Re: heat loss vs. evolution

John Pettit (
Mon, 27 Nov 1995 15:39:22 -0800

In article <>, (John Hansen) wrote:

> Dear Sir or Madam,
> I am a high school student that attends Mt.Shasta High School. My lab
> partner and I are doing a science project on: is there a biological
> advantage of being short and squatty in the arctic and long and lean and
> living in the tropics with respect to heat retention or heat loss? We have
> already researched that as your blood temperature rises above thermostat
> setting, the blood vessels near the skin surface are dilated. This means
> the supply of blood to the skin increases. If the air is cooler than the
> body surface, heat can transfer into the air. Animals that live in the hot
> climates have more exposed surface areas than animals that live in cooler
> climates.
> We have found that the surface area to volume ratios are important in
> understanding this question . What we were wondering is what materials we
> could use to test our hypothesis. We can't use live animals and want to
> model this problem using something else. Any information you could give
> us would be a lot of help, and would be greatly appreciated.
> Thank you for your time,
> Sincerely Tim Fredenburg and Cassie Hansen
> Please write me (Cassie) at
Hi there.
I just finished using an article that may be of some help to you. It's
not directly about evolution, but covers some of the points about heat
loss and surface area. The article can be found in:
Austin, Donald M. and Michael W. Lansing
1986 Body Size and Heat Tolerance: A Computer Simulation. Human Biology
The hypothesis is as follows:
"Surface area to weight ratio (SA/W) to increase as the mean annual
teperature in which a population lives increases" (pg 153).
I hope this helps.

John Pettit (home) (school)
University of Victoria
Victoria, British Columbia
*Macintosh PPC 7100/66AV*