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Re: Livezey and Zusi's paper plagued with convergence?



----- Original Message ----- From: "evelyn sobielski" <koreke77@yahoo.de>
Sent: Sunday, September 30, 2007 7:09 PM


PS: for all that's being said, I wouldn't have
quantitative analyses overrule qualitative ones in
every case.

What exactly do you mean by "qualitative"? Or perhaps I should ask how is it possible to measure the quality of a character?


Or in shorthand:
- "Cnemial crest present/absent" is not advisable as a
character.

Sure it is. Consider "frontals separate/fused": the latter condition occurs in anthropoids _and_ carcharodontosaurids _and_ pachypleurosaurs _and_ I forgot what else. Is it "not advisable as a character"? Not in the least: it is a perfectly good autapomorphy of Anthropoidea, _and_ one of Carcharodontosauridae, and so on.


What is not advisable is to use too few characters, or correlated characters.

- Good taxon choice will not necessarily increase
robustness (and might even decrease it), but overall
reliability (as testability of hypotheses hinges upon
it)

Where's the difference?

Increasing taxon sampling can lead to trouble if too few characters are available.

PPPS: I had a little dispute last week with a
co-student who claimed PAUP* was for molecular
analyses ONLY, "the Prof. said so". Unfortunately I
forgot the backronym of P.A.U.P. she gave me.
Something with "Alignment [of DNA sequences]" I think.
We actually had a brief shouting match (which was
shocking by itself because we are generally quite
close friends) as she stood by what I found to be an
entirely absurd "WTF doesn't EVERYBODY know this?!"
kind of thing.

Let me repeat my annual lamentation about the vertebrate paleontology department at the University of Vienna.