1 General properties of the biosphere
The biosphere is the fourth shell of the Earth, containing all living organisms and that part of the planet’s substance that is in continuous exchange with these organisms. The biosphere is the area of existence of living organisms on Earth. The first ideas about the biosphere as a zone of life belonged to the French naturalist J.B. Lamarck. Literally, the biosphere is the sphere of life, since “bios” is life, and “sphaira” is a ball, sphere. This term was first introduced by the Austrian geologist Eduard Suess in 1875.
Modern ideas about the biosphere were formulated by the Ukrainian scientist V.I. Vernadsky, first in separate articles, and then in lectures given at Charles University (Prague) and at the Sorbonne (Paris). The principles that Vernadsky developed were summarized in the book “Biosphere”, published in 1926.
The essence of Vernadsky's teaching lies in the recognition of the exceptional role of living matter, transforming the appearance of the planet. Vernadsky considered the surface of the Earth as a kind of shell, the development of which is largely determined by the activity of living organisms. Vernadsky proved that living organisms have a decisive influence on all geological processes that shape the appearance of the Earth. The vital activity of living organisms determines the chemical composition of the atmosphere, the concentration of salts in the hydrosphere, the formation of soils and other processes. Living organisms not only adapt to environmental conditions themselves, but also actively change them. It is living organisms that capture and transform the radiant energy of the Sun and create the endless diversity of our world.
The most significant feature of the biosphere is the biogenic migration of atoms of chemical elements, caused by the radiant energy of the Sun and manifested in the process of metabolism, growth and reproduction of organisms. (In other words, we can say that living matter converts the energy of solar rays into potential, and then into the kinetic energy of biochemical processes.) The biogenic migration of atoms in the biosphere is based on 2 biochemical principles: the desire for maximum manifestation (“omnipresence”) of life (the ability of a living substances quickly develop free space) and ensure the survival of organisms, which ensures biogenic migration itself.
Another major aspect of Vernadsky’s teaching is the idea he developed about the organization of the biosphere, which is manifested in the coordinated interaction of living and nonliving matter, in the mutual adaptability of organisms and the environment.
The biosphere includes the lower part of the atmosphere (up to the ozone layer - at an altitude of 20-25 km), the entire hydrosphere and the upper part of the lithosphere, that is, the area where life and living organisms exist. Currently, it is generally accepted that the upper boundary of the biosphere is located at an altitude of approximately 85 km above the Earth’s surface, since it is at this altitude (in the stratosphere) that spores of microorganisms are found in a latent (hidden, sleeping) state. The lower boundary of the biosphere is located in the depths of the lithosphere, where the temperature reaches 100 0 C and is located at a depth of 1.5-2 km and 7-8 km (depending on the type of rock). Recent evidence suggests that some bacteria can exist at temperatures from absolute zero to +180 0 C, in a vacuum, in nuclear reactors.
The total mass of living matter in the biosphere is 2.42 trillion tons (2.42∙10 12 tons; mass of the biosphere 10 19 tons), which is 2 thousand times less than the mass of the lightest shell of the Earth - the atmosphere (5.15 * 10 15 tons) , 10 million times less than the mass of the earth’s crust, a billion times less than the mass of the Earth (6 * 10 21 tons). Plant biomass (phytomass) is 2.4 * 10 12 tons, the biomass of animals and microorganisms (zoomass and bacteriomass) is 0.02 * 10 12 tons (in terms of dry matter). At the same time, the species differentiation of animals is 5 times greater than the species differentiation of plants (1.5-1.7 million animal species and 300 thousand (according to Belyavsky) -500 thousand (according to Kucheryavoy) plants).
A characteristic feature of living matter compared to non-living matter is its very high activity, high reaction rate (hundreds to thousands of times greater than that of non-living matter), for example, very fast metabolism. All living matter in the biosphere is renewed on average every 8 years. The biomass of the World Ocean is renewed in 33 days, and its phytomass daily, the phytomass of land - in about 14 years due to the longer life span of terrestrial plants. The caterpillars of some insects process 100-200 times their own weight in food per day; earthworms pass through their bodies the entire 1-meter layer of soil on Earth in 200 years.
Living organisms are characterized not only by passive movement (under the influence of gravity), but also by active movement (against the flow of water, the movement of air masses).
Thanks to living organisms, the biosphere performs the following functions:
energy (accumulation and transformation of energy);
gas (the ability to change and maintain the gas composition of the habitat);
redox (intensification of these processes in space under the influence of living matter);
concentration (the ability to collect atoms of chemical elements scattered in space in one’s body);
destructive (decomposition of both organic residues and inert matter);
transport (transfer of matter and energy as a result of active movement of organisms);
environment-forming (change in physical and chemical parameters of the environment);
informational (accumulation, consolidation in hereditary structures, transmission of information), etc.
For the first time, V.I. gave an assessment of the substance of the biosphere. Vernadsky. He considered the following types of matter (7 in total) to be the main components of the biosphere:
a) living matter (plants, animals, microorganisms);
b) biogenic substance - organic and organomineral products created by living organisms during geological history (coal, oil shale, peat, oil, biosphere gases - oxygen, carbon dioxide, water, ammonia, hydrogen sulfide and others), which are a source of extremely powerful potential energy;
c) inert substance (gravitating towards permanent, immobile) - rocks of inorganic origin (that is, formed by processes in which living matter did not take part) and water; this substance is a substrate or environment for living organisms to live;
d) bioinert substance - the result of the interaction of living and nonliving substances (sedimentary rocks, soils, silts - underwater soils, natural waters) and they represent significant biogeochemical energy in the biosphere; the ratio of living and nonliving matter in bioinert matter fluctuates; for example, soil consists on average of 93% mineral and 7% organic matter.
In addition to the listed types of substances, there are also substances in radioactive decay (polonium, radium, radon, uranium, neptune, plutonium, etc.), substances of scattered atoms (rubidium, cesium, niobium, tantalum form compounds at great depths in the earth’s crust, iodine and bromine reacts only on the surface of the Earth) and a substance of cosmic origin.
2 Composition and functioning of the biosphere
The main component of the biosphere is living matter, which refers to all living organisms. An organism is a living being of a certain level of biological organization (gene-cell-organ-organism-population-community). Organisms differ from inanimate nature by a certain set of properties: cellular organization (except for viruses and phages, precellular organisms); metabolism (metabolism), with the help of which the body’s homeostasis is maintained (self-renewal, constancy of the internal environment, etc.); movement, irritability, growth, development, reproduction, adaptation, etc.
The living matter of the biosphere consists of organisms of 3 main types:
producers or autotrophs are organisms that use inorganic sources for their existence, i.e. create organic matter by recycling solar energy, water, carbon dioxide and mineral salts; This type includes green plants of land and aquatic environments, blue-green algae, and some chemosynthetic bacteria;
decomposers or destructors (they are also heterotrophs, since they do not create organic matter, but consume ready-made ones) - organisms that decompose the organic products of dead organisms (both producers and consumers) into simple compounds - water, carbon dioxide, nitrogen dioxide, mineral salts (t i.e. convert organic matter into inorganic matter); these are bacteria, lower fungi; the number of species in this group is the smallest - there are 75 thousand species with a total weight of 1.8 * 10 8 tons.
The main driving factor in the development of processes in the biosphere is the biochemical energy of living matter. Let us consider the general scheme of the biological cycle of matter in the biosphere.
Scheme of matter and energy transfer in natural ecosystems
SUN substance
energy
PRODUCERS CONSUMERS CONSUMERS
1st order 2nd order
REDUCENTS
CHEMICAL SUBSTANCES
Producers (plants) produce organic matter through photosynthesis, consuming carbon dioxide, water and energy
6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2;
chemoproducers use the energy of chemical reactions (for example, sulfur producers - purple bacteria obtain the necessary substances not from water, but from hydrogen sulfide, and produce organic matter; there are also nitrate, nitrite bacteria);
1st order consumers (herbivorous animals) consume the organic mass of plants; consumers of the 2nd order (carnivores), 3rd (carnivorous plants, mushrooms) eat other consumers;
decomposers obtain energy by consuming the organic matter of producers and consumers, decomposing the dead bodies of plants and animals into simple chemicals (CO 2 , H 2 O, minerals), closing the cycle of substances in the biosphere.
