Evolution of the Organic World - Tutorial (Vorontsov N.N.)
On the way to the emergence of primary organisms
Probionga and their further evolution. How was the transition from biopolymers to the first living beings? This is the most difficult part of the problem of life. Scientists are trying to find her decision on the basis of model experiments. The experiments of A. I. Oparin and his employees received the greatest fame. Incusant to work, A. I. Oparin suggested that the transition from chemical evolution to biological associated with the emergence of the simplest phase proteined organic systems - probes capable of using substances and energy from the environment and on this basis to carry out major life functions - grow and exposed to natural selection . Such a system is an open system that can be depicted by the following scheme:
where S and L is the outer environment, and the substance entering the system, in the reaction product capable of diffing to the external environment.
The most promising object for modeling a similar system can serve as coacut drops. A. I. Oparin observed, as in colloidal solutions of the polypeptide, polisha-riding, RNA and other high-molecular compounds under certain conditions, a clots of yu "8 to 10 ~ cm3 are formed. These bunches are called coactervic drops or coacter. Around the droplets There is a border of a section that is well visible in the microscope. Coacutors are capable of adsorbing various substances. Chemical compounds can be made from the environment and go to the synthesis of new compounds. Under the action of mechanical forces, coacervate drops are crushed. But coactervats are not yet living beings. This is only the simplest Probionlov models that show only external similarity with such properties of living, as an increase and metabolism with the environment.
Of particular importance in the evolution of probionts played the formation of catalytic systems. The first catalysts were the simplest compounds, salts of iron, copper, other heavy metals, but their action was very weak. Gradually, biological catalysts were formally formed on the basis of prebiodic selection. Of the huge number of chemical compounds present in the "primary broth", the most effective combination of molecules were selected in the catalytic relation. At a certain stage of evolution, simple catalysts were replaced by enzymes. Enzymes control strictly defined reactions, and it was of great importance for improving the metabolic process.
The true beginning of the biological evolution is marked by the occurrence of probiions with code relations between proteins and nucleic acids. The interaction of proteins and nucleic acids led to the occurrence of such properties of a living, like self-reproduction, the preservation of hereditary information and its transmission to the subsequent generations - probably, at earlier stages of the fores, there were independent moles "Cool systems of polypeptides and polynuclees with a very imperfect metabolic metabolism and self-reproduction mechanism. . A huge step forward was made precisely at the moment when their association occurred: the ability for self-reproducing nucleic acids was supplemented by the catalytic activity of proteins. Probiions in which the metabolism was combined with the ability to self-reproduction, had the best perspective to be preserved in the prebelic selection. Further development is already Fully acquired features of biological evolution, which was carried out throughout at least 3.5 billion years.
We outlined reproductive, taking into account the data of the last ten
tiley, the concept of a gradual transition from chemical to biological evolution, which is associated with ideas A. I. Oparin. However, these ideas are not generally accepted. There are views of genetics, according to which life began with the emergence of self-reproducing nucleic acid molecules. The next step was to establish links between DNA and RNA and RNA ability to synthesize on the DNA matrix. Establishment of DNA and RNA communications with arisen as a result of abiogenic synthesis proteins molecules have a third stage of the evolution of life.
At the origins of life. It is difficult to say what were the first source for the whole living form of organisms. Apparently, it is raised in different parts of the planet, they differed from each other. All of them developed in an anaerobic medium, using ready-made organic compounds for their growth, synthesized during the chemical evolution, G. E. were heterotrophs. As the union of the "primary broth" occurred, other exchange methods began to occur, based on the use of chemical reaction energy for the synthesis of organic substances. These are chemoavtotrophotrophs (barrels, serobacteria). The next stage at the dawn of life was the occurrence of the photosynthesis process, which significantly changed the composition of the atmosphere: it turned into an oxidative. Due to this, it became possible an oxygen cleavage of organic substances, in which it turns out many times more energy than with oxless. Thus, life has moved to aerobic existence and could go to the land.
The first cells - prokaryotes - did not have a separate kernel. Later, in the process of evolution, under the influence of natural cell selection is improved. Following prokaryotm, eukaryotes appear - cells containing a separate core - then the specialized cells of higher multicellular cells arise.
