Krasilov, 1997. Metaecology-12. Organisms. Directionality. Diversity. Fitness. Coherence

Stairs (conclusion). Parallelism. Systemicity.

V.O. Krasilov. Metaecology. M.: Paleontological Institute of the Russian Academy of Sciences, 1997. 208 pp. Part 12.

Organisms. Directionality. Diversity. Adaptability. Coherence.

Crises. Biosphere rhythms. Progress. General scheme.

Organisms At one time it was believed that the living and the non-living existed according to incompatible laws and therefore had different origins. But the biosphere is first and foremost a system of biogenic cycling of matter in the outer shells of the Earth, which developed on the basis of abiogenic cycling involving photochemical reactions (such as the photolysis of water vapor in the atmosphere). The origin of life can thus be linked to the stabilization of the primary cycling system through the transformation of photochemical decomposition reactions into photosynthesis reactions proceeding with an increase in free energy. Organic films polymerizing on lava at high temperatures and pressures (obtained experimentally) could capture colored metal salts and utilize the energy of photochemical reactions for their own reproduction. Self-preservation is the fundamental property of any system, from a polymer to a cabinet of ministers. When speaking of the origin of life, we most often have in mind some kind of structures. But life, as L. von Bertalanffy correctly observed (L. von Bertalanffy, Problems of Life. N.Y.: Harper, 1952), is more a process than a structure. It is the process of maintaining the high-energy state of an organic system by extracting energy from the environment. Organic substances that entered the ocean probably accumulated in the form of an oil-like film. Based on model experiments, one can assume that at high temperatures and under the action of ultraviolet rays, proteinoid microspheres arose here (similar to those obtained by the American researcher S. Fox by heating a proteinoid mixture), polynucleotides, and multilayered membranes. It is believed that RNA was the primary matrix, since it can be synthesized without the participation of specialized enzymatic systems. The relationships between RNA particles and proteinoid microspheres could have been of the "predator-prey" type. This is indicated by the aggressiveness of the nucleic acids of RNA viruses invading the cell — perhaps the most ancient organisms surviving to our day — which are simultaneously capable of entering into symbiotic relationships with the host's genes. The primary RNA particles could also probably transform from predators into symbionts of the microspheres. They thus acquired a protein coat and, owing to their high selective capacity with respect to metabolic products, stabilized the internal environment of the microsphere. The evolutionary solution to the well-known "chicken and egg" paradox (the reproduction of proteins requires nucleic acids, the reproduction of nucleic acids requires proteins — so what came first, RNA, DNA, or proteins?) apparently lies in the fact that earlier there was neither "chicken" nor "egg" in the form we know them today. In the course of co-evolution, nucleotide and protein particles exchanged roles. Not only did their mutual dependence increase, but a revaluation of values took place — the transformation of ends into means and vice versa. Protein bodies served merely as casings for nucleic acids. But the casings were required to be stable, capable of adapting to various conditions. Over time their intrinsic value increased, and now the idea that DNA chose aardvarks and humans for its own reproduction sounds grotesque. We, the "casings," regard DNA as nothing more than a means of our own reproduction, and not without reason, although traces of the earlier relationship are still discernible in the mechanisms ensuring the stability of replication of the genetic matrix at the expense of the "casings." One of these archaic mechanisms is natural death. We have only indirect data on the initial stages of organic evolution, but we can assume that even then processes were already underway that would repeat themselves many times in the future: namely, the transition from antagonistic relationships to cooperation, the "assembly" of complex constructions from ready-made blocks, and the "revaluation of values" with a shift of the "ends-means" relationship in favor of the forming system of higher rank. As in the evolution of industrial production, the decisive role was played by the improvement of technology, which allowed the development of new energy sources and the transition to less scarce raw materials. The first photosynthesizers probably used hydrogen sulfide or other highly reduced compounds as the hydrogen donor rather than water. The ability to split water conferred independence from raw materials whose reserves are limited. Metabolic by-products — oxygen, for example — initially lethal to life, became increasingly involved in reproduction, becoming vital necessities. More complex technologies required specialization of species. Directionality In accordance with thermodynamic principles, the goal of development of every ecosystem and of the biosphere as a whole consists in reducing entropy production: in the ecosystemic sense, the ratio of dead organic matter (mortmass) withdrawn from cycling to the total mass of living matter (biomass). The latter in this context corresponds to the volume of the system, with which the ratio of externally incoming to internally accumulated energy of the system — its enthalpy — is directly correlated. These ratios explain the general tendency toward an increase in biomass. The primary bacterial biosphere, with its comparatively small biomass of microbial mats, produced enormous quantities of biokosic matter, as evidenced by deposits of shungite, black-shale, and iron-siliceous formations. The latter constitute approximately 20% of the total volume of sedimentary rocks. With the growth of biological diversity and the increasing structural complexity of microbial communities in the Late Proterozoic, the production of biokosic matter declined substantially (see H.J. Hofmann: J. Paleont., 1976, 50, 1040-1073). The appearance of multicellular organisms and their colonization of the land in the Silurian and Early Devonian resulted in an enormous increase in the biomass contained in the biosphere. It is well known that the biomass of the terrestrial biota many times exceeds that of the marine biota. Accordingly, subsequent changes in biomass were linked primarily to events on land, such as the lignification of plant tissues as a means of increasing their durability; the appearance of arborescent plants with deciduous shoots, as in the archaeopteridales; the development of leaves as periodically or gradually shed photosynthetic organs; the formation of vessels as the principal conducting elements and the associated increase in the potential volume of wood. In the course of these events, there was an increase in the biomass of