Adaptive values

[Ken Kinman]

     Of course, there is always some danger in declaring that any character
has a given "original" adaptive reason for having arisen.  Evolution is a
continuous process, and both the characters and "reasons they exist" can
change in ways that are not "in synch" with one another.  And the chicken or
the egg dilemma often pops up.
      I am not a botanist, but assume the ligule evolved from something that
might be termed a protoligule, whose function was quite different from the
"original" ligule (however you might want to define or delimit the latter).
Even carefully crafted hypotheses on such subjects may seem "out of reach"
or a matter of faith, but taken with a grain of salt they are useful and
help to push the envelope until empirical science has the tools to deal with
it in a more definitive manner.
     It's a slow and messy process sorting out such things, but this is not
surprising since evolutionary history was mostly a slow and messy process.
That's why I find biology a lot more interesting than mathematics.  But
given enough time and new evidence, what seem to be philosophical issues
will be addressed empirically once we know enough to put them in a more
appropriate context.
                       ------Ken

>From: John Grehan <jrg13 at PSU.EDU>
>Reply-To: John Grehan <jrg13 at PSU.EDU>
>To: TAXACOM at USOBI.ORG
>Subject: Adaptive values Selaginellaceae
>Date: Wed, 28 Jul 1999 08:28:25 -0400
>
>   But that tells us
>nothing about the original adaptive reason (or lack thereof) for the
>character. IMHO the ligule in Selaginella is vestigial; I imagine that one
>might find a species or two in which it serves some function. But none of
>that addresses why there is a ligule.
>----------------------------------------------------------------
>Curtis Clark
>
>
>
>I would suggest that its a matter of personal faith that functional
>states of characters are necessarily the reason why they exist.
>Its possible that the function exists as a result of the character
>or structure existing in the first place. Asking why something
>exists seems close to asking why do we exist - a sort of philosophical
>or religous question rather than a subject of empirical enquiry.
>
>John Grehan


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