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


George Olshevsky (Dinogeorge@aol.com) wrote:

<If you consider >taxonomy< as the recognition and >naming< of groups,
then  the genus is the basic unit, and recognizing genera is fundamental
to this  process.>

  I do not consider the ICZN's authoritization/recommendation of a
noun-based genus with a modifying species name as a valid argument to
regard that a genus is more important than a species. The species is the
basic phylogenetic structure in modern binomials, though recent works have
begun to regard either as subjective and refer to the morphology, at least
in vert. paleo., as the idealization of a new form. I have recommended
Flynn et al., before, on the description of two new traversodontids from
the Triassic of Madagascar, in JVP.

<In phylogenetics, however, populations are of paramount importance, with
species being recognized as groups of populations capable of
interbreeding. This, of course, cannot be done with fossil species, and
all we have to distinguish species in vert paleo is skeletal anatomy. Not
only are genera entirely subjective, they're paraphyletic. Otherwise all
living things would belong to the same genus. Consider the genus Homo.
Where does it begin, and where does Australopithecus end? Why shouldn't
all those species in Australopithecus each be called Homo

  I have argued this very point. There is only one true taxon, Biota,
unfortunately, where everything in a population-driven scheme is
considered inately unique. However, we sample individuals, not
populations, in that some genetic variance occurs within the population.
My genetics resemble more my parents than I do my siblings, as a result of
this, and problematically I can only be tied in ancestrally rather than
evolutionarily _forward_, or progressive genetic variation, with the rest
of subjective ol' *Homo sapiens* (a name that is as much politically as
morphologically supported).

  Problem is, in vert paleo, we have individuals only, and unless we
ignore taxonomy altogether, the systems must find a medium, a
compatibility that permits the two to operate together. I have also argued
that in whose system does these recent taxa have their own genus? Maybe
they are all the same genus or species and can therefore breed together?
There are splitters and there are lumpers even today. No reason why all
the elaphines recently reported cannot be more taxonomically allied.
Genetic variation within a species may also be minimal, or extensive, a
variety which does not help in rigid views of specific genetic isolation.
One man's genus is another girl's species :)

  The ideas of "genus" and "species" depend on the framework involved, and
in some cases they are compatible, in others not so. Genetics cannot be
assessed for any dinosaur save extant birds, and morphology is not the
thing in most neontologist ornithologist's views on bird taxonomy.
Meaning, if you work in one system, it is quite obvious you will have
intrinsic problems with the other. But, guess what? It means neither are
truly correct, now does it?


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.

Do you Yahoo!?
HotJobs - Search new jobs daily now