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To: js1138; Michael_Michaelangelo
I would like to see some research that clearly demonstrates non-random variation.

Your wish is my command.

A Biochemical Mechanism for Nonrandom Mutations and Evolution

A multitude of random mechanisms result in hypermutation under conditions of environmental stress and clearly contribute to the variability essential to evolution. However, since most mutations are deleterious, random mechanisms that increase mutation rates also result in genomewide DNA damage. Among microorganisms, from phage to fungi, the overall mutation rate per genome is remarkably constant (within 2.5-fold), presumably reflecting an obligatory, delicate balance between the need for variation and the need to avoid general genetic damage (24, 45, 57). Thus, mutator strains are not selected in nature but remain at 1 to 2% of the population (35, 52); under certain adverse conditions, they flourish for short periods but are then selected against, apparently because of widespread deleterious effects intrinsic to genomewide hypermutation. In contrast, hypermutation that is the consequence of starvation-induced derepression and transcriptional activation represents a very rapid and specific response to each adverse circumstance. The extent to which normal background mutations in nature are due to derepression mechanisms is difficult to estimate, but the location of most C-to-T transitions on the nontranscribed strand suggest that it may be significant. Regardless, a mechanism that limits an increase in mutation rates to genes that must mutate in order to overcome prevailing conditions of stress would surely be beneficial and therefore selected during evolution.

64 posted on 03/16/2005 9:25:44 PM PST by AndrewC (Darwinian logic -- It is just-so if it is just-so)
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To: AndrewC
Regardless, a mechanism that limits an increase in mutation rates to genes that must mutate in order to overcome prevailing conditions of stress would surely be beneficial and therefore selected during evolution.

That's interesting, but the mechanism sounds like something that evolved via Darwinian selection. At least that's how I read the text.

78 posted on 03/17/2005 3:56:47 AM PST by js1138
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To: AndrewC

I'm curious about your step one. It seems to violate a central dogma of molecular biology. What is the mechanism for communicating specific needs to the genome, and at what stage of reproduction does this occur?

Noble prizes all around for the people who can demonstrate this.


81 posted on 03/17/2005 4:48:50 AM PST by js1138
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To: AndrewC

Such genes might be selected in a evolutionary process, but the gene existence had to occur originally meeting the criterion closely explicable by ID. Without ID, the original existence of such genes would most likely have been eradicated in the selection process, because their utility was so rare as to make them the least favorable characteristics to remain.
Their presence today, contradicts evolution methods, but confirm an even more prolific ID.


481 posted on 03/19/2005 6:18:17 AM PST by Cvengr (<;^))
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