For those who are not familiar with character state optimization, all three characters in the above example show the same number of steps on the tree whether they are optimized as plesimorphies for the clade ((A,B)C) or as convergent on B and C. Either optimization requires 2 steps (a gain in the ancestor and a loss in A, or a gain in B and C independently). The only way to "decide" whether the above arrangement is para or polyphyletic is to decide a priori that the ancestor to B and C either has or does not have the character state 1. There is no evidence one way or the other so this decision would be subjective and not scientific. Let's see how Cking solves this one.

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