Kasylov, 1997. Metaecology-13. Crises. Biospheric Rhythms. Progress. General Scheme

Organisms. Directionality. Diversity. Adaptability. Coherence.

V.A. Krasilov. Metaecology. Moscow: Paleontological Institute of the Russian Academy of Sciences, 1997. 208 pp. Part 13.

Crises. Biosphere rhythms. Progress. General scheme.

General scheme (conclusion). Morality.

Crises define the boundaries of geological eras and periods lasting approximately 180 and 35 million years. Since the first figure corresponds to a galactic year, the idea arises that cosmic influences are the primary cause of biospheric crises. Indeed, the periodicity of major evolutionary events corresponds to orbital periods of precession, orbital inclination, eccentricity, and their combinations—24, 41, 96, and 413 thousand years—and, on geological timescales, to oscillations of the Solar System about the galactic plane and revolutions around the galactic center, 35 and 180 million years (with components of 6 and 23 million years), during which Earth experiences gravitational influences from concentrations of interstellar matter. (Our Galaxy is characterized by an asymmetric arrangement of the dense matter disk, which lies in the path of the Solar System during its orbit around the galactic center). Cosmic forces serve as the triggering mechanism in chains of interrelated events. The specific mechanisms governing geodynamic processes remain poorly understood. This is due to the general state of geodynamics as a science, which only relatively recently, with the advent of "new global tectonics" (1970s), moved beyond narrowly regional problems. The main achievement of global tectonics, now no longer so new, can be considered the establishment of the plate tectonics concept for Earth's solid shell and the possibility of significant displacement of plates relative to each other. However, neither the driving forces nor the patterns of plate movement were revealed. In my book "The Cretaceous Period" (1985) and other works, a rotational geodynamic model is substantiated. Its essence is that bodies of different density, composing the solid shell and deeper spheres, receive, according to the laws of physics, different rotational (angular and centrifugal) acceleration, causing their displacement relative to each other. Earth's matter is stratified into spheres of different density. The solid shell additionally consists of continental and denser oceanic plates. Rotational shifts of plates alter the ratio of land and sea, leading to the formation of folded belts. At the same time, displacements along density boundaries within the lithosphere and at its contact with the mantle generate magmatic melts fueling volcanic activity, and the accelerated rotation of the Earth's core relative to the mantle is the rotor that creates the magnetic field and governs its dynamics. Thus, the rotational model makes it possible to link all major geodynamic processes with a common energy source—Earth's rotation. The usual objection to the rotational model or its particular aspects is that rotational forces are insufficient to activate geodynamic mechanisms. However, corresponding calculations were performed for Earth's shells as monolithic formations. Their segmentation into plates substantially changes the picture. In any case, there is sufficient obvious evidence of rotational force action, such as the systematic orientation of the fault network in Earth's crust, asymmetry of oceanic coastlines, displacement of mid-ocean ridge axes in accordance with Coriolis rotational acceleration, etc. In the rotational model, the slowing of Earth's rotation, occurring under the influence of tidal friction (interaction with the Moon), and possible acceleration as a result of comet and asteroid bombardments (one of which apparently coincides with the mass extinction at the Cretaceous-Paleogene boundary), cause desynchronization of sphere rotation—and within them, of blocks or plates. As a result, movements occur at the boundaries of the core and mantle, mantle and lithosphere, oceanic and continental crust, causing magnetic field inversions, volcanic outbursts, changes in the geoid relief, sea level fluctuations, and, consequently, reorganization of atmospheric and oceanic circulation and global climate change. Since all these processes are interrelated, during crisis periods the overall instability of the biosphere as a system superimposed on Earth's outer shells increases. If, under stable conditions, evolution is directed toward specialization, the most efficient use of resources, then under unstable conditions, reduced efficiency means fewer species can coexist within one ecosystem. This is the general prerequisite for diversity reduction and mass extinctions. During crises, up to 50% or more of all species become extinct, but what is striking is not so much these figures as the sudden disappearance of dominant groups of fauna and flora, such as dinosaurs, ammonoids, giant lycophytes, and horsetails. Extinct species, as a rule, belonged to ecological dominants that determined the appearance of terrestrial and aquatic ecosystems during their flourishing. Understanding the selective nature of extinction is aided by the patterns of crisis-free development of ecological systems from pioneer stages through a series of intermediate stages to climax. Disturbances retard development at one of the intermediate stages. With prolonged maintenance of such a situation, the climax phase is, as it were, removed—climax species become extinct preferentially. They are the most characteristic, dominant species of their epoch. If a large group of organisms consists predominantly of climax species, as Late Cretaceous dinosaurs did, then extinction is irreversible. If, however, it also includes pioneer species, it still has chances for recovery. Pioneer species, by their life strategy, prove to be more resistant to crisis conditions. The extinction of dominant forms gives them a chance to realize their evolutionary potential. This is what happened with mammals after the extinction of dinosaurs. Thus, in the course of evolution, the last become first, and the first become last.

