Morg/Nich \sweating

Elaine Morgan (
Tue, 17 Jan 1995 15:53:32 +0000

Thank you. I needed the source papers because about ten
years ago someone wrote to New Scientist
that Elaine Morgan was talking nonsense; that eccrine
sweating in patas had been proved by Mahoney (1980).
That time it wasn't true; she never specified type of
gland or mentioned eccrines.

I'm not impressed by Hiley on the chimpanzee. In
measuring the cutaneous moisture loss he reports
that as the temperature rose from 18 degrees C to 38
degrees there was very little change from mean basal
values and the results were insufficient to allow a
significant statistical analysis. That is close to
Montagna's assertion that they don't use sweat-
cooling. Sweating was indeed recorded at 40 degrees C'
which happens to be the point at which the chimp becomes
"unable to maintain thermostasis" i.e. feels quite ill.
The sweating is as likely to have been a fear response
as a thermoregulatory one.

G. E. Foley reported in 1966 that when rhesus
monkeys were subjected to heat no evidence was found of
sweat production. Twenty years later they're sweating.
They can't have evolved the capacity so quickly- it must
be that in the 70's and 80's more anthropologists were
paying closer attention to the problem. Someone suggested
to me that AAT was the irritating grit in the oyster
that caused these new pearls of information to be secreted
(I couldn't possibly comment.)

Here's the bit you're waiting for. What Sheila
Mahoney did not specify in 1980 has now been specified
in spades. By 1980 Elizondo really got his act together
and I am not going to argue with him: patas use eccrine sweat-
cooling. This means (a) I have to accept that the latent
capacity in Old World monkeys to find a new use for their
non-volar eccrines can be activated in a terrestrial
habitat and (b) you have to accept that ST's front-
running explanation of human nakedness ("a necessary
accompaniment of sweat-cooling") has gone down the tubes.
The patas is a notably hairy sweat-cooling savanna-
dweller. Why isn't it as naked as we are if it was
responding to the same conditions?

I don't think you can sustain your theory that
humans switched to eccrine sweat because it was more fine-
tuned. There is considerable delay before it responds to
a rise in temperature. One estimate (Ingram & Mount,1975)
gives between 4 and 40 minutes. There is equally hazardous
delay in switching it off when the sweat is dripping into
the sand serving no purpose and causing dehydration and
heat cramps. Reactions of apocrines in anthropoids
are I agree spasmodic in operation (their function there
is pheromonal) but where, as in cattle, they have been
adapted for thermoregulation they work very smoothly.

You would now like to say: Right. Patas have
eccrines. Story over, AAT demolished, QED. It is not that
simple. Your constant theme is that the differences
between apes and men need no explanation but are merely
a continuation of trends already discernible in the differences
between monkeys and apes. This contention is simply untrue.
There are dozens of instances in which the path the hominids
took was bucking the trend, not following it. Let's test
out the proposition in the case of human skin.

A. DIFFERENCES which can be represented as a continuation
of a trend,
1. Apes have more eccrines than monkeys - in us this is
carried to extremes.

2. Apes have fewer apocrines..same thing applies.

3. Apes' skin has more elasticity than monkeys' - we
have most of all (among primates but cf the pig)

4. Homo is only land mammal lacking vibrissae but these
are already less noticeable in anthropoids than monkeys.

B. DIFFERENCES which are not continuations of a trend.

1. Nakedness. It is sometimes said: "Apes have sparser hair
than monkeys ; ours has gone further and practically
vanished." They are talking about two quite different
things viz. the density per of the follicles.
and the length of the hairs. We have no fewer follicles
per than apes. Indeed at one time ST fans used to
point out with glee that we have more - i.e. we are
actually hairier than apes so why does silly old AAT
pretend we are nakeder? Gary Schwartz has argued cogently
that the density is allometric. What makes us functionally
naked is that the hairs became SHORTER - many so short that
they do not appear above the surface of the skin. In
anthropoids there is no trend towards shorter body hair.

2. Sebaeous glands much more numerous and very much more active
-no trend to that.

3. Pubis and axillary hair differentiated and curly - no
trend to that.

4. Difficulties with wound healing (v. Madawar 1955) No trend
to that.

5. Outer surface of epidermis criss-crossed with congenital
wrinkles visible under microscope. No trend to that (In
primates but cf. elephant and see the same thing writ large)

6. Human skin displays sexual dimorphism -women's more
supple, fatty, and turgid. No trend to that.

7. Remaining body hair in human males longer on the chest
than on the back. No trend to that in any land mammal
(but common in semi-aquatics, v. Sokolov, Nature. 62)

8. Human skin is far more sensitive - each follicle has a
well-structures sensory nerve-organ. No trend to that.

9. Subcutaneous fat layer bonded to the skin. No trend to that
(but cf most aquatics)

In short we are a far cry from the patas or the apes.
Something must have happened to us that did not happen
to them.

I was surprised that Elizondo in his otherwise detailed
article made no reference to salinity in patas sweat. I
would like to know how the animals govern their salt and
water balance. I would like to know why the pig has eccrines
that it never uses and why nevertheless people talk of
"sweating like a pig"...Plenty more questions but I've run out
of time.

Elaine Morgan