[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Ken Kinman wrote:
<The hope of strict cladists that paraphyletic groups
(NOT wastebaskets) like Reptilia are going to be
abandoned is probably a pipe dream.>
Please don't characterize people you do not have the
mentality of to assume their thoughts. There is no
such thing as a strict cladist except as suggested by
Mayr. I've been reading up on Mayr's phylogenetic
opinion, and I'm not impressed.
<Vermes was a polyphyletic wastebasket, Reptilia is
Reptilia is only paraphyletic if you assume that
certain members included in the definition are not in
fact supportedly contained within that definition.
Remove a certain form, such as birds, on the sole
basis of their endothermy, and you enhance the
primitive view that the only real "Reptilia" is
composed of "cold-blooded" amniotes. On this matter, I
encourage analysis of giant tortoises and sea turtles
(gigantotherms [mass endotherms] and though
ectothermic, are not cold-blooded); similarly, tuna
active metabolizers, with a very interesting muscular
system. Avian metabolism differs strikingly from that
of mammals in application and respiration mechanics.
They are convergent in any phylogeny, even the
Pointedly, if you have a disagreement with the
phylogenies as presented, and feel they are incorrect
as to reconstructing relations (as assumed) then
disprove them, don't attack the workers producing the
results. These phylogenies (ALL phylogenies) as Mickey
Rowe, Tom Holtz, and Chris Brochu have all said, are
theories; test, retest, etc., ad infinitum vel nauseum
(you be the judge). Even if they are based on
genetics, these may not be the most agreeable or even
plausible phylogeny (take Whippomorpha, for example,
first proposed by Nikaido et al. 1999 (PNAS 96:
10261-10266 -- http://www.pnas.org).
<...but Michael Benton's soon-to-be published
criticism of the PhyloCode will hopefully help to
prevent much of the confusion he also believes the
PhyloCode will cause.>
Probably because it will require overhauling the
entire tree of life for the most part.
<Therefore I encourage those who continue to recognize
a traditional Reptilia,>
... to understand the point of the meaning, history,
and salvaging of an ancient name [I interject] ...
<although one needs to now indicate whether you are
using it in the traditional or cladistic sense.>
Since the traditional sense is hardly a valid taxon
based as it is on an exclusion of a descent form, the
traditional sense is a historic usage only, and
shouldn't even be capitalized. The vulgar noun
"reptile" and adjective "reptilian" can be used to
refer to this, but to call that paraphyletic grouping
Reptilia would be to suggest the paraphyly has at all
any valid phylogenetic signal, and the last decade and
a half have strongly suggested it doesn't. Mammals are
not reptiles, since the basal stock of such are also
ancestral to the most recent common ansector of
turtles, lizards and crocs (which incidentally
includes birds in nearly EVERYONE's schema) but
ophiacodonts and therapsids have "mammalian"
specializations not shared by the long succession of
"reptilian" forms (especially in the jaw). This
suggests, nearly insists, exclusive ansectry, and
because no-one in their right mind still suggests
*Morganucodon* or *Thrinaxodon* are reptiles and might
have any similarity to *Procolophon*, it is at best
highly improbable reptiles includes mammals or
excludes birds. There is extensive literature, based
on pure morphological analysis (as well as, but not
primarily comprised by, cladistic analysis of both
molecular and morphological data).
<Perhaps someday we will all refer to a more
traditional (but semi-paraphyletic) Reptilia once
Why? Does the taxonomic status of a paraphyletic
assemblage mean anything beyond the ability to
segregate birds from lizards and crocodiles and --
here's the pitch -- dinosaurs as if homeothermy was
<but in the intervening years (or decades), confusion
will continue as long as the cladisto-eclectic war
continues, now well into its fourth decade.>
Confusion persists (literature abounds for the last
entire millenium) where intuitive, "it feels right,"
and single character analyses or plots demonstrate an
opinion that are consistently (literature, again) at
odds with one another. Tools for analysis include our
analytical processes, logical systems and mathematics.
You can guess where this led.
Do I think there are flaws with the system? Yes
there are flaws, and so is the opinion of many
systematists who operate through cladisitics in some
small ways; you can only calibrate a motor by
operating it, Ken.
Jaime "James" A. Headden
Dinosaurs are horrible, terrible creatures! Even the
fluffy ones, the snuggle-up-at-night-with ones. You think
they're fun and sweet, but watch out for that stray tail
spike! Down, gaston, down, boy! No, not on top of Momma!
Do You Yahoo!?
Yahoo! Photos - 35mm Quality Prints, Now Get 15 Free!