The first solid evidence against spontaneous generation came in 1668 from Francesco Radi, who proved that no Maggots appeared in meat when flies were prevented from laying eggs. It was gradually shown that, at least in the case of all the higher and readily visible organisms, the previous sentiment regarding spontaneous generation were false. In Natural Sciences, ABIOGENESIS, or “CHEMICAL EVOLUTION”, means the study of Life on Erath. It could have begun from matter. Evolution is entirely a different phenomenon that concern how species grew and chose the environment to live along with timely changes. Amino Acids are considered the building block of the living organism. Some kind of chemical reaction occurred which was unrelated to life. As demonstrated by Miller-Urey which involved simulating the conditions of the early Earth. In all living things, these amino acids are organized into Proteins, and the construction of these proteins is mediated by Nucleic Acid. Thus the question of how life on Earth originated is a question of how the first nucleic acids arose.
Prokaryotes and Protobionts the single cell organism thought to be the first sign of life on Earth. Oldest ancient fossil microbe-like objects are dated to be 3.5 to 4 billion years old, approximately one billion years after the formation of the Earth itself. The ratio of stable Isotopes of Carbon, Iron and Sulfur shows the action of living things on Inorganic Minerals and Sediments and molecular biomarkers indicate Photosynthesis, demonstrating that life on Earth was widespread by this time. On the other hand, the exact sequence of chemical events that led to the first nucleic acids is not known. Genetic science has proved that all kind of life belong to common evolution ancestry on Earth. Biochemical predestination has been decided by a simple fact biochemical option. Biochemical reaction is simply the fact of this. Earth environment is suitable for these reactions due to five elements Energy, Air, Fire, Water and Soil. The surprising uniformity of the molecule is basis of living organism. Conflicting thesis of scientist can be discussed under one umbrella but uniformity in the mechanism cannot be ignored. The quality and message of DNA represent a language which is logically true for life on earth. We can investigate Amebae or Bacteria or any other organism genetic language is seems to be identical. Even the coding process in DNA is seems same in most of the organism studied by microbiologist. Amino Acid derived from Human Haemoglobin and its substitutions genetic code is similar to bacteria studied till now. Even developed animals red blood cell gene structure information in molecule in Haemoglobin is much similar. This suggests the genetic code appears to be same in all living organism. If there is any alien presence in Universe exist the Haemoglobin could be having same genetic code. Studies done to the date on Protein, DNA and RNA level have proved that most of the living organism from Amoebae, Virus, Bacteria and Human constitute with almost same In Mitochondria two type of Condon presence is bit surprising to scientist. Work is still in progress on this and cannot be concluded.
Despite this, the environment was one highly hazardous to life. Frequent collisions with large objects, up to 500 kilometers in diameter, would have been sufficient to vaporize the ocean within a few months of impact, with hot steam mixed with rock vapors leading to high altitude clouds completely covering the planet. After a few months the height of these clouds would have begun to decrease but the cloud base would still have been elevated for about the next thousand years. After that, it would have begun to rain at low altitude. For another two thousand years rains would slowly have drawn down the height of the clouds, returning the oceans to their original depth only 3,000 years after the impact.
According to Philosopher Aristotle it was a readily observable truth that Aphids arise from the dew which falls on plants, Fleas from putrid matter, mice from dirty hay, crocodiles from rotting logs at the bottom of bodies of water, and so on. It is like faith in God and Satan.