terrestrial vegetation, which constitutes the greater part of the living matter of the biosphere. If one compares the Euramerican Carboniferous forests — the most productive plant formation of the past — with contemporary tropical rainforests, it becomes apparent that in the former, woody species typically constitute about 50%, in the latter up to 70%; the maximum tree height in the former reaches 40 m, in the latter up to 60 m. At the same time, the former were coal-forming, whereas peat accumulation is uncharacteristic of the latter, and even the forest litter does not reach any appreciable thickness. In terms of tree species diversity (herbaceous plants are more difficult to compare, as only an insignificant fraction of them is preserved in the fossil state), modern forests many times surpass Carboniferous ones, having approximately 40-100 species per hectare, whereas in the Carboniferous, according to the richest localities representing comparable areas, this figure does not exceed twenty. Comparisons of this kind show that the growth of biomass on the scale of geological eras was accompanied by an increase in biological diversity and a decrease in mortmass production. Diversity In the general sense, diversity is an informational indicator of structural complexity, upon which both the absolute growth of biomass and the reduction of the relative increment of mortmass ultimately depend. Biological diversity serves as such an indicator for any biological systems. Thus an organism as a system is characterized by the diversity of physiological processes and the structures that support them, while the diversity of ecosystems is determined by the number of ecological niches, which we traditionally (though not entirely adequately) judge by the number of species. As the primary unit of classification of animals and plants, the species constantly attracts the attention of systematists. Species concepts diverge across a broad spectrum between Platonic eide and conventional subdivisions established for convenience. But species are distinguished not only by systematists and not only by humans, but also by animals, though perhaps with somewhat different boundaries. This means that species are closer to eide than to conventional divisions of an alphabetical reference guide. Species in the systematist's sense have meaning only as reflections (perhaps not always and not in every respect accurate) of species as elements of natural systems. The structure of a natural system satisfies the requirement of efficient utilization of available energy resources and represents a set of functional roles (ecological niches), the performance of which presupposes one or another level of specialization of organisms. The concept of the ecological niche troubles philosophically naive biologists with the idea of predetermination it contains: can niches exist without species, before them? However, the predetermination of a niche is the natural result of ecosystem development according to a predetermined scenario (of course, Smoktunovsky's Hamlet differs from Olivier's Hamlet, but these are merely performative variants of the idea of Hamlet). The more complex the structure, the higher the specialization, the fewer the waste products. A certain minimal set — producers of living mass, its consumers at two or more levels, consumers of dead matter — is obligatory and predictable in all cases. But these are very broad divisions of functional space, which are subdivided into ever narrower niches. Alongside efficiency, role specialization solves the problem of ensuring the stability of the system in its interactions with other systems. Some organisms firmly hold territory and maintain spatial structure, like trees forming the forest canopy; others fill gaps and colonize new spaces, like weeds. The differences between organisms are determined primarily by their position in the system and the role they perform. Somewhere at the intersection of role specializations lies a set of stable characters that determines the uniqueness of a species and of any other unit of natural classification (diagnostic characters are thus provided by nature itself, but we may for practical reasons select some of them rather than others, which introduces an inevitable element of subjectivism into the concept of species). The uniqueness of a species is a means of avoiding interspecific competition, which is weaker the smaller the overlap of ecological niches. Reproductive barriers normally arise between species, preventing the blurring of characters essential to the system and consolidated by it, but the degree of their permeability is also linked to role specialization. The system thus plays the role of a Platonic demiurge. Given the stability of its structure, one must speak of predetermination: roles without which the performance cannot take place will be filled one way or another. They carry the image of the ideal performer — the idea of the species, its eidos. The actual performer, as on a stage, does not perfectly match the ideal. Its influence on the role through feedback imparts dynamism to the process of mutual adaptation. As an indicator of the structural complexity of an ecosystem, closely related to its efficiency, diversity is subject to fluctuations that reflect general evolutionary tendencies. Closely linked to diversity is dominance — a systemic indicator characterizing the distribution of species abundances in a biotic community. When one or a few species have a much higher abundance than all others, one speaks of mono- or oligodominant communities. Their diversity is as a rule substantially lower than in polydominant communities. Thus dominance — a sign of high competitive ability — is combined with simplification of community structure. This regularity, as we shall see below, extends also to metaecological systems. An increase in diversity accompanies an increase in biomass and a reduction in mortmass production. Diversity is directly related to the individuation of species and inversely related to overlap of ecological niches (competition) and excess population abundance. The dynamics of diversity accordingly characterizes progressive, crisis-driven, or regressive development of an ecosystem and, on a global scale, of the biosphere. Evolutionarily progressive species promote increased diversity in other species cenologically associated with them by stabilizing the habitat and creating new niches (just as flowering plants created the niche of anthophilous animals). These correlations are examined in subsequent sections. Fitness The tautological nature of the theory of natural selection has been noted repeatedly: the most fit survive, i.e., those that survive. At the same time, some adaptations are simply remarkable. The flowers of orchids, for example, resemble the female of an insect. The male transfers pollen while attempting to mate with the flower. Yet even more remarkable is the fact that most plants manage perfectly well without such extravagant adaptations. The theory of natural selection