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

[Curtis Clark]

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