Perplexed in Peoria  wrote:

> "John Wilkins"  wrote in message
> news:c7hmdm$i0l$1{at}darwin.ediacara.org...
> [snip much]
> > Population structure is not inherited, although allele
> > frequency is sampled.  [snip]
> 
> > Species speciate differentially, a kind of sorting process, I grant you
> > that, but *selection*? That requires hereditability at the level
> > concerned (which doesn't happen for species, as new species are formed
> > from demes, and they inherit demic allele ratios, perhaps, sometimes),
> > and competition (of a population size large enough to overcome
> > contingency). Selection is a subset of sorting, and not all sorting
> > processes are selection processes. For example, you can sort pebbles by
> > water action in a riverbed, but it is not selection.
> >
> > As Eldredge noted, species do not "moremake" in the
requisite manner to
> > be subject to selection. They split, bud and become disrupted, but at
> > the species level their properties are not inherited. The principle of
> > parsimony suggests that if we can account for what happens in terms of a
> > lower-level process (i.e., a population genetic process) then the higher
> > level explanation is otiose.  [snip remainder]
> 
> I believe that your arguments don't apply to the kind of species-selection
> that I describe in my latest response to Guy.  Population structure
> can be heritable if that structure is an ESS.  Fluctuations from that
> stable structure are repaired.

Subtle. But is an ESS a species-level property or a population-level
property? By this I mean, is it a property that must be borne by the
entire species rather than by parts of it - is it an ESS in a population
because the boundary conditions of that population form that trade-off
to be stable, or is it something that must apply to entire species?

Moreover, a nascent species typically doesn't inherit the mean or mode
population structure of its parent. Changes in densities of variant
strategies are one of the things that is supposed to drive speciation.
> 
> Furthermore, although the maintenance of that population structure
> takes place using individual-level selection, I don't think that your
> parsimony argument applies - the species and its gene frequencies
> cannot be removed from the explanatory structure.

Why not? If a genus, to use a higher taxon term for argument, consisted
of a number of metaspecies, each of which was arrayed geographically in
populations similar to their nearest neighbour and with their own
population structures, would we need to employ the notion of a species
here? Perhaps "population" is the largest necessary group. So why is
"species" a causal player here?
-- 
Dr John S. Wilkins, www.wilkins.id.au
"I never meet anyone who is not perplexed what to do with their
 children" --Charles Darwin to Syms Covington, February 22, 1857
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