Early DNA replication systems

An enigma for abiogenesists to figure out. Evolution only acts on existing life, and the theory of evolution says nothing at all about the origin of life. This was over ten years ago, an enormous amount of RNA-enzyme and RNA-replicator work has been done in that time. As part of that work, it has been discovered that short RNAs are capable of synthesizing nucleotides , and that short RNAs are capable of efficiently and accurately catalyzing RNA replication - thus the two problems Orgel states as "so challenging" have since been solved. In fact the first paper (I think) describing self-replicating RNAs came out just two years after Orgel's comment.Scientists produced these enzymatic RNAs NOT by designing them, but by selecting for enzymatic activity from a few million randomly and chemically assembled RNAs. Absolutely no DNA or protein is required for any of this to occur. The conditions of primitive Earth were quite unlike "life today", so looking for evidence of abiogenesis based on current conditions is a fallacy.Also, "huge quantities" is a bit misleading. Only a single (or few) self-replicating RNAs would need to arise to allow evolution to begin (mutation and selection could act upon the replicator). Efficient replicators as described above are less than thirty bases long, if I remember correctly, so there is no "impossible" probability associated with it arising. Also, the smallest RNAs with enzymatic activity are only seven bases long. Those "helpful assumptions" are only helpful if one is trying to boost the improbability of abiogenesis "up to" something seemingly impossible; see - Lies, Damned Lies, Statistics, and Probability of Abiogenesis Calculations. Does your source provide the calculations so that we might check them, and their underlying "helpful assumptions"?Also, it is unlikely that life began with protein, yet those arguing against a naturalistic origin of life use protein "occurring" for calculations since it gives much lower probabilities of randomly happening (that are flawed in any case). More informed models of early RNA evolution show the evolution of essential ribozymes to be quite plausible.Ribozymes are an intricate part of cellular biology, they are still essential for human life. The same small RNAs required for vertebrate life are found conserved in the kingdom Archea, suggesting a quite "primordial" evolutionary origin.Hopefully I've showed that the gaps you've described in the RNA-world hypothesis have been filled. (To some extent "RNA"-world is a bit misleading - it was likely a "nucleotide"-world made up of RNA, RNA-analogs, and/or DNA; and at some later point protein.)However, I realize that the point of the thread is to get at the origins of DNA polymerase. RNA likely begat DNA, which is a simple chemical difference resulting in a great improvement in stability. Initial DNA may not have coded for protein, but may itself been active in catalysis, as part of chimeric DNA-RNA-zymes, or it may have been an inert byproduct of RNA transcriptase until ribosomal RNA appeared. Once ribosomes were in the picture, DNA-coded protein became a possibility, and thus the evolution of a DNA polymerase.A major point to realize is that chemical abiogenesis was a historical event that happened under unknown conditions. Abiogenesis research will never be able to "prove" exactly how it happened; but it can demonstrate ways it could have occurred. The "unlikelihood" of the process cannot be known, since the conditions of abiogenesis are unknown - for all you or I know, chemical conditions may have been absolutely perfect, essentially guaranteeing the arisal of life.It seems to me that you see two possibilities for the origins of life - a Creator or a Chemical Reaction. Personally, I see the catalysis of nucleotide polymers on a clay substrate under varying temperature conditions to be much more probable than an eternally-existing, omnipotent, deceitful intelligence. A lack of evidence for the chemical origins is not evidence for a Creator as you imply. Thus; we have some evidence for chemical origins, while we have no evidence for the other option you present.References:

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Ekland EH, Bartel DP. 1996 RNA-catalysed RNA polymerization using nucleoside triphosphates. Nature. Jul 25;382(6589):373-6.

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Chapple KE, Bartel DP, Unrau PJ. 2003 Combinatorial minimization and secondary structure determination of a nucleotide synthase ribozyme. RNA. Oct;9(10):1208-20.

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Johnston WK, Unrau PJ, Lawrence MS, Glasner ME, Bartel DP. 2001 RNA-catalyzed RNA polymerization: accurate and general RNA-templated primer extension. Science. May 18;292(5520):1319-25.

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McGinness KE, Wright MC, Joyce GF. 2002 Continuous in vitro evolution of a ribozyme that catalyzes three successive nucleotidyl addition reactions. Chem Biol. May;9(5):585-96.

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Szabo P, Scheuring I, Czaran T, Szathmary E. Nature. 2002 In silico simulations reveal that replicators with limited dispersal evolve towards higher efficiency and fidelity. Nov 21;420(6913):340-3.

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Leon PE. 1998 Inhibition of ribozymes by deoxyribonucleotides and the origin of DNA.J Mol Evol. Aug;47(2):122-6.

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Frimerman A, Welch PJ, Jin X, Eigler N, Yei S, Forrester J, Honda H, Makkar R, Barber J, Litvack F. 1999 Chimeric DNA-RNA hammerhead ribozyme to proliferating cell nuclear antigen reduces stent-induced stenosis in a porcine coronary model. Circulation. Feb 9;99(5):697-703.

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Terns MP, Terns RM. 2002 Small nucleolar RNAs: versatile trans-acting molecules of ancient evolutionary origin. Gene Expr. 10(1-2):17-39.

Thanks, and no problem.Just to reiterate, though - in none of those sources will you find rock solid evidence of how abiogenesis occurred, or how the "RNA world" (if it ever existed) specifically gave rise to the DNA/protein world.The overall point of abiogenesis research, in my opinion, is to show how things could have proceeded during the arisal of life. If reasonable naturalistic explanations are available, then there is no reason to make an unreasonable jump to a supernatural explanation.

I'd say because often the most rabid anti-evolutionists don't understand the theory of evolution, and so they assume it does speak to origins.I've also seen people describe Big Bang theory as part of the theory of evolution; or state that the theory of evolution claims to disprove the existence of God - both of which are absurdities. But literal or YEC creationists aren't just concerned with origins, they are also concerned with the age of the Earth, and that God created life as kinds, not as something that would evolve into kinds.Creationists mix up all of these other issues with evolution. Don't blame the evolutionists for that...(And I'm realizing we're totally off-topic now...)

There is zero evidence for the eternal omnipotent intelligence, so it is deceitful in that it has erased all evidence of its hand in the design process, and in fact has created all evidence to point away from a conclusion of design. Not to mention it is currently "hiding" itself from us... this is a subject for another thread.Also, I wasn't talking about "God", though I believe there are other threads here pointing out examples of His use of deceit in the Bible - it is off-topic here.