RE: Warm-Blooded debate

["Tomporowski, Steve" <Steve.Tomporowski@us.ms.philips.com>]

>bruce wrote:
>
>>Some dinosaurs did have sails similar to the pelycosaur Dimetrodon--why
>>should those sails have been used for any different purpose?
>
>>bruce
>
>This idea of sails always struck me as a strange suggestion (use for
>warming).  I mean of over 800 dinosaur genera, on three (correct me if I'm
>wrong) had any semblance of a sail.  If the sail were so necessary, as
>warming for an ectotherm, why didn't a higher percentage of dinosaurs have
>them.  I don't think 'warming' is a valid argument.
>

>>        If the sails were indeed used for heat transfer, they would
function to _lose_ heat as well as gain it.  In a worldwide subtropical
climate, not every beast would need to evolve such a structure.  Of course,
that can be said about any adaptive feature--that not everything that _can_
evolve _does_ evolve. >>

I agree that the function of sails would be warming and cooling.  I was lead 
to believe (maybe I'm wrong) that this would be a 'great' advantage to an 
ectothermic animal.  If it were such a great advantage, I would think that 
sails would be in the majority, not the minority, i.e. sail backed animals 
would quickly fill all niches by out-competing and eating all the non-sailed 
animals.  Are we witnessing evidence that sails are not a 'real' advantage? 
  Your opinion?

Steve