Paraphyly

Robert J. Soreng soreng at EROLS.COM
Fri Jun 13 10:17:59 CDT 1997


Take a close look at Cronquist's argument for Cyperales (Cyperaceae +
Poaceae) especially page 1135 An Integrated System of Classification of
Flowering Plants, 1981, and ask yourself if he willingly accepted
polyphyletic groups.  I think it is pretty clear that he was willing to
if they had converged enough and were closely related.  Subsequent
anatomical and molecular evidence have bolstered the position that
Joinvilleaceae is the sistergroup to Poaceae and that Cyperaceae and
Juncaceae are sistergroups.  But even in 1981 the placement of Poaceae
with Cyperaceae was on shaky ground, and Cronquist knew it. =20
Having said this, I'll toss into the ring a position that I've heard
some cladists recently take, that polyphylly is not theoretically
clearly distinguished from paraphylly.  I have not read anything about
this argument and can not defend it one way or the other, but am curious
as to what may have developed from it.
Robert J. Soreng
Smithsonian Inst.

Thomas G. Lammers wrote:
>=20
> At 07:58 AM 06-13-97 -0700, Joseph E. Laferriere wrote:
>=20
> > However, where Cronquist and I part company is when he
> >argued in favor of accepting POLYphyletic taxa. In my opinion, that
> >should never be done at any level.
>=20
> Did he REALLY??  Man, I missed that!  And I find it hard to believe.   =
I
> certainly consider polyphyletic taxa anathema, and can't believe Art
> wouldn't have thought so, too.  Can you quote me chapter-and-verse on t=
hat?
> I do recall him commenting on the idea of evolution across a broad fron=
t,
> which I guess could be polyphyletic if broad enough.
>=20
> Thomas G. Lammers
>=20
> Classification, Nomenclature, Phylogeny and Biogeography
> of the Campanulaceae, s. lat.
>=20
> Department of Botany
> Field Museum of Natural History
> Roosevelt Road at Lake Shore Drive
> Chicago, Illinois 60605-2496 USA
>=20
> e-mail:     lammers at fmppr.fmnh.org
> voice mail: 312-922-9410 ext. 317
>=20
> *******************************************************************
> "He uses statistics as a drunken man uses lampposts
>  -- for support rather than illumination."
>                                             -- Andrew Lang

--=20
MZ=90




More information about the Taxacom mailing list