Wednesday life occurrence. The main component of the living thing. In this regard, it can be assumed that life arose in an aquatic environment. In favor of this hypothesis, the similarity of the salt composition of seawater and blood of certain marine animals is indicated (Table),
The concentration of ions in seawater and blood of certain marine animals (sodium concentration was conditionally accepted for 100 \\%)
|
Sea water jellyfish swords |
100 3,61; T, 91 100 5.18 4,13 100 5.61 4.06 |
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as well as the dependence of the early stages of the development of many organisms from the aquatic environment, a significant variety and wealth of the sea fauna compared to the land.
The point of view is widespread, according to which the most favorable medium for the occurrence of life was the coastal areas of the seas and oceans. Here, at the junction of the sea, sushi, air, favorable conditions were created for the formation of complex organic compounds necessary for the occurrence of life.
In recent years, the attention of scientists attract the volcanic regions of the Earth as one of the possible sources of the origin of life. In the eruption of volcanoes, a huge amount of gases is distinguished, the composition of which largely coincides with the composition of gases formed the primary atmosphere of the Earth. In addition, high temperature contributes to the reactions.
In 1977, the so-called "black smokers" was found in the oceanic chute. At a depth of several thousand meters at a pressure of hundreds of atmospheres from the "tubes", water is coming out with a temperature of +200. . . + 300 ° C, enriched with gases inherent in volcanic regions. Many dozens of new births, families and even animal classes are open around the tubes "black smokers". Microorganisms are extremely diverse here, among which serobacteria is dominated. Perhaps life originated in the depths of the ocean in sharply contrasting conditions of temperature difference (from +200 to + 4 ° C)? What life was primary - water or land? Answers to these questions will be to give science of the future.
Is it possible to the emergence of life on earth now? The process of the emergence of living organisms from simple organic compounds was extremely long. In order for the Earth to flash, it took a lot of millions of years an evolutionary process, during which probions experienced a long selection for stability, on the ability to reproduce themselves like, on the formation of enzymes that control all chemical processes in live. The Stage of the Experts was, apparently long. If now on earth somewhere in the areas of intensive volcanic activity and there may be quite complex organic compounds, then the probability of any long existence of these compounds is insignificant. They will now be used by heterotrophic organisms. It was also understood by Ch. Darwin, who in 1871 wrote: "But if now (ah what a lot of if!) In any warm reservoir containing all the necessary ammonium salts and phosphorus and the affordable effects of light, heat, electricity and t . p., chemically formed protein capable of further increasingly complex transformations, this substance would immediately be destroyed or absorbed that it was impossible in the period before the emergence of living beings. "
Thus, modern knowledge of the origin of life on Earth leads to the following conclusions:
Life arose on Earth Abiogeny. Biological evolution preceded a long-term chemical evolution.
The emergence of life is the stage of the evolution of matter in the universe.
The pattern of the main stages of the occurrence of life can be checked experimentally in the laboratory and expressed in the form of the following scheme: atoms ---- * - simple molecules - ^ macromolecules -\u003e ultramolecular systems (probiongates) -\u003e single-cell organisms.
The primary atmosphere of the Earth had a recovery character. Because of this, the first organisms were heterotrophs.
Darwin principles of natural selection and survival of the most adapted can be transferred to prebiodiological systems.
Currently, living happens only from the living (biogeneous). The possibility of re-occurring life on Earth is excluded.
Check yourself
Based on the comparative characteristics of coacter droplets and living organisms, prove that life on Earth could occur abiogenic.
2. Why is it impossible for re-emergence of life on earth?
3. Among the currently existing organisms are primitive are mycoplasm. In size, they are less than some viruses. However, in such a tiny cell there is a complete set of vital molecules: DNA, RNA, proteins, farmeststs, ATP, carbohydrates, lipids, etc. Mycoplasma has no organoids, except for the outer membrane and ribosomes. What does the fact of the existence of such organisms mean?
1. What is life?
Answer. Life is a way of being of the essences (living organisms) endowed with internal activity, the process of developing organic structure bodies with a sustainable predominance of synthesis processes over decay processes, a special state of matter achieved due to the following properties. Life is a way of existence of protein bodies and nucleic acids, which is a significant moment of which is the constant metabolism with the environment, and life is terminated with the termination of this exchange.
