occupied by arable lands, where people cultivate monocultures and consume more than half of their primary production. Arable lands account for less than 10% of the continental area of Earth. Taking into account that people do not consume primary production of the oceanic biota, we conclude that the anthropogenic consumption of primary production associated with arable lands does not significantly exceed the ecological limit outlined by the natural distribution (Figure 1.1 ). However, with allowance made for pastures and, especially, exploitation of forests, the global consumption of the net primary production of the biosphere by humankind appears to exceed the ecological limit by nearly an order of magnitude (dotted line in Figure 1.1 ). This results in violation of the global biotic regulation mechanism and entails the observed global environmental changes, in particular the unprecedented growth of the atmospheric CO2 concentration, acid rains, ozone depletion etc.
Modern practice of forest exploitation is based on the so-called forest
management. Forest management essentially represents a series of
anthropogenic impacts imposed on the forest community in order to maximise
biological production of economically valuable wood. The regulatory
potential of forest communities is completely neglected and destroyed
during such management. For example, fires (often referred to as
natural disturbances2) are commonly used in the United
States to speed up growth of valuable tree sorts.
2[Fires are indeed encountered in nature. However, indirect estimates show that more than 99% per cent of modern spontaneous fires are completely due to anthropogenic activities (see Section 6.8.3). Under natural environmental conditions fires represent a natural calamity and are encountered at least one hundred times less often than at present. To cope with fires the natural biota has invented a special mechanism of the quickest possible recovery of ecosystems disturbed by fires, i.e. the mechanism of forest succession (Sections 6.7 and 6.8).]
Such policy completely ignores the fact that fires eliminate most part of the organic matter accumulated in the community and, by doing so, deprive from nutrition the dominant species of the community (bacteria and fungi) that under natural conditions perform, together with plants, the most important work on environmental regulation. Burning of organic matter or any other way of its confiscation from the forest community can be compared to extermination of food resources that support working population of the society.
It is often stated that anthropogenic management may improve some ecological function of forests that at the moment seems to people to be the most important, e.g., to enhance sequestration of carbon in forests by restructuring their species composition, see, e.g., (Shvidenko et al., 1997). It is clear to everybody that only those who know how a mechanism works, may improve it. As shown in Chapter 7 (see also Section 1.13 below), ecological communities are characterised by unprecedented complexity and interrelation of all their components. Fluxes of information going through natural communities are such that people will never be able to account for all the characteristics controlled by the biota. Thus, people can in no way improve the functioning of the natural biota. In very much the same manner as any medicine given to a healthy man may only impair his condition, any anthropogenic impact imposed on natural communities may only disintegrate their functioning and weaken their regulatory potential.
Absolutely all medicines are carefully tested for possible dangerous indirect effects before they are offered to people. Chemists selling medicines are legally responsible for their quality. Medicines are tested on short-lived animals, while characteristic lifetime of trees is equal to one-two hundred of years. Thus, it is impossible to test the proposed "improving" ecological measures for their possible indirect effects, because such testing will take several decades in the least. Namely this fact allows people to speak eloquently about how the natural biota can be restructured in favour of the people. When the dangerous, possibly irreversible, environmental effects of the implemented measures come up in a hundred of years, there will be already nobody to punish. Thus, all ecological decisions connected with restructuring of natural communities are loaded with environmental danger.
Meanwhile estimates based on the analysis of the global carbon cycle (Section 6.5) show that if forest-rich states reduced the rate of forest exploitation by approximately 40% and allowed natural processes of recovery of forest communities to dominate on the protected areas, the present-day growth of atmospheric CO2 could be stopped. That effect would be due not to fixation of a certain amount of carbon in wood, as it is often stated, but due to restoration of the regulatory potential of the whole of the natural biota on the protected areas. Note that most developed countries that have completely exhausted their natural forests, remain perfectly prosperous in the economic sense without forest industry incorporated into their economy. In countries where forest industry does exist, it does not anyway play a major role in the economy. For example, according to the World Bank data (World Bank, 1997) the contribution of forest industry into the Russian Gross National Product does not exceed one per cent.
