Man is a part of the biosphere. Owing to his intellect and with the aid of auxiliary energy sources, mainly fossil fuels, man became a major geological factor. Man's activity brings about huge changes in the life environment which in turn provoke thoughts about the significance of these changes for man's own future. It is understood that man occupies the highest developmental level due to organisms that have developed before him and that his further development will continue in close dependence on both abiotic and biotic factors of the environment. When seeking suitable strategies in further social development, man has to give thought to the laws of mass motion and conversions in the Universe including the evolution of life and has to contemplate the conditions of his own future existence. About 5 billion years ago, the Sun formed as a giant atomic pile with a reliable pressure regulation. The radiation energy emitted by the Sun arises from conversion of hydrogen to helium. This reaction made possible the origin and evolution of life on Earth; now, in the hands of man, lt is a serious menace to life. It has now become quite clear that the origin of life was not the result of some "lucky coinci? dence", as held by some, but that it is a stage in the evolution of matter, a part of the general process of the development of the Universe and, especially, of our Earth. Elucidation of the nature of origin of life has not been simple. Many pieces of evidence had to be put together before the theory of a gradual transformation of inanimate to living matter was generally accepted. When the Soviet scholar Op arin published in 1924 his materialistic hypothesis on the origin of life as being due to chemical evolution, his opponents launched a vigorous campaign to suppress this hypothesis. In the beginning of the fifties an experimental proof was obtained for synthesis of precursors of biochemically important organic substances in the Earth's atmosphere. The ancient atmosphere, simulated by a mixture of methane, ammonia, hydrogen and water, was exposed to high pressure and electric discharges and aminoacids were found among the products of the reaction. The expe? riment was described by the American scientist Miller in a modest paper in Science in 1953. Miller's proof of the Oparin-Haldane hypothesis is an example of how scientists from countries with different political systems, who share the belief in peace and development of scientific knowledge, supplement each others' work. Similar experiments were repeated successfully many times, sometimes with application of nuclear radiation, but a definite end to discussions was provided by lunar expeditions which brought unambiguous proofs from space. Op arin, the father of the field of chemical evolution, received well-earned recognition at many conferences on the origin of life and the era of chemical evolution is also called "Oparin's era". Evolution of species of organisms began when first living entities ? perhaps structures compo? sed of nucleic acids in a proteinaceous coat ? started to produce progeny differing in both shape and function. Radiation was again active in the process as a mutagenic factor. Primitive organisms utilized at first the energy of organic substances accumulated in primordial seas. Ultraviolet radiation which was the main supplier of energy for synthesis of organic substances later became the main enemy of more sophisticated organisms. Life could proceed only in seas in certain depths, the ultraviolet rays being absorbed in superficial water layers. Mutual Inter? action of primitive photosynthesizing organisms with their environment, in which active radiation
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