presupposes a given set of environmental parameters to which adaptation must occur. If an organism survives and reproduces successfully, it is fit. It does not explain why creatures with limited reproductive capacity — elephants or humans, for example — are found at the end rather than the beginning of evolutionary lineages. More productive, apparently, is the examination of this problem in terms of systemic goals, since fitness is the capacity for stable existence within a system, achieved through interaction with positive feedback. If the goal consists in energetic efficiency, then adaptation lies in narrowing the ecological niche (specialization) and reducing abundance to limits that allow the population to maintain itself without depleting resources — i.e., to ensure it a stable existence. Since encounters between mating partners thereby become less frequent (while encounters with individuals of closely related species become more frequent), there arises the need for — sometimes extravagant — adaptations ensuring effective fertilization and isolation from other species. Thus the complex system of the tropical rainforest contains millions of species represented by small numbers of individuals. If the goal becomes resistance to external impacts, then adaptation proceeds in the direction of broadening the niche (despecialization) and the capacity to rapidly increase in numbers. Thus millions of lemmings periodically inundate the tundra and serve as prey even for the reindeer. Adaptation in the above sense is characteristic not only of population systems but also of genetic systems. In essence, the notorious problem of the inheritance of acquired characters reduces to the possibility of adaptation at the level of the genome. This possibility was at one time categorically denied. However, every highly organized system potentially possesses adaptive capacities, and the genome is no exception. External conditions alter the demand for particular products of matrix synthesis, compelling the genetic system through the principle of feedback to increase or reduce their production. The corresponding activation of some system elements at the expense of others entails regulatory and structural reorganizations that over time acquire an irreversible character. This is, of course, merely a schematic outline that does not reveal the diversity and complexity of the specific mechanisms of genome adaptation. For the time being, it suffices to note that adaptation is a multi-layered process occurring simultaneously at various levels of the organization of life. The most obvious error of traditional evolutionism consists in equating fitness with population growth, whereas in reality fitness consists in maintaining equilibrium. Under stable conditions, internal mechanisms of population regulation are developed, reducing the amplitude of fluctuations. Adaptation is first and foremost the development of properties that promote the attainment of a stable state by the system. In a system that is continually disturbed by external influences, the predominance of external regulatory mechanisms with negative feedback leads to sharp fluctuations in abundance and, consequently, to the acquisition of a capacity for rapid population growth, which can be regarded as the most primitive mechanism of adaptation, characteristic of the early stages of system development. Coherence One of the difficulties confronted by evolutionary theory consists in the fact that natural selection, by enhancing fitness, leads in some cases to increasing complexity and in others to simplification; and if the former is considered progress, then the latter must logically be recognized as regression. This contradiction is also resolved by means of the systems approach. In an ecological system with a stable structure, the interaction of elements comes to the fore, leading to the differentiation of functions and specialization. In coherently developing species, relationships of complementarity emerge, accompanied by the loss of functions that are transferred to partners (simplification), or by the perfection of specialized organs and the emergence of interaction mechanisms, as in plants and insects (complexification). Integration in some cases reaches symbiosis and transformation into what is virtually a single organism (lichens). There are grounds for supposing that the living cell arose on the basis of symbiosis. The symbiotic theory of the origin of cellular organelles is most fully developed with respect to chloroplasts. They display different structures and apparently derived from several groups of endosymbiotic photosynthesizers. Chloroplasts with three- and four-layered envelopes, as in euglenids and dinoflagellates, may have been acquired through two or more rounds of endosymbiotic integration and reduction. In cryptophyte algae, chloroplasts are found in periplastid compartments that also contain a nucleomorph (the remnant of a nucleus) and ribosomes of the eukaryotic type. This is all that remains of the eukaryotic symbiont — a red alga that in turn inherited its chloroplast from its prokaryotic symbiont. The more that becomes known about such multi-stage fusions, the more plausible appears the idea that the genomes of higher organisms are the result of the merger of genomes of various unicellular organisms. It is not by chance that we have cells with flagella and cilia. Thus through self-sacrifice — simplification and loss of autonomy — enmity is transformed into love. But coherent processes are at least partly reversible. Proviruses, integrating into the nuclear genome, function as regulatory genes, but when the system breaks down, the original antagonistic relationships manifest themselves in tragic fashion in oncogenesis. When the tropical rainforest is spoken of as a stable system, what is meant is the constancy of internal conditions, not resistance to external impacts — the conflation of these concepts leads to serious misunderstandings, particularly in conservation activities. The state approximating a stationary one is maintained through internal mechanisms regulating species abundances and is easily lost when external mechanisms are engaged — direct elimination or undermining of the resource base. Unfortunately, such systems do not possess sufficient resilience to resist natural catastrophes and human impact. With the disintegration of the system, evolutionary tendencies are reversed. The subtle mechanisms of interaction between species break down, giving way to coarser adaptations to abiotic factors (insect pollination replaced by wind pollination). Thus a specialist who has made a brilliant career in medicine or law, finding himself on a desert island, loses the skills so essential in the former system and masters the primary professions of hunter, woodcutter, and tiller of the soil. Species exit their systemic role and find themselves face to face with untamed elemental forces, against which in the first instance nothing can be opposed except accelerated development and