Monday, 23 May 2005

The Uncertain Future of the Y Chromosome

Or : males an endangered meta-species? From Nature :
At the present rate of decay, the Y chromosome will self-destruct in around 10 million years. This has already occurred in the mole vole, in which the Y chromosome (together with all of its genes) has been completely lost from the genome.
Accelerated degeneration of the Y chromosome is found in the 5–15% of severely infertile men whose infertility is caused by wholesale deletions of parts of this chromosome. Because mutations that cause infertility cannot be inherited, the relative abundance of Y-chromosome deletions in male patients suggests an extremely high rate of spontaneous DNA damage. Even microdeletions on the Y chromosome de-stabilize its transmission, frequently causing it to be lost during gamete production.
It's therefore a good job that we're steadily gaining ground in our knowledge of genetics. Perhaps the reason so many Men go into the Sciences is simply out of an unconscious desire for self-preservation?

In the long term, absolute selection against males with deletions that confer sex reversal or sterility will create strong pressure either to retain (and amplify) fertility genes, or for any fertile variant that replaces it. Could
the present race of humans eventually be replaced by a new variant (or several independent variants that cannot cross-hybridize) with an alternative sex-determining/differentiation system? Such a new hominid race could differ from present humans in many other characteristics, depending on the gene pool of the new variant’s handful of founders.
In other words, men must Mutate now and avoid the Rush.

Of course all this assumes that having males around is a good idea, and I know some who would argue that point.

It doesn't matter though. Long before the 10-million year deadline is past, possibly within the next century, our understanding of the situation will have improved so dramatically, and our ability to take action at the cellular level increased so markedly, that the problem will be solved.

Assuming you think it is a problem, of course.

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