Biospheric Rhythms The creator of the biosphere theory considered its main parameters—biomass, the volume of biogeochemical cycling—to be unchanging and, consequently, unrelated to organism evolution. In the proposed model, this problem receives a different interpretation: the directionality and periodicity of the historical development of biospheric parameters underlie all evolutionary processes. As early as the last century, geologists established that throughout the history of sedimentation, the ratio of land to sea periodically changed, with alternating geocratic and thalassocratic epochs. Approximately within the same time limits, epochs of glacial and non-glacial climate alternated, or, as they now say, cold and warm biospheres (although not so much the total amount changed as the redistribution of heat). No generally accepted explanation of these rhythmic processes exists to this day. In the rotational model (see above), they develop as a result of periodic changes in centrifugal force acting on plates of different density in the continental and oceanic crust, whose isostatic equilibrium levels either converge (flattening of the hypsometric curve, low continents, shallow seas flooding their margins) or diverge (uplift of continents, regression of epicontinental seas). Epochs of accelerated Earth's rotation are characterized by compression of polar regions and expansion of low-latitude zones, where extension zones with Mediterranean seas form. During rotation slowdown, mountain structures form from stacks of thrust sheets piled on each other. The causal connection between these processes and glaciations is undoubted, although not yet clarified in detail. Isolation of polar marine basins from warm currents and uplift of low-latitude land during geocratic epochs apparently played the main role here. C. Darwin wrote about the acceleration of evolutionary processes in connection with sea level fluctuations, but this idea found no reflection in the further development of evolutionary theory. Meanwhile, the biospheric significance of eustatic cycles cannot be overestimated. Thus, in connection with land reduction (to 40% during the Cretaceous period), almost an equivalent reduction of the entire biomass occurred (the possible increase in marine biomass does not compensate for the loss of continental). Since biomass serves as one of the main sinks of atmospheric CO2, its content increases substantially, causing global warming. The same factor contributes to increased productivity of plant communities (in particular, with doubling of atmospheric CO2, a ten percent increase in crop yield is expected), as evidenced by the gigantism of herbivorous animals (peratopsids, hadrosaurs, indricotheres, etc.). At the same time, more intensive chemical weathering on land and its products entering the ocean cause a burst of productivity in marine ecosystems. Simultaneously with cyclic fluctuations, geographical redistribution of biomass occurs according to the following scheme. 1. In geocratic epochs of glacial climate, polar fronts of cold air masses prevent heat transfer to high latitudes, causing heating of the low-latitude zone. 2. Simultaneously, rapid cooling of ascending warm air currents within the latter causes abundant precipitation. Humid tropical forests develop, concentrating enormous biomass. 3. Descending air currents at the flanks absorb moisture, promoting the development of arid belts. In middle and high latitudes, precipitation amount is controlled by cyclonic activity, limited by the cold anticyclone, within the domain of which humidity is insufficient for arboreal vegetation. 4. In thalassocratic non-glacial epochs, heat is more evenly distributed over Earth's surface, the equatorial zone is colder and drier, since ascending air currents cool slowly and gradually lose moisture beyond it. There are no humid tropical forests, nor are there distinct arid belts. Mediterranean (Tethys) seas ensure the stability of the subtropical anticyclone. The zone of cyclonic precipitation shifts to high latitudes, even to the high Arctic, where arboreal vegetation develops and the main biomass concentrates. Evidence of high productivity of Arctic biomes during the Cretaceous period—giant coal deposits of Arctic islands, northern Yakutia, and Alaska, the presence of dinosaurs there. In biblical 400-year cycles, calculated from the change of generations, the global flood fits. Sodom and Gomorrah, famine and flight to Egypt, Egyptian plagues and the opening of the Red Sea rift, Babylonian captivity and the birth of Jesus of Nazareth. The invasions of steppe nomads that shook the European forest zone—Huns, Mongols, Arabs—have the same periodicity. Geological and climatic events influenced the destinies of peoples to the extent that they were connected with changes in global biomass and its redistribution over Earth's surface—the relative productivity of natural biomes that fed humanity.