increased birth rates. Narrow specialization gives way to a tendency toward broadening of the ecological niche and increased general resilience across a wide spectrum of impacts. Acceleration of development often proceeds in such a way that organisms become sexually mature before reaching full development, sometimes at the larval stage. The features of incomplete somatic development with precocious maturation of the reproductive sphere are displayed by practically all ancestral forms of major groups of the animal and plant world. They are characteristic of the human as well, who resembles not so much the adult forms of great apes as their offspring. Acceleration as it were removes the terminal phase of development, and with it the characters of high specialization. For a specialized species — the camel, for example — it is easier to pass through the eye of a needle than to change the direction of evolution. And, as the American paleontologist Edward Drinker Cope construed his law of the "unspecialized": unless you become as children, you will not enter the next turn of evolutionary history.

Organisms At one time it was believed that the living and the non-living existed according to incompatible laws and therefore had different origins. But the biosphere is first and foremost a system of biogenic cycling of matter in the outer shells of the Earth, which developed on the basis of abiogenic cycling involving photochemical reactions (such as the photolysis of water vapor in the atmosphere). The origin of life can thus be linked to the stabilization of the primary cycling system through the transformation of photochemical decomposition reactions into photosynthesis reactions proceeding with an increase in free energy. Organic films polymerizing on lava at high temperatures and pressures (obtained experimentally) could capture colored metal salts and utilize the energy of photochemical reactions for their own reproduction. Self-preservation is the fundamental property of any system, from a polymer to a cabinet of ministers. When speaking of the origin of life, we most often have in mind some kind of structures. But life, as L. von Bertalanffy correctly observed (L. von Bertalanffy, Problems of Life. N.Y.: Harper, 1952), is more a process than a structure. It is the process of maintaining the high-energy state of an organic system by extracting energy from the environment. Organic substances that entered the ocean probably accumulated in the form of an oil-like film. Based on model experiments, one can assume that at high temperatures and under the action of ultraviolet rays, proteinoid microspheres arose here (similar to those obtained by the American researcher S. Fox by heating a proteinoid mixture), polynucleotides, and multilayered membranes. It is believed that RNA was the primary matrix, since it can be synthesized without the participation of specialized enzymatic systems. The relationships between RNA particles and proteinoid microspheres could have been of the "predator-prey" type. This is indicated by the aggressiveness of the nucleic acids of RNA viruses invading the cell — perhaps the most ancient organisms surviving to our day — which are simultaneously capable of entering into symbiotic relationships with the host's genes. The primary RNA particles could also probably transform from predators into symbionts of the microspheres. They thus acquired a protein coat and, owing to their high selective capacity with respect to metabolic products, stabilized the internal environment of the microsphere. The evolutionary solution to the well-known "chicken and egg" paradox (the reproduction of proteins requires nucleic acids, the reproduction of nucleic acids requires proteins — so what came first, RNA, DNA, or proteins?) apparently lies in the fact that earlier there was neither "chicken" nor "egg" in the form we know them today. In the course of co-evolution, nucleotide and protein particles exchanged roles. Not only did their mutual dependence increase, but a revaluation of values took place — the transformation of ends into means and vice versa. Protein bodies served merely as casings for nucleic acids. But the casings were required to be stable, capable of adapting to various conditions. Over time their intrinsic value increased, and now the idea that DNA chose aardvarks and humans for its own reproduction sounds grotesque. We, the "casings," regard DNA as nothing more than a means of our own reproduction, and not without reason, although traces of the earlier relationship are still discernible in the mechanisms ensuring the stability of replication of the genetic matrix at the expense of the "casings." One of these archaic mechanisms is natural death. We have only indirect data on the initial stages of organic evolution, but we can assume that even then processes were already underway that would repeat themselves many times in the future: namely, the transition from antagonistic relationships to cooperation, the "assembly" of complex constructions from ready-made blocks, and the "revaluation of values" with a shift of the "ends-means" relationship in favor of the forming system of higher rank. As in the evolution of industrial production, the decisive role was played by the improvement of technology, which allowed the development of new energy sources and the transition to less scarce raw materials. The first photosynthesizers probably used hydrogen sulfide or other highly reduced compounds as the hydrogen donor rather than water. The ability to split water conferred independence from raw materials whose reserves are limited. Metabolic by-products — oxygen, for example — initially lethal to life, became increasingly involved in reproduction, becoming vital necessities. More complex technologies required specialization of species. Directionality In accordance with thermodynamic principles, the goal of development of every ecosystem and of the biosphere as a whole consists in reducing entropy production: in the ecosystemic sense, the ratio of dead organic matter (mortmass) withdrawn from cycling to the total mass of living matter (biomass). The latter in this context corresponds to the volume of the system, with which the ratio of externally incoming to internally accumulated energy of the system — its enthalpy — is directly correlated. These ratios explain the general tendency toward an increase in biomass. The primary bacterial biosphere, with its comparatively small biomass of microbial mats, produced enormous quantities of biokosic matter, as evidenced by deposits of shungite, black-shale, and iron-siliceous formations. The latter constitute approximately 20% of the total volume of sedimentary rocks. With the growth of biological diversity and the increasing structural complexity of microbial communities in the Late Proterozoic, the production of biokosic matter declined substantially (see H.J. Hofmann: J. Paleont., 1976, 50, 1040-1073). The appearance of multicellular organisms and their colonization of the land in the Silurian and Early