The latest posting on Uncommon Descent tries to undermine the concept of a natural origin of life [Life From Chiral Crystals . . . Really?]. Maybe one of these days they'll actually put up some evidence to support Intelligent Design Creationism instead of always attacking science.1
Patrick is worried about the chirality problem, which can be pretty well explained by just applying a bit of common sense [Amino Acids and the Racemization "Problem"]. Unfortunately, it's not just the IDiots who are confused about the chirality problem. Many chemists and biologist also seem to have weird ideas about the requirement for 20 L-amino acids when life began.
Patrick quotes Timothy Standish who says,
Much as the Miller-Urey experiment demonstrated that it is possible to produce insignificant yields of a very few biologically important monomers in a laboratory device, Noorduin et al. demonstrated that chemists are capable of producing enantiomerically pure crystals under laboratory conditions. This laboratory technique fails to show a mechanism by which enatiomerically pure solutions of all 20 amino acids used in protein construction may have existed before the advent of life, not to mention the other chiral molecules found in living things. As a consequence, the chirality problem for chemical evolution remains unresolved by this technique.How many things are wrong with this paragraph?
1. Not holding my breath.
6 comments :
Well, the first thing that comes to mind is the assumption that "all 20 amino acids" are necessary. The second is the assumption that "enatiomerically pure solutions" are necessary. And this: "...not to mention the other chiral molecules found in living things." was probably neither one of the goals of the experiment nor an assertion made by the authors.
Glycine is achiral, so it should just be 19.
Patrick also said How did proteins composed of enantiomerically pure amino acids come to be? One Darwinian speculation posits that they were produced from an enantiomerically pure solution of amino acids.
I don't think I've ever heard a scientist make such a silly suggestion. It sounds like just the sort stupid idea that a creationist would invent for putting in the mouth of an imaginary "Darwinian".
Heck the assumption any amino acids at the start were necessary is absurd let alone any of the twenty commonly used today. Lots would have had to happen to arrive at the hypothesized RNA world let alone to get to modern life with DNA, RNA, & proteins and the like. They just have no sense of evolution at all. Life did not have to be like it is today, when are they going to get that through their skulls? No sense of time scales, no sense of chemistry, no sense of chance, of selection, of change, etc.
"As a consequence, the chirality problem for chemical evolution remains unresolved by this technique"
Yes, as opposed to the technique "God Willed It So" which is validated by tons of evidence and resolves the problem pretty darn well
Many creationist-types are geeked up about 'pure' reagents being required for abiogenesis. Whenever I ask how they know this, why they think this is so, I get no answer at all.
It is just another "argument" that scientifically ignorant rubes have latched onto because some 'hero' of their's said something about it at some point.
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