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Old 04-21-2003, 06:22 PM   #31
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Then I don't know what I said that you object to. I don't remember making any claim in this thread regarding probability as it relates to evolution in general.
Its quite simple: you suggest that abiogenesis should be able to produce amoebas of all things. Amoebas are possible the most complicated of all single celled organisms, and are the result of evolution from simpler precursors. Your proposed experiment, therefore, is worthless. What you SHOULD be requesting are experiments that attempt to synthesise replicating RNA from prebiotically viable materials. There are many such experiments.

Put simply: your suggestion that abiogenesis involves the chance creation of a cell, or anything like it, is wrong. Evolution 'in general' is responsible for them. Chance abiogenesis need only account for simple replicating molecules.
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Old 04-21-2003, 07:37 PM   #32
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Originally posted by Doubting Didymus
Its quite simple: you suggest that abiogenesis should be able to produce amoebas of all things. Amoebas are possible the most complicated of all single celled organisms, and are the result of evolution from simpler precursors. Your proposed experiment, therefore, is worthless. What you SHOULD be requesting are experiments that attempt to synthesise replicating RNA from prebiotically viable materials. There are many such experiments.
OK, now we're getting somewhere. In what respect and to what degree have such experiments been successful? And just what does probability have to do with it?

Quote:
Put simply: your suggestion that abiogenesis involves the chance creation of a cell, or anything like it, is wrong. Evolution 'in general' is responsible for them. Chance abiogenesis need only account for simple replicating molecules.
But chance is not involved in the assembly of such molecules into a cell? How so?
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Old 04-21-2003, 08:13 PM   #33
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Originally posted by yguy
OK, now we're getting somewhere. In what respect and to what degree have such experiments been successful? And just what does probability have to do with it?
I am not a biochemist, so I can not answer from the top of my head. I shall put out the call and return to this point shortly. In the meantime, feel free to do your own research.

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But chance is not involved in the assembly of such molecules into a cell? How so?
I did not say that chance was not involved in any way, just that the formation of said molecules into said cells is not random overall: natural selection of random mutations is like shuffling a deck, then selecting the aces to form your hand. There is randomness involved, but the end product does not resemble randomly generated phenomena.

In other words, the progression from RNA molecules to prokaryotic cells was the result of random mutation, filtered by natural selection. It is thus not meaningful to call the origin of the cell "random" and go on to claim that such a random occurance is too improbable to occur.
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Old 04-21-2003, 08:34 PM   #34
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It is near my bedtime but here is a brief outline of my review of the abiogensis issue as I see it right now. I’ll add the references later. I'll aim to write this up as a response to the evo/creato domain, rather than a "state of the art" review article (although just the bibliography I have generated is longer than most review articles I have read). The main creato B.S. will be from AiG, and ICR (surprise surprise surprise).

I) Abiogenesis is not the same as “spontaneous generation”
Abiogenesis is not necessarily germane to evolutionary biology.
Darwin, vitalism and the Operin/Urey hypothesis

II) The initial conditions on Earth, the Hadean
The massive impact aggregation of planetesimals
The chemical composition of planetesimals
NiFe,
chondrites (+ pre-impact weathering products),
cometary bodies
Impact chemistry of cometary bodies
Other extraterrestrial inputs
Faint Sun, snowball earth ==
reaction product concentration,
impact melting,
UV production of O3 from ices.

III) Crustal dynamics of the early Archean
The mantel preservation of primordial gases
Redox conditions of the Archean atmosphere
linkage of the atmosphere and the oceans
linkage of the crust and the atmosphere/ocean systems

IV) Abiotic generation of complex molecules on the Archean Earth
Abiotic amino acids
Abiotic sugars
Abiotic bases

V) Polymerization under abiotic conditions
Atmospheric
Cyclic (wet/dry, hot/cold)
Hydrothermal
Other mineral catalysts/templates

VI) Precellular evolution
Mostly (but not entirely) about Carl Woese
Mineral
Minimal enzymes
Chirality (mostly an inflated issue)

VII) Likely parts of the earliest organisms, and the endosymbiont hypothesis of cell formation

VIII) Steps that have left a geochemical trace, and a timeline

IX) What is missing+Panspermia+probability confusions

Nitey nite
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Old 04-22-2003, 05:52 PM   #35
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I spent about 4 hours today filling in references to the outline I posted last night. I have got to the "L"s, and the text is 9 pages.

I have meetings tomorrow.

So, do I post partial bits?

I don't like that idea. Rather, I thought that I would finish placeing the references into the outline and then (if it seems worht while) I could post the dang thing in chunks.
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Old 04-22-2003, 06:05 PM   #36
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I just had another Idea.

Why don't you all just select the parts of my outline that seem to be worth finishing, and I will make them my priority.
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Old 04-22-2003, 06:44 PM   #37
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Quote:
Originally posted by Dr.GH
I just had another Idea.

Why don't you all just select the parts of my outline that seem to be worth finishing, and I will make them my priority.
I think Yguy would benifit most from information about abiotic generation of complex molecules on the Archean Earth, and also polymerization under abiotic conditions, which I assume will include some reference to generating selfreplicating RNA molecules?
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Old 04-23-2003, 03:57 AM   #38
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Its funny while you guys are arguing this were you aware that a virus has been found that can form DNA from RNA and ATP?

This was a stumbling point for abiogenesis. RNA and ATP can be replicated outside of cells even but DNA is trickier.

I think the problem was they couldn't find away for RNA or ATP to be convert to DNA and DNA hasn't been found outside of cells. Usually DNA is neede to produce more. This virus is PHI- 46 or something like that.
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Old 04-23-2003, 05:18 AM   #39
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This is always a good starting point for information, too.

Talk Origins - Abiogenesis

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Old 04-23-2003, 07:05 AM   #40
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Do you have a reference for that paper Jabu? I cant find anything in the literature similar to what you describe.
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