Thermoregulation... was Re: Aquatic ape theory

J. Moore (
Sun, 15 Oct 95 13:52:00 -0500

Ja> Yes, I should have been a bit clearer here. What I meant was that the
Ja> elephants in Africa didn't grow their hair back. I reckon the real
Ja> answer here is that hair only works as an insulator when dry, whereas
Ja> subcutaneous fat works both when dry or wet, so if an animal species
Ja> loses its hair and develops sub-cutaneous fat in an aquatic environment
Ja> and then returns to the land, the selective pressure to re-grow the hair
Ja> for insulation is reduced by the fat layer's presence.
Ja> James Borrett.

In the face of Caroline Pond's evidence on fat distribution, it
can't be said that the fat we have is due to the need for
insulation (at least not with any accuracy). You are also
ignoring the issue of size and temperature control, which has
nothing to do with an aquatic environment. Large animals tend
to heat up more than small, unless they have features that help
them radiate heat better, such as the large ears of elephants,
or long limbs (as in humans since H. erectus), or (relative)
hairlessness. Another example of a large land animal is the
rhino, and this is a counter example to your idea even if your
elephant example were correct. Your theory has to be cohesive
to have explanatory power; you can't just say evolution "worked"
for elephants but rhinos were immune or something.

Jim Moore (

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