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#21
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"Ross Langerak" wrote:
Jack has a point here. The formation of amino and nucleic acids is determined by the laws of chemistry, and was demonstrated by the Urey-Miller experiment. But as far as I know, the order that nucleic acids can be strung together to form RNA is not determined by any laws of chemistry. One sequence is just as valid as any other. Well, not really. This is where *selection* comes in. Some are more stable than others, and last longer. Some catalyze various reactions, including RNA polymerization. These variants are *not* equal. The peace of God be with you. Stanley Friesen |
#22
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Jack Crenshaw wrote:
Mike Painter wrote: snip It should be noted that Hoyle was an astronomer (and fair sci-fi writer). I'm not sure what Wickramasinghe was but neither were biologists. Though Fred Hoyle was almost certainly wrong more than once in his career, it was still an illustrious one -- surely moreso than yours or mine. It was Hoyle who worked out the mechanism for the production of heavier elements inside supernovae: So? How does this make him qualified to speak on *biology*? *Every* time I have heard him speak on biology he has been wrong. His "ideas" about _Archaeopteryx_ were totally uninformed, for instance. I wouldn't discount his knowledge so quickly. I would - nucleosynthesis in stars has *nothing* to do with abiogenesis, except in the trivial sense that it supplied the elements involved. Before I listen to his ideas on biology he has to demonstrate knowledge of *biology*. The peace of God be with you. Stanley Friesen |
#23
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In talk.origins, "Ross Langerak" wrote in
. net: .... Some creationists like to use hemoglobin as an example of something that could not evolve by chance. They typically make the same error that Hoyle and Wickramasinghe did, in that they calculate the odds against a particular sequence of residues occurring, rather than the odds against producing a protein or enzymes with the desired characteristics. I am not familiar with any enzymes, so I used hemoglobin as an example instead. Presumably, the results would be similar. I recall hearing, maybe on NPR's Science Friday, that there are hemoglobin substitutes in development and that they are dramatically smaller molecules. Does anyone have any useful details or a recommendation about where to read about it? |
#24
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![]() "David Jensen" schrieb im Newsbeitrag ... In talk.origins, "Ross Langerak" wrote in . net: ... Some creationists like to use hemoglobin as an example of something that could not evolve by chance. They typically make the same error that Hoyle and Wickramasinghe did, in that they calculate the odds against a particular sequence of residues occurring, rather than the odds against producing a protein or enzymes with the desired characteristics. I am not familiar with any enzymes, so I used hemoglobin as an example instead. Presumably, the results would be similar. I recall hearing, maybe on NPR's Science Friday, that there are hemoglobin substitutes in development and that they are dramatically smaller molecules. Does anyone have any useful details or a recommendation about where to read about it? Besides, there are lots of organisms that don't use hemoglobin. Greetings! Volker |
#25
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![]() "Stanley Friesen" wrote in message ... "Ross Langerak" wrote: Jack has a point here. The formation of amino and nucleic acids is determined by the laws of chemistry, and was demonstrated by the Urey-Miller experiment. But as far as I know, the order that nucleic acids can be strung together to form RNA is not determined by any laws of chemistry. One sequence is just as valid as any other. Well, not really. This is where *selection* comes in. Some are more stable than others, and last longer. Some catalyze various reactions, including RNA polymerization. These variants are *not* equal. I had considered that, but I didn't see how that would help, as the likelyhood that a stable chain of nucleotides would be able to self-replicate isn't any more likely than an unstable chain. Are you suggesting that there are only a few stable chains, and that one of them just happens to self-replicate? |
#26
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![]() "Volker Hetzer" wrote in message ... "David Jensen" schrieb im Newsbeitrag ... In talk.origins, "Ross Langerak" wrote in . net: ... Some creationists like to use hemoglobin as an example of something that could not evolve by chance. They typically make the same error that Hoyle and Wickramasinghe did, in that they calculate the odds against a particular sequence of residues occurring, rather than the odds against producing a protein or enzymes with the desired characteristics. I am not familiar with any enzymes, so I used hemoglobin as an example instead. Presumably, the results would be similar. I recall hearing, maybe on NPR's Science Friday, that there are hemoglobin substitutes in development and that they are dramatically smaller molecules. Does anyone have any useful details or a recommendation about where to read about it? Besides, there are lots of organisms that don't use hemoglobin. Obvious examples would be plants, and single-celled and small multicelled organisms that allow oxygen to diffuse through their bodies. But, can you provide an example of a larger organism that transports oxygen by some means other than hemoglobin? Do insects actually tranport oxygen, or do they just let it diffuse into and out of their bodily fluids? |
#28
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Jack Crenshaw wrote in message ...
