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Re: Bird reduce their "heating bills" in cold climates



--- On Tue, 7/6/10, Tim Williams <tijawi@yahoo.com> wrote:

> From: Tim Williams <tijawi@yahoo.com>
> Subject: Re: Bird reduce their "heating bills" in cold climates
> To: dinosaur@usc.edu
> Cc: tijawi@yahoo.com
> Date: Tuesday, July 6, 2010, 12:00 AM
> 
> Jura <pristichampsus@yahoo.com>
> wrote:
> 
> 
> > There are some good evo-devo reasons to assume that
> the
> > transition scales to feathers was an all, or nothing
> kind of
> > affair (well, scales to filamentous stuff at least). 
> 
> 
> I thought that there was good evo-devo evidence that this
> transition did not take place at all.  Instead, work by
> Prum and Brush indicates that feathers are evolutionary
> novelties, and did *not* evolve from scales.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Yeah, there seems a bit of a divide on this. Prum and Brush insist that 
feathers are complete novelties while Sawyer & Knapp argue for a common -- 
scaly -- foundation. Xu and Guo gave a great rundown of the current status of 
feather evolution.

See:

Xu, Xing, and Guo, Yu. 2009. The Origin and Early Evolution of Feathers: 
Insights from Recent Paleontological and Neontological Data. Vertebrata 
Palasiatica. vol 10:311-329.

Jason