Simple and powerful experiments

Let’s admit it, all scientists have secrets. There is a simple and elegant experiment (or two) we wish we had thought of, or had performed ourselves. For me, the Urey-Miller experiment fits the bill. A two-page Science report published in 1953 shook the world and became an instant classic in the history of science.

In order to test plausible conditions on the early Earth, Miller came up with an ingenious idea: to circulate a mixture of four simple compounds (nitrogen, water, hydrogen, and methane) that were likely present back then, through a chamber where electric discharge was constantly applied through the gaseous mixture. This discharge was designed to simulate the rough primordial times. After several days, mercury chloride was added to the reaction mixture in order to ensure that bacteria did not have a chance to grow, thereby polluting the results. The analysis of the reaction mixture indicated the presence of amino acids such as alpha-alanine, beta-alanine, and glycine. This was a milestone in our understanding of how protein building blocks are formed. You might argue that this experiment does not prove how chirality emerged, which is true. In a way, the Urey-Miller experiment is a “low hanging fruit” that catalyzed our search for the origins of life. There is even a Gordon Conference dedicated to this subject. As you can imagine, there are some interesting, if not eccentric, folks who attend that gathering. Regardless, I wish I had thought of this experiment…

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http://www.sciencemag.org/content/117/3046/528.short

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