species concepts (this is long!)

[John Grehan]

Please hit the delete now if nitpicking over definitions (particularly on a 
Lepidoptera list) is not your cup of tea (and my apologies for pursuing the 
subject).

>If species definitions did not matter, there would not
>be an enormous body of literature dealing with the
>issue (I could cite over 100 publications here).

My view is that definitions do not matter in the sense that they
are not a solution to anything. They just summarize a particular
view. Arguing over definitions does not, of itself, solve anything.

>If
>they did not matter, people would have no reason to
>argue over them.

In that sense I agree - people take time over what matters
to them (myself included).

>In fact the use of various species
>concepts have huge implications in conservation (see
>Barrowclough et al. 1996)

Different criteria would have different implications I agree.

>Well, this may be close to the truth in practice, but
>cannot be taken literally (read Wheeler & Meier,
>2000!).

Please state what you think Wheeler & Meier have to say
in that respect.

>  So definitions are the foundation of
> > objectivity?
>
>I don't know about that, but without definitions for
>terms, I don't think they can be used very
>objectively.  Without a definition for a species or
>subspecies, those things simply become "whatever some
>taxonomist says they are."

It seems to me that in making a definition one is indeed making things
whatever someone says they are. I agree that definitions provides
terms of reference, but
whether the application is any more 'objective' or not
is something I am not so sure of. In my own field of biogeography
one can define a Darwinian center of origin in all sorts of ways
without the concept itself becoming any more objective in reality.


>They are working hard at it!  That is why they have
>proposed species concepts.

It seems to me that instead of a 'standard definition' for species
the trend is for a multiplicity.

>All of the following modified definitions of species
>concepts are VERY WRONG, way off!  These are complex
>concepts, and require many printed pages to explain and
>illustrate.  You should read the literature before
>trying to summarize these!

So far as I can see the concepts are not that complex at all, and my 
rewording may indeed have some validity with respect to the fact that
each definition provides an essential, spatiotemporally unrestricted 
quality to the species.



> > In terms of spatio-temporal independance these
> > different definitions are
> > really not all that different afterall.
>
>Actually, yes they are.  Some of these concepts deal
>well considering contemporary and fossil taxa
>simultaneously (while some do not).  It is all
>discussed in the literature.

This does not matter in the sense that the definitions appear to refer to 
spatio-temporally unrestricted essences.


>Ok, then how are you are going to justify your opinion?

One can 'justify' ones opinion in any way one may like. Whether one's 
justification is 'better' than any other is something that defies pre-diction.

>I guessd I answered this already by pointing out that
>there is a huge body of literature devoted to the
>topic.

Huge body or not, does not for me, provide the defining essence of time 
well spent. Was there not a time when the question of how many angels may 
dance on the end of a pin was regarded as time well spent?

>Actually, I think the abundance of species
>concepts shows how important they really are to working
>taxonomists.

It shows that this is a preoccupation of a number of people - yes.

>I encourage you to publish your views on
>why species concepts are a waste of time!  They would
>be frequently cited, at least!

Unpopular views are not necessarily of general interest. The fact is
that for many taxonomists debating definitions is time well spent for them.

> > >This enables
> > >workers to defend each and every taxonomic
> > decision
> > >they make on the grounds of their species
> > concept.
> >
> > Why bother having to defend one's taxonomic
> > decision. If there are
> > competing views and all have validity, defense
> > seems to become irrelevant.
>
>Apply this to the real world and the legal system.
>Think about it.  If you can't defend your taxonomic
>decisions (= actions), you have no business making
>those decisions in the first place.

Ability to 'defend' one's position is simply a rhetorical device. Good for
lawyers and scientists engaged in influencing opinion.

>I would really love to see some citations to back up
>these two statements.  You state them as facts, let's
>see the proof [or inother words, please defend your
>statements].  I would really like to see papers
>supporting these views.

Read Lakatos. But that's not a defence.

> > This is just one philosophical view. Under this
> > criterion witchcraft is
> > science.
>
>I would love to see the citation for this!!!

Again, read Lakatos.

>I cannot claim this is, strictly speaking, true.
>However, the weight of the liturature dealing with the
>topic says that the most parsimonious explanation for a
>problem is the best (from a scientific point of view).

Yes its just the most popular view of things.

>While not all authors on the topic agree (certainly
>anyone using maximim liklihood algorighms would not),
>this disagreement seems unique.  The more ad hoc
>principles that go into a hypothesis, the less testable
>it becomes, and therefore, the less desirable it
>becomes (as far as a scientific theory goes, even most
>ML proponents agree with this in general).

One one takes this position then obviously it is true.


>The best
>theories are the simplest and easiest to disprove.

Propaganda


>Without definitions, you can't define what you are
>doing, and it is not repeatable.  Then it is not
>science.

Ah - so definitions make science! Interesting.

John Grehan


 
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