Re: Morgan; various
Thomas Clarke (clarke@acme.ist.ucf.edu)
3 Nov 1995 14:08:32 GMT
In article <47aug1$iat@geraldo.cc.utexas.edu> Alex Duncan
<aduncan@mail.utexas.edu> writes:
> In article <479cs8$iu9@news.cc.ucf.edu> Thomas Clarke,
> clarke@acme.ucf.edu writes:
> >distal limb elements
> Can you read? I said DISTAL LIMB ELEMENTS. If you can pinch an inch on
> your forearm (especially the ventral surface) then you must be a
> grotesquely obese individual.
I guess I missed the "pinch an inch". Still when I pinch the skin of
my forearm [which is dorsal and which ventral? - the arms rotate -
the skin asymmetry seems to be inside/outside not front-back when the
arms are in the standard military attention position] I can detect
a layered structure, the thin millimeter or so of actual(?) skin, underlain
by several millimeters of differently tectured fattry(?) material.
> I did not say PROXIMAL LIMB ELEMENTS.
Nor did I read it this way.
> However, even there, fat distribution is not what we would expect to see.
> Especially on the arms, fat tends to be concentrated on the dorsal
> surface, leaving basically paper thin (heat radiating) skin over the
> ventral surface.
Need to clear up what is dorsal and what is ventral and also what
is the terminology for inside (next to body) and outside (away from
body).
> There is also a sexual distinction in how fat is
> distributed in these regions, with females tending to put on more fat on
> upper arms and thighs than males.
Sure, when the layer is too thin, females stop estrous since they
do not have the reserves needed to nourish a fetus.
Od you know if there is sexual dimorphism of fat layers among apes?
> The point is that if we have aquatic ancestors, we should expect to have
> LOTS of fat on the arms and legs to protect against hypothermia. We
> don't.
Can you read? In other posts I have expressed neutrality regarding
an aquatic episode. I favor the fat layer being a response to
hairlessness in the night air. Also, in the response that
started this dialog I was more concerned with your statements that
the human fat layer is not significantly different from that of
apes.
My experience with cold is that if you keep the core body well
insulated (body fat, proximal limb fat will do nicely) that the
distal limbs can get quite cold. I have walked miles in subfreezing
weather wearing thin "Florida" pants, but a borrowed "Northern" parka.
My legs got cold and and even a little numb, but still functioned.
So actually the fat layer is about what I would expect for protection
from cold night air in the absence of hair.
Tom Clarke
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