Addendum (Striking a Balance)

[Ken Kinman]

     Not much time, so rather than rehash old ground, I'll make some general
observations.  Parsimony without weighting probably works "relatively" well
at the species level.  But as you go to higher taxonomic levels (and the
gaps in our information get larger), the underlying true phylogeny probably
tends to get increasingly non-parsimonious and homoplasies increasingly
problematic.  This helps explain why invertebrate phylogenies at phylum and
class level are so controversial.
     It is at phylum and class levels that weighting becomes particularly
important, and that is where taxonomic judgment (including intuition about
weighting) becomes critical.  Obviously we must each judge the judgments of
others as well, and we generally come to the conclusion that some scientists
do it extremely well, others do it very poorly (and a whole continuum in
between).
     Therefore, the higher the taxonomic level, the more skeptical I am of
computer output (especially when not weighted).  However, I think judgment
trumps weighting!!!   So I would trust the "non-weighted" analysis (if such
a thing *really* exists) of an excellent scientist over the weighted
analysis of a poor scientist, and the higher in the taxonomy the more
important this becomes.  There are a lot of other variables (complicating
the process), but those discussed above are particularly important to me.
     Some might think this makes me too subjective or biased, but in any
case, I think it is better to consciously examine your biases than it is to
ignore them and be less aware of how they may be affecting your work on a
subconscious level.  Minimizing unconscious subjectivity is probably even
more important than minimizing subjectivity overall, but doing either is
definitely easier said than done.
                 ------Ken Kinman
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