London: Volcanoes and lightning may have provided vital spark in creating life on Earth, an old and ‘forgotten’ 1950s study suggested.

To come to the conclusion, researchers, led by the University of California at San Diego, used modern techniques to re-analyse the ‘primordial soup’ gas samples created in 1958 by pioneering US Prof Stanley Miller.

The researchers discovered a multitude of amino acids, the basic building blocks of life, which can be assembled together to form proteins, a newspaper reported.

In 1953, Prof Miller carried out the famous experiment attempting to recreate the atmospheric conditions present just before life appeared on Earth around four billion years ago.

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.

Now, Prof Jeffrey Bada, one of Prof Miller's students, led the California University team to study the samples using modern techniques some 1,000 times more sensitive than earlier
available to his teacher.

The findings revealed a plethora of organic compounds, including 23 amino acids. Around 20 amino acids, linked together in chains, make up the proteins that provide the material for building cells and all the organic machinery of living things.

The glut of amino acids was greater than that produced in Prof Miller's original "primordial soup" experiment and two other follow-up studies.

The California University team was also able to improve on the results of a 2008 re-analysis of the original samples which made use of modern techniques.

"Much to our surprise, the yield of amino acids is a lot richer than any experiment Miller had ever conducted. This really not only enhances our 2008 study but goes further to show the diversity of compounds that can be produced with a certain gas mixture," Prof Bada said.

The findings support the theory that volcanoes played a key role in the creation of life. Volcanic eruptions are a major source of hydrogen sulphide and lightning discharges, and were much more common when the Earth was young.

Prof Bada also found that the amino acids in Prof Miller's samples were similar to those found in meteorites, indicating that processes involving hydrogen sulphide may have helped spread the seeds of life throughout the Solar System.