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How did DNA evolve?
Evolution assumes DNA exists, but as yet no account has been provided as to how

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How did DNA evolve?
jeeprs
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Posted 10/09/09 - 07:55 PM:
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#41
I suppose I have been somewhat idiosyncratic in my approach. However generally speaking, I am trying to put the case that the presence of humans in the cosmos is not just a happenstance, and cannot be solely explained with reference to evolutionary theory. I will admit I do believe there is a 'great intelligence' behind it all, but I am sure it cannot be proven; that is one of the parameters of the situation in my view. And in any case, I don't see it as removing any personal responsibility for the working out of one's own destiny, and to that extent I am certainly not an orthodox Christian. Believing it just doesn't cut it in my view, you have to understand what it means.

The Alan Watts quote - I can't remember which of his books this was in. I found it again on a quotations page. It might have been in The Book: On thr Taboo against Knowing Who you Are - but I am not sure. The other two books I referred are the one above by Conway Morris, who is a theist, and At Home in the Universe: The Search for the Laws of Self-Organisation and Complexity, by Stuart Kaufmann, who is not.

A quote from one Amazon review of the latter:

The basic idea of Kauffman's book is that the complexity we see in nature (including life or technology) is contingent to math, i.e. can be explained and predicted by mathematical reasoning. The same is true of statistical thermodynamics and evolution. He states that Darwin's evolutionary theory explains only how complex life emerged from simple life, but it does not explain how simple life emerged from matter. There is probably a larger jump in complexity from matter to the first simple cell, than from that simple cell to a modern human being. Darwin does not explain that first jump. Kauffman doesn't either even though he is convincing in showing that life must have started through autocatalytic sets of molecules. He points out that these sets are self-organizing, stable and can vary as a reflex to external stimuli. What he mentions, but does not explain, is that autocatalytic sets can (or must) self-reproduce, a necessary step before evolution sets in. On page 66 of the paperback edition he states that "such breaking in two happens spontaneously as such [auto-catalytic] sets increase in volume", but, maddeningly, he does not explain how or why. One has to wonder: if life is such a necessary result of matter (therefore the title "at home in the universe") why then has it proven so difficult to synthesize anything approaching life in the laboratory? He doesn't say.




Edited by jeeprs on 10/09/09 - 08:00 PM
vander
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Posted 10/12/09 - 10:06 PM:
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DNA is constructed from a combination of seven amino acids within a context of temperature and pressure.

The specification of the construction and evolution of biology is the logic structure which is the paradigm that integrates science.

See the essay, "The Logic of the Universe", located at: http://members.westnet.com.au/paradigm/forever.pdf

vander
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Posted 10/13/09 - 02:28 AM:
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You need to divorce the concept of "evolution" from "abiogenesis". They are very different processes. Evolution involves the selection of genetic material passed from a species to its descendants. You need something that reproduces or replicates first. Darwin didn't explain the first jump because he focused more on the origin of species rather than the origin of life. So evolutionary theory doesn't really apply before the appearance of a self-replicating molecule.

But discovering possible paths, (not necessarily the actual path), isn't so difficult. This just came out last May:

some blog wrote:
John Sutherland, a chemist at the University of Manchester, and his colleagues claim to have figured out how ribose, phosphate and the nitrogenous (nitrogen-bearing) molecules known as nucleobases first came together to form nucleotides—the building blocks of the RNA world from which life is thought to have emerged."My assumption is that we are here on this planet as a fundamental consequence of organic chemistry," Sutherland told The New York Times. His secret was running the experiment in stages, only adding phosphate in the final step. So far, the team has succeeded in building two of the four nucleotides; the molecule pictured [left] is cytosine, the nucleobase that, until now, scientists were unable to combine with sugars and phosphates to form the RNA nucleotide ribocytidine phosphate.

Is the latest discovery a real breakthrough or just another high-profile paper to tease the navel-gazers of the science world? Jack Szostak of the Massachusetts General Hospital wrote in a commentary that the new discovery "will stand for years as one of the great advances in prebiotic chemistry."


I think Kauffman's approach was probably pointing out that abiogenesis was a mathematical inevitability given the right combination of circumstances in the environment. Having difficulty synthesizing doesn't detract from probability as much as understanding and a lack of imagination. It is a "negative proof". Even if something can't be proven, doesn't mean it is false. Nobody would claim that it is impossible for a female rabbit to make baby rabbits with a male rabbit simply because it proves very difficult to do in the laboratory and there is no need to call for the necessity of intelligence. It just required the right environment, (some wine, candles, music -- preferably Barry White, and 2 rabbits of the opposite sex), and enough time. In the end, we are are just the all singing, all dancing, self-replicating molecules of the world and little else.

Ethics is the measuring of morality. Morality is the measuring of good. Good is the measuring of benefit. Benefit is the measure of values.
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