Re: "Non-shivering thermogenesis"?

[Ronald Orenstein <ornstn@home.com>]

At 03:22 PM 31/07/00 +0000, Henri Rönkkö wrote:
> He speaks of "non-shivering thermogenesis". I was just entertaining myself 
> with Bakker's letter "Dinosaur Bioenergtics - a reply to Bennett and 
> Danzell, and Feduccia" from year 1974 in the volume 28 of Evolution, pages 
> 497-503. In his letter, Bakker states that NSTG has something to do with 
> the activity of sodium pumps of the cell membranes. He refers to a paper 
> to which I - surprisingly - don't have access to. I'd be grateful if 
> someone could clear up this mess of mine a little.

There are a number of ways to maintain a body temperature above ambient 
without shivering.  Basking and gigantothermy are the most obvious.  Living 
leatherback turtles, for example, do not (as far as I know) shiver, 
but  maintain body temperatures of up to 26 degrees C in 8 degree seawater 
through a combination of large size, a subcutaneous insulating layer that 
helps retain heat generated by normal muscle activity, a countercurrent 
exchange system in the flippers to reduce heat loss, and possibly the use 
of dark skin to absorb radiant solar heat.

Of course shivering isn't the only way we maintain body temperature either 
- it is only one of a number of metabolic processes.  So we engage in 
"non-shivering thermogenesis" too.
--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2          mailto:ornstn@home.com