Origin Of Life

The Miller-Urey experiment, conducted in 1953, tested the idea that the building blocks of life could form spontaneously under the conditions of the primitive Earth. Miller created a closed apparatus containing methane, ammonia, hydrogen, and water vapour to mimic the early reducing atmosphere, and passed electric sparks through it to simulate lightning. After running it for a week, he detected amino acids and other simple organic molecules, supporting the hypothesis of chemical evolution, that complex organic compounds arose abiotically from simpler inorganic precursors. The option of spontaneous generation from non-living mud refers to the discredited abiogenesis idea of life appearing fully formed, which is different from gradual chemical evolution. Panspermia, the notion that life arrived from outer space, was not what this experiment tested. Special creation is a non-scientific belief that the experiment neither addressed nor supported. As described in NCERT Class 12, Chapter 7 (Evolution), this experiment backed the Oparin-Haldane theory of chemical origin of life. As a verification step, producing organic molecules from inorganic gases directly demonstrates chemical evolution, confirming the correct hypothesis.