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Re: "Non-shivering thermogenesis"?
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:email@example.com