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Saturday, October 10, 2009

BRYONET: two naming systems side-by-side

BRYONET

I am also not going to vote. My position is that we should invent a
completely new system (google phylocode to see the beginnings of this
for higher taxa) that allows one to name monophyletic clades at any
level, even down very low, while leaving the old-fashioned binomial
system in place. Thus, were I to vote, I would vote that nominal taxa
at the Linnean rank of species need not be changed in circumscription
to be made into things that are monophyletic (i.e. I'm for stability).

I refrain from voting because I fear this would be counted as a vote
against naming small clades, or else allowing people to name them but
only as vigilantes (which is what happens now in nearly every issue
of Systematic Botany, American Journal of Botany, Molecular
Systematics and Evolution, etc.). In the bear example, I would have
no problem with people continuing to use the Linnean binomial for the
paraphyletic group brown bear (Ursus arctos: I hope you can see that
this is in italics to denote the old system), just as I am
comfortable using names like algae, bryophyte, pteridophyte, dicot,
and Scrophulariaceae, which I think are all paraphyletic.
Nevertheless, in the new system, which for now would stand side-by-
side the old system, there would be no paraphyletic group for brown
bears. The new system would permit one to recognize a clade for polar
bears and a clade for all those kinds of bears to which Zander
refers, these might have names like clade-Maritimusbear and clade-
Zanderbear, with the "clade-" part of the name being something that
you may drop if you are not afeared of being misunderstood.
Maritimusbears are a kind of Zanderbear. See how nice is rolls off
the tongue, and notice there is nothing in the name Zanderbear to
make you assume it is a species any more than Elephant ought to be
assumed to be a single species.

Also, were I to discover a new Linnean species boundary that I deemed
worthy of recognition, I would go ahead and update the taxonomy in
both systems. Say, I decided that the Blinda acuta of the high Sierra
are worthy of noting as distinctive from the widespread Blinda acuta
that many people around the world know and love, and that I had
studied this closely enough to have concluded that the Sierran
endemic arose from within the western North American part of the
larger group. I would go ahead and fix up the Linnean names: Blindia
sierrae for the new endemic and Blinda acuta for the paraphyletic
remainder. (The name Blindia acuta would be unchanged but its
circumscription would be contracted.) I would also name a new endemic
clade under the new system, clade-Sierranacuta, and of course, I
would leave unchanged in circumscription clade-Acutablindia. As you
can see, it would not take very many new discoveries before the new
phylogenetic names grew away from the old Linnean names. It wouldn't
be long before Blinda acuta (without segregates) ended up much more
narrow than c-Acutablindia (which would be unaffected by discovering
the distinctiveness of endemic subclades).

I'm not sure what would eventually happen to the old system. I guess
some things might fall out of usage, perhaps many of the higher taxa
that noone ever liked much anyway. But the parts that people find
useful, perhaps including the binomials for species-ranked taxa,
would be maintained outside of the phylogenetic classification. My
position is that whether I like it or not, people who are studying
evolutionary relationships are not going away and they should be
encouraged to give names to their findings. If new finds like (my
imagined) Sierranacuta are given only names like subclade-7 of
clade-9 of Blinda, the research findings are not going to be as
useful to other people as if they enter into language. The least
upsetting way to do this is to establish a new system of
classification next to the old system.

I've changed my mind before, but this is my current reaction to the
ballot.

--Paul Wilson
California State University Northridge
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