In general, the biosphere is very similar to a giant superorganism, in which the dynamic constancy of the physicochemical and biological properties of the internal environment and basic functions is automatically maintained. Thus, the biosphere is a system of interacting organisms and inanimate components of nature, and not just their totality.
In the modern view, the biosphere is a global ecosystem, an open system with its own “input” and “output”. “Input” is a stream of solar energy coming from space. “Output” are substances created during the life of organisms that, for various reasons, “fell out” of the biological cycle. This is the so-called “exit into geology” - oil, coal, sedimentary rocks, etc.
When studying the interaction of organisms with each other and with the environment, the concept of “ecosystem” is used. An ecosystem is a collection of different types of organisms living together and the conditions of their existence, which are in a natural connection with each other. The term was proposed by English. scientist A. Tansley (1935). There are 4 levels of ecosystems:
microecosystems (rotting tree trunk; lichen cushion: algae, fungi, small arthropods);
mesoecosystems (forest, pond, steppe, lake, etc.);
macroecosystems (continent, ocean);
global ecosystem (Earth's biosphere).
A synonym for the concept of “ecosystem” is the term “biogeocenosis”, proposed by the Soviet ecologist Sukachev (Vlad. Nik.). According to the definition, biogeocenosis is an area of the earth’s surface with relatively homogeneous vegetation, fauna, climatic and soil conditions, which together represent components of a single organism, interconnected by metabolism and energy. The concept of biogeocenosis corresponds to a mesoecosystem.
The relationships of living beings with each other and with nonliving matter are very complex. The number of possible connections between ecosystem members is determined by the formula:
A= ------------- ,
where A is the number of connections, N is the number of species in the ecosystem. For example, N = 1 thousand, A = 1000 * 999/2 500 thousand. Among these numerous connections there are extremely important, irreplaceable ones. (People’s interference in biosphere connections, the significance of which they have a rough idea of, often leads to undesirable consequences. For example, in the 30s in Norway they decided to destroy birds of prey (snowy owls, hawks), which reduced the number of polar partridge; hunters were given bonuses , benefits for the destruction of birds of prey; an epidemic broke out among partridges, which almost completely destroyed this species; in this case, owls and hawks played the role of orderlies.)
The most important connections are food, energy.
In addition to energy, food and chemical connections, they play a major role in the biosphere. informational communications. Living creatures on Earth have mastered various types of information: visual, sound, chemical, electromagnetic.
Unfortunately, the system of connections in the biosphere has so far been deciphered in general terms. From the point of view of cybernetics, the biosphere is a gigantic system, which, like its constituent parts - biogeocenoses, is described as a “black box”. The processes occurring inside it are encoded by nature. It is safe to say that the ecosystem in its main features is self-regulating, self-organized(see above - the organization of the biosphere is one of its most important features, according to Vernadsky). Ecologists explain the self-organization of the system with information that degrades the ecosystem. It is contained in living organisms, in their genetic code and ability to adapt to changing environmental conditions.
The above-mentioned features of the biosphere (the ability for maximum manifestation of life, high activity of living matter, the ability for self-regulation, etc.) make it sustainable system. Summarizing the results of research in the field of geology, paleontology, biology and other natural sciences, Vernadsky concludes that “the biosphere is a stable dynamic system, the equilibrium in which has been established in its main features since the Archeozoic and has been invariably active for 1.5-2 billion years. " Vernadsky proved that the stability of the biosphere during this time was manifested in the constancy of its total mass (10 19 tons), the mass of living matter, the energy associated with living matter (4.21 * 10 18 kJ), as well as in the constancy of the average chemical composition of living matter substances.
Vernadsky associates the stability of the biosphere with its diversity. All functions of living organisms in the biosphere (formation of gases, oxidation and reduction processes, concentration of chemical elements, etc.) cannot be performed by organisms of any one species, but only by their complex. This implies an extremely important point developed by Vernadsky: the Earth’s biosphere was formed from the very beginning as a complex system with a large number of species of organisms, each of which played its own role in the overall system. Without this, the biosphere could not exist at all, that is, the stability of its existence was immediately laid down by its complexity.
In accordance with the Winner-Shannon-Ashby law of necessary diversity, which is considered the basic cybernetic law, a system only has the resistance to block external and internal influences when it has sufficient internal diversity. Thus, diversity(species diversity of living organisms, diversity of natural zones, climatic conditions of existence, diversity of habitat, etc.) is another important feature of the biosphere. Based on ecosystem concepts, species diversity is not just an arithmetic value below which the living world should not fall. This is the real need of every species existing on the planet in the trophic chains of biogeocenoses and the biosphere as a whole. Species diversity must be preserved for the normal functioning of the biosphere.
3 Origin and evolution of the biosphere
The first scientific theories regarding the origin of living organisms on Earth were the theories of A. Oparin and J. Haldane. (Oparin, a Russian biochemist, put forward a hypothesis in 1923 about the possibility of the emergence of organic compounds without the participation of living matter.) According to these theories, at the dawn of geological history, abiogenic synthesis occurred, that is, in the first earthly oceans, saturated with various simple chemical compounds, under the influence the heat of volcanoes, lightning strikes and other environmental factors began the synthesis of more complex organic substances and biopolymers. Complex amino acid molecules were randomly combined into polypeptides, which in turn gave rise to the first living creatures of microscopic size.
This hypothesis has one significant drawback. There is not a single fact that would confirm the possibility of abiogenic synthesis on Earth of at least some simple living organism from non-living compounds. Thousands of experiments on such syntheses have been carried out in many laboratories around the world. The American S. Miller (1953), based on the possible composition of the Earth's primary atmosphere (nitrogen, ammonia, hydrogen, water, methane), passed an electric discharge through a mixture of gases in a special device. He managed to obtain molecules of some amino acids (the basis of protein). These experiments were repeated many times, and some scientists managed to obtain fairly long chains of simple proteins. That's all! No one was lucky enough to get even one of the simplest living organisms. Even if you use complex equipment and certain conditions, which actually did not happen on Earth.
Recently, mathematicians have calculated that the probability of the emergence of a living organism from non-living blocks is practically zero. L. Blumenfeld proved that the probability of the random formation of at least one DNA molecule (deoxyribonucleic acid) during the entire existence of the Earth is 10 -800.
The theories of abiogenic synthesis and geological data contradict. No matter how far we penetrate into the depths of geological history, no traces have been found on Earth of a period when life did not exist on it. Paleontologists have found fossil remains of rather complexly organized creatures - bacteria, blue-green algae, simple fungi in rocks that are 3.8 billion years old (the formation of the Earth was 4-4.5 billion years ago).
However, theories of abiogenic synthesis are widespread and popular nowadays. These theories are based on some general principles: 1) accumulation in the ocean of organic substances synthesized abiogenically; 2) in zones of concentration of organic substances, molecules capable of self-copying (replication) arose; 3) on the basis of replicators, mechanisms of matrix synthesis (including protein biosynthesis) and a genetic code were formed, which ensured the emergence of cells of living matter.
Religion views the emergence of life on Earth as an act of creation by God.
Some scientists, including Vernadsky, believe that living organisms were brought to Earth from space with meteorites or space civilizations.
Vernadsky was sure that life is geologically eternal, that is, there was no era in geological history when our planet was inanimate. He also believed that life is the same eternal basis of the Cosmos as matter and energy are. Based on the idea of the biosphere as an earthly, but at the same time a cosmic mechanism, Vernadsky connected its formation and evolution with the organization of the cosmos. “It becomes clear to us that life is a cosmic phenomenon, and not a purely earthly one.” “... There was no beginning of life in the Cosmos that we observe, since there was no beginning of this Cosmos. Life is eternal, just as the Cosmos is eternal.” (This is confirmed by the ability of organisms to perceive information from space, the sensitivity of organisms to the action of electromagnetic fields, etc.)
All evolutionary theories, starting with Charles Darwin, are based on the position that development proceeds from simple to complex, and that genetic information is controlled by the environment through natural selection of the fittest individuals. However, this does not take into account at all that it is the simplest creatures - prokaryotes - that are best adapted to various earthly conditions. They existed on Earth without noticeable changes in their structure for 3 billion years and during their entire existence they so significantly changed the environment and the biosphere as a whole that with the advent of new, complexly organized organisms they were forced to fade into the background. They currently thrive in places where nothing else can exist: in the concentrated salt waters of some lakes, high-temperature hydrothermal vents, even in nuclear reactors. Thus, there is an evolutionary dead end.
