al109rs{at}yahoo.com (Rick) wrote in news:c0lmk6$2mta$1{at}darwin.ediacara.org:

> In Adam's Curse Brian Sykes says this:
 
> "Over the last hundred generations, going back to well before the
> birth of Christ, the mitochondria you got from your mother had
> experienced only 2,400 potentially risky cell divisions. Compare that
> to your Y-chromosome, if you have one, which has been copied about
> five hundred thousand times over the same period."
 
> This is one of the reasons why he claims that men are doomed in the
> next 100,000-200,000 years unless we evolve (naturally or articially)
> a new way of triggering men (instead of relying on the genes carried
> in the Y-chromosone).
 

I think this conclusion assumes that the Y canot correct mistakes. But 
check out this research:

"Instead, the Y appears to exchange genes between the two copies of 
repeated sequences that lie near to each other as mirror images.

This phenomenon, called gene conversion - the non-reciprocal transfer of 
genetic information from one DNA molecule to another -- has been previously 
observed on a small scale over long evolutionary timescales between 
repeated sequences on the same chromosome, but not at the dramatic 
frequency apparently employed by the Y chromosome. "

The article is at: http://www.genome.gov/11007628

If I read it right, it means that the Y is not as susceptible to mutation 
as was once thought. 

Yours,

Bill Morse
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