The Miller and Urey experiment is an experiment that mimicked the conditions on earth before evolution took place. They made an atmosphere that contained water, H2, methane, and ammonia which are believed to be abundant in the earth's atmosphere before evolution. The experimental apparatus that they used also simulated lightning with sparks, and after the gas mixture was exposed to lightning/spark, was allowed to cool/condense back in the apparatus for analysis. When the author's of the study analyzed the sample, they were able to find important organic compounds that are essential to life such as amino acids, DNA, RNA, and lipids, which are all very important building blocks for the formation of life on earth.
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