Re: AAH: humans long-distance runners?

Pat Dooley (
Mon, 12 DEC 94 21:37:51 -0500

PioneerTom <> writes:

>The reason that an evaporative system moves heat so well is the high
>"latent heat" of water, dicovered in the 18th century by joseph Black.

If it evaporates it removes heat; if it drips off it is effectively
wasted. The human sweating system is unique in its inability to regulate
sweating to minimise wasteful dripping.

>While it is true that humans need much water in a hot dry environment,
>most prey animals and many edible plants require even more. Thus, the

What is your source for these claims? All the references I've seen
put humans high up on the water requirements scale. In desert
conditions, humans lose 10-15 litres per day. As my father drily
noted, when he was helping chase Rommel out of North Africa,
you peed once in the morning and that was it. I recently saw a
ducumentary about a troop of baboons trying to survive in a
severe drought in Southern Africa. They were going for many days
at a time without drinking.

All this discussion on removing heat ignores another problem for
hairless animals - deserts and savannah environments get very cold
at night. Every savannah animal except for some very high mass
animals has a fur coat to keep them insulated.

Pat Dooley