Question

Explain how did the experiment conducted by S.L. Miller substantiate that life evolved from preexisting nonliving organic molecules.

Answer 1

In 1953, S.L. Miller, an American scientist created similar conditions on a laboratory scale. He created electric discharge in a closed flask containing CH₄, H₂, NH₃ and water vapour at 800°C. He observed the formation of amino acids. In similar experiments, others observed, the formation of sugars, nitrogen bases, pigment and fats. Analysis of meteorite content also revealed similar compounds indicating that similar processes are occurring elsewhere in space. With this limited evidence, the first part of the conjectured story, i.e., chemical evolution was more or less accepted. The first non-cellular forms of life could have originated 3 billion years back. They would have been giant molecules (RNA, Protein, Polysaccharides, etc.). These capsules reproduced their molecules perhaps. The first cellular form of life did not possibly originate till about 2000 million years ago. These were probably single cells. All life forms were in a water environment only. This version of biogenesis, i.e., the first form of life arose slowly through evolutionary forces from non-living molecules is accepted by the majority.