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


> HP Peter Buchholz:
> <The point I have been making, and will continue to make is that a
> phylogenetic hypothesis, a cladogram, is the DATA telling you OBJECTIVELY
> what the hypothesis should and could be.  The just-so-story of Linnean
> systematicists is again, the anti-scientific way of looking at reality.
> [...]
> Linnaeus' system has been modified in response to new knowledge.  For one
> thing, he never heard of dinosaurs, and now they're right up there with
> birds and reptiles (!).

According to some, not all -- to those that _like it better that way_.
Therefore "just-so-story".

> At any rate, I'm taking as a given that a
> classification scheme must not contradict evolution.

Good! So I can stop teasing you with Vermes! :-) (But I think you should
stop mentioning the "horseback" quote then.)

> [...] saying the
> Linnaean alternative is unscientific because not objective.

Well, Linnaean taxonomy can't possibly be done without paraphyletic taxa.
Phylogenetic taxonomy removes this one source of subjectivity. But Linnaean
taxonomy is not an alternative, or even a contradiction in the first place,
to the method of cladistic analysis, and the latter is scientific.

> <Why "consensus"? What characters the MRCA had is predicted by
> hypotheses.>
> Yes, and another, superseding hypothesis can change the character list.
> What makes one hypothesis supersede another?  Consensus.

Nope. Testing. The hypothesis that is more parsimonious supersedes all
others (or at least it should be that way :-] ).

> This is not complete stability.

As complete taxonomic stability is either omniscience or ignorance, it can't
be the goal! The goal of phylogenetic taxonomy is solely the stability of

> The inclusion of Archie could also change some day.

Not when it's specifically mentioned as belonging to Aves _in the definition
under PhyloCode_. We have to wait for January 1, 200n, to see this sort of
thing in effect.

> The Linnaean system had been in place for a long time before Jefferson,


> still here more than 200 years later,


> has a good chance of being around for a long while.

Nope. Now a better alternative is in sight. (Actually, at least 2, if you
count the Kinman System... but then, the latter suffers from having few but
mandatory ranks and far too few names.)

> Still, the lurking serious point is that Jefferson appreciated the
> system because it was accepted for so long.

And because he neither had an alternative nor saw any need for thinking up
one. All I say is Darwin.

> He knew how difficult it was to
> obtain agreement on anything, and his reason for leaving out bones is
> (paraphrasing again) that they introduced subtlety and subtlety creates
> disagreement.

Too bad. See above, complete taxonomic stability is highly suspect. (Not
entirely my phrase: see http://palaeo.gly.bris.ac.uk/phylocode/biolrev.html
for the refs.)

> So, meditatively tonight, I think there's good reason for valuing quiet
> agreement, rather than disturbance, so long as the settled idea doesn't do
> any harm.

Fine, fine, but when the agreement causes even more harm, then away with it.
If that can be accomplished by such simple things as elections, then fine,
if a revolution is needed, then so be it. B-(  ;-)