Re: Bipedalism and endurance (Re: AAH - enough already)
Phillip Bigelow (firstname.lastname@example.org)
Tue, 13 Dec 1994 02:46:27 GMT
email@example.com (Francis Davey) writes:
>goodness sake there must be some work on the efficiency of different animal
>cooling methods, can't someone provide a *citation* so we can drop all this
>silly common sense conjecture and rely on some real work?
This is a valid complaint. I recently made the claim that a small,
hairless hominid (smaller than Lucy, if one accepts that the aquatic phase
happened prior to A. afarensis) would suffer hypothermia on a regular basis
if the hominid was even semi-aquatic, and even if it was living in a
semi-tropical environment. I based this on the _total_ lack of small,
hairless semi-aquatic mammals in our modern world. _Small_ endothermic
animals need thick fur and occassionally thick, oily
fur to keep them warm. This is also true in equatorial Africa today.
So... here are some references that discuss the general problems
of keeping warm, when one is small and endothermic. There are many
SERIOUS physiological problems in being a small, hairless aquatic mammal.
I wish the Aquatic Ape proponents would learn from these articles:
Grigg, G.C., Beard, L.A., and Augee, M.L., 1989. Hibernation in a
monotreme, the echidna (Tachyglossus aculeatus). _Comparative Biochemistry
and Physiology, a Comparative Physiology_ 92(4) pp. 609-612.
Bozinovic, F. and Rosenman, M., 1988. Comparative energetics of South
American cricetid rodents. _Comparative Biochemistry and Physiology, a
Comparative Physiology_ 91(1), pp. 195-202.
Koteja, P., 1987. On the relation between basal and maximum metabolic rate
in mammals. _Comparative Biochemistry and Physiology, a Comparative
Physiology_ 87(1), pp. 205-208.
Crawshaw, L., Grahn, D., Wollmuth, L., and Simpson, L., 1985. Central
nervous regulation of body temperature in vertebrates: Comparative aspects.
_Pharmacology and Therapeutics_ 30(1), pp. 19-30.
enjoy the reading, folks! :)