dvunkannon
Posts: 1377
Joined: June 2008
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Denews joins David Tyler in a daisy chain behind Robert (not James) Shapiro in an attack on the RNA Wold, via Shapiro's review of David Deamer's new book, "First Life".
http://www.uncommondescent.com/origin-....robable
First thing to note is that Shapiro has an academic axe to grind, since he is pushing an alternate OOL theory of metabolism first. (But not pushing very hard, you don't see a lot of publications supporting his ideas. More like the carping "Birds aren't dinosaurs" comments from the Oregon State University professor who is a diehard on that subject.) So Tyler, a YEC, is just playing 'enemy of my enemy is my friend' by getting in line behind Shapiro. If Shapiro even noticed him back there, he'd laugh.
Deamer is pushing a pretty standard RNA World scenario for OOL, with the twist that he thinks that containing vesicles were a prerequisite for OOL. Vesicles that let in small molecules, but trap larger ones inside can raise the concentration of active RNA polymers and protect them from a number of environmental effects. All good for surface of the Earth OOL, though the hydrothermal vent OOL theories have their own ideas about tiny cracks in the structure of black smokers that serve the same function of concentrating chemicals.
Shapiro can't actually criticize Deamer's own work on the self assembly of vesicles from abiotically produced hydrocarbons. Deamer has taken material from meteorites, mixed it in water, and seen vesicles form. Instead, he attacks the RNA World hypothesis in general, as Tyler does, through quoting a story of Deamer's about trying to start life in a volcanic puddle. The 'in the wild' experiment fails, since most of the pre-biotic material winds up sticking to the clays at the boundaries of the puddle.
Anyone thinking this through will see that Deamer's experiment has more pedagogic or editorial function than it has scientific value. The clay is buffering the system, and until he adds more material than the buffer will absorb, nothing interesting is going to happen. He knows that. This 'designed to fail' experiment is meant to push the reader in the direction of his own preferred hypothesis that you need pre-existing vesicles to protect the reactions from too much interaction with the environment.
Of course, there is a lot of other research that the interactions with clays a good thing for OOL, tethering the RNA, protecting it from UV, etc. Jack Szostak's lab has combined the best of both worlds with bits of clay inside the vesicles. There is even a version in which water drops pick up a clay shell while floating in the air, an idea that lets OOL start even before the oceans have formed (or when they boil away).
But the message that Shapiro chooses to take away from all of this is that lab results don't necessarily mean anything in the real world. Why take this conclusion? Because he is trying to criticise the work of Sutherland, et al. in synthesizing RNA bases.
With Sutherland 2009, we finally saw how there was a workable path from small molecules to the RNA bases. Life works with polymers of hydrocarbons, amino acids, and nucleosides to make lipids, proteins and R/DNA. So now we have a much better understanding of how to build the building blocks, and hook the building blocks together, in all three major areas.
This success is a real downer for Shapiro's alternate theory, so Shapiro is left to carp from the sidelines. His opinion that what is done in the lab can't be transferred to the real world would of course evaporate if it was _his_ lab that produced some results... Tyler would also make an about face if Jonathan Wells ever produced something in his lab at the secret DI research facility on Volcano Island.
DeNews is clueless to all this subtext. As a model post-modern Christian culture warrior, poo flinging is fine no matter who was taking a poop on what or why. She's happy to pick it up and start tossing.
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I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima
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