Re: Why we age, was Re: SOCIOLOGY: On Betting on Aging

From: Jim Fehlinger (fehlinger@home.com)
Date: Sun Mar 18 2001 - 06:40:58 MST


"Robert J. Bradbury" wrote:
>
> You are getting to a large degree into whether species move
> towards K-strategy or R-strategy (which I'm too lazy to
> go lookup now to define { I must be catching the Spike Virus }).

>From _Darwin Machines and the Nature of Knowledge_ by
Henry C. Plotkin, 1993, Harvard University Press (paperback
edition, 269 pages; see
http://www.amazon.com/exec/obidos/ASIN/0674192818

p. 145

        [One way] for an organism to reduce the amount of
        significant change it has to deal with... is to
        reduce the period of time between conception and
        reproductive competence... This means that the
        ratio of life-span length to numbers of offspring is
        low... This is a characteristic 'life-style' of
        animals known to ecologists as r-strategists...
        These r-strategists usually live less than one
        year...; they develop rapidly; they are usually of
        small body size; and they normally reproduce over
        just a single period. This is the life-history
        strategy common to most invertebrate animals and
        clearly one that is... relatively successful...

p. 151

        In general, the kinds of animals that would evolve
        intelligent adaptations are relatively long-lived
        and produce relatively few offspring in their
        lifetime; that is, the ratio between the length of
        life and number of offspring is high. Such animals
        usually develop quite slowly and have a relatively
        large body size. They are what ecologists refer to
        as k-strategists...

This suggests that, over the course of the entire history
of life on Earth, r-strategy came first (and is still the most
common), but a few more complex organisms invented
k-strategy (including the ones that gave rise to us).

Jim F.



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