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Re: Cladistic Idea

Thanks for your explanations, everybody.  I understand now: with the fossil
record as incomplete as it is, we need to use all the information we have.

I do want to argue one point, however.  David Marjanovic wrote:
<<Naturally, it gets worse if the fossil record is worse and D through J isn't a
clade that exclude A, B and C.>>

And Jason Brougham wrote:
<<We should
never conclude from this that opossums are more advanced than mastodons.
Nor that painted turtles evolved into snapping turtles.>>

But surely my idea doesn't rest on the assumption that the earlier taxa are also
the most primitive, and that the later taxa all nest together to the exclusion
of the earlier ones.  There's nothing to stop my hypothetical series of
constrained trees from coming out with a topology like this:

   |  `--+--A
   |     `--D
      |  `--+--E
      |     `--H

Is there?