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Re: FEATHERS
(BTW, thanks to those who responded to my questions on mesosaurs and
dinosaur shoulders.)
Darren Naish wrote (10/3/96; 3:52p):
>With re to the 'feathers evolved as insulators' thread..
>Feathers are the most complex structure to have grown out of
>vertebrate skin _ever_. To argue that this structure _just happens_
>to have been, later on, usefully exapted for flight is illogical.
>The only way to explain the initial appearance of feathers is to
>say that they evolved for aerodynamic purposes.
I'm having trouble with these sentiments. I would like to reword the
above statement, to produce an alternative view that is equally
impossible to dispute because of its metaphysical qualities.
"Feathers are the most complex structure to have grown out of vertebrate
skin _ever_. To argue that this structure _just happens_ to have been,
later on, usefully exapted for insulation is illogical. The only way to
explain the initial appearance of feathers is to say that they evolved
for insulative purposes."
In any wording, the last sentence would clearly be incorrect. This group
has already proved that there are many ways, all quite logical, to
explain the initial appearance of feathers. Also, I don't think it has
been established that complex structures cannot arise for insulative
purposes. Would a horse say that five-toed feet could not have arisen
simply for walking? (Yes, I know that the first tetrapods were
polydactylous--five isn't the issue.)
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Norman R. King tel: (812) 464-1794
Department of Geosciences fax: (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712 e-mail: nking.ucs@smtp.usi.edu