The creator of the theory of natural selection, Darwin himself, could not explain the phenomenon when, in the process of evolution, not the most progressive forms often have advantages. According to Darwin, a trait is fixed in subsequent generations if, thanks to it, the organism better adapts to living conditions. The natural environment itself carries out selection - that’s why it is called natural. A better adapted individual has a greater chance of surviving and producing offspring. Life shows many exceptions to this rule, even in the evolution of man himself. A more intellectually developed, experienced, educated person should better adapt to life, since he knows better how to navigate in certain circumstances, however, statistical data show that it is precisely people in professions that require higher intelligence who have fewer descendants.
In The Origin of Species, Darwin wrote that any complex organ arose as a result of numerous successive minor changes. However, thousands of such organs have now been discovered that do not comply with this rule, that is, there is no analogue of the organ in other species, for example, the gland that secretes poison in a snake, or the “capacitor” in an eel that delivers an electric shock.
Darwin believed that every species must be preceded by an almost identical parent species. However, the findings of geologists confirm that all species replaced each other unexpectedly abruptly, almost unchanged during their existence, and also unexpectedly disappeared.
If evolution really occurred through a gradual change in certain traits of species with their subsequent consolidation, then among the fossil remains of organisms there should have been a large number of intermediate forms, but in a certain layer of rocks we find the remains of only one species, and in the adjacent layer - of a different type. This cannot be explained by an incomplete paleontological picture - why did the intermediate forms of organisms disappear?
Let us consider the main stages of the evolution of the biosphere.
The first living organisms on Earth were prokarites (~ 3 billion years ago) - the simplest organisms whose cells lack a nucleus: bacteria, blue-green algae; they arose in the hydrosphere). Prokaryotes were anaerobes, i.e. existed in an oxygen-free environment (lived deep in the seas). They obtained the substances and energy necessary for life, mainly using the organic substances of the “primordial broth.” But at the same time or a little later, some organisms could obtain the necessary energy through chemical reactions (in the process of chemosynthesis) or (later) as a result of the absorption and conversion of solar energy (in the process of photosynthesis). The first chemosynthetic organisms oxidized sulfur in hydrogen sulfide to molecular sulfur or iron (+2) to iron (+3). The first photosynthetic bacteria are cyanobacteria (blue-green algae). They created molecules of simple sugars from carbon dioxide and water with the help of sunlight, releasing oxygen. Oxygen accumulated in the atmosphere, gradually replacing methane and ammonia. Aerobic organisms appeared in the ocean that used oxygen to oxidize glucose (for the oxygen breakdown of simple sugars). Living matter populated all hydrosulfur, including the surface layers of the ocean and its shallow waters. Prokaryotes had a huge impact on the composition of the atmosphere, hydrosphere, and lithosphere (increasing the oxygen content in the atmosphere, accelerating the processes of rock destruction, soil formation, etc.).
After prokaryotes, eukaryotes appeared on Earth - organisms whose cells contain a nucleus (~ 1.5-2 billion years ago). At first they were unicellular, and then multicellular organisms appeared (~ 700 million years ago). It is believed that about 600 million years ago, the most important evolutionary process began in the biosphere - the settlement of continents by living organisms. The first of these were lower autotrophic plants. About 500 million years ago, vascular plants and insects appeared. Gymnosperms appeared about 350 million years ago, and flowering (angiosperms) plants and mammals appeared at the end of the Jurassic period - about 100 million years ago (in the Mesozoic era). In the Cenozoic era: ~ 50 million years ago cereals appeared, ~ 20 million years ago the species diversity of mammals increased, the oxygen content in the atmosphere became close to modern times.
Thus, the biosphere was formed in the early stages of the development of life on Earth, and very quickly and in a rather complex form. K. Tsiolkovsky believed that numerous types of simple organisms arose on Earth at the same time. Vernadsky also emphasized the same idea.
What causes the variability of living beings in general? What is the driving force of evolution? The discovery of the genetic code has brought us closer to solving this mystery. It turned out that the double helix of DNA encrypts all the information about the organism, and according to this program its individual development occurs. (The structure of the genome* (*genome is a set of genes contained in a single set of chromosomes of a given organism) of highly organized organisms is very complex - there are 3 million nucleotide pairs in human DNA** (**nucleotide is a complex compound, an integral part of nucleic acids, high-molecular organic compounds, and other biologically active compounds).) Consequently, the variability of organisms, the emergence of new species in the process of evolution, are associated with a change in entries in the genetic code. It has been proven that genetic information is disrupted under the influence of mutagenic factors - radiation, active chemicals such as pesticides, temperature, etc. The environment is increasingly polluted by these factors due to human technological activities. The question arises: are we preparing ourselves for a “genetic” catastrophe?
Based on the achievements of genetics, it can be assumed that the evolution of the organic world occurs due to the appearance of mutations, that is, random deviations in the genetic record under the influence of mutagenic environmental factors. If new properties are beneficial for the organism, they are fixed by natural selection.
But: the results of genetic research indicate that most mutations are harmful to the body. Individuals that are born after the mutagenic influence of radiation or chemicals are infertile and non-viable. It is also known that new species artificially bred through hybridization tend to “split” into their predecessors over time (a hybrid of a wolf and a dog splits into a wolf and a dog after several generations). This indicates that the body resists the accumulation of errors (mutations) in the genetic code - including the code repair mechanism. The conclusion follows: the emergence of a new species of organisms due to mutations is unlikely.
If you compare the structure of a cell in the human body and a cell of a simple animal (for example, a ciliate), you cannot find any fundamental differences. However, each of the cells of highly organized beings, in addition to its normal functions (respiration, metabolism), also performs certain special functions related to the life of the organism. In an isolated state, a cell of a highly organized organism cannot live; it functions only in collaboration and cooperation with other cells.
The program for the functioning of a cell is written from the very beginning in its chromosomal structure, contained in genes.
The study of the evolution of the biosphere allows us to conclude that every living creature is born, develops, and fulfills its life program as an integral part of a huge superorganism - the biosphere. It, in turn, is a product of the cosmic superorganism – the Galaxy. And all galaxies are, as it were, cells of a super-superorganism - the Cosmos.
K. Tsiolkovsky summed up his thoughts about us and our place in the Cosmos: “Everything is generated by the Universe. She is the beginning of all things, everything depends on her. Man and his will are only a manifestation of the will of the Universe... not a single atom of the Universe escapes the sensation of a higher intelligent life. It is possible that the question “What gave birth to the Universe?” You can’t bet at all.” Tsiolkovsky believed that one can only guess about the cause of the Cosmos.
We know only in general terms how the program of evolution of the biosphere is carried out. In particular, it was determined that in general, the process of evolution can be considered as an increase in the volume of genetic information. For example, the amount of information in mammals is 100 thousand times greater than in bacteria. Moreover, not only the size of the genetic chain, but also its structure are of great importance. The evolution of the biosphere also shows that with any impact on the biosphere (natural or anthropogenic), its homeostasis is ensured by preserving biological diversity.
We can state another feature of the evolution of the biosphere - its increasing pace. So, if we conditionally take the age of the Earth (4.5 billion years) as one day (24 hours), then in such units life on Earth exists for approximately 20 hours, the first living organisms came out of the sea onto land 6 hours 35 minutes ago, mammals exist for 3 hours 46 minutes, man - for the last 10 seconds. And the greatest changes in the composition and characteristics of the biosphere occurred precisely in these 10 seconds.
4 Human evolution. Noosphere
The appearance on Earth of Reason, the bearer of which is man, radically changed the course of the evolution of the biosphere. According to some scientists, including the famous biologist and science fiction writer I. Efremov, only a person in earthly conditions could become a bearer of reason. (Science-fiction writers: Simak - intelligent flowers, Strugatsky - dogs, Lem - a thinking ocean of protoplasm. American biologist Bilinsky believes that under certain conditions intelligent reptiles and octopuses could appear on Earth.) For this, a person has everything necessary: powerful sense organs and, above all, vision, which can cover a large space and accurately record objects; developed limbs capable of performing work; The form of a person, his features as a thinking animal are not accidental; they most closely correspond to an organism that has a huge thinking brain. What does "huge brain" mean? Most anthropologists today believe that there is a certain minimum brain level below which its owner cannot become intelligent. This is 700-750 cm 3. However, on the other hand, brain mass is not the only condition for an animal to become intelligent. Even more important is its structure, in particular the internal structure of the cerebral cortex.
