The chief lesson from a new article in this week’s Science is, never, ever throw out out your samples. Most people are probably familiar with Stanley Miller’s classic biochemistry experiment, in which he produced amino acids in a simulation of Earth’s early atmosphere [PDF]. That experiment was groundbreaking, but since it was published in 1953 geochemsists have questioned whether it accurately reflected conditions on ancient Earth. But another of Miller’s experimental results, which went unpublished until now, may be the response to that criticism.
Volcanic steam: the origin of
life on Earth?
Photo by vtveen.
After Miller’s death in 2007, one of his former graduate students inherited a bunch of boxes full of Miller’s experimental products. The box included products from an experiment simulating steamy conditions around a volcanic vent. The student, Jeffrey Bada, decided to re-analyze the preserved product using (among other approaches) high-performance liquid chromatography, a method of identifying organic compounds that wasn’t available when Miller did his original work in the 1950s. It turns out that the volcano experiment produced an even richer array of amino acids than Miller knew [$-a]. Enough, maybe, to lay the groundwork for life. That’s what Bada and his coauthors argue:
Reduced gases and lightning associated with volcanic eruptions in hot spots or island arc–type systems could have been prevalent on the early Earth before extensive continents formed. … Amino acids formed in volcanic island systems could have accumulated in tidal areas, where they could be polymerized by carbonyl sulfide, a simple volcanic gas that has been shown to form peptides under mild conditions.
Naturally, this is only a jumping-off point for further work, starting with replication of Miller’s original experiment. But it’s a useful discovery, and a cautionary tale to any grad student who’s careless about record-keeping – you never know when that throwaway result will turn out to be useful.
A.P. Johnson, H.J. Cleaves, J.P. Dworkin, D.P. Glavin, A. Lazcano, J.L. Bada (2008). The Miller volcanic spark discharge experiment Science, 322 (5900), 404-404 DOI: 10.1126/science.1161527
S.L. Miller (1953). A production of amino acids under possible primitive Earth conditions Science, 117, 528-9 Full text (PDF)