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Monday, October 12, 2009

Re: BRYONET: local endemics


Hi David,

Glad you found the paper interesting -- it is meant to be thought-
provoking. There is an alternative point of view paired with my paper
in the same book, written by Michael Claridge, another arch-
conservative, biological species concept (BSC) advocate who makes
similar points to yours. I don't feel right about distributing that
paper ahead of publication since it isn't mine, but your reaction
gives plenty of material for discussion.

You tip your hand in your third paragraph where you equate "useful"
and "real" -- those are actually two very different things. Many
distinctions that people find "useful" (e.g., UFOs, astrology, human
racial and ethnic categories) are not "real" (better defined in the
sense of existing independently of human perception). Science is all
about trying to critically examine what people take for granted.

I wholeheartedly agree that many people find the species rank useful,
the issue is whether this perceived utility is backed up by reality.
The majority of the US public finds "species" useful because they are
creationists. I'm not saying you or other BSC advocates are
creationists, but I hope these strange bedfellows would concern you a
little. As I say in the paper, my opinion is that both Mayrian BSC
advocates and creationists are being influenced independently by a
much more ancient intellectual tradition stemming from the ancient
Greeks, that the natural world must be made up of some kind of
fundamental "atoms". But modern science shows that isn't the case in
either physics or biology.

You don't need to lecture me about punctuated equilibria (PE) -- I was
a grad student taking classes with SJ Gould at Harvard when that was
being proposed and debated (I read some of those papers in proof!). I
am a big fan of PE, and think that it describes evolutionary change at
a number of nested levels (not restricted to what we often call the
species level). Despite what you say, one can document punctuated
change at the molecular level, and it has been amply documented both
at the molecular and paleo level. An important concept, but it
doesn't negate the point I made in the paper. Divergence of lineages
(including by PE) occurs below and well above the level you call
"species". So does natural selection!

As for the nature of monophyly and why it is important for consistent
phylogenetic classification, as I said to John Game there is no point
rehashing that literature -- it has been well debated for over three
decades and the community has moved on. I can certainly understand
why someone who does not like monophyletic classification would not
like the Phylocode; all I can tell you is don't use it. As Paul
Wilson nicely wrote, the two codes will exist in parallel for awhile,
maybe quite awhile. Or maybe not so long, given that students who
lack the intellectual baggage entrenched in many parts of systematics
have no problem seeing the value of the Phylocode and the lank of
value of the ranks.... We'll see how it goes!



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