All this means that a complete permanent ban on commercial logging in all the remaining global forest estate will by no means lead to collapse of the global economic system. If such radical measure is taken, the present day global changes will not only be stopped but even reversed. As a result, the non-perturbed preindustrial global environment will be restored. Meanwhile the present-day situation remains paradoxical, when the natural regulatory mechanism of forests communities, which is vitally important to the whole humanity, is being destroyed by about one per cent of the world's working population. The future generations of humans are likely to categorise the modern forest exploitation together with such antihumanitarian crimes of the past as, for example, the Inquisition of the medieval ages.
1.12 Conserving biodiversity or biotic regulation?
For a very long period of civilisation development natural species of the biosphere have been classified as useful for people, useless for people and harmful for people. Useful species were those few species that were actively used by people in agriculture, cattle-breeding, medicine etc., harmful species were those that interfered with anthropogenic activities. Useful species were protected, harmful species were struggled with. The rest of the biosphere species, of no particular interest to general public, were not protected and could be done away with if their conservation could stop the progress of civilisation.
At present there exist many scientific as well as public movements for conservation of biodiversity. But still there are no commonly accepted scientific arguments for conservation of biodiversity. Arguments that are put forward either are based on aesthetics or represent an appeal to the unique nature of species genomes and the impossibility to restore them in case of species extinction. The weakness of such arguments is often evident even to those people who put them forward. The overwhelming majority of people cannot afford watching biological species within their natural ecological niche. Most people have to content themselves with infrequent visits to zoos, where a random selection of species (large animals mostly) is usually represented. Nobody has ever tried to conserve species of bacteria, though they, as we have seen, play a most important role in the biosphere. Regarding the genetic aspect of species conservation, one should note that until now people have been using about several hundred species from the existing ten million (Thomas, 1990) and the number of the widely used species has no tendency to grow. There are no reasonable grounds to expect that all the ten million species of the biosphere will ever be used by humankind. It remains unclear why people should protect them, often at the expense of economic growth, the benefits of which, in contrast to that of conserving biodiversity, are very transparent. It is not surprising that the decision-makers in all countries are very reluctant in sacrificing the economic progress to a poorly argued task of biodiversity conservation.
The concept of the biotic regulation of the environment provides a very clear scientific base to the necessity of biodiversity conservation. Natural species of the biosphere are not aesthetic objects to be looked at by humans, they are not hypothetical genetic resources of humankind or potential forest pests. They are indispensable parts of the working mechanism of maintenance of favourable for people environment on both local and global scale. Each species inside the community performs strictly specified work on stabilisation of the environment. The programme of this work is determined by the species genome. And due to the unique nature of species genomes this work cannot be done by any other species.
Summing up, there is an urgent need for a new conservation strategy aimed at ensuring the continued biotic regulation of global environmental conditions, as the present focus on the conservation of biodiversity per se is incapable of securing Earth's environment. This new strategy must recognise the need for sufficiently large areas of terrestrial landscapes to be allowed to continue without human interference.
1.13 Biotic regulation cannot be replaced by technology
Natural biota has been keeping the global environment in a favourable for life state during the four billion years of life existence. There is no doubt that, provided the necessary limitations on anthropogenic activities are imposed, the natural biota will be able to further perform that important regulatory function.
On the other hand, the on-going development of the civilisation yields considerable progress in the industrial technology. Many technological processes of today, though expensive, ensure almost total purification of wastes and do not cause local pollution. It may seem that further progress in science and technology may result in creation of a technological system that would be able to regulate the environment on a global scale and could substitute the existing natural mechanism of the biotic regulation.
At a closer look, however, such possibility proves to be improbable (see Chapter 7 for a detailed treatment of this problem). This statement can be easily proved when comparing information processing capacities of the natural biota and civilisation.
The main energy flux in any natural community goes through plants, fungi and unicellular organisms. Cellular metabolism results in strictly specified ordered chemical reactions that pertain all molecules of the cell. It means that the flux of information goes through memory cells of molecular size. Using the known value of cellular metabolism, it is possible to estimate information flux going through one bacterial cell. It turns to be of the order of information flux processed in a modern PC. In the biosphere each square micron of Earth's surface is covered by about one hundred cells of various organisms. Surface area of the biosphere coincides with that of Earth and constitutes 5 x 1026 square microns. Thus, the total number of cells in the biosphere is of the order of 1028—1029 cells, i.e. about 20 orders of magnitude (!) more than the world population of humans. Even if all people on Earth had one PC each, our civilisation would be able to process an information flux that is 20 orders of magnitude smaller than it is processed by the natural biota.
