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RE: The validity of cladograms (was Re: giant birds)



The answer is an overwhelming yes!!! In the majority of cases
cladograms of extant organisms based on morphological characters are
congruent with those based on morphologicl characters. I have mentioned
this a couple of times to support my view that cladistics is the best
method we have for reconstructing the phylogenies of extinct organisms.
Your message implies that phylogenetic analysis of DNA is somehow
"different" to that of morphological characters. Molecular characters
(DNA) can be analysed using exactly he same methods as morphologicl
characters (i.e. parsimony). Molecular characters can also be analysed
using a modelling approach (i.e. maximum likelihood), and by a
clustering approach (neighbour joining). The latter is not usually
considered reliable enough on its own for evolutionary reconstructions.

If yes, then why is it in paleontology, 90 % of the time, different authors
come up with different cladograms? Why isn't there more of a consensus? T
thought Cladograms were suppose to 'clean' things up, but there are now
hundred's of node names? I personally don't care if diplodocus was first on
a clade than Apatosaurus, they lived at the same time. Its like everyone is
looking up a family list, and it's always different.
Tracy