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DNA mutations are caused by?

  1. Nov 15, 2006 #1
    Hello, I'm trying to compile a list of factors that could cause a DNA strand to be damaged or modified (denaturalized).

    I'll list a few that I can think of, if you can add some or nix some of mine, please help me and reply, thanks.

    1. Radiation (like gamma rays from the sun)
    2. Chemicals (compounds like benzene that bind to the dents [I forget the technical word] in DNA's helical shape.)
    3. Viruses (viruses that insert their own genes to that transcriptase produces clones of themselves)

    Going out on a limb now....

    4. Environmental stress
    5. Adaptation and Evolution (human tail bones are vestiges of primate tails)
    6. Low Energy Radiation (Radio, Microwave, IR, Visible light?)
    7. Bacteria???
     
  2. jcsd
  3. Nov 15, 2006 #2

    selfAdjoint

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    This is exactly the wrong way to think about mutation! Think of the DNA as naturally changing, undergoing SNP's (single nucleide polymorphisms: replacements of one of the four bases by another at some location) all the time. The big backgound level for evolution is Neutral Evolution, meaning indistinguishable from random. If no identifiable change is operating at the phenotype level, if there is no adaptive gradient, neutral evolution is still going on. It is going on in your body right now!.
     
  4. Nov 15, 2006 #3

    Monique

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    I sure hope not! There are MANY mechanisms that prevent your DNA from mutating. And DNA is NOT naturally changing, those changes are prevented by the above mechanisms, DNA replication is done with high fidelity.

    A SNP is a variation, not a mutation. You call a mutation a SNP when 80% of the population is variant for that base.
     
  5. Nov 15, 2006 #4

    Monique

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    For more information on mutations and mutagens, you can find a summary here http://www-personal.k-state.edu/~bethmont/mutdes.html#origins

    Points number 5 and 6 don't cause DNA to be damaged, but adaptation is a driving force that selects certain mutations in a population. Point 7 is true, but this is because of the stress of inflammation that bacteria cause (environmental stress). Some other environmental stresses are things as mechanical stress (constant rubbing) or stress from heat (hot water). There is a population in Japan that eats their rice boiling hot, they have a high incidence of mouth and throat cancers.
     
  6. Nov 15, 2006 #5

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    I think #5, Adaptation and Evolution, is incorrect. Evolution may decide which mutations are successful and which ones aren't, but it isn't a cause for mutations. Same goes for environmental stress.
     
  7. Nov 15, 2006 #6

    Monique

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    If you would have read my post you would have seen that I already adressed those two points. The environmental stress balances on how you define the term, smoking can be defined as an environmental stress and thus cause mutations.
     
  8. Nov 15, 2006 #7

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    I read 20% of it. Don't you know to first delineate the points of your post in the first paragraph and expand on them only in the remaining body? :smile:
     
  9. Nov 16, 2006 #8

    Thanks Monique you seem to give the most knowledgeable answer.
     
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