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RE: Princeton Field Guide



In reply to David Marjanovic, "*Varanus* is a nightmare with 70 species[,]" I 
wrote:

<<As opposed to a non-nightmare of 69 species? Or a nightmare of a single 
species with 70 subspecies?>>

David responds:

<As opposed to something one can handle. With genera being completely 
subjective anyway, this crass utilitarianism is as good a reason as any!>

  How is this more effective, or utile, than the previous "70 species in one 
genus" approach? They are both equally subjective, with both labels equally 
utilitarian. Even if we weren't thinking in Linnaean terms, the difference 
between *Varanus* with 70 species and a *Varanini* with ten genera and, say, 
some monotypic genera and others with a mere ten or so, is nothing. There is no 
difference but the way we label the intervening nodes between the taxa that 
seem to matter more (species) to biologists, and those that matter more to 
egotists (genera).

  The primary difference between these two prospects, and one (hidden) reason I 
despise the practice of arbitrarily splitting taxa like that is because the 
practice of naming genera out from existing species does little more than 
"re-containering" for the sake of itself, without any scientific reasoning 
behind it. The idea stems -- if not synonymous with -- the idea that the 
"genus" is a real, viable, and actual phenomenon, useful as both tool and 
artform. It is, actually, bunk. Thus splitting in this manner (note I do not 
refer to naming new taxa straight off) has no effective means of contribution 
than to provoke this discussion. 

  The same is actually true of lumping:

  I am as much a critic of Greg Paul's erection of a genus-group taxon 
*Giraffatitan* without any phylogenetic reasoning as I am of his lumping of 
*Deinonychus* into *Velociraptor,* or even more egregious, the [unscientific, 
barely justified] treatment of all non-*Oviraptor* oviraptorids as *Citipati*!

  My argument has always been that a stable phylogenetic hypothesis should 
precede taxonomy in this form, and that when it is consistent, the labels at 
individual nodes do not have to be in one form or another. Treatment of the 
"genus" as warranting special treatment from other taxa only predicates use of 
the Linnaean system, and this leads to the idea that *Varanus* cannot, for some 
reason, have 70 species. Of course it can. And so can *Varanidae,* and 
*Varanoidea,* etc.

I asked (edited): "[W]hat preciesly is gained by splitting these subgroupings 
into equivalent "genera"?"

David replied:

<That we can talk about these subgroupings at all. As I'm sure you know, the 
ICZN doesn't allow us to have more than two ranks between genus and species: 
the subgenus and the "group of species" (sometimes called superspecies, but, 
strangely, that term is not in the Code).>

  The Code does not mandate the intervening ranks. Nor does the Code indicate 
that only what it says must be used, and that no other ranks can exist. Where 
does this fiction come from? It seems odd how the infraclass or the subgenus 
even became, if the Code didn't already specify it first!

  But that's not really my response. We may discuss, as we have been, any group 
(ranked or _not_) simply because it has a name. But what is really odd, I 
think, is that I haven't mentioned the Code at all in this until this post, in 
response to David: The issue does not require the disbanding of the Code (which 
can change in accordance by dropping all formal recognition of ranks, or 
dropping all formal recognition of super- and sub-ranks and simply recognize 
rank-groups, although this is still meaningless, but better facilitates 
communication). Instead, the issue involves simply naming taxa without having 
to use the concept of "genus" which for some reason escapes scientific 
definition (there are a lot of attempts at formal concepts, but no real 
definition). yet I can hear from people that something _should_ or _should not_ 
be a "genus"!

Cheers,

Jaime A. Headden
The Bite Stuff (site v2)
http://qilong.wordpress.com/

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

"Ever since man first left his cave and met a stranger with a different 
language and a new way of looking at things, the human race has had a dream: to 
kill him, so we don't have to learn his language or his new way of looking at 
things." --- Zapp Brannigan (Beast With a Billion Backs)