Tim Tyler  wrote:

> John Wilkins  wrote or quoted:
> 
> > So do the flocking behaviors confer fitness on the group/species
> > summatively, so to speak, or is there something about selection on the
> > group/species needed to explain flocking and the resultant increases in
> > fitness?
> > 
> > I would suggest that Williams' conclusion, ""A
neontological species is
> > ... a key taxonomic and evolutionary concept but has no special
> > significance for the study of adaptation" (p252) still holds true, and
> > almost every argument for species-level selection is the result of a
> > failure to discriminate between species-level properties and lower level
> > properties.
> 
> The death and reproductive success of species critically depends on the
> properies of their members - and so it is important to include them
> in arguments about species selection.
> 
> Failure to include them would be a *big* mistake.

I agree. This is what Williams refers to as the summational fitness of a
group.
> 
> Species selection is about differential reproductive success of
> species on the basis of their heritable traits.

And not those of any lower level entity, like a deme fitness or a kin
group fitness, or an allele fitness.
> 
> The issue of whether individual traits combine additively to produce
> species traits - or not - is *completely irrelevant* to the issue.

No, it is the very core of the debate. As Williams noted, if you can
explain the adaptations of a group through the adaptations of the parts
of the group, then (by the principle of parsimony) you do not need to,
and it would be otiose to, invoke adaptations of the group.

He made a distinction between biotic (group) adaptations and organic
(organism-level) adaptations. What is it we need to explain here? If a
group has features that can be explained as the sum of the adaptations
of the organisms it contains, then that is a total and sufficient
explanation. To invoke "clutch regulation" type explanations that run
*counter* to the organic adaptations of the group's members is a heavy
burden, and it requires that there are adaptations *of the group and
only of the group* that must be explained, and which cannot be explained
by individual adaptations.
> 
> As for the idea that species hardly have any heritable traits -
> that is a crazy fantasy.
> 
> It is plainly evident that species have many significant heritable traits
> - since species of animal give rise to more species of animal, species
> of plant give rise to more species of plant - and so on - creating a 
> large tree of related species.
> 
> Species are characterised by a pool of technological knowledge
> about how to survive in a gene pool - and this knowledge *is*
> heritable - and *is* transmitted to offspring species.

Well, wee reach our limits now. I have said all I can say - so far I
remain unconvinced by all these obvious facts that species selection is
even possible, let alone real. You remain unconvinced by all these
obvious logical and metaphysical arguments. Who'd have thought...?
-- 
John S Wilkins PhD - www.wilkins.id.au
  a little emptier, a little spent
  as always by that quiver in the self,
  subjugated, yes, and obedient.  -- Seamus Heaney
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 6/2/04 6:25:27 AM