2. What hypothesis of the life of life are you known?
Answer. Various ideas about the occurrence of life can be combined at five hypotheses:
1) Creationism - Divine Creation of Living;
2) spontaneous origin - living organisms arise spontaneously from a non-living substance;
3) the hypothesis of a stationary state - life always existed;
4) Hypothesis of Panxermia - Life is listed on our planet from the outside;
5) the hypothesis of biochemical evolution - life arose as a result of processes subject to chemical and physical laws. Currently, most scientists support the idea of \u200b\u200babiogenic birth in the process of biochemical evolution.
3. What is the main principle of the scientific method?
Answer. The scientific method is a set of techniques and operations used in constructing a scientific knowledge system. The main principle of the scientific method is not to perceive anything on faith. Any statement or refutation of something should be checked.
Questions after § 89
1. Why is it impossible to confirm or refute the idea of \u200b\u200bthe divine origin of life?
Answer. The process of the Divine Creation of the world thinks as the place only once and therefore inaccessible to research. Science is engaged only by those phenomena that can be observed and experimental research. Consequently, from a scientific point of view, the hypothesis of the divine emergence of a living cannot be proved nor refute. The main principle of the scientific method is "do not take anything to faith." Therefore, it should not be logically conflict between the scientific and religious explanation of the occurrence of life, since these two spheres of thinking mutually exclude one other.
2. What are the main provisions of the hypothesis of Oparin - Holdane?
Answer. In modern conditions, the emergence of living beings from inanimate nature is impossible. Abiogenic (i.e. without the participation of living organisms) the emergence of living matter was possible only in the conditions of an ancient atmosphere and the absence of living organisms. The ancient atmosphere included methane, ammonia, carbon dioxide, hydrogen, water pairs and other inorganic connections. Under the action of powerful electrical discharges, ultraviolet radiation and high radiation from these substances, organic compounds could occur, which accumulated in the ocean, forming "primary broth". In the "primary broth" from biopolymers formed multi-molecular complexes - coackers. Metal ions came from the external medium in the coackers, acting as the first catalysts. Of the huge number of chemical compounds present in the "primary broth", the most effective combination of molecules were selected, which ultimately led to the emergence of enzymes. On the border between the coackers and the outer medium, lipid molecules were built, which led to the formation of a primitive cell membrane. At a certain stage, protein probions included nucleic acids by creating single complexes, which led to the occurrence of such properties of a living, like self-reproduction, preserving the hereditary information and its subsequent generations. Probionals, in which the metabolism was combined with the ability to self-reproduction, one can already be considered as primitive scrolls, the further development of which occurred under the laws of the evolution of living matter.
3. What experimental evidence can be given in favor of this hypothesis?
Answer. In 1953, this hypothesis A. I. Oparin was experimentally confirmed by the experiments of the American scientist S. Miller. In the installation created by them, the conditions were simulated, presumably existed in the primary atmosphere of the Earth. As a result of experiments, amino acids were obtained. Similar experiments were repeated many times in various laboratories and made it possible to prove the principal possibility of synthesis in such conditions of almost all monomers of major biopolymers. In the future, it was found that under certain conditions of monomers, synthesis of more complex organic biopolymers are possible: polypeptides, polynucleotides, polysaccharides and lipids.
4. What is the difference between the hypothesis A. I. Oparin from the hypothesis of J. Holdane?
Answer. J. Holdane also put forward the hypothesis of abiogenic birth of life, but, unlike A. I. Oparin, he gave the championship not to proteins - coacervatable systems capable of exchanging substances, but nucleic acids, that is, macromolecular systems capable of self-reproduction.
5. What are the arguments lead opponents, criticizing the hypothesis of Oparin - Holdane?
Answer. The hypothesis of Oparin - Holdane has the weak side to which its opponents indicate. Within the framework of this hypothesis, it is not possible to explain the main problem: how the high-quality leap from a non-living to living happened. Indeed, for self-assessment of nucleic acids, enzyme proteins are needed, and for the synthesis of proteins - nucleic acids.
Give the possible arguments of "for" and "against" the hypothesis of Panxermia.
Answer. Arguments for:
Life at the prokaryism level appeared on Earth almost immediately after its formation, although the distance (in the sense of the difference in the complexity of the organization) between the prokaryotm and mammal is comparable to the distance from the primary broth before the launch;
In the event of the birth of life on any planet of our galaxy, it, as shown, for example, the estimates of A.D. Panova, for the period of all about several hundred million years can "infect" the whole galaxy;
Finds in some artifact meteorites, which can be interpreted as a result of microorganisms (even before the meteorite on earth).
