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The validity of cladograms (was Re: giant birds)



I am interested by this notion of cladograms being untestable as it looks to
me like we have a control test with extant organisms.  Ie, get a bunch of
skeletal experts to draw up a cladogram as they would with fossils, but
based on living animals.  Then get a dna comparison of all the species
involved and compare the more reliable dna test with those of the cladogram
to see if they compare.  Has this or anything like it been done?  BTW, I'm
assuming the dna test is more reliable than cladistics, otherwise:

Barrister:    Can you prove that this man is the father of your child?
Plaintiff:      Yes sir, I got a palaeobiologist to look at their bones and
it's conclusive...

Yours sincerely,
                          Samuel Barnett



> Since we have found ourselves debating cladistics again, and hearing the
question of how valid it is, here's an idea for an interesting experiment:
>
> Let's say that a researcher is attempting to build a cladigram for the
dromaeosaurs.  That person goes through the rigors of a cladistic analysis.
Now, lets say that, by some horrible bookeeping error, one finds that the
data for a sauropod and (HORRORS) a ceratopian has been included with the
data for dromaeosaurs.  Now, according to cladistic theory, the resulting
cladigram should look something like this:
>
>         DM        SP     CT
>         \         /      /
>          \       /      /
>           \     /      /
>            \   /      /
>              V       /
>               \     /
>                \   /
>                 \ /
>                  V
>
> Where CT = Ceratopian; SP = Sauropod; DM = Dromaeosaur Mess
>
> The question I have is: Has this been done?  Will we get the result above
or something else?  If we get a cladigram that includes CT *within* DM, we
could be in trouble.
>
> Along these lines, since the researcher is the one who decides what
characters are used in a cladistic analysis, does this make the cladigram
subective?
>
>
> Rob Meyerson
>
> ***
> Politicians and diapers have one thing in common. They should both be
changed regularly and for the same reason.
>
>
>
>