In article <3tuqp5$87a at sifon.cc.mcgill.ca>, Graham Dellaire <popa0206 at PO-Box.McGill.CA> writes:
> Hello all,
>> Well actually there is evidence that when you pick say myoglobin or some other
> gene and use accumulated mutations to determine divergence of two species there is
> a serious flaw. The premise that mutations occur in these two genes, in two different
> organisms in two different genomic contexts, at the same rate is most likely wrong.
>> It is well established and being accepted finally that the genome is made of
> many "domains" of which the accessibility to enzymes and oxidative agents etc
> that might cause damage to the DNA and hence mutations differs. The accessibility
> although not conclusively linked in all cases can reflect transcription status, time of
> replication and/or rates of recombinaition. It is already known that transcription and
> DNA repair (specifically Nucleotide Excision Repair) are intimately linked. Now if you
> have domains with different transcriptional activity you can have different rates of
> mutation that is reflected in efficiency of DNA repair.
>>> So to make a long story short molecular clocks with such a basis are invariably inaccurate!
Strange then that myoglobin changes in such a clock-like manner when you
actually LOOK AT THE DATA. Something is wrong somewhere, methinks.
> Graham Dellaire Snail Mail:
> Red Cross, Research
> McGill University Montreal Blood Services
> Faculty of Medicine 3131 Sherbrooke St. East
> Div. of Experimental Medicine Montreal, QC, Canada
> E-mail: popa0206 at po-box.mcgill.ca H1W 1B2
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