In modern people, brain volume ranges from 1200-2000 cm3. Scientists have found that the potential capabilities of the human brain exceed physiological needs by many orders of magnitude. The development of the brain of the first homonoids occurred much faster than environmental changes required. The human brain reached its modern level of complexity long before culture and civilization arose. According to some estimates, the modern human brain is used to no more than 2-3% of its potential. It seems that human evolution foresaw the future needs of man in advance and endowed him with such a “computer”, the main nodes of which are blocked and will be used someday later.
From a genetic point of view, humans' closest relatives in the animal kingdom are monkeys. The structure of the DNA molecules of humans and chimpanzees differs by only 2%. According to geneticists, humans separated from the great apes about 5 million years ago. But the predecessors of humans - Australopithecus, and then Neanderthals and Sinanthropus - are not our ancestors. Scientists now believe that the evolution of modern humans began much closer to the present time than previously thought. About 200 thousand years ago, for what reason it is still unknown, a small group of people of the modern type (Cro-Magnons) appeared in southern Africa, whose descendants 100 thousand years later settled Africa, and then settled throughout the world (through the Isthmus of Suez, reaching Eurasia). They differed from Neanderthals in their tall stature, slender body, high forehead, but less physical strength. For some time, Neanderthals lived next to Homosapiens, but they could not withstand the competition with intelligent creatures. Over time, Neanderthals did not develop, but degraded, since later Neanderthals stand further from modern humans than earlier ones. This is a dead-end branch (just like synanthropes and other forms of ancient homonoids).
The ancestral home of man was established based on the study of DNA of different racial groups. Most of the DNA is concentrated in the nuclei of cells. In each generation, nuclear DNA changes as the ancestral lines of the father and mother are shuffled. But cells contain DNA from metachondria (special formations that provide the cell with energy). Metachondria DNA is inherited only through the maternal line, i.e. this DNA can only change through random mutations. American biologists, based on an analysis of the DNA of metachondria, have established that all modern people from different regions have the same ancestor, and, in addition, a “genetic” clock also fell into the hands of specialists - due to mutations, DNA changes its structure by 3% over 1 million years. Thus, it was found that the oldest DNA is in African women (200 thousand years), the youngest is in Asian women (100 thousand years), and the youngest is in European women (50 thousand years). Consequently, human migration went from Africa to Asia and then to Europe; Racial differences among people arose relatively recently.
Human evolution is unusual. Unlike all other organisms, humans use fire, tools, housing, clothing, and other means and techniques to create their own stable environment. A person does not need to change his organization under the influence of changes in the environment. Therefore, its physical evolution practically stopped. While preserving his internal environment, man continues to change the environment on an ever larger scale. Considering the potential capabilities of the human brain, one can imagine a person’s capabilities for self-improvement and intellectual development.
Man is a new factor in the Earth's biosphere. Man not only influences the environment, but also changes at high speed the structure of the very foundations of the biosphere. In this regard, the concept of the noosphere arises. The concept of “noosphere” appeared in connection with the assessment of the role of man in the evolution of the biosphere.
The concept of “noosphere” is associated with the appearance of man in the biosphere and his evolution.
The term noosphere was first proposed in the 30s by French philosophers and natural scientists (Teilhard de Chardin, Le Roy). Literally, the term means “sphere of the mind” (noos – mind).
The noosphere is the highest stage of development of the biosphere, associated with the emergence and establishment of a civilized society in it, with the period when intelligent human activity becomes the main determining factor of development. Scientific thought and human activity have changed the structure of the biosphere, causing physical and chemical changes in all its shells (atmosphere, lithosphere, hydrosphere).
The concept of “noosphere” was filled with meaning and developed by Vernadsky, in particular, in 1944, in the article “A few words about the noosphere,” published before his death, the scientist gives his thoughts on the further development of the biosphere and its transition to a new quality - the noosphere. Vernadsky emphasized the special role of living matter in planetary processes, in the creation and development of the biosphere. Among all living beings, he singled out man as a powerful geological force capable of influencing the course of various processes in the Earth's environment and near-Earth space covered by its influence. A person is able to rebuild this environment according to his ideas and needs (thanks to human labor and intelligence).
Indeed, over the past 500 years, humanity has mastered new forms of energy - steam, electric, nuclear; learned to use almost all chemical elements. Man penetrated deep into the earth and rose tens of kilometers above its surface, went into outer space, and built space stations.
Humanity has mastered the entire biosphere and gained much greater independence from the environment than other organisms. According to Vernadsky, the noosphere is the environment surrounding humans, in which the natural processes of metabolism and energy are controlled by society. Man, according to Vernadsky, is part of the biosphere, its specific function. At the same time, the human impact on nature is sharply different in nature from other forms of living matter. Since some changes in the biosphere that have occurred under the influence of human activity are undesirable for people, Vernadsky believes that they should make certain efforts to, for example, save some species of plants and animals. Moreover, only what is useful and beneficial to people should be preserved in the biosphere. In general, the environment is alien to a person and his culture and puts pressure on a person. The biosphere is considered as a building material for creating the noosphere. The human mind in the future will be the main guiding force in the development of the noosphere.
Vernadsky's approach to this problem is essentially rationalistic. The noosphere in Vernadsky's view is actually synonymous with the technosphere that is being created on Earth today. Now within the noosphere there are: the technosphere - a set of artificial objects created by anthropogenic activity, and natural objects changed by this activity; anthroposphere – the totality of people as organisms; sociosphere - the sphere of social production activity, social relations.
Vernadsky believed that man, with the help of reason, can control processes in the biosphere. “At a certain stage of his development, a person is forced to take responsibility for the further evolution of the planet, otherwise he will have no future.” Indeed, man has achieved great achievements: he went into space, mastered the secrets of thermonuclear energy, and learned to clone animals. However, 50 years after the publication of Vernadsky’s works, it turned out that the development of the technosphere contributes to the destruction of the biosphere, in particular its main areas vital for human existence. And now it is obvious that the evolution of human society should not be aimed at conquering the natural environment, but at its harmonization. (Girusov: the disruption of the development of human activity should not go against, but in unison with the organization of the biosphere, for humanity, forming the noosphere, is connected with all its roots to the biosphere.)
According to modern ideas, the noosphere is a sphere of harmonious interaction between nature and society. This is an ideal future. The determining factor in the functioning of the noosphere is not spontaneous natural development, but high human intelligence, reason, and wisdom. The basis of the noospheric process should be the transition of humanity to social autotrophy (provision of energy resources and raw materials based on the integrity of social production and biotechnology - repeated reuse of natural and synthesized substances and materials). To transition to the noosphere, it is necessary to overcome the conflict between the cyclical and non-waste nature of biogenic processes of metabolism and energy. It is necessary to overcome the consumerist approach to nature, conservatism of thinking, create more advanced production technologies, and move to reasonable, rational management.
The noosphere also implies the life of people in a world without wars and social disasters, in a world of material prosperity, environmentally friendly products, and an unpolluted environment.
Today, Vernadsky’s idea, according to which the human mind can control all processes in the biosphere, looks absolutely unrealistic. Yu. Odum believes (1986) that despite the capabilities and abilities of the human mind to control natural processes, it is nevertheless too early to talk about the noosphere, since a person cannot predict all the consequences of his actions. This is evidenced by the many environmental problems that have arisen on our planet.
A number of scientists (Kurazhkovsky, 1992) believe that it is correct to speak at the present time about the existence of the initial stages of development of the noosphere, which have fundamental differences from its future state. Modern Russian philosopher V. Kutirev believes that the noosphere as harmony is a typical example of utopia.
Define the science of ecology.
Name the main sections of traditional ecology.
Who and when introduced the term “ecology”?
When did ecology emerge as an independent discipline?
What periods can the history of environmental development be divided into?
What does modern ecology study?
What is a “global environmental crisis”?
What are the main phenomena that mark the current global environmental crisis?
What does the concept of “natural environment” include?
What spheres does the atmosphere consist of?
Name the characteristic features of the troposphere and stratosphere.
In what area is the ozone layer located?
What is the chemical composition of the atmosphere?
