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A bit of cladobabble was Re: Cearadactylus - long, but with sausages
Original Message by Philidor
Sunday, 22 December 2002 14:07
> HP Unwin commented:
> Yes, not surprisingly, there is some homoplasy in my analysis. But as
> Pteranodon, Nyctosaurus and Quetzalcoatlus are deeply nested within other
> clades the homoplasy is clear.
> I'd hardly be able to criticize the analysis itself, but this statement as
> written is circular. How do we know some characters are homoplastic?
> Because the animals are in other clades. How do we know the animals are in
> the other clades? Because the characters which would remove them from
> those clades are homoplastic.
As nobody else answered so far -- I think it's worth an onlist answer -- I'll
How do we know some characters are homoplastic? Because the animals are in
other clades. How do we know the animals are in the other clades? Because
putting them elsewhere would require much more homoplasy than we could
destroy that way. That's what's called parsimony, and it's why cladistic
analyses are done with such huge amounts of characters.
Original Message by Philidor
Sunday, 22 December 2002 14:21
> Oh, and HP Unwin added:
> PS High horse says he has just ejected two people who were trying to break
> into his stable...
> He adds that any basis for classification which cannot be observed from his
> back is questionable because it might lead to disagreement and rancor. He
> values consensus and universal agreement,
Come on. We're in science here, not in Austrian politics. When there are 2
different opinions, at least one of them is wrong, and if their compromise
happens to be correct, both original ideas are wrong, not correct.
> even with the plebeian pedestria.
The conflict* with those outside the ivory tower can be avoided by using and
defining all those fancy names like Aves, Avialae, Pygostylia... and to a
certain degree by school.
* Which exists because not everyone knows the whole diversity of life and
death... apart from that it's different in different languages. German
speakers will accept it if you tell them that yeast is a mushroom** just like
microsporidia, that every crustacean is a crayfish, every
bivalve/lamellibranch/pelecypod a clam, every cephalopod a, literally,
"inkfish", and much more. On the other hand, there are no simple different
names for loons and grebes (probably because the former don't occur so far
south in Europe), only rather artificial "sea divers" and "lobe divers", with
the individual names of species of both groups ending in "diver". There isn't
much internationality among horse riders, there's quite some disagreement,
even though I haven't heard of downright rancor so far :-) .
** Oh. In Austria, and AFAIK southern Germany, this will depend on which of
the two words you use. One of them, the diminutive of "sponge", is used more
like mushroom in English, for those with macroscopic mushroom-shaped parts.