Tim Tyler  wrote:

> John Wilkins  wrote or quoted:
> 
> > And what reason do we think there has been species *selection*?
> > 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.
> 
> This depends on what you count as a species trait.
> 
> I notice that plant species tend to be descended from other plant
> species.  It seems that the species property of being a plant
> *is* inherited by other species.

The "inherit" here is a logical inheritance. Species are descended from
prior species. All species that descend from the last common ancestor of
plants have the taxonomic status of that LCA, but they need not have the
same properties, not physical ones, anyway.
> 
> I would say that at the species level, their properties *are* inherited.
> 
> IMO, you can only claim that species properties are not inherited if you
> adopt a curious (and IMO very counter-intuitive) notion of what properties
> species are permitted to have - and you exclude practically everything
> from that set - so that the remaining set of things that
> count as species properties is grossly impoverished.
> 
> The case for doing this is *highly* unclear.
> 
> It makes perfect sense to me to describe a species as having the
> properly of being eucaryotic.
> 
> Yet the curious terminology you (and some others) seem to favour would
> reject this - and say that it is not the *species* that it eucaryotic -
> but all the *individuals* that compose it.
> 
> I must say, I don't see what the point of this terminology is -
> besides needlessly confusing people an awful lot of people.

I think it is a matter of what one counts as the default or "null"
position here. I believe that the burden is upon those who argue for
emergent or collective properties to play a causal role that is not
merely the (vector) sum of the parts to show that they exist in some
actual manner. I have no problem with nominal properties (being a plant,
being a eukaryote), but they play, so far as I can tell, no causal role
in any way. Individual plants that are autotrophic, or commensuals, or
whatever they are, play a causal role. But "being a plant" is merely a
statement of ancestry.

It is a common tack since Plato to argue that more inclusive entities
must behave like less inclusive entities - it is known to scholars of
that the philosophy of science as the macrocosm-microcosm distinction.
But that is an asusmption not backed up by anything but our
predispositions to impute to the unknown the properties of the known.

"Species" is a statement about lineages no longer recombining, at least
for sexual organisms. Some may do this because they are cohesive
systems, but very few do, as I have said.

The confusion here is to assume that what we have always said about
large-scale things like species must be right, and the result has been
half a thousand years of confusion and amphiboly. The "curious
terminology" though, has been in place for as long and longer - it is
merely what we now call mereology; the logic of parts. The fact that
there is even a fallacy named for it (of composition) should indicate
this.
> 
> > I am unaware of any case that necessitates a species-level selection
> > process. Of course, this is an argument from my own ignorance, so I can
> > be (and often am, as Larry sometimes notes) wrong.
> 
> Me neither - /even/ with my *much* looser notion of species selection.
> 
> One of my favourite examples of species selection (which you would
> probably see as sorting) is extinction of large organisms by asteroids.
> 
> However there's a disadvantage to this example - the largest creatures
> that have ever lived are alive today.
> 
> If this demonstrates anything it is probably that looking for examples
> where species selection is opposed to individual level selection is
> pointless - individual selection will win by a walkover.
> 
> Perhaps what species selection enthusiasts should be looking for is traits
> where individual-level selection is more-or-less agnostic.
> 
> Now - if only there were a few more traits that fitted this description ;-)

Or any at all?
-- 
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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