Devonian resulted in an enormous increase in the biomass contained in the biosphere. It is well known that the biomass of the terrestrial biota many times exceeds that of the marine biota. Accordingly, subsequent changes in biomass were linked primarily to events on land, such as the lignification of plant tissues as a means of increasing their durability; the appearance of arborescent plants with deciduous shoots, as in the archaeopteridales; the development of leaves as periodically or gradually shed photosynthetic organs; the formation of vessels as the principal conducting elements and the associated increase in the potential volume of wood. In the course of these events, there was an increase in the biomass of terrestrial vegetation, which constitutes the greater part of the living matter of the biosphere. If one compares the Euramerican Carboniferous forests — the most productive plant formation of the past — with contemporary tropical rainforests, it becomes apparent that in the former, woody species typically constitute about 50%, in the latter up to 70%; the maximum tree height in the former reaches 40 m, in the latter up to 60 m. At the same time, the former were coal-forming, whereas peat accumulation is uncharacteristic of the latter, and even the forest litter does not reach any appreciable thickness. In terms of tree species diversity (herbaceous plants are more difficult to compare, as only an insignificant fraction of them is preserved in the fossil state), modern forests many times surpass Carboniferous ones, having approximately 40-100 species per hectare, whereas in the Carboniferous, according to the richest localities representing comparable areas, this figure does not exceed twenty. Comparisons of this kind show that the growth of biomass on the scale of geological eras was accompanied by an increase in biological diversity and a decrease in mortmass production. Diversity In the general sense, diversity is an informational indicator of structural complexity, upon which both the absolute growth of biomass and the reduction of the relative increment of mortmass ultimately depend. Biological diversity serves as such an indicator for any biological systems. Thus an organism as a system is characterized by the diversity of physiological processes and the structures that support them, while the diversity of ecosystems is determined by the number of ecological niches, which we traditionally (though not entirely adequately) judge by the number of species. As the primary unit of classification of animals and plants, the species constantly attracts the attention of systematists. Species concepts diverge across a broad spectrum between Platonic eide and conventional subdivisions established for convenience. But species are distinguished not only by systematists and not only by humans, but also by animals, though perhaps with somewhat different boundaries. This means that species are closer to eide than to conventional divisions of an alphabetical reference guide. Species in the systematist's sense have meaning only as reflections (perhaps not always and not in every respect accurate) of species as elements of natural systems. The structure of a natural system satisfies the requirement of efficient utilization of available energy resources and represents a set of functional roles (ecological niches), the performance of which presupposes one or another level of specialization of organisms. The concept of the ecological niche troubles philosophically naive biologists with the idea of predetermination it contains: can niches exist without species, before them? However, the predetermination of a niche is the natural result of ecosystem development according to a predetermined scenario (of course, Smoktunovsky's Hamlet differs from Olivier's Hamlet, but these are merely performative variants of the idea of Hamlet). The more complex the structure, the higher the specialization, the fewer the waste products. A certain minimal set — producers of living mass, its consumers at two or more levels, consumers of dead matter — is obligatory and predictable in all cases. But these are very broad divisions of functional space, which are subdivided into ever narrower niches. Alongside efficiency, role specialization solves the problem of ensuring the stability of the system in its interactions with other systems. Some organisms firmly hold territory and maintain spatial structure, like trees forming the forest canopy; others fill gaps and colonize new spaces, like weeds. The differences between organisms are determined primarily by their position in the system and the role they perform. Somewhere at the intersection of role specializations lies a set of stable characters that determines the uniqueness of a species and of any other unit of natural classification (diagnostic characters are thus provided by nature itself, but we may for practical reasons select some of them rather than others, which introduces an inevitable element of subjectivism into the concept of species). The uniqueness of a species is a means of avoiding interspecific competition, which is weaker the smaller the overlap of ecological niches. Reproductive barriers normally arise between species, preventing the blurring of characters essential to the system and consolidated by it, but the degree of their permeability is also linked to role specialization. The system thus plays the role of a Platonic demiurge. Given the stability of its structure, one must speak of predetermination: roles without which the performance cannot take place will be filled one way or another. They carry the image of the ideal performer — the idea of the species, its eidos. The actual performer, as on a stage, does not perfectly match the ideal. Its influence on the role through feedback imparts dynamism to the process of mutual adaptation. As an indicator of the structural complexity of an ecosystem, closely related to its efficiency, diversity is subject to fluctuations that reflect general evolutionary tendencies. Closely linked to diversity is dominance — a systemic indicator characterizing the distribution of species abundances in a biotic community. When one or a few species have a much higher abundance than all others, one speaks of mono- or oligodominant communities. Their diversity is as a rule substantially lower than in polydominant communities. Thus dominance — a sign of high competitive ability — is combined with simplification of community structure. This regularity, as we shall see below, extends also to metaecological systems. An increase in diversity accompanies an increase in biomass and a reduction in mortmass production. Diversity is directly related to the individuation of species and inversely related to overlap of ecological niches (competition) and excess population abundance. The dynamics of diversity accordingly characterizes progressive, crisis-driven, or regressive development of an ecosystem and, on a global scale, of the biosphere. Evolutionarily progressive species promote