The Hypothesis of Panxermia (Life is listed on our planet from the outside) does not respond to the main question, as life arose, and transfers this problem into some other place of the universe;
Complete Radio Universe;
Since it turned out that all our universe is only 13 billion years (that is, our entire universe is only 3 times older (!) Planet Earth), then the time for the birth of life somewhere there ... It remains very little. To the nearest stars of the A-Centauro star distance - 4 sv. of the year. Modern fighter (4 speed) will fly to this star ~ 800,000 years.
Ch. Darwin in 1871 wrote: "But if now ... in any warm reservoir containing all the necessary ammonium and phosphorus salts and the affordable effects of light, heat, electricity, etc., chemically formed protein capable of further , increasingly complex transformations, then this substance would immediately be destroyed or absorbed that it was impossible in the period before the emergence of living beings. "
Confirm or refute this statement Ch. Darwin.
Answer. The process of occurrence of living organisms from ordinary organic compounds was extremely long. In order for the Earth, life was originated, a multiple millions of years had an evolutionary process during which complex molecular structures, primarily nucleic acids and proteins, were selected for stability, on the ability to reproduce their likes.
If now on Earth somewhere in the areas of intensive volcanic activity and there may be quite complex organic compounds, then the probability of any long existence of these compounds is insignificant. The possibility of re-occurring life on Earth is excluded. Now living creatures appear only due to reproduction.
as well as the dependence of the early stages of the development of many organisms from the aquatic environment, a significant variety and wealth of the sea fauna compared to the land.
The point of view is widespread, according to which the most favorable medium for the occurrence of life was the Brejden areas of the seas and oceans. Here, at the junction of the sea, sushi, air, favorable conditions were created for the formation of complex organic compounds necessary for the occurrence of life.
In recent years, the attention of scientists attract the volcanic regions of the Earth as one of the possible sources of the origin of life. In the eruption of volcanoes, a huge amount of gases is distinguished, the composition of which largely coincides with the composition of gases, which have evidenced by the primary atmosphere of the Earth. In addition, high temperature peracters contributes to reactions.
In 1977, the so-called "black smokers" was found in the oceanic chute. At a depth of several thousand meters at a pressure of hundreds of atmospheres from the "tubes", water with a temperature of + 200 comes out. . . + 300 ° C, enriched with gases inherent in vul-canine areas. Around the tubes of "black smokers" from-indoor many dozens of new births, families and even animal classes. The micro-ganisms are extremely diverse here, among which serobacteria predominate. Perhaps life originated in the depths of the ocean in sharply contrasting conditions of temperature difference (from +200 to + 4 ° C)? What life was primary - water or land? Answers to these questions pre-give to science of the future.
Is it possible to the emergence of life on earth now? The process of the emergence of living organisms from ordinary organic compounds was extremely long. In order for life on Earth, it took a lot of millions of years an evolutionary process during which probions experienced a long selection for stability, on the ability to reproduce their likes, on the formation of enzymes that control all chemical processes in alive. The Stage of the Experts was, apparently long. If now on earth somewhere in the areas of intensive volcanic activity and there may be quite complex organic compounds, then the probability of any long existence of these compounds is insignificant. They will now be used by heterotrophic organisms. This pony is still Ch. Darwin, who in 1871 wrote: "But if now (ah what a lot of if!) In any warm reservoir, containing all the necessary ammonium salts and phosphorus and affordable light, heat , electricity, etc., was chemically specified by a protein capable of further increasingly complex transformations, then this substance would immediately be destroyed or absorbed that it was impossible in the period before the emergence of living beings. "
Thus, modern knowledge of the origin of life on Earth leads to the following conclusions:
Life arose on Earth Abiogeny. Biological evolution preceded a long-term chemical evolution.
The emergence of life is the stage of the evolution of matter in the universe.
The pattern of the main stages of the occurrence of life can be verified experimentally in the laboratory and expressing in the form of the following scheme: Atoms ---- * - simple molecularly - ^ macromolecules - > Ultramolecular systems (probions) - > Unicellular organisms.
The primary atmosphere of the Earth had a recrypt ha-racter. Because of this, the first organisms were heterotrophs.
Darwin principles of natural selection and survival of the most adapted can be transferred to prebiodiological systems.
