At 07:25 PM 21/11/99 EST, Curt wrote:
>Alleles for extended
>survival (hypothetically with no other effect) are
>effectively "cheaters" and oust competing alleles for
>short lifespan because they also get the benefit of
>their carriers reproducing longer.
Presumably alleles *conducing to* extended *fertile* lifespan (I don't believe they could have no other effect) might always fare less well, stochastically, than competitors that permit more frequent remixing of immunological defence genes, etc. But is that correct? If you live long and mate throughout that extended span, why should your meioses create fewer or inferior recombinations than those of your offspring? Outbreeding, I guess...
It does look to me as if critters without effective predators (elephants by size, us by smarts, boids on the wing) tend to conserve genetic changes in the direction of extended longevity - but *we* don't seem to extend *fertility* very well. Yet the Grandmother hypothesis (that sterile oldies look after the kids, allowing mother to produce more of the same genes), while appealing, hadn't worked out mathematically last time I checked.