increased diversity in other species cenologically associated with them by stabilizing the habitat and creating new niches (just as flowering plants created the niche of anthophilous animals). These correlations are examined in subsequent sections. Fitness The tautological nature of the theory of natural selection has been noted repeatedly: the most fit survive, i.e., those that survive. At the same time, some adaptations are simply remarkable. The flowers of orchids, for example, resemble the female of an insect. The male transfers pollen while attempting to mate with the flower. Yet even more remarkable is the fact that most plants manage perfectly well without such extravagant adaptations. The theory of natural selection presupposes a given set of environmental parameters to which adaptation must occur. If an organism survives and reproduces successfully, it is fit. It does not explain why creatures with limited reproductive capacity — elephants or humans, for example — are found at the end rather than the beginning of evolutionary lineages. More productive, apparently, is the examination of this problem in terms of systemic goals, since fitness is the capacity for stable existence within a system, achieved through interaction with positive feedback. If the goal consists in energetic efficiency, then adaptation lies in narrowing the ecological niche (specialization) and reducing abundance to limits that allow the population to maintain itself without depleting resources — i.e., to ensure it a stable existence. Since encounters between mating partners thereby become less frequent (while encounters with individuals of closely related species become more frequent), there arises the need for — sometimes extravagant — adaptations ensuring effective fertilization and isolation from other species. Thus the complex system of the tropical rainforest contains millions of species represented by small numbers of individuals. If the goal becomes resistance to external impacts, then adaptation proceeds in the direction of broadening the niche (despecialization) and the capacity to rapidly increase in numbers. Thus millions of lemmings periodically inundate the tundra and serve as prey even for the reindeer. Adaptation in the above sense is characteristic not only of population systems but also of genetic systems. In essence, the notorious problem of the inheritance of acquired characters reduces to the possibility of adaptation at the level of the genome. This possibility was at one time categorically denied. However, every highly organized system potentially possesses adaptive capacities, and the genome is no exception. External conditions alter the demand for particular products of matrix synthesis, compelling the genetic system through the principle of feedback to increase or reduce their production. The corresponding activation of some system elements at the expense of others entails regulatory and structural reorganizations that over time acquire an irreversible character. This is, of course, merely a schematic outline that does not reveal the diversity and complexity of the specific mechanisms of genome adaptation. For the time being, it suffices to note that adaptation is a multi-layered process occurring simultaneously at various levels of the organization of life. The most obvious error of traditional evolutionism consists in equating fitness with population growth, whereas in reality fitness consists in maintaining equilibrium. Under stable conditions, internal mechanisms of population regulation are developed, reducing the amplitude of fluctuations. Adaptation is first and foremost the development of properties that promote the attainment of a stable state by the system. In a system that is continually disturbed by external influences, the predominance of external regulatory mechanisms with negative feedback leads to sharp fluctuations in abundance and, consequently, to the acquisition of a capacity for rapid population growth, which can be regarded as the most primitive mechanism of adaptation, characteristic of the early stages of system development. Coherence One of the difficulties confronted by evolutionary theory consists in the fact that natural selection, by enhancing fitness, leads in some cases to increasing complexity and in others to simplification; and if the former is considered progress, then the latter must logically be recognized as regression. This contradiction is also resolved by means of the systems approach. In an ecological system with a stable structure, the interaction of elements comes to the fore, leading to the differentiation of functions and specialization. In coherently developing species, relationships of complementarity emerge, accompanied by the loss of functions that are transferred to partners (simplification), or by the perfection of specialized organs and the emergence of interaction mechanisms, as in plants and insects (complexification). Integration in some cases reaches symbiosis and transformation into what is virtually a single organism (lichens). There are grounds for supposing that the living cell arose on the basis of symbiosis. The symbiotic theory of the origin of cellular organelles is most fully developed with respect to chloroplasts. They display different structures and apparently derived from several groups of endosymbiotic photosynthesizers. Chloroplasts with three- and four-layered envelopes, as in euglenids and dinoflagellates, may have been acquired through two or more rounds of endosymbiotic integration and reduction. In cryptophyte algae, chloroplasts are found in periplastid compartments that also contain a nucleomorph (the remnant of a nucleus) and ribosomes of the eukaryotic type. This is all that remains of the eukaryotic symbiont — a red alga that in turn inherited its chloroplast from its prokaryotic symbiont. The more that becomes known about such multi-stage fusions, the more plausible appears the idea that the genomes of higher organisms are the result of the merger of genomes of various unicellular organisms. It is not by chance that we have cells with flagella and cilia. Thus through self-sacrifice — simplification and loss of autonomy — enmity is transformed into love. But coherent processes are at least partly reversible. Proviruses, integrating into the nuclear genome, function as regulatory genes, but when the system breaks down, the original antagonistic relationships manifest themselves in tragic fashion in oncogenesis. When the tropical rainforest is spoken of as a stable system, what is meant is the constancy of internal conditions, not resistance to external impacts — the conflation of these concepts leads to serious misunderstandings, particularly in conservation activities. The state approximating a stationary one is maintained through internal mechanisms regulating species abundances and is easily lost when external mechanisms are engaged — direct elimination or undermining of the resource base. Unfortunately, such systems do not possess sufficient resilience