Harold Urey (1893-1981), was a pioneering chemist in the US DEPARTMENT of ENERGY/SCIENCEPHOTO LIBRARY
The famous 1950s origin-of-life experiment may have been more accurate than we originally thought.
Miller-Urey's influential experiment proved that water, hydrogen, and methane can be used to form many of the proteins necessary for life on Earth. Stanley Miller and Harold Ureys goal was to recreate early Earth's chemical environment.
Researchers never considered whether the contents of the containers used in their experiments had an effect on the results.
Ernesto Di Mauro, from the Institute of Molecular Biology and Pathology, Rome, Italy, said that we don't know why nobody has looked at it before. Sometimes it's the simple things that people overlook.
Di Mauro and his colleagues repeated the experiment using the same type of borosilicate-glass container as the original, and also reran it with a Teflon container. They added glass chips to their Teflon container mixture in a third repeat of the experiment.
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Because glass contains silicates, the team thought that complex molecules would be created by reactions in glass. Di Mauro says that silicate can be dissolved on the surface of a mixture, and this can affect the type of reactions that occur.
Teflon, on the other side, was not widely used in the 1950s, when Miller and Urey conducted their experiment. It is chemically inert, and has no such effect.
The glass beaker contained the largest variety of complex organic reactions products, according to the Di Mauros team. The Teflon glass beaker that contained glass chips produced less complex compounds than the one with no glass. This is likely because the combined surface area of the glass chips was smaller than the glass beaker. Even less complex compounds were produced when the experiment was conducted in a Teflon container with no glass.
Di Mauro says that glass is similar to rocks on Earth. It catalyzes the reaction.
Silicates make up more than 90% of the Earth's crust. They are also found on planets such as Mars where they may have catalysed reactions that could be crucial for the origins of life.
Valentina Erastova, University of Edinburgh, UK, states that I am surprised no one has ever looked at it before. This study confirms to me that Miller-Urey's experiments were smarter than I thought.
Journal reference: Scientific Reports, DOI: 10.1038/s41598-021-00235-4