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Re: Cloning prehistoric animals...
gejd@concentric.net wrote:
> With regard to mammoths and other long-extinct species, it is still a
> question of "could we". There may be some DNA in the teeth and
> tissues, but it is probably somewhate denaturized, not enough
> operational DNA left to create a mammoth, even if the remainder could
> be replaced with elephant DNA. We still have no technical tools that
> can accurately "read" a single strand of DNA and do it again and
> again, to extract redundant information from many strands. In
> addition, the weaker hydrogen bonds in some areas will unravel for all
> of the strands, so redundancy doesn't work. There may be enough DNA to
> analyze it and determine the kinship relations of mammoths to
> elephants. It is not likely that there will be enough to make a
> mammoth.
Um, actually, we can and do have the technical tools and have had for
over 15 years. I have been doing so as my job for almost 10. Accurately
replicating single strands of DNA is commonplace. That is not the
problem. Hydrogen bonding is not a problem as you don't need double
stranded DNA and the bonds within a single strand are not hydrogen
bonds. If you have enough to analyze, you have enough to replicate.
Actually, the process of analyzing requires replicating it numerous
times. Denatured DNA is no problem and is part of the procedure for
replicating it. I think what you actually mean is degraded, which is
completely different. This involves actually breakage of the strands and
loss of sequence. This is the problem. Once the strands start breaking
up and actual sequence is lost, there is no way to get that back.
Of course, simply having the sequence is only the first and simplest
piece of cloning extinct DNA. You then have to put it in the right order
and have it methylated properly and no one has the slightest clue how to
do that. If we did, cloning would be commonplace and not the expensive
time consuming shot in the dark procedure it is now. There is so much
more to the function of DNA than the sequence it is almost beyond
belief. This is where the "could we" comes into play.
But, in answer to all this, yes, if we can find complete strands, or at
least enough that we can deduce the proper arrangement, there is no
reason why we shouldn't be able to clone a mammoth with enough work. We
don't need much DNA, just a tiny piece of good quality that can be
analyzed.
Joe Daniel