Some experimental samples put aside for 50 years have provided new evidence that life on earth could have been kick-started by volcanoes.
Stanley Miller - famous for his 1953 'primordial soup' experiment showing the synthesis of organic compounds - shelved a set of samples from a smilar experiment and never came back to them.
But more than 50 years later, Jeffrey Bada, Miller's former student and a Scripps Institution of Oceanography, UC San Diego professor of marine chemistry, discovered the samples in Miller's laboratory material and analyzed them using modern techniques.
The results suggest that there was a far more diverse range of organic compounds on the early Earth than scientists had realized.
"Much to our surprise the yield of amino acids is a lot richer than any experiment [Miller] had ever conducted," says Bada.
The findings support the theory that the first amino acids were created by the compbination of lightning and atmospheric hydrogen sulfide from volcanoes.
Bada also found that the amino acids produced in Miller's experiment with hydrogen sulfide are similar to those found in meteorites.
Miller didn't in fact succeed in creating the sulfur-rich amino acids until the 1970s. And it now appears that the 'lost' mix more closely resembled early Earth conditions than did the gases in his more famous previous experiment.
"Unbeknownst to him, he'd already done it in 1958," says Bada.