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Re: ABSRD BAND on Sinornithosaurus feathers



On Tue, 20 Mar 2001 12:49:27  
 Tim Williams wrote:
>
>
>Are you likewise suggesting that mammalian hair originally evolved for a 
>purpose other than insulation?

Mentioning mammals brings up an interesting point.  Although I know relatively 
little about the evolution of mammals as a group, judging from what I've read 
mammal hair has been modified from sensory bristles (whiskers and the like, for 
example).  Basically, hair evolved from these bristles, much as feathers 
developed from the "fuzz" George, Tom, et al. are discussing.  

The sulphur hypothesis seems a little weak to me, but George is right when he 
says that the sulphur idea wouldn't be restricted to any type of animal, while 
insulation as a hypothesis would basically be restricted to warm-blooded 
animals only.  Obviously, birds are warm-blooded, but I would definitely tend 
to say that endothermy developed after the feathers (like it developed after 
hair in mammals, if I'm not mistaken).

Perhaps, then, the fuzz we are discussing served a sensory function, much like 
early mammal hair?  Sensory bristles or structures are surely not restricted to 
any type of animal (i.e. cold blooded, warm blooded, etc.).  While I don't 
really know how fuzz or feathers could be used as a sensory organ, I would say 
that it is at least likely.  Of coures, sexual display may also be another 
reasonable hypothesis.  

I, personally, am anxious to see the results of the bird genome projects that 
Mike Keesey mentioned.  Actually, I am quite anxious to see what HP Alan Brush 
has to say about them.  I recall several intersting list discussions involving 
Dr. Brush in which feather codons and the like were discussed.  

Interesting stuff, although I tend to shy away from the entire evolution of 
flight debate.  

Steve

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