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Dendrochronology and DNA mutation rates?

  1. Mar 3, 2007 #1
    Using dendrochronology to get DNA mutation rates?

    A question:

    Would it be possible to use DNA analysis in combination with tree ring dating get an accurate DNA mutation rate?

    By extracting DNA from the inner rings of a tree, shouldn't it be possible to compare it to the DNA from outer still living part of a tree? By doing so you could have a accurate time between mutations(?)

    Now this is a pretty obvious experiment, so what my question really is, is this:

    1) Does what I say make any sense? ( I really don't know much about trees and so forth)

    2) Is it possible? ( How quickly does DNA degrade? Might it be that there isn't any good DNA left in the inner rings? Are there other problems? )

    3) Is the average life time of a tree too short to get any real long term mutation rate predictions?

    4) Has this research already been done? (If so, could anyone point me toward an article? )

    Thanks in advance and greets from a college student :blushing:

    Edit: Just to clear something up, I indeed meant somatic cell changes. I don't know what kind of mechanisms a tree has to eliminate them, but I initially thought there might still be enough to overwhelm it. But to be honest, now that I've though some more about it, I really don't think this will work at all. Nevermind this mindfart :uhh:
    Last edited: Mar 3, 2007
  2. jcsd
  3. Mar 4, 2007 #2


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    The problem is that the inner rings of a tree are not composed of living cells, but dead, empty cells, so there is no DNA to be extracted from them.
  4. Mar 5, 2007 #3

    jim mcnamara

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    Xylem (woody tissue) is essentially dead within a few months of the creation of the tree ring as Moonbear indicated. In some instances there are tiny amounts of cytoplasm locked inside some specialty cells, like ray parenchyma in the xylem.

    There are tree species like the bristlecone pine that live for 10000+ years. However, within a few dozen years a lot of the xylem tissue is exposed to bacteria. You may have seen spalted wood - this is caused by bacterial deposition. Really old trees are virutally always like a straw - completely hollow. It is possible by working with different sections of the tree trunk to work backwards in time getting cores. But they have all been exposed to foriegn DNA from saprophytes and pathogens, nesting birds, burrowing beetles, etc.

    So whatever DNA you do encounter is guaranteed to be flummoxed after 100+ years, let alone 10000.
  5. Mar 7, 2007 #4
    Right, I figured as much.

    I do understand that the inner part of a tree is dead, but thought maybe that the DNA that was initially in there might be good for a while. A while however isn't very useful if you are talking about many 1000's of years for some trees.

    Thanks for the replies :smile:
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