Explanation

20000 million years. Experimental Evidences of Chemical Evolution Experi ik mentally chemical theory of evolution performed by SL Miller and HC Uray in 1953. He created electric discharge in a closed flask containing $CH_{4},H_{2},NH_{3}$ and water vapour at 800 C. He observed formation of amino acids. In similar experiments other the observed, formation of sugar, nitrogen bases, pigments and fats [image:7_image31.png] The first non-cellular forms of life could have originated-3 billion years back. The first cellular form of life did not possibly originated till about 2 billion years ago because the conditions were non-biogenic at that time. This version of biogenesis, i.e., the first form of life arose slowly through evolutionary forces from non-living molecule was accepted by majority