Currently, living happens only from the living (biogeneous). The possibility of re-occurring life on Earth is excluded.
Check yourself
\ . Based on the comparative characteristics of coacter droplets and living organisms, prove that life on Earth could occur abiogenic.
2. Why is it impossible for re-emergence of life on earth?
3. Among the currently existing organisms are primitive are mycoplasm. In size, they are less than some viruses. However, in such a tiny cell there is a complete set of vital molecules: DNA, RNA, proteins, farmeststs, ATP, carbohydrates, lipids, etc. Mycoplasma has no organoids, except for the outer membrane and ribosomes. What does the fact of the existence of such organisms mean?
Earth history and methods of studying
The painting of the evolutionary process from its start to this day recreates the science of an ancient life - paleontology. SCIENTIFICAL-PALEONTOGOLOGISTRATICS CONTRIBUTING THE REDUCED EPODS ON POSTMED REASONS OF THE BODY OF THE CASES OF THE PAST, SURE IN EARTH FOLDERS. Geological layers Therefore, it is possible to formally call the pages and heads of the stone chronicles of the history of the Earth. But is it possible to accurately determine their age, and at the same time the age of fossil organisms concluded in these formations?
Geochronology methods. There are a variety of methods for determining the age of fossil residues and layers of rocks. All of them are divided into relative and absolute. Methods relative geochronology proceed from the idea that more
surface layer is always younger under it. It is also taken into account that for each geological era is characterized by its own definite appearance - a specific set of animals and plants. Based on the study of the sequence of the layer of geological section, the layer of layers is drawn up (Stratigraphic scheme) of this area. Paleon-Tologic data allow you to identify the same or similar species in the layers of various geological cuts of different countries and continents. On the basis of the similarity of fossil forms, it is concluded that the synchronization of the layers containing the so-called leading fossils, i.e. them accessories to one and that Sametime.
Methods absolute geochronology Based on the natural radioactivity of some chemical elements. For the first time, offered to use this phenomenon as a standard time PierreCurie (1859-1906). Strict constancy of the speed of radioactive decay led to the idea of \u200b\u200bdeveloping a single accurate chronolo-gickery of land history. Later, this issue was developed by E. Rutherford (1871-1937) and other scientists
To determine absolute age, "long-life" radioactive isotopes are used, suitable for studying the age of the oldest layers of land. The rate of decay of the radioactive iso-pop is expressed by a half-life. This time, during which, any initial number of atoms is reduced by twice, knowing the half-life of the corresponding isotope and measuring the ratio of the number of radioactive isotope and the products of its decay, one can determine the age of that ^ or other rock. For example, the half-life of uranium-238 is equal to 4.498 billion years. Kilo-grams of uranium, in whatever rocks he lay down, after 100 million years old gives 13 g of lead and 2 g of helium. Consequently, the more in the mountain rock of the uranium lead, the lard of it, its turning, the oldest. This is the principle of the "radioactive clock". The considered example illustrates the oldest method of isotopic geochronology - lead. It is named so because the age of rock is determined by the accumulation of lead during the collapse of uranium and thorium. As a result of the Radioactive decay of uranium-238, lead-206, uranium-235, lead-207 occurs and during the decay of T-Riya-232 - Swing-208.
Depending on the final product of the radioactive decay, other methods of isotopic geochronology are developed: helium, carbon, potassium-ar gonda and.
To determine the geological site up to 50 thousand years, the broad-ko-ko is applied to radiogle mat. It is based on the fact that under the action of cosmic radio.Sh.in and the atmosphere of land nitrogen turns n radioactive me: UTUP carbon "C, with a half-life of 5,750 years, in living organisms due to a constant exchange with the concentration of radioactive isotope of coal-kind constant, whereas after death and termination of exchange
the substances of the radioactive isotope "" * C begins to decompose. Knowing the half-life, you can very accurately determine the age of or-genic remnants: coal, branches, peat, bones. This method is given by the epochs of the glaciation, the stages of the ancient human civilization and T-d.
In recent years, the dendrochronological method is successfully developed. Having studied the influence of weather conditions on the growth of annual rings on wood, biologists found out that the alternation of the rings of a low and high increase gives a unique picture. By drawing out the averaged wood growth curve for each area, it is possible to dawn any piece of wood up to a year. Thus, for example, Soviet archaeologists accurately date the age of wood used for the construction of ancient Novgorod.