No computer technology of future generations can cover the information flux gap of 20 orders of magnitude between the biota and civilisation. To do that it would be necessary to build computers with memory cells of molecular size and cover the Earth's surface with a continuos network of such computers, i.e. to re-create the natural biota in its preindustrial state. Thus, we conclude that natural biota is the only possible mechanism of formation and stabilisation of a suitable for life global environment and climate.
1.14 Ecological problems of humankind
Ecological problems of humankind are unprecedented in the biosphere. No other species has ever come so close to complete extermination of its own ecological niche. Which is more, no other species has ever threatened the integrity of the biosphere as a whole, like people do today. We will now briefly discuss the peculiarities of our own species that have caused such situation.
All life-important knowledge of the environment in immobile organisms — plants, fungi — is confined to their genetic hereditary information. Meanwhile, in order to move, locomotive animals need to have concrete information about the place where they live and about other components of environment, that are encountered during the lifespan of a certain organism. Such information changes from one generation to another during the whole time of species existence and cannot therefore be written in genomes of locomotive animals. Once written, it may become useless for the next generation. Thus, during their lifespan locomotive animals need to process additional non-genetic information about their environment. Such information accumulates in the memory of each locomotive organism (which in most animals is localised in brain) and vanishes with death of the organism.
Transmission of non-genetic information from one generation to another is biologically forbidden. Such situation guarantees against transmission of wrong information about environmental conditions that may change during the lifespan of the next generation. Mountains become hills, brooks turn into rivers, lakes become bogs, old trees are replaced by young ones etc. Information that correctly characterises environment at one moment of time, may become wrong at the next moment. Transmission of such information may lead to wrong behaviour of organism in the next generation and disintegration or even degradation of the biological community. That is why transmission of this information is genetically forbidden in all biological species except Homo sapiens.
Homo sapiens proved to be able to accumulate cultural information that, as well as the genetic information of a species, can be transmitted from generation to generation. But, unlike genetic information, the amount of cultural information increases from generation to generation. Homo sapiens is a unique biological species that can learn and use knowledge of environment accumulated by former generations.
At present the cultural information of the whole humankind is comparable to the genetic information of Homo sapiens as a species (Chapter 7). The major part of the present-day cultural information of humankind is represented by scientific information about the surrounding phenomena. Fundamental studies of physical, chemical and biological laws of nature gave people an opportunity to work out technology-based applications of the acquired knowledge. People were able to inhabit all continental areas of Earth and began to actively explore the outer space.
Development of energetic and technology enabled people to adapt to almost any environmental conditions encountered in the biosphere. When inhabiting new territories, people transformed nature into a most favourable for them state. People cut down forests and dried out bogs to build houses, turned large territories into fields and pastures to get food. People built mines, roads and factories. These activities were necessarily accompanied by industrial and agricultural wastes being emitted into the transformed environment.
In the meantime people changed the structure of natural biological communities, reducing population numbers of those species that people were not dependent upon, and increasing population numbers of useful species, that gave necessary products like meat, crops, timber etc. People also changed genetic programmes of natural species creating new breeds of cattle and new sorts of agricultural plants. As a result, ecological communities began to lose their ability to compensate environmental perturbations, while namely the human-induced degradation of the environment became the most important of destabilising factors.
People began to pollute the environment in the ancient past. But until the beginning of the 20th century natural biota had been able to counteract the anthropogenic pollution (Section 6.4). Pollution was noticeable only in local areas, where it could be easily coped with. Meanwhile on regional and global scales environment was maintained by the natural biota in a healthy and stable state. Ecology as a science was mainly concerned with interactions of species of natural ecological communities with their environment and was considered as a branch of biology.
When the rate of anthropogenic pollution began to increase together with the rate of human-induced degradation of natural biological communities, the natural biota began to lose its ability to stabilise environment on regional and global scales. People realised that the current state of environment strongly depends on anthropogenic impact imposed on it. As a result, ecology turned into a much wider branch of knowledge than it used to be, and began to comprise not only biological, but also economic, political and ethical issues.