What are the main ecological functions of the atmosphere?
What is "lithosphere"?
How is soil formed?
What components does soil consist of?
What are the main ecological functions of the lithosphere in general and soil in particular?
What does "hydrosphere" include?
What are the fresh water reserves on Earth?
Name the main ecological functions of the hydrosphere.
Give the concept of “biosphere”.
What are the main features of the biosphere (according to Vernadsky)?
Name the main quantitative characteristics of the biosphere.
What is the main component of the biosphere?
What are the characteristics of living matter?
Name the main types of matter in the biosphere, give examples.
What are the boundaries of the biosphere?
Define the concepts “producers”, “consumers”, “decomposers”.
What is the general scheme for the transfer of matter and energy in the biosphere?
Give the main characteristics of producers, consumers, decomposers.
What hypotheses exist about the origin of life on Earth?
Give a brief description of the main stages of the evolution of the biosphere.
How does human evolution differ from the evolution of other living organisms?
What is the "noosphere"?
Who and when introduced the concept of “noosphere”?
The concept of the biosphere. Composition of the biosphere.
That part of the lithosphere, hydrosphere and atmosphere of the Earth in which plant and living organisms exist and develop is called the biosphere. Otherwise, the biosphere is the shell of life. It includes not only the plant cover and animal population of the planet, all rivers and lakes, the water mass of the oceans, but also the soil layer, a significant part of the troposphere and the uppermost layer of the earth's crust - the weathering zone. There are practically no areas on the earth's surface where there is no life. Even in hot and arid tropical deserts or on the surface of high-altitude glaciers and polar ice, microbes and other microorganisms have been found.
The biosphere (from the Greek bios - life, sphaira - ball) is the area of systemic interaction between the living and bone matter of the planet. It represents a global ecosystem - the totality of all biogeocenoses (ecosystems) of our planet.
The first ideas about the biosphere as a “region of life” and the outer shell of the Earth were expressed at the beginning of the 19th century by J. Lamarck. In 1875, the Austrian geologist E. Suess first introduced the modern term “biosphere” into the scientific literature, meaning by it the area of interaction between the main shells of the Earth: the atmosphere, hydro- and lithosphere, where living organisms are found.
The merit of creating the integrity of the doctrine of the biosphere belongs to V.I. Vernadsky. Using this term, he created the science of “biosphere”, introduced the concept of “living matter” - the totality of all living organisms, and also assigned living organisms the role of the main transformative force of planet Earth, taking into account the activities of organisms not only at the present time, but also in the past. Therefore, the biosphere is all the space where life exists or has ever existed, i.e. where living organisms or products of their vital activity are found. That part of the biosphere where living organisms are found at the present time is usually called the modern biosphere or neobiosphere, and ancient biospheres are referred to as former biospheres, otherwise paleobiospheres or megabiospheres. Examples of the latter are lifeless accumulations of organic substances (deposits of coal, oil, gas, etc.) or reserves of other compounds formed with the direct participation of living organisms (limestones, shell rocks, formations of chalk, a number of ores, and much more).
The biosphere includes:
· Aerobiosphere - the lower part of the atmosphere;
· Hydrobiosphere - the entire hydrosphere;
· Lithobiosphere - the upper horizons of the lithosphere (solid shell of the earth).
The boundaries of the neo- and paleobiosphere are different.
The upper limit is theoretically determined by the ozone layer. For the neobiosphere, this is the lower limit of the ozone layer (about 20 km), which attenuates harmful cosmic ultraviolet radiation to an acceptable level, and for the paleobiosphere, this is the upper limit of the same layer (about 60 km), because oxygen in the Earth’s atmosphere is the result primarily of the vital activity of vegetation.
In most cases, the ozone layer is indicated as the upper theoretical boundary of the biosphere without specifying its boundaries.
In practice, the maximum altitude above sea level at which life can exist is limited by the level up to which positive temperatures remain and plants can live. Above, up to the “snow line,” only spiders and some ticks live. Even higher, living organisms can only be encountered by chance.
At altitudes of 7500-8000m, another abiotic factor reaches a critically low value for the vast majority of organisms - absolute atmospheric pressure. Birds and flying insects, which predominantly occupy the lower zone, are the most dependent on pressure.
According to modern ideas, the entire thickness of the World Ocean is completely occupied by life.
The lower limit of the existence of active life is traditionally determined by the ocean floor of 11022 m (the maximum depth of the Mariana Trench) and the depth of the lithosphere, characterized by a temperature of 100 degrees C (about 6000 m, according to ultra-deep drilling data on the Kola Peninsula). Basically, life in the lithosphere is distributed only a few meters deep, limited to the soil layer.
Sedimentary rocks, almost all of which have undergone processing by living organisms, define the lower boundary of former biospheres, which, however, does not fall on the continents below the greatest depths of the ocean.
Environmental environmental factors. Their classification. Describe abiotic and biotic factors.
Living things are inseparable from their environment. Each individual organism, being an independent biological system, is constantly in direct or indirect relationships with various components and phenomena of its environment or, in other words, habitat, affecting the state and properties of the organism.
Environment is one of the basic ecological concepts, which means the entire spectrum of elements and conditions surrounding an organism in the part of space where the organism lives, everything among which it lives and with which it directly interacts.
Environmental factor - any element of the environment that can directly or indirectly influence a living organism, at least at one of the stages of its individual development, is called an environmental factor.
Environmental factors are diverse, and each factor is a combination of a corresponding environmental condition and its resource.
Environmental environmental factors are usually divided into two groups:
· Factors of inert (non-living) nature - abiotic or abiogenic;
· Wildlife factors - biotic or biogenic.
On the other hand, in origin, both of them are both natural and anthropogenic, i.e. directly or indirectly related to human activities, which not only changes the regimes of natural environmental factors, but also creates new ones by synthesizing pesticides, fertilizers, medicines, etc.
Abiotic factors.
In the abiotic part of the environment (in inanimate nature), all factors can primarily be divided into physical and chemical. However, to understand the essence of the phenomena and processes under consideration, it is convenient to represent abiotic factors as a set of climatic, topographic, cosmic factors, as well as characteristics of the composition of the environment (aquatic, terrestrial or soil).
To the main climatic factors include solar energy, temperature, precipitation and humidity, environmental mobility, pressure, ionizing radiation.
Energy of sun propagates in space in the form of electromagnetic waves. For organisms, the wavelength of the perceived radiation, its intensity and duration of exposure are important. The illumination of the earth's surface varies significantly depending on the time of year, day, latitude, and the state of the atmosphere.
Due to the rotation of the Earth, light and dark periods periodically alternate. Flowering, seed germination in plants, migration, hibernation, animal reproduction and much more in nature are associated with the length of the day.
Temperature.
At temperatures below freezing, a living cell is damaged and dies, and at high temperatures, enzymes are denatured. The vast majority of plants and animals cannot withstand negative body temperatures. The upper temperature limit is rarely understood above 40-45 degrees.
Temperature, like light intensity, depends on latitude, season, time of day and slope exposure.
Precipitation and humidity.
Water is essential for life on Earth; in ecological terms, it is unique. Under almost identical geographical conditions on Earth, both a hot desert and a tropical forest exist. The difference is only in the annual amount of precipitation: in the first case 0.2 - 200 mm, and in the second 900 - 2000 mm.
Precipitation is closely related to air humidity. Dew and fog form in the ground layer of air, and at low temperatures, frost falls.
Land plants obtain water mainly from the soil. low precipitation, rapid drainage, intense evaporation, or a combination of these factors lead to drying out, and excess moisture leads to waterlogging and waterlogging of soils.
Air humidity as an environmental factor, at its extreme values, enhances the effect of temperature on the body.
Air saturation with water vapor rarely reaches its maximum value. Humidity deficit is the difference between the maximum possible and actually existing saturation at a given temperature. This is one of the most important environmental parameters, since it characterizes two quantities at once: temperature and humidity. The higher the moisture deficit, the drier and warmer it is, and vice versa.
Precipitation regime is the most important factor determining the migration of pollutants in the natural environment and their leaching from the atmosphere.
Mobility of the environment.
The causes of the movement of air masses (wind) are primarily the unequal heating of the earth's surface, causing pressure changes, as well as the rotation of the Earth. The wind is directed towards warmer air. Wind is the most important factor in the spread of moisture, seeds, spores, chemical impurities, etc. over long distances.