Like annual rings of trees, reflect the daily, seasonal and annual coral growth line cycles. These marine invertebrates, the outer part of the skeleton is covered with a thin lime layer called eptecé. With good preservation on EPNTEK, clear rings are visible - the result of periodic changes in calcium carbonate deposition rate. These formations are grouped into the belt. American Paleontologist J. Wels Dock-Hall (1963) that ring lines and belts on the epiterate corals are daily and annual education. Exploring modern types of rhyme-forming corals, it counted about 360 lines in their annual belt, so that the line corresponded to the growth in one day. Interestingly, corals who lived at-measure 370 million years ago, in an annualized belt there are from 385 to 399 lines. Based on this, J. Welts came to the conclusion that the number of days a year in the distant geological time was more than in our era. Indeed, as astro-nomic calculations and paleontological data show, the land is rapidly faster and the duration of the day therefore was about 22 hours. Knowing the sequence of the appearance of certain organisms and the age of different layers of the earth's crust, scientists in general have drawn the chronology of the history of our planet and described the development of life on it.
The calendar Stories of the Earth. The history of the Earth is divided at long intervals - era. Era are divided by etcriot Periods - by era Epochs - on century. (Earth history calendar is presented on the table.)
Separation on era and periods are not accidental. The end of one era and the beginning of the other marked by significant transformations of the Earth's face, a change in the ratio of sushi and the sea, intensive-in-forming processes
Nablished UR. Greek origin: kitarhsy. - Below the oldestarchey - ancient proterozoa - primary lifepaleozoic - ancient lifemesoza - Middle life.cenozoic- New life (Fig. 40).
j. 55
Mammal flourishing
Flower reptile
Amphibian flourishing
Conquest sushi.
Ancient vertebrae
The appearance of the ozone screen
Sponges, worms
Archeocitis
Education of Kursk Iron Ore
Hydroid polyps-many-cells. Green hydrogen-lee eukaryotes. The appearance of soils Blue-green Vascha - 1 Dorosli. Bacteria J RDOT
Appearance Life
Vulcanism, water steam condensation, accumulation of secondary atmosphere
Education Earth crust
Formation of the planet
Fig. 40. The cultivation of life development on earth
Geochronological table
Continue (in million years old) | started to this day (in million years) |
|||
Cenozoa | Quaternary Golocene 0.02 0.02 Pleistoce 1.5 1.5 |
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Tertiary Pliocene 11 Neogen |
||||
Continued
paleogen | Oligo prices Eocene Paleocene | ||
Late early | |||
Late early | |||
Mesoza Paleozoa | Late medium early | ||
Late early | |||
Middle Early | |||
Late medium early | |||
Late early | |||
Late medium early | |||
Late middle | |||
Proterozoa | Late Protero Zoy Rife | ||
Late medium early | |||
proterozoa | |||
Early Proterozoa | |||
1100--1400 3500-3800 |
|||
Qatarhey |
Check yourself
1. What is the essence of the main methods of dating rocks and fossil residues of organisms?
2. What is the principle of action of "radioactive hours"?
3. What is the calendar of the history of the Earth?
Development of life in the Precambrian
More recently, Paleontologists could deepen in the history of life only at 500-570 million years and the balance of the paleontological chronicles began with the Cambrian period. In the Precambrian sediments, long time could not detect the remnants of organisms. But if you keep in mind that 7/8 of the geological history of the Earth takes the Precambria, then the rapid development in recent years is understandable in recent years.
Archey. Paleontological data of the ancient sedimentary reservoirs show that the donorganism stage of the evolution continued 1.5 -!, 6 billion years after the formation of the Earth as the planet. Qatarhai was a "performance without spectators." Life originated on the verge of Qatarhaya and Archey. This is evidenced by the discovery of the residues of microorganisms in the early Arhea breeds of 3.5-3.8 billion years. A little known about life in Archey. Mountain breeds of Archey contain a large amount of graphite. It is believed that graphite comes from the remains of organic compounds, in the composition of living organisms. These were cellular about "Cariots - Bacteria and blue-green. Products of the livelihood of these primitive microorganisms are the ancient sedimentary rocks (stromatolys) - limestrigas in the form of pillars found in Canada, Australia, Africa, in the Urals and in Siberia. The bacterial base has sedimentary breeds of iron, nickel, manganese. Up to 90% of world sulfur reserves arose as a result of the life of serobacteria. Many micro-organisms are active participants in the formation of colossal, still few explored mineral resources-at the World Ocean. There found the deposits of iron, manganese, copper, nickel, cobalt. The role of microorganisms and the observation of combustible shale, oil and gas are greatly.
