As Cladistics and "Eclecticism", Aves, paraphyly flow on

[Dave Walter]

Hi Curtis,

I see a difference between defending paraphyly and using established
paraphyletic group names that haven't been supplanted by a set of generally
accepted hypothesised monophyletic groups.  From your dicot example I
assume that someone has published (I think I remember my wife talking about
it - she works on orchid pollination as well as mites) a convincing
analysis showing that monocots were derived from within the dicots,
rendering the latter paraphyletic?

If so, the older hypothesis that dicots and monocots were sister groups
would be out (at least for the moment).  Only having an acarolgist's
understanding of higher plant systematics, this would leave me with a
problem when I have to talk about plants.  I know that I can refer to
dicots and monocots and get across the basic dichotomy that I want
(although it isn't as rich in information as I once assume and is somewhat
misleading).  I also know that if I immediately familiarize myself with the
most recent hypothesis and try to adopt any proposed new taxa that a) the
students will be confused and b) the hypothesis (and proposed taxa) may
very well change again soon.

I still use Reptiles, Dinosaurs (as at least one 'strict cladist' seems to
do too), and Dicots, but I do try to avoid the latinized versions of group
names that appear to be paraphyletic (except, hypocritically, for mite
names - but I'm avoiding them now because no one would know what I was
talking about).  As far as I'm concerned they are flawed taxa, but still
useful concepts (vs polyphyly, which is evil - however, I use the 3 Domains
without a caveat, although I am not especially looking forward to some
bright student questioning my inconsistency).  Does these usages make me a
practitioner of Eclecticism?  I've never really thought about it before,
but logically, I am guilty, guilty, guilty.  Are there really some people
out there that aren't?

Cheers,

Dave Walter

At 09:28 PM 3/02/02 -0800, you wrote:
>At 03:26 PM 2/3/02, Dave Walter wrote:
>>I've learned that the inherently paraphyletic nature of
>>speciation events is one of the things that are best not talked about, but
>>it must make even the most fundamentalist of cladists uneasy.  More
>>importantly, it is becoming increasingly obvious that reticulate evolution
>>is important in many, if not most, sexual groups.
>
>Maybe I'm not a fundamentalist. One of the clades of plants I study has two
>documented cases of homoploid hybrid speciation, and another has a
>reasonably clear case of speciation through peripheral isolation. Evolution
>is messy. If it were straightforward, we would have figured it out long ago.
>
>But I see in none of this *any* support at all for accepting clearly
>paraphyletic groups such as Reptilia or Dicotyledonae. I have to wonder
>sometimes at the value to "eclectists" of defending these groups. What is
>so important biologically about "reptileness" that we should preclude ever
>recognizing Archosauria or Sauropsida in our formal classification? It's
>almost as if to give in on that one "battle" would mean that the eclectists
>would lose the entire war.
>
>
>--
>Curtis Clark                  http://www.csupomona.edu/~jcclark/
>Biological Sciences Department             Voice: (909) 869-4062
>California State Polytechnic University      FAX: (909) 869-4078
>Pomona CA 91768-4032  USA                  jcclark at csupomona.edu

Dr David Evans Walter
Senior Lecturer & Coordinator for Entomology Flexible Learning
Department of Zoology & Entomology
Project Leader, Cooperative Research Centre for Tropical Plant Protection
The University of Queensland, St. Lucia Campus,
Brisbane, Queensland 4072 Australia
Tele. (61)(7) 3365-1564; Fax (61)(7) 3365-1922
Webpage = http://www.uq.edu.au/entomology/david.evans.walter.html
Mite Image Gallery = http://www.uq.edu.au/entomology/mite/mitetxt.html
Email =  D.Walter at mailbox.uq.edu.au