Researchers used modern techniques to re-analyse 'primordial soup' gas samples created in 1958 by pioneering US biochemist Stanley Miller. They discovered a multitude of amino acids, the basic building blocks of life, that can be assembled together to form proteins.
In 1953, Miller conducted the famous experiment in which he attempted to recreate the atmospheric conditions present just before life appeared on Earth around four billion years ago, the Daily Mail reports.
By sending an electric spark through a mixture of methane, ammonia, water vapour and hydrogen to simulate lightning, he generated several simple amino acids and other organic compounds. But the original 'primordial soup' was a little thin. It did not contain a rich enough array of organic chemicals to produce the complex structures needed for life.
For his 1958 experiment, Miller took the crucial step of adding hydrogen sulphide -- an evil-smelling toxic gas released by volcanoes -- to the mix. The new 'primordial soup' samples he created at Columbia University, New York, were shelved and catalogued, but not analysed.
Results from a new study of the samples using modern techniques 1,000 times more sensitive than those available to Miller were published in the journal Proceedings of the National Academy of Sciences. "Much to our surprise, the yield of amino acids is a lot richer than any experiment Miller had ever conducted," said University of California's Jeffrey Bada, who led the research and was one of Miller's students.
The findings support the theory that volcanoes played a key role in the creation of life.