Ecological problems of the civilisation manifested themselves clearly when the anthropogenic disturbance of natural biological communities closely approached a certain threshold level, beyond which biota loses its ability to stabilise the environment. Evidently, the "below-threshold" stable existence of human civilisation that took place in the past, is possible in the future as well. To ensure it, it is necessary to substantially restrict anthropogenic activities on the planet and, inevitably, impose constraints on the growth and sustainable number of the world human population. The concept of unlimited economic growth, inherent to the modern thinking, is in apparent contradiction with the mentioned above principles of stable existence of civilisation. It is evident that unlimited growth will finally lead to over-exploitation of natural biota and complete loss of its stabilising properties. Then people would have to maintain suitable for life environment themselves, using available scientific and technological knowledge. We have seen in the previous section that such a perspective appears to be absolutely improbable.
Functioning of natural species that assures biotic regulation of the environment, is determined by the genetic information coded in genomes of these species. This information is hereditary and remains unchanged during the whole period of species existence. Genetic programme of any species is tightly coupled to the natural environmental conditions where the species exists, i.e. to its natural ecological niche. The work performed by species within a community remains meaningful and contributes to the environmental stability if only such work is performed in the natural ecological niche.
Homo sapiens, as well as all other species, originated in the process of biological evolution. Modern paleontological data provide an opportunity to trace the whole succession of evolutionary events that had lead to the origin of Homo sapiens. Thus, Homo sapiens, as all other species, originally belonged to a certain ecological community. Inside the community Homo sapiens, as well as all other species, did a certain amount of work aimed at stabilisation of the environment.
When a species is placed under distorted environmental conditions, actions of individuals that remained meaningful in the natural ecological niche no longer correspond to the task of environmental stabilisation. Moreover, under distorted conditions activity of living individuals may even enhance adverse environmental changes and cause complete degradation of the environment. Such situation is often observed when a certain species invades an alien ecological community. In the framework of its own ecological community this species performs correct work aimed at most effective stabilisation of the environment in concert with all other species of the community. But within an alien community the same behavioural programme of actions may come in conflict with programmes of the aboriginal species. This leads to disintegration of community, degradation of environment and, finally, death of the population of the alien species. Examples of such local ecological catastrophes include, between others, introduction of alien mammals (goats, rabbits) into ecosystems of small islands, invasion of alien seaweed into waters of countries with active foreign trade etc. Also, it is a well-known fact that in many countries the public opinion is seriously concerned with destructive influence that is imposed on aboriginal natural biological communities by alien species that penetrate into the country with purchased biological products.
Behavioural patterns of animals have a genetic basis, i.e., they are written into the species' genome. Thus, when an animal is placed under unnatural conditions of a foreign ecological niche, the strategy of its behaviour does not change significantly. In other words, animals proceed to work according to the old genetic programme, which under distorted conditions may cause degradation of the environment. The same effect is achieved when under normal environmental conditions the species' genome is artificially modified. In such a case the genetic programme of a species no longer corresponds to environmental stabilisation and its carriers are forced out from normal ecological communities. For example, artificial breeds of domesticated animals and sorts of plants may only exist when directly supported by people. Left alone, they are forced out by their wild competitors (e.g., planted cultures are choked by weeds).
Within the natural ecological niche the genetic programme of Homo sapiens should ensure correct behaviour of people that would allow them to exist sustainably and contribute to the environmental stability of their own niche. Such sustainable way of living can be still observed in indigenous societies. Behaviour of people is based on the genetically encoded programme of positive and negative emotions. All things modern people tend to do, e.g., improve their living standard or care for children, are based on that genetic programme of emotions.
During the preindustrial era those actions of people that brought about positive emotions corresponded to environmental stability of the ecological niche of humans. Development of civilisation has not changed the genetic programme of humans, so that the same actions still bring about positive emotions. However, development of civilisation drastically changed the environment where people now live, as compared to the natural ecological niche of humans. Meanwhile human activities, including political and economical ones, continue to be governed by genetically programmed system of emotions. Those ideals and goals of people that had fit the natural ecological niche and ensured its stability, prove to be destabilising in the modern world. Such situation leads to further degradation of natural biota, regional and global environmental changes, continuing population growth, growing social tension, decay of genetic information of the Homo sapiens species (manifested in increasing frequency of all kinds of physical and mental disorders).
So far the civilisation has been developing spontaneously in the direction determined by the genetically coded emotional programme of people. Human brain has been continuously solving the problem of bringing about positive emotions. It is namely this emotion-based spontaneous development of civilisation that has resulted in the modern unfavourable environmental situation.
