Re: longevity

J. R. Molloy (
Fri, 19 Nov 1999 10:06:14 -0800

>>He can
>>not find any down side to the mice at all but he speculates there must be
>>one someplace because otherwise evolution would already have found
>>this fix;
>This is debatable. As you all know, we are far from perfect organisms. Mice
>also have lots of room for improvement and we can't expect evolution to
>select them all. It can be argued in many ways the fact that p66 is no
>longer important (being an ancient gene that is no longer important, having
>another version that is more stable, etc.). Of course it can have some
>important function we can't easily detect, but the point is that I don't
>think we should assume evolution as a perfect and final process. The
>distribution in humans of the various types of cholesterol is an excellent
>example (if you're not aware, the most hazardous type of cholesterol is the
>most abundant and vice-versa).
--Joao Pedro de Magahaes

In further support of your comments, I'd add that evolution may select for short-lived individuals in order to speed up the process. By analogy, a species that reproduces every three months has the ability to adapt to a changing environment more successfully than a species that takes three decades to reproduce.

A short life span represents nature's way of increasing the clock rate, so to speak, for a given population, thereby accelerating the rate of evolution and adaptability for that population, and in turn, increasing its chances to thrive as a species (although not so much as individuals).