Blue-green, bacteria quickly apply to Archee and become the owners of the planet. These organisms did not have a separate nucleus, but had a developed metabolic system, the ability to reproduce. Blue-green, in addition, there is a photo of a photo seating device. The appearance of the latter was the largest spam aromyrffe in the evolution of wildlife and opened one of the paths (probably specifically earthly) formation of free oxygen.
By the end of Archey (2.8-3 billion years ago) the first appear
colonial algae, fossil remains of which Ni-Dena in Australia, Africa, Soviet Union.
Paleontological studies will gradually complement the picture of life in the early stages of its evolution. In the meantime, the chronology of that distant time is delineated only schematically. Stone chronicle has already begun, but the traces of "writing" E. Deta is very rare
Ozone hypothesis Screen. The most important stage in the development of life on earth is closely related to a change in oxygen concentration I am an atmosphere, the formation of the ozone screen. This assumption was expressed by American scientists G. Berkner and L. Marshall in the late 60s of our century. Now it is confirmed by the data of Biogeochemistry and Paleontology. Due to the vital activity of blue-green, the content of free oxygen in the atmosphere ^ ". Requests the so-called" Pasteur point "of the oxygen concentration - 1% of its concentration in the modern atmosphere - created prerequisites for the appearance of the aerobic respiratory control mechanism. Provided Anaerobic (oxless) processes. The occurrence of breathing was a large aromorphosis, which resulted in many times the release of energy for the processes of life-life.
The accumulation of oxygen led to the emergence of the primary ozone screen in the upper layers of the biosphere, which opened the immense horizons for the flourishing of life, since it prevented the penetration of destructive ultraviolet rays.
The appearance of the ozone screen and the transition from the anaerobic pro-Cesses to breathing is performed in the Venda - the latest stage of the Proterezhoy and leads to the development of photosynthetic organisors - MOV - avtotrophov In the rich solar energy of the ocean's upper layers. In turn, the accumulation of organic compounds as a result of photosenthesis of organic compounds created conditions for the evolution of their consumers - heterotrophic organisms.
In Paleozoic, on the verge of silica and Devon, the oxygen content in the atmosphere reached 10% of its modern concentration. By this time, the power of the ozone screen has grown so much that it made the way out of living organisms on land.
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Currently, life on Earth cannot arise abiogenic way. Darwin wrote in 1871: "But if now ... in any warm reservoir, containing all the necessary ammonium salts and phosphorus and the affordable effects of light, heat, electricity, chemically formed protein, capable of further increasingly difficult transformations, then The substance would immediately be destroyed and absorbed that it was impossible during the occurrence of living beings. " Life arose on Earth Abiogeny. Currently, living happens only from living (biogenic origin). The possibility of re-occurring life on Earth is excluded.
Panxermia theory.
In 1865, the German doctor of Richter put forward hypothesis cosmosoev
(space primits) in accordance with which life is eternal and primitive, inhabiting world space, can be transferred from one planet to another.
In 1907, a similar hypothesis put forward the Swedish natural scientist S. Arrhenius, suggesting that in the universe there are always embryos of life - parisermia hypothesis.He described how the planets and live disputes of microorganisms go to the world space of the particles of substances, dust and live disputes of microorganisms. They retain their vitality, flying in the space of the Universe due to light pressure. Finding on a planet with suitable living conditions, they begin a new life on this planet. Many were supported by this hypothesis, including Russian scientists S. P. Kostichev, L. S. Berg and P. P. Lazarev.
This hypothesis does not imply any mechanism to explain the primary occurrence of life and transfers the problem to another place of the universe. Libih believed that "the atmosphere of celestial bodies, as well as rotating cosmic nebulae, can be considered as non-erase storages of a lively form, like eternal plantations of organic embryos," where life is scattered in the form of these embryos in the universe.
For the rationale of Panxermia use rock paintings with the image of objects similar to rocket or cosmonauts, or the appearance of UFOs. The flight apparatus flights destroyed faith in the existence of a reasonable life on the planets of the solar system, which appeared after the discovery of Skipareli channels on Mars in 1877.
