The Nature of Mutations II

The original thread, The Nature of Mutations, has been damaged. Recovery is a remote possibility, and I will explore what options I can. I am very sorry and apologize for the inconvenience. Please resume discussion in this thread.[Following is added by edit:]The original thread has now been restored to the extent possible.------------------
--Percy
   EvC Forum Administrator[This message has been edited by Admin, 07-02-2003]

Does anyone remember where this topic had got to before it underwent Saltation? Is PPLG still posting or has he taken his ball and gone home? I seem to recall that the OP,which is still available along with a good chunk of the start of the thread, showed some major misconceptions on the nature of mutations, fundamental molecular biology and evolutionary theory. I'm sure most of those must have been adressed somewhere within the 23 pages worth of posts. Was a generally acceptable working defninition of what constituted a mutation ever finally decided upon however? I can't recall.

It ended when I pointed out to Mr. Pamboli that if he had read the manifesto he would know what the evidence was for semi-meiosis. I now direct all skeptics to section V-2 The evidence from cytogenetics. As for the ether being responsible for a lapse of 21 postings, let me say that the ether doesn't even exist. salty

As per the Forum Guidelines, evidence should be included as part of the discussion rather than referenced in another source. However, it would be entirely appropriate to describe the evidence here in outline form and reference another source as providing detail.------------------
--Percy
   EvC Forum Administrator

As I recall, Phospho claimed he was moving and did not know when he would return to posting. However, there were several issues raised that got most of the rest of us into an interesting discussion as to how does one define mutation....then as you mentioned, the thread was as-salt-ed.

Hi salty,
Let's try a different approach here.
First as a ground rule (no I am not an Admin and this is not a forum rule) to facilitate discussion, rather than making a broad statement and then referencing your entire manifesto or a chapter, paraphrase your reference in an attempt to support your point.
i.e. instead of the evidence for semi-meiosis is section V-2, state explicitly what in section V-2 you believe supports your claim.Now, to the subject at hand...how would you define mutation?cheers,
M

Why not keep it short and broad, 'A heritable change'. This will even cover weirdo concepts such as Semi-meiosis and endosymbiosis, not that I consider these 2 concepts to have equal standing!If you just want a definition of genetic mutation you just have to add 'in the character of DNA', I say character in order to allow for heritable epigenetic modifications and chromosomal rearrangements.

Hi WK,
The question I posted to salty was to see if he could respond as I believe (like with everything else) he has an esoteric concept of what mutations are. I am curious as to how he will respond if he actually makes a real attempt...stranger things have happened Regarding your definition, while I agree with it and is similar to what I proposed, we got bogged down in a discussion as to whether meiotic recombination should be included in the definition of mutation..and epigenetics also makes a concise definition rather difficult. The origin of the question was Phospho's assertion that no mutation can be beneficial...this was preceded by an erroneous definition that genetic mutations were a change in amino acids in proteins that rendered them disfunctional.cheers,
M

Yes, I remember Phospho's rather skewed grasp of molecular biology and genetics. I realised that your question was for Salty, I just thought I would throw in the simplest of the definitions I recalled from the previous thread, and one which is non specific and consequently versatile.

Point mutations (base pair substitutions) for all practical purposes can be ignored as having evolutionary significance as they are either neutral or deleterious. One can almost say that the only good point mutations are the ones that return the locus to the wild type. As anyone would know who has read my papers, I believe that, as in ontogeny, the information for phylogeny was present from very early on. The role of chromosome restructuring was to release (derepress) information which could lead to saltational speciation as well as the formation of the higher taxonomic categories.As for your precious ground rules about summarizing, I don't believe in it which is why I insist always on quoting my sources directly as I did M.J.D. White in section V-2 of the Manifesto. If you don't choose to read it and then respond to his judgements, then don't. To paraphrase an old saw : "You can lead a man to the literature, but you cannot make him read". Or, I might add, comprehend.Over at brainstorms, they ignored White as well. I think I know why. It is for the same reason he has been ignored by the whole neoDarwinian camp. His conclusions cannot be reconciled with a sexual model for evolution."All great truths begin as blasphemies" George Bernard Shawsalty

Hi WK,
Your definition is actually the most concise to come out of the two Nature of Mutations threads so in future discussion we should probably link back to your post.I noticed a slightly related issue arose in your debate with Symansu in the Free for All where he made some strange assertions about DNA not being a liquid, somehow related that statement to blending inheritence and concluded Darwin was wrong...I am paraphrasing the argument...his definition of mutation would also be enlightening..or at least humorous cheers,
M

Dear Salty,Did you see the letter to 'Nature' towards the end of last year showing benefits to sexual reprodcution in populations of Chlamydomonas Reinhardtii. The fitness of sexual and asexual populations was compared subsequent to different levels of bottlenecking and shown to be most beneficial in wider bottlenecks where it allowed the populations to overcome problems from clonal interference. Or alternatively there is a paper on the evolution of an experimental population of RNA viruses characterising the various beneficial point mutations in that population. Which clearly shows that in some cases point mutations can increase fitness. TTFN,WK

Dear wounded, I have never denied sexual reproduction as a beneficial device. I have in fact extolled it. It is not however, in my studied judgement, capable of supporting macroevolution. salty

Hi salty,
Still looking forward to your definition of mutation...but given your last post, I would ask that you make a more thoughtful answer than that which you just gave to Wounded King. You clearly did not read either of the references he provided and your answer was to claim you opinion was based on a "studied" judgement. Having not read the references of WK, how can your judgement be considered studied?In any case, please give us your "studied" definition of mutation. We can deal with micro and macro evolution later.cheers,
M

IIRC Syamsu's definition of mutation was pretty standard, it was just his views on how mutation related to variation, evolution and natural selection that were unusual.