This site is not maintained. Click here for the new website of Richard Dawkins.


← Researchers Discover Remnant of an Ancient 'RNA World'

squinky's Avatar Jump to comment 20 by squinky

Very interesting article. Is the RNA world conceivable? Yes. The problem I have with it is that all the heavy lifting is done now by extremely sophisticated enzymes (proteins) that perform functions nearly impossible to imagine how catalytic RNA could do (metabolism, cell wall synthesis, etc) the most difficult are:
How were nucleotides synthetized in the RNA world (ribose and deoxyribose) which are the building blocks of RNA (and DNA)? How was template-directed nucleotide polymerization done (how was RNA "activated" and most importantly, how was 3' vs 2' RNA correctly formed (they can equilibrate) without a ribosome? While I can buy self-replicating RNA kindof, I can't imagine how:
1) It formed in the first place
2) How it acquired chiral, activated precursors
3) How it found more nucleotides to keep going (there are many dead-end reactions, so what)
4) Morph from a simple self-replicating system(and we can't even get these things to self-assemble in the lab) to the first cell that contains RNA and no proteins. Is it alive? Does it metabolize something or use energy? How does this little cell travel to more nutrients when it has no motor proteins?

The RNA world (while there are glimpses of evidence) to me is a placeholder hypothesis of abiogenesis. I have many problems with it.

Fri, 18 Jul 2008 10:47:00 UTC | #202386