Pressure.
Within the globe there are constant areas of high and low atmospheric pressure.
Periodically, areas of low pressure form in the atmosphere with powerful air currents moving in a spiral towards the center, which are called cyclones. They are characterized by high rainfall and unstable weather. Opposite natural phenomena are called anticyclones. They are characterized by stable weather, weak winds and, in some cases, temperature inversions. During anticyclones, sometimes unfavorable meteorological conditions arise that contribute to the accumulation of pollutants in the surface layer of the atmosphere.
Ionizing radiation.
Under the influence of cosmic radiation, new nuclei of radioactive atoms are constantly being formed in the atmosphere, the main ones being carbon-14 and tritium. The radiation background of a landscape is one of the indispensable components of its climate. All living things on Earth have been exposed to radiation from Space throughout the history of existence and have adapted to this.
The influence of abiotic factors largely depends on the topographic characteristics of the area, which can greatly change both the climate and the characteristics of soil development. The main topographical factor is altitude. With altitude, average temperatures decrease, the daily temperature difference increases, the amount of precipitation, wind speed and radiation intensity increases, and pressure decreases.
Another important topographic factor is the exposure (illumination) of the slope. In the Northern Hemisphere it is warmer on the southern slopes, and in the Southern Hemisphere it is warmer on the northern slopes. Another important factor is the steepness of the slope, which affects drainage. Water flows down the slopes, washing away the soil, reducing its layer. Terrain is one of the main factors influencing the transfer, dispersion or accumulation of impurities in the atmospheric air.
Our planet is not isolated from the processes occurring in outer space. The Earth periodically collides with asteroids, comes close to comets, and is hit by cosmic dust, meteorite substances, and various types of radiation from the Sun and stars.
Many factors have accumulated that confirm the influence of Space on life on Earth.
Important natural abiotic factors include fires, which, under a certain combination of climatic conditions, lead to complete or partial burning of terrestrial vegetation.
Biotic factors.
All living things surrounding an organism in its habitat constitute the biotic environment or biota. biotic factors are a set of influences of the life activity of some organisms on others.
The relationships between animals, plants, and microorganisms are extremely diverse. The main form of manifestation of these connections is the food relationships of organisms of various categories, which form the basis of food chains, networks and the trophic structure of the biota.
In addition to food connections, spatial relationships also arise between plant and animal organisms.
Biotic factors affecting plants as primary producers of organic matter are divided into zoogenic and phytogenic.
Zoogenic biotic factors. The factors affecting the influence of animals on vegetation primarily include eating the whole plant or its individual organs. Eating branches and shoots by animals changes the shape of the tree crown. Plants damaged by animals acquire protective devices (thorns, thorns), form excess phytomass, and intensively grow the remaining leaves. There is also a positive influence of animals on the life processes of plants, for example, pollination by insects and birds.
Phytogenic biotic factors.
Plants, experiencing diverse influences from neighboring plants, simultaneously influence them themselves. Everywhere there is interlacing and fusion of roots, and the branches of neighboring crowns and other trees intertwining.
Any plant community, in turn, influences the totality of abiotic characteristics of its habitat.
Living organisms play a vital role in the processes of soil formation and functioning. First of all, these include green plants that extract nutrients from the soil and return them back with dying tissues. Vegetation creates a continuous flow of ash elements from the deeper layers of the soil to its surface, i.e. their biological migration.
The soil is constantly inhabited by many organisms of various groups. Moves and holes help mix and aerate the soil and facilitate root growth. Passing through the digestive tract of the worm, for example, the soil is crushed, mineral and organic components are mixed, and the soil structure is improved.
In which the total activity of living organisms manifests itself as a geochemical force on a planetary scale.
The biosphere is the shell of the Earth, the composition, structure and energy of which are determined by the total activity of living organisms. The concept of the “biosphere as a region of life” and the outer shell of the Earth dates back to the biologist Lamarck (1744–1829). The term biosphere itself was introduced by E. Suess (1875), who understood it as a thin film of life on the earth’s surface, which largely determines the “face of the Earth.” The merit of creating a holistic doctrine of the biosphere belongs to V.I. Vernadsky. The formation of his biosphere thinking was greatly influenced by the works of V.V. Dokuchaev on soil as a natural historical body.
The biosphere covers part of the atmosphere up to the height of the ozone screen (20–25 km), part of the lithosphere, especially the weathering crust, and the entire hydrosphere. The lower boundary descends on average 2–3 km below the land surface and 1–2 km below the ocean floor. Vernadsky considered the biosphere as an area of life, including, along with organisms, their habitat. He identified seven different, but geologically interconnected types of substances: living matter, biogenic matter (fossil fuels, limestones, etc., i.e., matter created and processed by living organisms), inert matter (formed in processes in which living organisms do not participate), bioinert substance (created simultaneously by living organisms and during processes of inorganic nature, for example soil), radioactive substance, scattered atoms and substance of cosmic origin (meteorites, cosmic dust).
Sources
Materials used:
- From the site Geographer.ru.
- Yakhontova L. K., Zvereva V. P. Biosphere factor in hypergenesis
ENE material
Living matter performs the following biogeochemical functions: gas (migration of gases and their transformations); concentration (accumulation by living organisms of chemical elements from the external environment); redox (chemical transformations of substances containing atoms with variable valence - compounds of iron, manganese, trace elements, etc.); biochemical and biogeochemical functions associated with human activity (technogenesis, a form of creation and transformation of matter into life, stimulating the transition of life into a new state - the noosphere). The combination of these functions determines all chemical transformations in biochemistry. The evolution of biology is dialectically related to the evolution of forms of living matter (organisms and their communities) and the complication of its biochemical functions, which take place against the background of the geological history of the Earth.
The following main aspects are distinguished in the doctrine of biology: energy, which illuminates the connection of biosphere-planetary phenomena with cosmic radiation (mainly solar) and radioactive processes in the bowels of the earth; biogeochemical, reflecting the role of living matter in the distribution and behavior of atoms (more precisely, their isotopes) in biogeochemistry and its structures (see Biogeochemistry); informational, studying the principles of organization and management carried out in living nature in connection with the study of the influence of living matter on the structure and composition of bacteria; spatiotemporal, covering the formation and evolution of various structures of the earth in geological time in connection with the peculiarities of the spatiotemporal organization of living matter in the earth (problems of symmetry, etc.); noospheric, studying the global effects of humanity on the structure and chemistry of the planet: the development of mineral resources, the production of new substances that were previously absent in the planet (for example, pure aluminum, iron and other metals), the transformation of the biogeocenotic structures of the planet (deforestation, drainage swamps, plowing of virgin lands, creation of reservoirs, pollution of water, soil and atmosphere by products of economic activity, application of fertilizers, soil erosion, afforestation, construction of cities, dams, fishing, etc.). The entry of man into space, beyond the borders of Earth, will stimulate the development of new aspects of the study of the biosphere. An essential aspect of the doctrine of biology is the idea of interrelations (direct and feedback) and the conjugate evolution of all structures of biology. This idea forms the basis for the development of the problem “biosphere and humanity” by many national and international organizations, scientific centers and laboratories. This problem is solved by events in which many countries participate, for example, the International Hydrological Decade, the International Biological Program (see International Biological Program), etc. The increased interest in the study of biology is due to the fact that the local human influence on agriculture, characteristic of all previous history, was replaced in the 20th century. its global influence on the composition, structure and resources of B. There is no area of land or sea on the planet where traces of human activity have not been found. One of the striking examples is the global fallout of radioactive fallout - products of nuclear explosions. In the atmosphere, ocean and on land there are everywhere (even in very small quantities) combustion products of oil, coal, gases, waste from chemical and other industries, pesticides and fertilizers carried away from fields in the process of water and wind erosion. The intensive and irrational use of Baltic resources - water, gas, biological, etc., aggravated by the arms race, nuclear weapons testing, etc., has dispelled the myth of the infinity and inexhaustibility of these resources. Numerous examples of destructive human activity and, unfortunately, rare examples of his creative activity (including in terms of nature conservation) testify to the relevance of reasonable management of earthly affairs by intelligent humanity, which is possible only during the transition from spontaneous capitalist production to the planned economy of a socialist and communist society . The natural scientific basis for a rational approach to the problem of “the biosphere and humanity” - one of the most ambitious problems of our time - is the doctrine of biology and biogeocenology - disciplines that study the general principles and mechanisms of the functioning and evolution of communities of living organisms in certain spatial and temporal conditions. The modern structure of biology is the product of the long evolution of many systems of varying complexity, consistently striving for a state of dynamic equilibrium. The practical significance of the doctrine of B. is enormous. Particularly interested in the development of this teaching are health care, agriculture and fishing, and other branches of human practice, which more often than others face “retaliatory strikes” from B., caused by the unreasonable or careless transformation of nature by man.