Progress This contradictory concept is often equated with evolution itself. If the fittest always win, then today we have the fittest. However, Voltaire already ridiculed the progressives who believed (like Leibniz, a prototype of Pangloss) that everything is for the best in this best of all worlds. Darwin himself noted that many modern species (e.g., brachiopods) are simpler and seem more primitive than extinct ones. In sessile and parasitic organisms, adult forms are more primitive than their larvae. To resolve such contradictions, a version of different forms of progress has been proposed, which can combine or oppose each other. Biological progress is not necessarily accompanied by morphological progress. And even vice versa, morphophysiological regression (simplification of structure and functions in adult parasites to the point where they become almost a sac of sex products) can contribute to biological progress (victory in the struggle for existence). So, everything is for the best. But if, of two competing species of Drosophila, for example, one wins at temperatures below 22 °C, and the other wins above 27 °C, then which one is more progressive? And if dinosaurs defeated theriodonts, only to be defeated in turn by mammals, relatives of theriodonts, then what is progress? Evaluating progress by the outcome of competitive struggle, we inevitably come to the conclusion that this concept only makes sense in relation to more or less closely related, competing forms: the progress of fish is not at all the same as the progress of bees, and therefore, it is generally meaningless to compare a fish and a bee, as K. Baer once did. Progress is thus equated with specialization. Indeed, specialization is largely irreversible, and most predictable changes are associated with it (it is not difficult to predict, for example, the development of strong limbs in a tree-dwelling animal or webbing between fingers in an aquatic one). Even evaluations based on the principle of "better-worse" do not seem out of place here. Technologically, the human hand is clearly better than a monkey's, as it can perform many more operations. However, many consider specialization an evolutionary dead end ("Cope's Law"), and almost everyone believes it has limits. During crises, specialized forms die out first. The simplest in evolutionary terms are much more durable than the more complex organisms that appeared later. Let's try to define progress not from the perspective of a bee, fish, or human, but from the perspective of life itself. The opposite of life is death. The progress of life, therefore, consists in increasingly successful resistance to death, and the meaning of improvement is in approaching immortality. In the course of progressive life development, organisms become more and more "alive," the probability of their death from unforeseen causes decreases. When it is reported that after a typhoon, the beach is covered with a thick layer of rotting algae, thousands of fish washed ashore have died, and hundreds of birds, a few people were injured – they received medical assistance – these numbers themselves characterize progress. Organisms that we intuitively perceive as lower possess almost unlimited adaptive capabilities, but adaptation comes at the cost of huge losses. Higher organisms can be called so not because they are more complex, more efficient, or closer to us, but because they pay a smaller tribute to death. In the biosphere, there is a continuous death, a devaluation of living energy – the production of entropy. Progress, as in any developing system, consists in reducing entropy production. Higher organisms differ from lower ones primarily in lower entropy production – the death of living matter – in their populations. All other criteria are derivative. In particular, sexual reproduction is an indicator of progress, as it helps preserve genotypes that carry unfavorable mutations in the homozygous state, and thus reduces the level of mortality, as does increased fertility, care for offspring, intelligence, ability to learn, predict, etc. Evolutionary progress consists in the accumulation of such properties, and the human species possesses them to a greater extent than any other. At the same time, the development of human civilization can be seen as a natural continuation of evolutionary trends originating from unicellular organisms. With an increase in the level of organization, the function of individual preservation becomes increasingly important relative to the function of species preservation (genetic matrices), which in lower organisms is achieved at the cost of the destruction of many individuals in the process of natural selection. Adaptations that protect against unforeseen environmental changes – protective structures and reactions, thermoregulation, and other homeostatic properties, care for offspring – usually develop not in one, but in several evolutionary lines, ensuring their more reliable preservation (parallelism is a peculiar means of preservation). Due to this, in the course of progressive evolution, there is an accumulation of adaptive traits that form a multi-layered protective belt. Another way of preservation is to reduce the unpredictable by developing the ability to predict approaching events. For lower organisms, any change is unpredictable, the consequences are catastrophic, and the preservation of life requires mass sacrifices. The higher the organization, the lower the probability of death – not of life in general, but of each living being – from unpredictable influences. This is achieved by developing more diverse relationships with the environment, the ability to perceive and process more information due to the complication of both the information apparatus – sensory organs, nervous system, signaling systems, computational and analytical abilities – and the genome structure. Prediction is initially based on lawful empirical generalizations, accessible to higher animals, and then on the explanation of events – a unique ability of intelligent humans.