to resist natural catastrophes and human impact. With the disintegration of the system, evolutionary tendencies are reversed. The subtle mechanisms of interaction between species break down, giving way to coarser adaptations to abiotic factors (insect pollination replaced by wind pollination). Thus a specialist who has made a brilliant career in medicine or law, finding himself on a desert island, loses the skills so essential in the former system and masters the primary professions of hunter, woodcutter, and tiller of the soil. Species exit their systemic role and find themselves face to face with untamed elemental forces, against which in the first instance nothing can be opposed except accelerated development and increased birth rates. Narrow specialization gives way to a tendency toward broadening of the ecological niche and increased general resilience across a wide spectrum of impacts. Acceleration of development often proceeds in such a way that organisms become sexually mature before reaching full development, sometimes at the larval stage. The features of incomplete somatic development with precocious maturation of the reproductive sphere are displayed by practically all ancestral forms of major groups of the animal and plant world. They are characteristic of the human as well, who resembles not so much the adult forms of great apes as their offspring. Acceleration as it were removes the terminal phase of development, and with it the characters of high specialization. For a specialized species — the camel, for example — it is easier to pass through the eye of a needle than to change the direction of evolution. And, as the American paleontologist Edward Drinker Cope construed his law of the "unspecialized": unless you become as children, you will not enter the next turn of evolutionary history.

Diversity. In a general sense, diversity is an informational indicator of structural complexity, on which both the absolute growth of biomass and the reduction of the relative growth of dead mass ultimately depend. Biodiversity serves as such an indicator for any biological system. For example, an organism as a system is characterized by a diversity of physiological processes and the structures that support them, and the diversity of ecosystems is determined by the number of ecological niches, which we traditionally (though not entirely adequately) judge by the number of species. As the basic unit of animal and plant classification, the species constantly attracts the attention of systematists. Species concepts cover a wide spectrum – from Platonic eidos to conditional subdivisions identified for convenience. But species are distinguished not only by systematists, and not even only by humans, but also by animals, although perhaps within somewhat different limits. Thus, species are closer to eidos than to conditional divisions of an alphabetical directory. Systematists' species make sense only as a reflection (perhaps not always and not entirely accurate) of species – the elements of natural systems. The structure of a natural system corresponds to the requirement of efficient use of available energy resources and represents a set of functional roles (ecological niches), the performance of which implies a certain level of organism specialization. The concept of an ecological niche troubles philosophically naive biologists with the idea of predetermination it contains: can niches exist without species, before their appearance? However, niche predetermination is a natural result of ecosystem development according to a predetermined scenario (of course, Smoktunovsky's Hamlet differs from Olivier's Hamlet, but these are only performance variations of Hamlet's idea). The more complex the structure, the higher the specialization, the less waste. A certain minimum set – producers of living mass, its consumers of two or more levels, consumers of dead matter – is mandatory and predictable in all cases. But these are very broad divisions of functional space, which are subdivided into increasingly narrow niches. Along with efficiency, role specialization solves the task of ensuring system stability in its interactions with other systems. Some organisms firmly hold territory, preserve spatial structure, like trees that form a forest canopy; others fill gaps, colonize new spaces, like weeds. Differences between organisms are primarily due to their position in the system and their role. Somewhere at the intersection of role specializations lies a set of stable traits that determine the uniqueness of a species and any other unit of natural classification (diagnostic traits, thus, are given by nature itself, but we can choose certain ones for practical reasons, which introduces an unavoidable element of subjectivity into the understanding of a species). The uniqueness of a species is a way to avoid interspecific competition, which is weaker the less the ecological niches overlap. Reproductive barriers usually arise between species, preventing the blurring of traits that are essential for the system and fixed by it, but the degree of their permeability is also related to role specialization. The system, thus, acts as a Platonic demiurge. Due to the stability of its structure, we have to talk about predetermination: roles without which the performance will not take place will be occupied one way or another. They carry the image of the ideal performer – the idea of the species, its eidos. The specific performer, as on stage, does not fully correspond to the ideal. His influence on the role in the feedback loop provides dynamism to the process of mutual adaptation. As an indicator of the structural complexity of an ecosystem, closely related to its efficiency, diversity fluctuates, reflecting general evolutionary trends. Closely related to diversity is dominance – a systemic indicator that characterizes the distribution of species abundance in a biotic community. If one or several species have a significantly higher abundance than all others, then they speak of mono- or oligodominant communities. Their diversity is usually significantly lower than in polydominant communities. Thus, dominance – a sign of high competitiveness – is combined with a simplification of the community structure. This pattern, as we will see later, extends to meta-ecological systems. An increase in diversity is accompanied by an increase in biomass and a decrease in dead mass production. Diversity is directly related to species individualization and inversely related to ecological niche overlap (competition) and excess population size. The dynamics of diversity, accordingly, characterize the progressive, crisis, or regressive development of an ecosystem and, on a global scale, the biosphere. Evolutionarily progressive species contribute to increased diversity of other species, cenotically related to them, by stabilizing the habitat and creating new niches (similar to how flowering plants created the niche of anthophilous animals). These correlations are discussed in the following sections.

