- Chemogenic Evolution Condition on primitive earth about4-billion year ago was such which Favored chemical evolution. Where temperature is too much high and atmosphere had nitrogen in the form of ammonia, carbon in form of methane and oxygen in the form of water vapors (H2o) but there was no free oxygen so the primitive atmosphere was reducing. These Compounds were called protoplasmic compounds. As earth cooled down, it developed a solid crust which later formed Depressions and elevations. Atmospheric vapors condensed and finally came to surface as rain Thus ocean form.
Haldane proposed that these Simple organic compounds gradually accumulated in water bodies and finally thin hot soup or broth was formed. This set the stage for the chemical reaction. Oparin and Sydney Fox proposed that complex organic compounds Synthesized abiogenetically on primitive earth later accumulate and Formed large colloidal cell like aggregates called probionts.
This form of life probably originated 3-billion years back. These would have giant molecules containing RNA-protein polysaccharides etc. these maintain an internal environment. But their main drawback was that they were unable to reproduce. These microscopic structures were called Coacervates