The Nature of Mutations

I'm going to try and keep score.First there has to be agreeement on the definition of mutation. Could someone propose a definition?

• The Milano mutation: No rebuttal. Point for Phospho.
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• Culex Pipiens Mosquito: Difference of opinion is possibly due to different definitions of mutation. Tie.
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• RNASE1 AND RNASE1B genes: No rebuttal. Point for Phospho.
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• Nylon eating bacteria: Solid rebuttal. Point to evolutionists.

Score: Phospho 2-1/2, evolutionists 1-1/2I'll revise the score as discussion of the examples of beneficial mutations continues.--Percy

I thought I'd put in a vote for my favorite definition of mutation so far. My vote's a bit biased because I'm not sure I understood the recombination mutation argument very well.I liked the definition that a mutation is any difference between offspring DNA and parent DNA. Any sequence in the offspring that wasn't in the parent (or one of the parents for sexual reproduction) is a mutation. But are there any significant mutation categories that fall outside this definition?--Percy

Since yesterday some rebuttals from the evolutionist side have been posted. I'll provide another score update when the Creationist responses come in, but for now this is how I have the score. The mere fact of a rebuttal doesn't matter, the rebuttal has to be effective:

• The Milano mutation: Strong and detailed rebuttal from cjhs in Message 66 and by Fedmahn Kassad in Message 59. Point for evolutionists.
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• Culex Pipiens Mosquito: The definitions of mutation proposed so far would decide this point in favor of the evolutionists. Point for evolutionists.
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• RNASE1 AND RNASE1B genes: Solid rebuttal by Fedmahn Kassad in Message 59. Point for evolutionists.
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• Nylon eating bacteria: Solid rebuttal. Point to evolutionists.

Score: Phospho 0, evolutionists 4--Percy

Before my recent hip replacement surgery I was keeping score on this thread on the points raised by PhospholipidGen in Message 52. Trying to resume now, I add to my previous comments and rescore the discussion:

• The Milano mutation: Strong and detailed rebuttal from cjhs in Message 66 and by Fedmahn Kassad in Message 59.
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  PhospholipidGen responds in Message 108, but crashfrog and Fedmahn Kassad provide more than adequate rebuttal in Mesasge 109 and Message 122. Crashfrog pointed out that Phospho has so far not supported his contention that mutations must be deleterious because they "diminish the original purpose." FK reiterated this point ("...you certainly have an odd way of looking at mutations."), and for now it still appears that Phospho's position is mere semantics, particularly where he says, "I did not deny that it has a beneficial side-effect," since this is something he apparently would like to ignore when determining whether a mutation is beneficial.
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  Point for evolutionists.
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• Culex Pipiens Mosquito: The definitions of mutation proposed so far would decide this point in favor of the evolutionists.
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  No new points raised other than to say, "See the previous posts on transposons and adaptational variants."
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  Point for evolutionists.
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• RNASE1 AND RNASE1B genes: Solid rebuttal by Fedmahn Kassad in Message 59.
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  No new points raised other than to say, "See the previous posts on transposons and adaptational variants."
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  Point for evolutionists.
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• Nylon eating bacteria: Solid rebuttal.
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  No new points raised other than to say, "See the previous posts on transposons and adaptational variants."
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  Point to evolutionists.

Phospho has a paragraph of general argument at the end of Message 108, and while it bears generally on the topic of mutations, I could not see how to apply it to the specifics of the above mutations.Score: Phospho 0, evolutionists 4--Percy

I think we still need to agree on a definition of mutation. We proposed this one: --Percy

The goal was to create a simple definition. Let's stick with the simple definition where any difference in DNA between parent and offspring is a mutation. Then there can be different types of mutations. I'm not the best person to create a list of different mutation types, but a few I can think of are:

• Single nucleotide substitution
  
• Single nucleotide deletion
  
• Single nucleotide addition
  
• Sequence duplication
  
• Sequence deletion
  
• Transposon
  
• Organism mediated (isn't there a better term for this?)
  

--Percy

Hi Mark,I can't answer your question. As I said, I'm not the best person to list different types of mutation. Someone else take over, please!

The only strong feelings I have about this is that mutation should be defined broadly and simply, and that there definitely should not be a list exceptions of things that are genetic changes but aren't mutations. While you could set up the definitions to work for the exception approach, it would no longer be simple, and I don't think it would be consistent with the definitions in biology textbooks. For example, see the definition of mutation in this site's glossary.

--Percy

Mark writes: How about; mutation is a change in genetic material that is passed on from one cell to another via mitosis, meiosis, or recombination?

Maybe this could be covered by adding the word "heritable"?

--Percy

Hi Mark,How about, "Mutation is a heritable change of genetic material."

--Percy

Species is an important concept for classification, but in the context of evolution the term has to be permitted extreme flexibility. What constitutes a reproductive barrier and the degree to which it applies is fluid and inconstant in evolution.I think ring species are illustrative of the problem inherent in trying to use any classical definition of species with evolution. Let's postulate a hypothetical ring species with species names A through H. A is geographically adjacent to B is geographically adjacent to C and so forth, with H being geographically adjacent to A again. Let's further postulate that all species of the ring are reproductively compatible with any adacent species, but not with any species further away than that.This means that A can reproduce with H and B, but not with any other species of the ring. So one could argue the A, H and B are actually just sub-species of the same species. Except that while H can reproduce with A, it can't reproduce with B. Okay, so you reclassify and say that A and H are subspecies of the same species, and that B is a different species. But someone else argues that it is actually A and B that are subspecies of the same species, and that it is H that is a different species. And someone else argues for the original position, that A, H and B are all different species, which probably makes the most sense.But of course, now that you've decided that all species of the ring are different species, you can no longer claim to be using the classifical definition of species, the one that includes a reproductive boundary. And this is entirely appropriate for evolution, because evolution does not view species as static, but rather as a dynamic ebb and flow of currents of changing allele frequencies, with reproductive boundaries that are just as fluid and are a function of widely variable morphological and genetic compatibilities.--Percy