Miller-Urey Experiments repeated
Saw this on Scientific American Online. Researchers have repeated the Miller-Urey experiments using the 'right' mixture of gases in the primordial atmosphere along with a new twist. Miller-Urey's original experiment produced amino acids, but the atmosphere used (methane and ammonia) was unlike the early atmosphere on earth. When Miller-Urey repeated the experiment, few amino acids were produced. The latest experiment adds what is essentially a buffer to the water system in the form of iron and carbonate. The addition of these buffers resulted in more neutral water system and bingo amino acids were formed.
The question remains as to whether or not the new experiment faithfully reproduces conditions on the early earth. Carbonate rocks are not present in abundance until later in Earth history (3.5 Ga) and certainly dissolved iron was present in the water as evidenced by Archean-age banded iron formation. The carbonates that are present in Greenstone belts are also ankerites (iron-rich carbonates) lending further support to the conditions mentioned in the news article (Veizer et al. 1989).
I like how the article mentions creationists view on this and no doubt they will respond to the latest experiment.
Cheers
Joe Meert
ref:
Veizer et al., 1989 Geochimica Cosmochimica Acta, 53, 859-871
posted by Unknown @ 7:14 AM
2 comments
2 Comments:
I've never been particularly concerned about the actual conditions of the experiment. What it demonstrates, regardless of conditions, is that one step (atoms and small molecules to larger molecules) in the chemical origin of life is feasible. The more significant steps in development of precellular life remain mysterious. Since there's no fossil evidence for these steps they're likely to remain intellectually challenging for some time.
On the other hand neither creationism nor intelligent design have shed light on any steps in the origin of life.
2008 saint paul year
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