[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Taxa nomy (and intro)



  Ha ha, my angiosperm genus is better than your vertebrate order, so
nyah! This is _exactly_ why ranks are useless in communication. A rank
lacks equal content with any other rank, as they are defined based only
relative to other ranks, and to make equal content fit the rank is as
subjective as otherwise.

  However, this:  "But I would reiterate that phylogenetic taxonomy seems
to have no place for those taxa which group together organisms that share
features useful for identification, but which are phylogenetically
unplaced or uncertain - for instance, many yeast genera in fungi[,]" 
illustrates part of the problem of pairing a Linnean and PT system, and
why the "best of both" still has baggage, a lot of it from the Linnean
side.

  Rather, note that under PT, all taxa are equal and without rank. And
under any scientific analysis, if some yeasts are found to be closer fungi
than others, then that's fine. They don't need a "special" clade to show
that our labels (e.g., "yeast") mean anything differently among taxa.
Every taxon includes taxa, and is contained by taxa, wether ranked or
without, and in species, this includes subspecies and races, and so forth,
ad infinitum until you hit a single individual (comprised as we are
cellularly of multiple organisms). Fungi amongi are still fungi in the
general, "lay" form, but may contain forms that are not conventional
fungi; this is not backwards or a drawback -- this is progress. Revising
concepts of relationships means that the methods we have by way of
treating them in arrangements must also evolve, and reflect scientific
approaches to providing systematics. Linnean treatements are subjective
and wholly without scientific merit, and the idea that phyla are equal,
even if the term phylum is never used, is a by product of this. Mollusca
and Annelida, Arthropoda, Echinodermata, and Chordata ... all these are
being shown to be arranged not parallel to one another but in somewhat of
a hodgepodge basally, as well as some being closer to one another than
some of the others are. The classic example of birds (Class Aves) being
found within theropods (Suborder Theropoda) must note then that "class" is
a poorly and ill-defined concept, or that "suborder" is. The arguments for
retention are almost purely historical or depend on the whole "content by
numbers" issue, which is ridiculous. A beetle "family" has often more
genera in it than the whole of non-avian Dinosauria, and that's a HUGE
difference, but not using families as labels, then we find that some
clades have more included taxon labels than others, and _that's ALL_.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

__________________________________
Do you Yahoo!?
Yahoo! Search - Find what you?re looking for faster
http://search.yahoo.com