Literature:
- Vernadsky V.I., Izbr. soch., vol. 5, M., 1960;
- by him, Chemical structure of the Earth's biosphere and its environment, M., 1965;
- Kovda V.A., Modern doctrine of the biosphere, “Journal of General Biology”, 1969, vol. 30, No. 1;
- Perelman A.I., Landscape Geochemistry, M., 1961;
- Timofeev-Resovsky N.V. and Tyuryukanov A.N., On the elementary biochorological divisions of the biosphere, “Bulletin of the Moscow Society of Naturalists,” 1966, v. 71(1);
- Hilmi G.F., Fundamentals of Biosphere Physics, Leningrad, 1966;
- Duvigneau P. and Tang M., The biosphere and the place of man in it, trans. from French, M., 1968.
V. A. Kovda, A. N. Tyuryukanov.
This article or section uses text from the Great Soviet Encyclopedia.Biosphere- the totality of parts of the earth’s shell (litho, hydro and atmosphere), which is populated by living organisms, is under their influence and is occupied by the products of their vital activity. The term "biosphere" was coined by Eduard Suess in 1875. He made a great contribution to the development of the study of the biosphere
Introduction
The current ecological situation on our planet leaves much to be desired, so first of all it is worth paying attention to the relationship between humanity and the biosphere. Pollution of the biosphere is the root cause of disease and premature death. The main task of our time is to prevent irreversible changes associated with environmental pollution. Society is constantly developing, but along with progress, the quantitative and qualitative nature of biosphere pollution is growing. Humanity as a whole, and not individual countries, must take care of creating a system of environmental protection, otherwise you will simply have to live in a spacesuit.
The concept of "biosphere"
A significantly different idea of the biosphere was formulated in 1875 by the Austrian geologist E. Suess. In the monograph “The Origin of the Alps” He speaks of an “independent biosphere” as a special shell of the Earth formed by living organisms. In the final chapter of the large three-volume work “The Face of the Earth” (1909), this author writes that the concept of “biosphere” arose as a consequence of the ideas of J. Lamarck and Charles Darwin about the unity of the organic world.
The beginning of the biological concept of the biosphere, as a collection of organisms inhabiting the Earth, as a living shell of the planet, dates back to the works of Suess. This view was shared by many Russian geographers, for example N. M. Sibirtsev (1899), D. N. Anuchin (1902), P. I. Brounov (1910), A. A. Grigoriev (1948), English researcher and philosopher J. Bernal (1969). French scientists E. Leroy (1927) and P. Teilhard de Chardin (1965, 1969) also took Suess’s definition as a basis, but interpreted it in an idealistic sense. According to Teilhard, the biosphere - a living layer of the planet - is one of the stages of the incarnation of God.
Suess's idea of the biosphere as a special shell of the earth was also used by V.I. Vernadsky (1926), having, however, invested in it a significantly different, biogeochemical, content. The biosphere, according to Vernadsky, is the area of distribution of life, which includes, along with organisms, their habitat. Teilhard de Chardin, in the Collection of Articles “The Future of Man” (1969), expressed his disagreement with such an interpretation, which clearly contradicts his idealistic concept of evolution.
The development of a biogeochemical concept of the biosphere was closely connected with the practical activities of V.I. Vernadsky in the Commission of the Academy of Sciences for the study of natural production forces of Russia (beginning of 1915).
The beginnings of this idea can be found already in the statements of scientists of the 17th and 18th centuries. , in the book “Cosmos” by A. Humboldt and Dokuchaev.
Currently, both understandings of the biosphere, according to Suess and according to Vernadsky, exist. N.V. Timofeev-Resovsky suggests talking about the biosphere in a narrow and broad sense. It seems more appropriate to use this concept, putting into it the meaning given by Vernadsky - the area of distribution of life, using for the biosphere in the “narrow sense” the expressions: “totality of organisms”, “film of life”, “living cover of the Earth”, “biota”, "bios".
The upper boundary of the biosphere, according to Vernadsky (1965), passes at an altitude of 15-20 km, covering the entire troposphere and the lower part of the stratosphere: ozone is located at the poles in a layer of 8-30 km, in the tropics 15-35 km. From below, the Biosphere is limited by sediments on the bottom of the oceans (to a depth of over 10 km) and the depth of penetration of organisms and liquid water into the bowels of the Earth. The underlying lithosphere, upper stratosphere, ionosphere and outer space serve as the environment for the biosphere. The main energy source ensuring the functioning of the biosphere is the radiant energy of the Sun.
Thus, the biosphere is a special thermodynamic open shell of the Earth, the matter, energy and organization of which are determined by the interaction of its biotic and abiotic components. It therefore includes the totality of organisms and their remains, as well as parts of the atmosphere, hydrosphere and lithosphere inhabited by organisms and modified by their activities.
The most important function of the biosphere is the regular, increasing over time, recreation of living matter in number, weight and amount of accumulated and retained energy. Man perceives this function as the biological productivity of the biosphere, its parts (ocean, soil, fresh water) or its individual ecosystems and biogeocenoses (deltas, meadows, taiga, grain fields, etc.).
The concept of the biosphere. The study of the diversity of forms of the organic world and the patterns of its development will not be complete without understanding the place and role of living organisms in general on the entire planet Earth.
The term “biosphere” was proposed in 1875 by the Austrian geologist Eduard Suess (1831 --1914), but he did not give its exact definition. Half a century later, Russian geochemist V.I. Vernadsky (1863-1945) created the doctrine of the biosphere, the main provisions of which he outlined in a small brochure published in 1926 entitled “Biosphere”. IN AND. Vernadsky called the biosphere the shell of the Earth, the main role in the formation of which belongs to living organisms.
Living matter is the main biogeochemical force in the biosphere. The main component of the biosphere is living matter - the totality of all living organisms on the planet, expressed numerically in elementary chemical composition, mass, and energy. This substance is geochemically extremely active, since during the processes of nutrition, respiration, excretion, and reproduction, it is closely connected with the environment, due to which almost all chemical elements pass through the biogeochemical link in the general chain of transformations. Thus, the life activity of organisms is a deep and powerful geological process of a planetary nature. The migration of chemical elements from the body to the environment and back does not stop for a second. This migration would have been impossible if the elemental chemical composition of the organisms had not been close to the chemical composition of the earth's crust. IN AND. Vernadsky wrote: “An organism deals with an environment to which not only it is adapted, but which is also adapted to it.”
Thanks to green plants that carry out the process of photosynthesis, complex molecules of organic substances are created in the biosphere. The energy contained in them is used for vital processes by heterotrophic organisms. This is the cosmic function of the green plants of the biosphere. Without living matter, the work of a solar ray would be reduced only to moving gaseous, liquid and solid bodies across the surface of the planet and temporarily heating them. Living matter acts as a giant battery and a unique transformer of bound radiant energy from the Sun. Solar energy without living matter would not carry out creative activity on Earth, since it could neither stay on it nor be transformed into the energy necessary for this.
Solar energy is captured primarily by plants. But all living matter takes part in retaining and transforming the energy of the Sun contained in them, moving it across the surface, as well as from the external to the deeper layers of the planet. This process is carried out through reproduction, subsequent growth and movement of organisms. Reproduction rate, according to V.I. Vernadsky, is the rate of transmission of geochemical energy in the biosphere.
The elementary structural and functional unit of the biosphere is biogeocenosis. It is in biogeocenosis that organisms and their habitat are closely mutually adapted to each other and thanks to this, the biological circulation of substances is carried out - the basis of the infinity of life
on the planet. In the course of the biological cycle, limited reserves of chemical substances become infinite, since they are in continuous circular circulation. Therefore, the circulation of substances in the form of biogeochemical cycles is a necessary condition for the existence of the biosphere. The entire cycle of substances in the biosphere occurs thanks to one source of energy - the Sun. A close relationship has been established between the amount of solar energy entering the planet and the amount of living matter produced. Thus, as a result of many years of research by scientists from different countries, it was possible to calculate that approximately 150-200 billion tons of dry organic matter are formed in the biosphere every year.
