Re: longevity

J. R. Molloy (
Sun, 21 Nov 1999 15:46:40 -0800

Curt Adams wrote,
>It can, it's just that any individual advantages will overwhelm the group

So, if individuals who live shorter than average lives produce more generations because of their shorter life cycle, would this tend to overwhelm an opposing group tendency toward greater longevity?

>Roughly, a group allele benefits only with the frequency of groups going
>extinct. An individual allele benefits with the frequency of individuals
>dying. Obviously the latter is far more common, so the selection to improve
>individual fitness is typically orders of magnitude larger than group

If reproductive frequency varies among individuals (which, as you point out, it does), aside from offering an advantage in the form of increased generational mutability, doesn't faster reproduction give speedy breeders a numerical advantage, since their genes would increase in the group faster than the genes of slower reproducers?

>There's an experimental problem in that the power of group selection is
>generally lower than the lowest effects on individual selection we can
>detect. So we can't say that individual selection on any particular real
>trait or allele is low enough for group selection to go.

Yes, it stands to reason that the group would tend to dilute any mutation occurring as a result of individual selection. Groups tend to assimilate and disperse any freak genetically induced traits (at least those which don't result in infertility). Could shorter life spans, which would increase the frequency of such occurrences, accelerate the Evolution of the entire group? --J. R.