However, during the process of cultural evolution people have discovered an important factor that allows to work out emotion-independent strategies of behaviour. It is the scientific approach. This method of exploring environment formed the basis for the scientific and technological revolution of the two last centuries that predestined current ecological problems of humankind. It is not unlikely that all major discoveries that could help people to effectively transform their natural environment have been already made by scientists (Ginzburg, 1985). The fundamental science is now tackling issues of doubtful potential importance to the modern problems of humanity. This is presumably the reason of the observed decreasing enthusiasm featuring decisions of many governments to support fundamental scientific research.
However, fundamental scientific research is the only method that could help people to find a way out from the present-day ecological crisis. Using this method people can find out what life style is optimal for Homo sapiens as a species. What is more favourable for people — living in industrial landscape with all modern conveniences of the civilisation but deprived of free communication with nature due to high population density and high degree of industrialisation or living inside natural ecological communities having, possibly, lower levels of consumption. To answer these questions serious fundamental research is needed. At present, however, such questions are not even put forward. The predominating viewpoint in most countries is that priority should be by all means given to high standard of living, which implies good food, clothes and housing at sacrifice of surrounding nature, global ecological safety and ethic and health requirements of people with respect to communication with nature. Yet only fundamental investigations of the above questions and working out an emotion-free but reason-based strategy of development of our civilisation can help people overcome the global ecological crisis.
It is clear to everybody that the global population of people cannot increase infinitely, because the size of our planet is finite. Yet Earth is very large, and it makes an impression that the limits on population growth imposed by the finite size of the planet will only become tangible in a distant future.
More rigid limits on the global human population are usually associated with the necessity to feed all people (Daily et al., 1998). Already at present more than ten per cent of human population is starving. Unfair distribution of food and other resources over different countries is usually considered as the main reason for such situation. Solution to the food problem is sought in the social sphere. A more intensive exploitation of Earth's resources is also considered as a possible way out.
Very different limitations on the global population growth are imposed by the condition of conservation of the regulatory potential of natural biota on a global scale. These limitations are dictated by the task of ensuring long-term environmental stability for secure development of an infinite number of future generations of people. To quantify these limitations is one of the ultimate goals of this book (see Section 6.5).
Until now the importance of the global demographic problem has been underestimated both by general public in most countries of the world as well as by specialists in different fields of science and culture. So far evaluation of scientific discoveries in different fields of knowledge has been based on the criterion of catering for positive emotions of people. Such use of scientific knowledge has led to further cultivation of the natural biota, population growth and degradation of the environment.
Overpopulation of Earth presents the most important global ecological problem of today. Until now the on-going exponential population growth of humankind (not encountered in any other natural species of the biosphere) was regarded as a natural state of affairs, Figure 1.2. In the eighties all humankind rejoiced on the occasion of birth of a five billionth human being. The birth of a six billionth human inhabitant of Earth in the end of 1999 was met with a more pronounced reservation.
Figure 1.2. World human population growth.
However, only India and China have attempted to regulate population growth on a state level. In other countries negative population growth may be envisaged as a catastrophe on a national scale. In mass media calls for depopulation are from time to time compared to genocide. The most important thing is that such attitude towards the overpopulation problem is shared by the overwhelming majority of general public in most countries. This becomes especially clear from the fact that very few political leaders touch upon that problem in their election campaigns.
What causes such attitude towards one of the most important problems of today? Why any attempts to analyse the problem on scientific grounds are either ignored, hushed up or repulsed? Those few people who do come to think seriously over the problem and immediately realise its importance and the vital necessity of most urgent measures, may get an emotional impression that there exists a global-scale conscious plot of subversive actions aimed at undermining the stability of humankind's existence by means of well-conceived propaganda against limits to population growth.
However, as soon as the destabilising attitude towards population growth is basically the same in all countries and threatens the existence of the whole humanity, it seems unreasonable to look for some mystique external forces that are consciously working in that direction. Rather, the reasons of such situation are to be sought in the genetically programmed system of emotions governing behaviour of Homo sapiens individuals.
