Brian:
>>This would indicate, to me anyway, that the ball is back in
>>Miller's court.
Me:
>I'm not so sure. Exactly what amino acids were condensed into
>oligopeptides? And didn't they get anything larger than six glycines
>linked together?
Brian:
>(1) glycine (2) no
>You seem to be missing the point. Go back and read the quotes
>that Steve gave. The implication of Miller's experiment is that
>the hydrothermal vents are a sink for organic materials. This
>creates a potentially serious problem due to the relatively
>rapid circulation of the early oceans through these vents.
>Matsuno's results call Miller's into question. The vents may
>not have been destructive. They may also have been generative.
Maybe I'm missing the point, but I don't see how Matsuno's results
call Miller's into question (at least serious question). As you suggested,
I reread the quotes, where both talk about these vents destroying
rather than creating "complex organic compounds." I don't consider
glycine a "complex organic compound," thus its survival doesn't
seem all that relevant. Matsuno's results would be more significant
if they dealt with other more complex amino acids and short peptides
composed of these amino acids. The Miller/Bada paper looked at
leucine, serine, and aspartate and found them all to decompose rapidly.
Furthermore, they too noted that glycine was stable under these heated
conditions (more accurately, glycine concentrations rose as the more
complex amino acids decomposed).
Also, don't forget that amino acids are not the only organics important
in abiogenesis. The ingredients of the RNA world would quickly
be decomposed under these hot vents condition (for example, sugars
survive only a few seconds at these high temps).
So I still don't see how the Matsuno results put the ball back in Miller's
court as they didn't address anything other than glycine.
Mike
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