Thus, the creation of the doctrine of the biosphere was an important achievement of mankind. For the first time, living nature began to be viewed as an integral system that closely interacts with the abiotic environment. IN AND. Vernadsky laid the foundations for modern scientific ideas about the planetary and cosmic significance of life, about the interconnection and interaction of living and inanimate nature.
Extent of the biosphere. On planet Earth, there are several geospheres within which life exists (Fig. 7.2).
The atmosphere is the air envelope of the Earth. With height, the air density quickly decreases: 75% of the mass of the atmosphere is concentrated in a layer up to 10 km, 90% - up to 15 km, 99% - up to 30 km, 99.9% - up to 50 km. Air, devoid of moisture and solid impurities, consists of nitrogen (78.1%), oxygen (21%), argon (0.9%), carbon dioxide (about 0.03%) and small amounts of some other gases.
Great influence on the state of the atmosphere, i.e. The formation of weather and climate is played by various impurities - variable components of the atmosphere. The most important of them is water, which is contained in the form of water vapor in the lower 20-kilometer layer of the atmosphere. Water vapor, together with carbon dioxide, methane and some other impurities, participates in heating the inner layers of the atmosphere (the so-called greenhouse effect). This is due to the ability of the atmosphere to transmit solar radiation to the Earth's surface and absorb thermal radiation reflected from it. Due to the greenhouse effect, the temperature in the atmosphere increases with decreasing altitude, and its lower layers become warm.
The biosphere region extends only in the lower layer of the atmosphere - the troposphere (from the Greek tropos - change). The height of the troposphere varies from 8-10 km at polar latitudes to 16-18 km at the equator. Above the troposphere is the stratosphere (from Latin stratum - layer) with a height of 100 km. In it, at an altitude of 15-25 km, free oxygen under the influence of solar radiation is converted into ozone (O 2 -> O 3), which, forming a screen, absorbs short-wave ultraviolet radiation, which is harmful to living organisms.
Lithosphere (from the Greek lithos - stone) is the outer hard shell of the planet. There are two layers in it: the upper one is a layer of sedimentary rocks with granite and the lower one is basalt. The layers are unevenly distributed, so in some places granite comes to the surface. The limit of distribution of living matter in the lithosphere does not fall below 3-4 km. At this depth, only anaerobic bacteria can be found. The highest density of living matter in the lithosphere is observed in the surface layer of the earth's crust - the soil.
The hydrosphere is the totality of the waters of the oceans, seas, lakes, rivers, groundwater and ice sheets. The hydrosphere forms the discontinuous watery shell of the planet. The bulk of the water is concentrated in the World Ocean, the average depth of which is 3.8 km, the maximum (Mariinsky Trench of the Pacific Ocean) is 11.034 km. A small part of the hydrosphere is represented by fresh water.
Living organisms inhabit the entire thickness of the hydrosphere down to its maximum depths, but their greatest density occurs in the surface layers and coastal areas, heated and illuminated by the sun. Zones of direct contact and active interaction of the lithosphere, atmosphere and hydrosphere are most densely populated by living organisms, since in these places the most favorable conditions for life are created - optimal temperature, humidity, the presence of oxygen and chemical elements necessary for the life of organisms.
Spatial heterogeneity of the biosphere. The living conditions for organisms in the biosphere are extremely diverse. They differ especially in terrestrial and aquatic environments. Therefore, continental and oceanic parts of the biosphere are distinguished.
The continental part of the biosphere - land - occupies 148 million km 2, or 29% of the total area of the planet. Its peculiarity is extreme heterogeneity, expressed in the presence of latitudinal and altitudinal zonality.
Latitudinal zoning is determined by the sphericity of our planet and the tilt of its axis of rotation, as a result of which the earth’s surface is unequally provided with heat and moisture. Tropical and subtropical zones receive the greatest amount of heat, polar zones receive the least. There is a big difference in the provision of different areas with moisture. For example, the tundra is characterized by an excess, and deserts - a lack of atmospheric precipitation; regions of temperate latitudes are characterized by average water supply values.
The altitudinal landscape zonation of the continental part of the biosphere is formed due to the fact that as the altitude of the area increases, the air becomes more rarefied, with less oxygen, carbon dioxide and water vapor, and its temperature decreases. Due to the lack of carbon dioxide and moisture, the normal course of photosynthesis is disrupted, so higher plants do not grow at altitudes above 6 thousand m.
The oceanic part of the biosphere occupies 361 million km 2, or 71% of the planet's area. The determining factors for the life of organisms in it are the salt and gas composition of water, the content of nutrients, depth, and mobility of water. This part of the biosphere is also characterized by zoning. In terms of living conditions, the polar and equatorial-tropical zones of the hydrosphere, as well as its surface part illuminated by the sun, and the deep zone where sunlight does not penetrate, differ especially from each other. The most favorable for the development of life in the hydrosphere is a small coastal zone (8%) - the shelf, which is well illuminated and heated by the sun's rays, and is provided with a sufficient amount of mineral nutrition elements coming from bottom sediments and the land surface. Most of the area of the World Ocean bottom is located at depths of more than 4000 m and about a quarter of the area is at depths of more than 5000 m. The temperature here is low (from 0.5 to 4 ° C) and fairly constant. Light does not penetrate this area. On the seabed, organic residues accumulate in the form of silt and other sediments.
Distribution of living matter in the biosphere. The biomass of living matter of producers (green plants) and consumers (animals and microorganisms) in the oceanic and continental parts of the biosphere is given in Table 7.1.
The data presented in the table indicate that the bulk of the living matter of the biosphere (over 99.8%) is concentrated on the continents. The contribution of the oceanosphere to the total biomass is only 0.13%.
Biomass of Earth organisms (dry matter)
Biomass of living matter
Organisms of the continental part, oceanic part billion tons % billion tons %
Green plants 2400.0 99.2 0.2 6.3
Animals and microorganisms 20.0 0.8 3.0 93.7
Total: 2420.0 100.0 3.2 100.0
On the continents, the living matter of plants predominates (99.2%), in the ocean - animals (93.7%). However, comparing their absolute values (2400 billion tons and 3 billion tons, respectively), we can say that the living matter of the planet is predominantly represented by green land plants. The biomass of organisms incapable of photosynthesis is less than 1%.
Despite the fact that the biomass of land plants in absolute value is three orders of magnitude greater than that of ocean plants, the rate of biomass growth per unit time for oceanic plants (algae) is much higher (Table 7.2).
The ratio of total annual production (P) to the amount of biomass (B) in some plant communities of land and ocean
Plant communities P/B per year
Woody vegetation of forests 0.018
Vegetation of meadows, steppes, arable land 0.670
Complex of plants of lakes and rivers 14.0
Marine phytoplankton 150.0
The intensive division of microscopic phytoplankton cells, their rapid growth and short duration of existence contribute to the rapid turnover of ocean phytomass, which on average occurs in 1-3 days, while the complete renewal of land vegetation takes 50 years or more. Therefore, despite the small amount of ocean phytomass, its annual total production is comparable to the production of land plants.
Every year, about 150 billion tons of dry organic matter are formed in the biosphere through the process of photosynthesis. In the continental part of the biosphere, the most productive are tropical and subtropical forests, in the oceanic part - estuaries (river mouths expanding towards the sea) and reefs, as well as zones of rising deep waters - upwelling. Low plant productivity is typical for the open ocean, deserts and tundra.
The biosphere is the area of distribution of living organisms on planet Earth. The vital activity of organisms is accompanied by the involvement of various chemical elements into the composition of their body, which they need to build their own organic molecules. As a result, a powerful flow of chemical elements is formed between all living matter on the planet and its habitat. After the death of organisms and the decomposition of their bodies to mineral elements, the substance returns to the external environment. This is how the continuous circulation of substances occurs - a necessary condition for maintaining the continuity of life. The largest mass of living organisms is concentrated at the boundary of contact between the lithosphere, atmosphere and hydrosphere. In terms of biomass, consumers predominate in the ocean, while producers dominate on land. On our planet there is no more active and geochemically powerful substance than living matter.