Once Earth was the lifeless planet with a sad stony landscape. Even the most modern methods of a research do not allow to define yet precisely when and how exactly the first life forms appeared here. Scientists still argue whether the first live objects on Earth were created or were brought from space here.
Instruction
1. It agrees one of the oldest hypotheses, life arose in interstellar space several billions years ago, and already then was accidentally brought to Earth. The simplest living organisms, so-called disputes, had no opportunity to develop in space. Having got to Earth, they appeared in favorable conditions and laid the foundation for infinite mutations during which on the planet the flora and fauna were formed. As indirect confirmation of this theory of a panspermia serve unsuccessful attempts to synthesize life in vitro.
2. Adherents of other hypothesis consider that life in the Universe is unique and could arise only on Earth. About 4 billion years ago the created planet began to cool down. Its atmosphere which part water vapors, nitrogen and carbon dioxide were was gradually formed. The climate became warmer that was promoted by presence at the Earth's surface of gases. Optimal conditions for synthesis of living organisms were so created.
3. It is considered to be that synthesis of proteins came in primary "broth" from amino acids. Fragments of these structures connected among themselves not in a random way, and in a certain sequence. Researchers are inclined to believe that the mechanism of synthesis of proteins submits to strict regularity and is put in matter nature. If origin of life was absolutely accidental, the probability of emergence of biological forms would be incredibly small.
4. Development of life on Earth came from simple to difficult, in full accordance with laws of dialectics. Amino acids, proteins and enzymes at association became cages which are considered as a basis of all live. Taken separately, components of cages will not be live. The separate cages constructed in a uniform system laid the foundation for more complex biological structures. Such system transition increased abilities of organisms to survival in hostile environment.
5. Both main theories of emergence of life on Earth assume that live matter can quite exist also in other corners of the Universe. It is quite possible that in the near future researchers will manage to find the new centers of life where evolution of matter took place in other conditions and a bit different way.
6. All hypotheses discussed by scientists do not deny the fundamental fact that life could arise only at a certain stage of development of the world. Wildlife is naturally allocated from inorganic matter, povinuyas to operation of mechanisms which so far completely do not give in to a scientific explanation. As soon as there are suitable conditions, with need there is life. It is possible that Earth in this regard was lucky more than other planets.