BIOGENESIS (life from life)
According to this view, life can origin only from its pre-existing form, not from non-living components. That means to originate new life, there should be pre-existing life. The Three experiment in biogenesis are :- Redi`s Experiment Spallanzani`s Experiment Pasteur`s Experiment
1. Redi`s Experiment
Conducted by Fancesco Redi (1626-1698), an Italian Doctor. This was conducted to demonstrate that maggots could not be created from flesh or meat but the smell of meat attracted flies to come and lay egg on flesh. He took 3 jars, A, B & C placing lumps of boiled meat in them Jar A- Covered by parchment paper; Jar B- by fine muslin dolt; Jar C- uncovered. Few days later, meat decayed in all 3 jars but maggots appeared only in uncovered jars. Thus, it proves theory of Biogenesis.
2. Spallanzani`s Experiment
Conducted by Lazzaro Spallanzoni (Italian Scholar) To oppose abiogenesis Hay infusions were put in 8 test tubes, four of them (air tight) while remaining were uncovered (air free) Few days later, he found thick growth of micro-organism in air-tight tubes while not in air-free test tube. Conclusion: Air contaminated with microorganisms entered the air free test tubes where their growth occurred. Theory of biogenesis was proved.
3. Pasteur`s Experiment
Conducted by Louis Pasteur, a French microbiologist. An experiment in support of Biogenesis. He prepared hay infusion in a swan0necked flask. The infusion was boiled to kill the microbes and to make it sterile. The experiment was left for observation for a few days. His observation showed that the flask remained free of life for several months (about 18 months). Later, he broke the neck of flask, making the hay infusion come in contact to air. The microbes appeared in the hay infusions. He conducted that life originates from pre-existing life only.
Miller & Urey`s Experiment
An experiment support by biochemical origin of life Conducted by Stanley Miller and Urey Created the probable condition of primitive atmosphere in the earth. Use CH4, N2, H2, H2O etc.