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You commented:
<I see now a new difference in opinion
here. It's not cladistics or phylogenetic taxonomy you guys don't like,
it's the assumption of parsimony in evolutionary theory.>
We were looking at 3 subjects, science and
manipulation of reality, cladistic analysis, and nomenclature based on that
analysis. 'Twas not I who mentioned parsimony (which is part of
analysis).
Still, now that you've brought it
up...
Let's say that in looking at available examples,
you knew about 1 definite situation that violated parsimony and 99 that
followed parsimony. Then you could conclude that parsimony probably
applies most often in situations similar to the 99. You could
even analyze the 99 situations in an attempt to find what was 'lacking' in
the situation in which it did not.
Now, you can apply parsimony, believing
it is probably applicable to a specific past situation. You
will never have a definitive answer (distant past evolution can be
neither observed nor rerun), but you can
come up with a most likely scenario. That scenario is subject to change
(being only most likely) and to question in a way that a direct observation
or even a 'theory' like evolution is not. The hypothesis remains
the property of the person who made it and those who agree with
it.
(I'm purposely leaving out what appear to be
logical flaws in the methodology because I'd have to be a lot more knowledgeable
to assert them with enough certainty to make them solid grounds for
criticism. Someday, I'd enjoy hearing the comments of a formal logician
who has studied cladistics closely.)
In addition to the fact that the methodology a
priori cannot guarantee accuracy, there are also errors/subjective elements to
the data. Human beings are making these decisions about which animals to
include, what characters are present/absent, and how to code,
particularly relative codings like ratios above or below a certain
threshold. I'm not criticizing the effort, but we know accuracy
is a progressive process.
There are also the effects of missing data because
fossils which would prove essential have not been and may never be
found.
And then, after all that, the results of the
computer program have to be interpreted. Even with all the skills of
the scientist looking at sheets of computer paper, the preference for a result
with 17 reversals, say, compared to 18 is not what you would want to call an
unarguable increase in credibility.
So, Pete, if by objective you mean unarguably
accurate, cladistics isn't there. If you mean without opinion, cladistics
isn't there, either.
You concluded:
<So what if parsimony doesn't come up with the
tree you constructed in your head? What are you left with in the absence
or parsimony? Munificence makes science become impossible: there are so
many infinitely more complicated schemes why bother testing any of
them?>
Parsimony and the other problems all make the
results of the analysis less than totally reliable. You ask about
alternatives. I don't know how I'd go about finding one that didn't have
the same flaws, though someone else might. Should we stop trying to make
sense of all these fossils (which are at the same time both many and far
short of what we need)? No.
But at the same time, I'd argue that we shouldn't
be dismissive of alternatives. We're not fending off inadequate
challenges to perfect accuracy, we're making a continuing attempt to
improve our understanding, with no guarantee of a successful result, and no
certainty that we have made much progress so far.
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