From: jqb@netcom.com (Jim Balter)
Date: Wed, 30 Oct 1996 01:27:23 GMT

In article <789400881wnr@chatham.demon.co.uk>,
Oliver Sparrow   wrote:
>  writes:
>
>>  but the conclusion that the suffering of the underlings
>> is selected for because it benefits the overlings, that seems a bit of a
>> stretch, don't you think?
>
>Not really. Only the alpha males get to breed: what helps them is what
>gets passed on. There are many examples of what are called 'polymorphisms',
>genetic packages which have two phenotypes, or expressed forms. Sacrificial
>phenotypes are common. Indeeds, brightly coloured insects are often thus
>coloured to remind bird that that form tasted horrible the last time that they eat it.
>Not a lot of use to the devoured example, however, which stood out like a screaming
>invitiation to the naive bird.

But is there a dual phenotype here?  How does one benefit the other?  Let me
do some exploring here. Insect genes have (at least) two phenotypical
strategies: be hard to see, or taste bad and be easy to remember.  Taste bad
and be easy to see doesn't seem to be better than taste bad and be hard to
see.  Apparently bright colors, or the specifics of these brightly colored
insects (assuming only "bright color" because that's what *we* notice
anthropomorphizes the whole enterprise) fits bird's memory mechanisms.  But
the brightly colored ones confer no advantage to the non brightly colored ones
unless the birds have some way of associating them (smell? perusing
etymological texts?), and if they did, the bright colors wouldn't be necessary
in the first place.  In fact, the standard "individual selection" argument is
that, given such a linkage, there would be evolutionary pressure away from
bright color, since it is advantageous to be associated with an easy-to-see
bad tasting bug *and* be hard to see.  Of course at some point the drift would
be enough to cut the association, and birds would dive after those harder to
see but presumably tasty morsels.  Thus, if bugs are genetically linked by
smell, say, and some are easy to spot but taste bad, there should be a drift
of the whole group towards hard-to-see (but still taste bad and smell alike),
unless the reproductive capabilities are concentrated in the harder-to-see
ones.  Is there reason to think that's the case?  If so, then indeed the
bright ones are the sacrifices for their fecund sisters.  Otherwise, we are
back to a single phenotype that is memorably yucky.

> (Sheesh! These guys never cease to amaze me.)
>
>Ethnologists? Or nature?

The former is an aspect of the latter, eh?

>> For one thing, group selection has been largely ruled out by most
>> responsible authors going all the way back to J.B.S. Haldane.
>
>No, no, no: group selection (if by this you mean the propagation of a 
>gene or cluster of genes which confer group, rathert than individual 
>advantage) is well established and, after all, logical. For example, pack animals
>which support the dominant (breeding) pair get their genes propagated if they are blood 
>relations of them. Their support is directly related to the degree of relationship.
>How does this work? Astonishingly, amny mammals (including, at a preconscious 
>level H sap) can smell if they are relations. 

I think Dawkins' notion of gene selection cuts through the confusion:
selection pressure is on genes, not groups or individuals.  Groups can serve
to propagate genes just as individuals can.  Ants are an extreme example of
individual sacrifice for the sake of gene propagation.
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