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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.)


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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