Re: Guide for anti-AATers

9 Nov 1995 22:00:37 GMT

Phillip Bigelow ( sez:
`VINCENT@REG.TRIUMF.CA (pete) writes:

`>Benjamin H Diebold ( sez:

`>`How do you explain the other animals that swim and dive, but that still
`>`have hair? There are many mammals that spend varying amounts of time in
`>`the water, but yet have hair. Why wouldn't the same selective advantage
`>`in less body hair apply to them?

`>I don't think you'll find any with hair. Fur, they have. Considerably
`>different. Fur is a definite advantage for an aquatic animal,
`>whereas hair is probably just a nuisance, and possibly a serious
`>liability. It's not thick enough to insulate, nor oily enough
`>to shed water.

` From a biological point-of-view, Pete, hair and fur are the same thing.
`They are homologous. Where is your reference that states that hair is
`different from fur?

No, I don't have one. Since I wrote this I've been trying to remember
where I encountered this distinction. What I remember is that
distinctions were made based on the number of strands coming
from each follicle, and the division of the coat into long
`guard' strands and short frizzy insulating strands.

>From a practical viewpoint, ignoring the question of the validity
of my previous statement, one could argue that which direction
a creature evolved would be dependent on what they had to bring to
the problem. A creature with an already thick coat of hair or
fur would be more likely to evolve in a direction that enhanced
this coat, whereas one with a relatively thin coat of hair, which
would retain water while not being dense enough to provide insulation
value when wet, might be more likely to evolve toward losing
that hair. The benefit is obvious: with less hair, water will
rapidly run off the body, rather than sitting in place til it
evaporates, removing the heat of evaporation with it.

========================================================================== <== faster % Pete Vincent % Disclaimer: all I know I
% learned from reading Usenet.