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Re: The iguanodont paper



--- "T. Michael Keesey" <keesey@gmail.com> schrieb:

> On Dec 8, 2007 4:30 PM, evelyn sobielski
> <koreke77@yahoo.de> wrote:
> >
> > I would go as far as to say that from the point of
> > evolutionary ecology, *most* paraphyletic groups
> are
> > interesting.
> 
> I guarantee that for every interesting paraphyletic
> group you can
> think of, I can name a dozen uninteresting ones.
> Here's five for
> starters:
> - non-zorapteran bilaterians
> - non-zorapteran, non-canine opisthokonts
> - non-zorapteran, non-canine, non-testudine
> eumetazoans
> - non-dinosaurian eukaryotes
> - all eutherians except for Marilyn Monroe

Of course you can define an almost arbitrarily high
number of symplesiomorphic groups. I only considered
those that have been around as taxonomic entities.

> > Phylogeny is not really important there,
> > just as for a hawk it's not really important what
> its
> > prey is related to, only that it has the right
> size.

> > Phylogenetic information cannot be entirely
> dismissed
> > in almost all cases, and in some it does provide
> > fascinating insight. For example the ability to
> deal
> > with (break down and/or sequester) Fabaceae toxins
> is
> > autapomorphic in Lepidoptera and has evolved quite
> > often (at species-level resolution).
> 
> Wouldn't evolving quite often prevent it from being
> autapomorphic?

Would it?

* As far as anyone can tell it is not plesiomorphic
for Lepidoptera (we don't know what "proto-caddisfly"
larvae fed on before the lineage became aquatic)
* It is not synapomorphic either (it's absent in the
most basalmost lepidopteran lineages AFAIK)

I might have said "among Lepidoptera".

This might serve to illustrate a few points about
characters too. On the surface, the ability to deal
with Fabaceae toxins (most of which are rather
stereotypical from a chemist's standpoint) could be
scorad as a single character. But that may well wreck
the analysis. Not much is known about *how* they do it
on the molecular level, but it seems that the
biochemical pathways and enzymes in each of the
Fabaceae-detoxifying lineages are quite unique (though
there are perhaps 5 people researching this, a fair
bit is known about *what* happens to the toxins:
sometimes they are broken down, sometimes they are
sequestered intact. Palatability of the caterpillars
varies accordingly).

There might have been a bit of HGT going on.

> > But among
> > Noctuidae (the largest family among the butterfly
> and
> > "true" moth clade Macrolepidoptera IIRC) it seems
> a
> > plesiomorphy.
> 
> Interesting.

The same goes for swallowtail butterflies and
relatives and Aristolochiaceae toxins. The ability to
deal with Passifloraceae toxins seems more restricted,
essentially one lineage of Nymphalidae (Heliconiinae -
the famous longwings) and a few other species and
perhaps the odd genus or two.

> > There is also some apocryphal Medieval Chinese(?)
> > classification with hilarious taxa - I think some
> > Spanish or French writer/philosopher lists it. If
> you
> > have ever seen it, you ought to know what I mean.
> Does
> > anyone have the details?
> 
> Andreas Johansson posted the link. The writer, Jorge
> Luis Borges, was
> Argentinian. Like much of the literature he wrote
> about, it is
> completely (and amusingly) invented.

Thanks Andreas! In fact, I had come as far as to
suspect Borges, but then I couldn't find anything - or
rather, I found the Wikipedia article on "Tlön, Uqbar,
Orbis Tertius" first, which led to not really caring
about the classification thing anymore for the time
being ;-)


Regards,

Eike


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