The general scheme of the task of ecosystem evolutionary theory is to link the change in ecosystem parameters - biomass, productivity, mortmass - with the evolution of organism diversity, their life strategies and morphology, the mechanisms of inheritance of these changes, and ultimately to arrive at patterns related to humans and their evolutionary future. As we have already said, an ecosystem is formed to support a certain process: in the case of an ecosystem, the process of converting non-living substance into living substance. This work is carried out with a certain efficiency coefficient, which can be, in the first approximation, estimated by the ratio of biomass to mortmass, since the existing biomass is a positive result of the ecosystem's work, and the accumulated mortmass is a negative result, un-reprocessed waste (one can argue that mortmass creates a certain stability reserve and that under conditions of constant stress, for example, in the permafrost zone or in the desert, it is necessary; however, this only proves that under stress conditions, ecosystems are less efficient if necessary; similarly, states in danger create powerful defensive structures, which are necessary but do not indicate the efficiency of the economic system). Efficiency is achieved, first of all, through role specialization - the distribution of ecological niches, which underlies species differentiation and thus determines their diversity. Humid tropical forests convincingly demonstrate a direct relationship between diversity and biomass and an inverse relationship with mortmass. Biomass increases along with the complexity of the internal structure, the indicator of which is diversity. To understand the mechanisms that govern diversity, let's imagine a situation where one species occupies the entire living space (which the human species consciously or unconsciously strives for and has almost achieved in urban environments). This must be a species with great adaptive capabilities and high resistance to a wide variety of influences, allowing it to ignore heterogeneity in conditions, i.e., to perceive the environment as "finely grained" (for a species more sensitive to environmental conditions, the same environment would be "coarsely grained"). However, as the population grows, consumption increases, and according to a well-known ecological rule, a shortage of trophic resources reduces resistance to any influences (everyone could have verified the validity of this rule from their own experience). This factor forces the habitat to be limited to a part of the living space with optimal conditions for the given species, leaving the rest to other species (thus, the energy crisis forces us to abandon expensive programs for exploring the depths of the sea, the Far North, and other habitats unfavorable to humans). Now the "coarsely grained" nature of the environment is increasingly felt. In fact, any heterogeneity of conditions can be used to delineate ecological niches and increase the number of species. At the same time, the appearance of another species at any trophic level introduces additional heterogeneity, opening up new niches at lower and higher levels, and these, in turn, affect the middle ones, and so on. Thus, the transition to a "coarsely grained" strategy of occupying ecological space includes a positive feedback mechanism that ensures exponential growth of diversity. It is known, however, that the growth of diversity does not continue indefinitely; the exponential curve flattens out at a more or less high level. This level - the carrying capacity of the ecosystem - is determined by trophic resources and the efficiency of their use. Trophic potential depends on the amount of incoming solar radiation (more in low latitudes than in high latitudes). The variable quantities here are the Sun's luminosity and orbital parameters, and efficiency is inversely related to two main ecological parameters - the average overlap of ecological niches and the average population density. In the course of progressive evolution of the ecosystem, as well as during a short repetition of its ecological succession, both of these decrease. Niche overlap tends to zero, which means a transition to non-competitive coexistence. Population density tends to be sufficient for stable reproduction. In unstable conditions, this value is higher, as it includes excess density, which serves as a buffer against harmful influences. Organisms. Direction. Diversity. Adaptability. Coherence. V.A.Krasylov. Metaecology. M.: Paleontological Institute of the Russian Academy of Sciences, 1997. 208 p. Part 13. Crises. Biospheric Rhythms. Progress. General Scheme. General Scheme (conclusion). Morale.

General scheme (conclusion). Morale.