Re: Triassic Sauropods

["philidor11" <philidor11@snet.net>]

<Now replace each pair of coin tosses by a different bistate character in
two related taxa [which are] being analyzed cladistically. Let the taxa
evolve for a few million years to give the characters some time to shake out
(a "long branch"; this amounts to playing the game with a few score coin
tosses).
What happens?
Quite a few characters, just by chance, are going to shake out the same way,
just like your coin tosses being alike 50% of the time. This is the "noise"
in cladistic analysis. How many characters have to shake out alike before
you
have a genuine phyletic relationship?>

Are you sure that you have many bistate characters?  Doesn't coding
present/not present still leave room for ambiguity?
Anyway, trick question.  By definition, assuming that there are related sets
of adaptations which you're counting separately and that the animals have
similar diet/climate, and also given a fairly high frequency of changes
occurring (by extending the time if for no other reason), you have a
guaranteed noise generator.
So, your implied assertion is unarguable.  Wouldn't it be better to identify
different lineages only after they are so far different that noise won't
confuse the issue?