Pavil Natanovich wrote: Jack Crenshaw wrote in message ... Ok, here's the problem with your mathematics. Say -- just for argument's sake -- that Hoyle and Wickramasinghe got it right, and the odds against life arising spontaneously really are 10^(10,000). Your argument goes: but there's 6 billion people on earth. Let's include all people who ever lived, and make it 10^10 people. Now the odds drop "dramatically," to 10^9990. Same with your other points. Take off "several orders of magnitude." How many is that? 10? 20? Ok, now we're down to 10^9970 against. I guess you can see how this is going to go. Use up all the possible alternative DNA sequences you mention, and all the ones no one has thought of yet, and you're still not going to make much of a dent in that enormous number. The number of people have absolutely nothing to do with the number of potential possible combinations. For that matter, neither do the number of organisms that have ever lived, which incidentally is enormous. Count all the bacteria that have ever existed, over the course of the last several billion years. The problem is that the 10^9970 number is entirely bogus. It represents nonsense on so many different levels it is difficult to know where to begin. Therefore, you choose not to? I did not think it was necessary to belabor the obvious. First let us examine the assumptions. When we look at a chain of events from the end, the final product of probabilities becomes vanishingly small. To reduce the likelihood of any event all that is necessary is multiplying the independent probabilities of yet more events in the chain. At the beginning there is no chain. There are only branching possibilties, and it is impossible to know what will be the final result. As a simple illustration, suppose we flip a fair coin, and limit the outcome to one of two states: H or T. If we decide to flip the coin twice in succession there are four possible outcomes. If we remove some restrictions the number of outcomes increases. We don't have a good idea what the restrictions are on evolution. We have no idea how the first organisms formed. How can someone assign probabilities based on ignorance? When flipping a coin, what percent of the time does the coin fall on an uneven surface where it is difficult to determine which side is up? I've played many games spoiled by arguments over the state of the chance cubes. What is the probability you flip an coin and lose it, or flip it and it rolls into a pile of other indistinguishable coins? Select a DNA molecule. How many atoms does it contain? Suppose we arrange these in a line, and substitute any random element from the periodic table (roughly 92 naturally occurring elements). The odds of creating that one specific DNA molecule using this obscenely stupid process is probably less than 10^10000. Better would be to limit the choice of elements to those forming A, T, G, & C bases. But that is still nothing like how it probably happened originally. Of course, one DNA molecule is not life. But it would be just as stupid to use the same type of logic to calculate the odds of a water molecule spontaneously forming. Water is H2O. The odds against this particular molecule forming are 92^3, or a little under 10^6. On the other hand, water forms spontaneously when oxygen and hydrogen combine. How easy is that? In an environment that favors the natural synthesis of complex molecules, the probability of life forming might easily approach 1. Since know neither how it happened or what combinations viable, it seems a stretch to assign probabilities. The real question is: What is the complexity of a simple molecule -- simple enough to form spontaneously, complex enough to be self-reproducing -- constructing itself through random chance? Self replicating RNA molecules have arisen via natural means in the lab. Citation? Jack I misspoke. RNA has been synthesized. Self replicating RNA has also been synthesized, but not apparently not yet from plausbible prebiotic conditions. http://www.santafe.edu/sfi/publicati...ract/199811098 http://www.emc.maricopa.edu/faculty/...okPROTSYn.html |
#29
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In our last episode, "Ross Langerak" wrote:
... But, can you provide an example of a larger organism that transports oxygen by some means other than hemoglobin? ... Easy. Just Google up the word "hemocyanin". One example: the octopus. -- Mark Meyer |
#30
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