Adaptability. The theory of natural selection has been repeatedly noted for its tautology: the fittest survive, i.e., those who survive. At the same time, some adaptations are simply astounding. Orchid flowers, for example, resemble female insects. The male carries pollen, trying to mate with the flower. However, even more striking is the fact that most plants get along perfectly well without such extravagant adaptations. The theory of natural selection assumes a certain given – a set of environmental parameters – to which one must adapt. If an organism survives and reproduces successfully, it is adapted. It does not explain why creatures with limited reproductive capacity, such as elephants or humans, are at the end, not at the beginning of evolutionary lines. It is likely more productive to consider this problem in terms of systemic goals, as adaptability is the ability to exist stably in a system, achieved through interaction with positive feedback. If the goal is energy efficiency, then adaptation consists in narrowing the ecological niche (specialization) and reducing numbers to limits that allow the population to be preserved without depleting resources, i.e., to ensure its stable existence. Since encounters between mating partners become rarer (and with individuals of related species – more frequent), there is a need for – sometimes extravagant – adaptations that ensure fertilization efficiency and isolation from other species. For example, the complex system of the tropical rainforest contains millions of species, represented by a small number of individuals. If the goal is resistance to external influences, then adaptation proceeds towards expanding the niche (unspecialization) and the ability to rapidly increase numbers. For example, millions of lemmings periodically flood the tundra and serve as food even for reindeer. Adaptation in the aforementioned sense is characteristic not only of population but also of genetic systems. In essence, the notorious problem of the inheritance of acquired characteristics boils down to the possibility of adaptation at the genome level. This possibility was once categorically denied. However, every highly organized system potentially has adaptive capabilities, and the genome is no exception. External conditions change the need for certain matrix synthesis products, forcing the genetic system, by feedback, to increase or decrease their production. The corresponding activation of some elements of the system at the expense of others entails regulatory and structural rearrangements that eventually become irreversible. This is, of course, only a schematic outline that does not reveal the diversity and complexity of specific genome adaptation mechanisms. It is sufficient to note that adaptation is a multi-layered process that occurs simultaneously at different levels of life organization. The most obvious error of traditional evolutionism is the identification of adaptability with an increase in numbers, whereas in reality, adaptability consists in maintaining equilibrium. In stable conditions, internal mechanisms for regulating numbers are developed, which reduce the amplitude of fluctuations. Adaptation is primarily the development of properties that contribute to the system's stable state. In a system constantly disturbed by external influences, the prevalence of external regulatory mechanisms with negative feedback leads to sharp fluctuations in numbers and, as a consequence, the acquisition of the ability for rapid population growth, which can be considered the most primitive mechanism of adaptation, characteristic of the early stages of system development.

Coherence. One of the difficulties facing the theory of evolution is that natural selection, by increasing adaptability, leads to complication in some cases and simplification in others, and if the former is considered progress, then the latter, by logical requirement, must be recognized as regression. This contradiction is also resolved using a systems approach. In an ecological system with a stable structure, the interaction of elements comes to the fore, leading to the division of functions and specialization. In species that develop in a coordinated manner, complementary relationships develop, accompanied by the loss of functions transferred to partners (simplification), or the improvement of specialized organs and the appearance of interaction mechanisms, as in plants and insects (complication). Integration in a number of cases reaches symbiosis and transformation into what seems like a single organism (lichens). There are reasons to believe that the living cell originated from symbiosis. The symbiotic theory of the origin of cell organelles is most developed concerning chloroplasts. They have different structures and likely originate from several groups of endosymbiotic photosynthesizers. In this case, chloroplasts with three- and four-layered envelopes, as in euglenoids and dinoflagellates, could have been acquired as a result of two or more rounds of endosymbiotic integration and reduction.