Humankind as a whole is composed of several races and a great variety of nations, that may be compared to subspecies and populations of other species of the biosphere. Different subspecies and populations of a single species may have morphological and behavioural differences. However, as shown in Section 1.6, these differences are caused by different localisation of random deviations from the normal genetic programme of the species in different populations and subspecies of that species (see also Chapters 9 and 10). Meanwhile the meaningful genetic information is the same in all populations and subspecies of a single species. The total number of genetic deviations is limited by the stabilising selection and is also approximately the same in different populations of the same species. On this basis, all populations of a single species may be considered as genetically equivalent.
The same way of reasoning may be applied to races and nations of people. Therefore, racism, as well as nationalism, that assume the existence of genetic differences in the levels of organisation between different races and nations, does not have any scientific grounds and has been rejected by the overwhelming majority of the human society.
Unlike many other animals, humans are characterised by a very high degree of sociality genetically encoded into the species genome. People that inhabit the same territory tend to form associations of different levels of hierarchy. Within such associations (families, communities, nations, states) people are divided according to their professional specialisation. As a result of specialisation, all members of a single association become dependent upon each other. The internal correlation of states (association of the highest level) is maintained by competitive interaction of states on a political, economical and other arenas.
Sociality of humans consists in correlated interactions of people. As well as all other properties of living objects sociality of humans is genetically encoded into our species. Decay of the genetic information responsible for sociality is prevented by competitive interaction of different associations of people, let us call them for simplicity countries. Sociality is maintained due to the fact that countries with high degree of sociality (i.e. high degree of correlation between its members) appear to be more competitive than countries with low degree of sociality. If competitive interaction of nations were forbidden, sociality as a genetic property of people would undergo rapid decay.
Sociality of humans is manifested in the fact that people enjoy social contacts. The great number of existing parties, communities, movements etc. shows that being within a correlated association of friends, co-citizens, co-thinkers etc. brings about positive emotions in the majority of people. Naturally, most people try to increase the competitive capacity of the association to which they belong, be that a football team, a political party or a country.
Sociality forms the basis for such noble feeling as patriotism, which makes people give their lives for the happiness of their motherland. However, sociality is also responsible for such phenomena as wars, racism and nationalism. In the modern world such manifestations of the sociality threaten the existence of the whole civilisation. Another genetically pre-programmed property of humans, their ability to critically analyse the observed phenomena and accordingly correct their behaviour, helped people to realise that threat and begin a world-wide campaign against military conflicts and any manifestations of racism and nationalism.
Sociality is ultimately responsible for the unwillingness of the modern humankind to impose limitations on the population growth. People act to increase the competitive capacity of their country. The competitive capacity of a country is to a large degree determined by the total number of citizens. World history of the last several thousand years may be reduced to a succession of events when more rapidly growing nations invaded territories of slowly growing (sustainable) aboriginal nations and quickly forced the latter out from their territories. In such a manner territories of the Americas, Australia, Siberia and the Far East in Russia were invaded.
There exists therefore a contradiction between the emotional desire of people to maintain high competitive capacity of their state or nation on the one hand, and the understanding that unlimited population growth threatens the existence of humankind and should be struggled with, on the other. A solution to the problem should be sought in finding different ways of competitive interaction of countries, which may be elaborated at the level of United Nations and assume the form of international laws. Such safe ways of competition may involve interactions of people in the spheres of sports, science and culture. However, such way of civilisation development will remain an utopia until the majority of people begin to realise the danger of unlimited population growth and become capable of conscious emotion-free actions in that regard. This stresses the need of ecological education of people all over the world.
On the above basis, the following conclusions can be made:
— Like social animals, people form large internally correlated associations (countries) and maintain their level of organisation via competitive interaction of countries.
— Competitive capacity of a country is tightly coupled to the population number of its citizens. As a result, the more rapidly growing nations gradually acquire advantage on the world's political arena.
— Although the human population growth presents the most serious threat to the global environmental stability, it is at present disadvantageous to most countries to impose limits on population growth of its citizens.
— Until such situation persists, humanity is rapidly moving towards a global ecological catastrophe.
— Competitive interaction of countries cannot be done away with, as far as sociality is a genetically programmed property of humans.
— The way out is to be sought in uncoupling the competitive capacity of countries from the population number of its citizens by means of finding new forms of competitive interaction between countries and elaboration of new norms of the international law. To decide how to do it should become the most important urgent task of the modern world community.