Lovellum counted on Mars 700 channels. The network of channels covered all the continents. In 1924, the channels were photographed, and most scientists saw the proof of the existence of a reasonable life. Photographs 500 channels recorded and seasonal changes in color, which confirmed the ideas of Soviet astronomer G. A. Tikhov about vegetation on Mars, since lakes and canals had a green color.
Valuable information on physical conditions on Mars was obtained by the Soviet Space Agency "Mars" and American seating stations "Viking - 1" and "Viking - 2". Thus, the polar hats experiencing seasonal changes were consisting of an aqueous vapor with an admixture of mineral dust and from solid carbon dioxide of dry ice). But while traces of life on Mars not found.
The study of the surface from the board of artificial satellites made it possible to assume that the channels and rivers of Mars could arise as a result of molding under surface water ice in the zones of increased activity or inner heat of the planet, or during periodic climate change.
At the end of the sixties, interest in pyppermia hypothesis reared. When studying the substance of meteorites and comets discovered "alive precursors" - organic compounds, blue acid, water, formaldehyde, cyanogens.
Formaldehyde was detected in 60% of cases in 22 studied areas, its clouds with a concentration of approximately 1000 molecules / cm. cube Fill extensive spaces.
In 1975, the predecessors of amino acids were found in the lunar soil and meteorites.
The concept of a stationary state of life.
According to V. I. Vernadsky, it is necessary to talk about the animation of life and manifestations of its organisms, as we say about the intake of the material substrate of the celestial bodies, their thermal electrical, magnetic properties and their manifestations. Everything living happened from the living (Radi principle).
Primitive single-cell organisms could occur only in the Earth's biosphere, as well as in the biosphere of the Universe. According to Vernadsky, natural sciences are built on the assumption that life with its special qualities does not take any participation in the life of the universe. But the biosphere must be taken as a whole, as a single living space organism (then there is no question about the beginning of the living, about the jump from the non-living to the living).
Hypothesis "Chulbiosis".
She concerns the pre-preparation of a doctor and his abilities.
There are various forms of the district ancestor - "bioid", "Biomonade", "microsphere".
According to the biochemistry of P. decker, the Bioid's structural basis is viable non-equilibrium dissypal structures, that is, the opening of the microsystem with the enzymatic apparatus catalyzing the metabolism of the Bioid.
This hypothesis treats activity to a cell ancestor in a metabolic spirit.
As part of the hypothesis of "Golobiosis", the biochemists of S. Fox and K. Dose are their biopolymers capable of metabolism - complex protein synthesis.
The main disadvantage of this hypothesis is the absence of a genetic system with such a synthesis. Hence the preference of the "molecular progenitor" of any living, and not the primary protect structure.
Hypothesis of Genotyosis.
The American scientist Holdane believed that the primary was not a structure capable of exchanging substances with the environment, but a mocomolecular system, similar to a genome and capable of reproduction, and therefore, called the "bare genome". The general recognition of this hypothesis received after the opening of RNA and DNA and their phenomenal properties.
According to this genetic hypothesis, nucleic acids as a matrix basis for protein synthesis occurred at the beginning. For the first time, it was put forward in 1929 Möhller.
It is experimentally proved that uncomplicated nucleic acids can be replicated without enzymes. The synthesis of proteins on ribosomes comes with the participation of T - RNA and P - RNA. They are capable of building not just random combinations of amino acids, but ordered protein polymers. Perhaps the primary ribosomes consisted only from RNA. Such wasteless ribosomes could synthesize ordered peptides with the participation of molecules T - RNA, which bind to P - RNA through mating bases.
At the next stage of chemical evolution, matrices appeared, which determined the sequence of molecules T - RNA, and thus the sequence of amino acids that bind to T - RNA molecules. The ability of nucleic acid to serve as matrices in the formation of complimentary circuits (for example, synthesis and - RNA on DNA) is the most convincing argument in favor of ideas about the leading value in the process of biogenesis of the hereditary apparatus and, therefore, in favor of the genetic hypothesis of the origin of life.
3. How did life appear on earth
The modern concept of living on Earth is the result of the widespread synthesis of natural sciences, many theories and hypotheses put forward by researchers of different specialties.
