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Re: A Further Note
Dwight W. Read (dread@ANTHRO.UCLA.EDU)
Thu, 1 Aug 1996 12:36:45 -0700
Snower replies:
>Suppose a society of which the members were strictly monogamous, and all
>selection of mates was by lot. There would be no biological evolution
>within this society. No differential reproductive success, regardless of
>individual accomplishment, or individual success in meeting environmental
>challenges. Intra-social competition, if it occurred, would be biologically
>irrelevant.
>
A clarification is needed. Random mating is not equal to no evolution.
Rather random mating is just one of the assumptions underlying
Hardy-Weinberg equilibrium. Evolution defined as change in allele
frequencies in a breeding population will occur, for example, when there is
differential fertility (random mating does not imply equal fertility; e.g.,
with cystic fibrosis, a lethal genetic disorder in homozygous form, and
where almost certainly there is random mating with respect to the trait,
heterozygous women are more fertile than homozygous normal females) or where
there is differential survivability by phenotype then selection is operating
and will change allele frequencies regardless of random mating.
>Competition is thereby automatically thrown to the group level. ...
> Therefore, in a contest with
>survival at stake, the one culture prevails over the other. This seems to
>me to be natural selection, but of a culture system, not of a biologic
>trait.
Competition will lead to a kind of selection, but it is not "natural
selection" as defined by Darwin. "Natural selection" already has a
technical definition, hence the term should not be used as a cover term for
any kind of "selection" that occurs in living populations.
>This process, as it was repeated over and over, would eliminate
>diversity. There would finally be a common cultural pattern discernible in
>all the different surviving societies. But there would still be a great
>deal of diversity, just as all the individual members of one species are
>biologically very diverse, yet do exhibit a common base. It seems to me to
>be appropriate to call this natural selection, but admittedly of a different
>kind.
>
I assume by eliminating diversity you are meaning something like: if group
A, B C Etc. were currently socially organized along the lines, say, of a
primate troop, and group D comes up with a hunting-gathering type of
organization, then competition between group D and groups A, B, C would
likely lead to extinction of those groups with a primate kind of
organization (lose of diversity) leading to a common pattern
(hunting-gathering, the common base) in all new societies E, F, .... , but
within this common pattern there would be diversity of a different kind in
that there are alternative ways to construct a society based on a
hunting-gathering type of organization. No problem here--I've published a
paper making precisely this kind of argument. ("Foraging society
organization: A simple model of a complex transition" European Journal of
Operational Research (Special Issue: Modelling Complex Systems II) (1987)
30:230 - 236).
D. Read
dread@anthro.ucla.edu
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