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To: Ichneumon
You can lead a donkey to water...
148 posted on 04/03/2004 5:32:01 AM PST by greenwolf
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To: greenwolf
From Are the Odds Against the Origin of Life Too Great to Accept?:

Murray Eden and the Wistar Institute

Schroeder cites a Wistar institute conference as showing evidence of the improbability of evolution. The symposium was transcribed from audio and published in 1967 as Mathematical Challenges to the Neo-Darwinian Interpretation of Evolution, a Symposium Held at the Wistar Institute of Anatomy and Biology April 25 and 26, 1966, Paul Moorhead and Martin Kaplan, eds. Needless to say, this is quite out of date. Worse, it does not support Schroeder at all. Only one paper comes anywhere near proposing that the origin of life and subsequent evolution is improbable: Murray Eden, "Inadequacies of Neo-Darwinian Evolution as a Scientific Theory" (pp. 5-20). He does not really argue that evolution is improbable, but rather that no present theory accounts for certain peculiarities of life on earth, especially the fact that all living organisms are composed of a very tiny fraction of all the possible proteins.

In particular, Eden argues that given all "polypeptide chains of length 250 [amino acids] or less...There are about 20^250 such words or about 10^325" (p. 7). This number is ripe for quoting, but it does not stand as the odds against life, and even Eden did not even imply such a meaning--to the contrary, he admits that perhaps "functionally useful proteins are very common in this space [of 10^325 arrangements]," and facing tough criticism in a discussion period (where his paper was torn apart, pp. 12-9) he was forced to admit again that perhaps "there are other domains in this tremendous space which are equally likely to be carriers of life" (p. 15). But his main argument is that life is concentrated around a tiny fraction of this possible protein development "space" and we have yet to explain why--although his critics point out why in discussion: once one system involving a score of proteins was selected, none others could compete even if they were to arise, thus explaining why all life has been built on one tiny set of proteins. One thing that even his critics in discussion missed is the fact that his number is wrong: he only calculates the number of those chains that are 250 acids long, but he refers to all those and all smaller chains, and to include all of those he must sum the total combinations for every chain from length 1 to 250. Of course, the number "250" is entirely arbitrary to begin with. He could have picked 100, 400, or 20. He gives no arguments for his choice, and as we have seen, this can have nothing to do with the first life, whose chain-length cannot be known or even guessed at [5].

Among the huge flaws in Eden's paper, pointed out by his critics, is that he somehow calculates, without explanation, that 120 point mutations would require 2,700,000 generations (among other things, he assumes a ridiculously low mutation rate of 1 in 1 million offspring). But in reality, even if only 1 mutation dominates a population every 20 generations, it will only take 2400 generations to complete a 120-point change--and that even assumes only 1 point mutation per generation, yet chromosome mixing and gene-pool variation will naturally produce many at a time, and mix and match as mating proceeds. Moreover, a beneficial gene can dominate a population faster than 20 generations, and will also be subject to further genetic improvements even before it has reached dominance. I discuss all of these problems in my analysis of Schroeder above. But in the same Wistar symposium publication, C. H. Waddington (in his "Summary Discussion") hits the nail so square on the head that I will quote his remarks at great length:

The point was made that to account for some evolutionary changes in hemoglobin, one requires about 120 amino acid substitutions...as individual events, as though it is necessary to get one of them done and spread throughout the whole population before you could start processing the next one...[and] if you add up the time for all those sequential steps, it amounts to quite a long time. But the point the biologists want to make is that that isn't really what is going on at all. We don't need 120 changes one after the other. We know perfectly well of 12 changes which exist in the human population at the present time. There are probably many more which we haven't detected, because they have such slight physiological effects...[so] there [may be] 20 different amino acid sequences in human hemoglobins in the world population at present, all being processed simultaneously...Calculations about the length of time of evolutionary steps have to take into account the fact that we are dealing with gene pools, with a great deal of genetic variability, present simultaneously. To deal with them as sequential steps is going to give you estimates that are wildly out." (pp. 95-6)

150 posted on 04/03/2004 5:46:40 AM PST by VadeRetro
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To: greenwolf
You can lead a donkey to water...

...but you can't make him think.

217 posted on 04/03/2004 1:42:01 PM PST by Ichneumon
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