As I understand it, the first DNA is supposed to have "replicated" from a non-DNA analogue - i.e. a simpler molecule or molecules on which DNA could be built. It would be helpful to my understanding, and perhaps others, if AFJ could explain why that is impossible.
I like the way you want me to jump through hoops, while you lay down an unteseted gauntlet--the incremental fantasy which has never been demonstrated, nor observed in nature. Below are the biochemists--see what they say.
I do not know what kind of organic chemistry background you have. If you do not have much, you will become bored with this information. You seem to be giving me vague principles that are not proven by science. Only acedemically endorsed, speculative hip shots, with no demonstrable confirmation.http://en.wikipedia....orld_hypothesisThe molecular biologist's dream is a phrase coined by Gerald (Jerry) Joyce and Leslie Orgel to refer to the problem of emergence of self-replicating RNA molecules as any movement towards an RNA world on a properly modeled early Earth would have been continuously suppressed by destructive reactions. It was noted that many of the steps needed for the nucleotides formation do not proceed efficiently in prebiotic conditions. Joyce and Orgel specifically referred the molecular biologist's dream to "a magic catalyst" that could "convert the activated nucleotides to a random ensemble of polynucleotide sequences, a subset of which had the ability to replicate".http://www.arn.org/d...rnaworld171.htmJoyce and Orgel further argued that nucleotides cannot link unless there is some activation of the phosphate group, whereas the only effective activating groups for this are "totally implausible in any prebiotic scenario", particularly adenosine triphosphate. According to Joyce and Orgel, in case of the phosphate group activation, the basic polymer product would have 5',5'-pyrophosphate linkages, while the 3',5'-phosphodiester linkages, which are present in all known RNA, would be much less abundant. The associated molecules would have been also prone to addition of incorrect nucleotides or to reactions with numerous other substances likely to have been present. The RNA molecules would have been also continuously degraded by such destructive process as spontaneous hydrolysis, present on the early Earth. Joyce and Orgel proposed to reject "the myth of a self-replicating RNA molecule that arose de novo from a soup of random polynucleotides" and hypothesised about a scenario where the prebiotic processes furnish pools of enantiopure beta-D-ribonucleosides.Reference not available http://gow.epsrc.ac.uk/Error.aspx
The associated molecules would have been also prone to addition of incorrect nucleotides or to reactions with numerous other substances likely to have been present.
This is a no brainer Ringo. Contamination. You said "transitory equilibrium" could possibly happen in a pool of water, with constitunts continuously wahing in and out. I'm absolutely positive that in minutes, if every pool on earth was suddenly isolated as it sits, thermodymic equalibrium would take place, because all the chemical reations that could happen would happen. You would have all sorts of products, but no life. In fact, the biochemists point out that the phosphate products in a prebiotic Earth would not even be the ones FOUND IN RNA!! You may MAYhave some short RNA chains, but they would break down, as they ar much more subject to hydrolysis than DNA. This leads me to the point I have been making about catobolic and anabolic principles in life.http://en.wikipedia....arison_with_DNA
The RNA molecules would have been also continuously degraded by such destructive process as spontaneous hydrolysis, present on the early Earth.
RNA, because it is contains ribose sugar, instead of deoxyribose (DNA), is much less stable, and more open to degradation than DNA. They're saying that there is a hydroxyl group (-OH) in the " pentose ring in the 2'
position..." in RNA that is not present in DNA. This makes more open to hydrolysis, a degrading catabolic reaction. As you might know, hydrolysis happens in many biochemical readtions. Amino acids contain carboxyl groups (COOH) which link to the (NH2) amine portion of the amino acid. These link by dehydration sythesis
(the removal of an H20--an H from NH2, and an -OH from the COOH) and break by hydrolysis
(an insertion of an H2O--restoring seperate NH2 and COOH). This is how proteins form and break down. But proteins are well bonded, and therefore more stable (protein has to be broken more by acids or enzymes, and it does not denature as easily as RNA, because it is already well bonded). Single strand RNA is much more open to the hydrolysis break down than proteins, because of that open hydroxyl group on the '2. See it below? An RNA nucleotide. From left to right you have the phospate, and then the pentose molecule is in the middle (the ribose sugar). That's the molecule that wiki is saying makes it more susceptible to hydrolysis--because it is connected to the 2nd carbon (the carbons are inferred in organic chemistry structures. There is no C but where ther is a corner--that's a carbon). Go to middle ribose. Now go to the carbon on the right of the "O"--that's '1 carbon. Now go to the left and down to the '2 carbon. The -OH is a hydroxyl. RNA has this but DNA has an H. This makes it more susceptible to hydrolysis.
Decomposition of a chemical compound by reaction with water, such as the dissociation of a dissolved salt or the catalytic conversion of starch to glucose.