Re: Origin of Clothing
From: tadchem (thomas.davidson_at_dla.mil)
Date: 01/21/05
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Date: 21 Jan 2005 11:37:34 -0800
Strange Creature wrote:
> The idea that there is a complete transition from
> black to white with no shades in between, is a
> phenomenon intrinsic to American history, if not
> the Sahara desert.
Actually it is at best a rare event and at worst an oversimplification.
> Basic selection factors at
> least as far as I have heard, with respect to
> skin color, tend to fall under skin cancer,
> vitamin D production, and possible camoflage
> during hunting or gathering.
Early humans started breeding at puberty and generally were done by the
time they had lived long enough to develop adult skin cancer - little
selecction pressure there.
Natural camoflage usually involves the development of patterned
pigmentation to confuse the outline (silhouette) or background-matching
coloration.
Vitamin D production (which selects for light skin) would have been
important in climates where sunburn (which selects for dark skin) was
unlikely .
> The amount of near ultraviolet radiation that
> falls upon the earth, tends to depend relatively
> heavily upon the angle that the sun is in the
> sky. A small level of cloud cover will only
> scatter and diminish it very slightly, however
> a heavy level of cloud cover will often
> reduce it to a greater extent. Also, snow
> glare will tend to reflect ultraviolet
> radiation off the ground and also magnify the
> level of ultraviolet radiation presented by
> the environment.
Local weather and climate is important. The UV index in Seattle is
*much* lower than it is in Fargo (at about the same latitude) because
the cloud cover at Seattle is almost always *heavy* due to geographical
considerations, while that at Fargo is nearly always light to none -
again for geographic reasons.
> The sun will of course,
> produce little ultraviolet radiation at
> night.
Duh!!! The sun's UV output is nearly constant, 24/7. You just aren't
*exposed* to it at night.
> I am not sure what level of UV
> output that a campfire will put forth.
There is effectively no UV output from a cool wood flame.
> Man probably left Africa for at least the
> southern part of Eurasia about 1 to 3
> million years ago.
Homo erectus migrants left no surviving descendants. The earliest
African emigrants to leave surviving descendants left about 70,000 BCE
and moved along the shores of the Indian Ocean to the east, leaving
enclaves along the way (e.g. Andaman and Nicobar Islands, Malaysia, the
Philippines).
> Man did not colonize the most northern
> parts of Eurasia, at least for during the
> highth of the ice ages, if not the
> interglacials, until at least the past
> 50,000 or so years, or only slightly
> longer. Lack of extremely ancient evidence
> for man in North and South America might
> at least possibly indicate this.
The last glaciation of the PLeistocene (about 10,000 to 15,000 years
ago) lowered the sea level 100 +/- 30 meters - enough to permit a
stroll from Siberia to Alaska along the coast.
> Man did not go on long ocean voyages
> until the last 50,000 to 70,000 years
> or so. Lack of extremely ancient
> evidence for man in Australia might
> tend to indicate this.
The lowered sea levels of the Ice Ages would have allowed foot traffic
from Asia to New Guinea and Australia.
> However, lighter
> skin will be able to produce more
> vitamin D to protect against rickets,
> for those early humans who had not
> inferred the immediate idea, of possibly
> eating animal livers in order to
> compensate.
I think it is rather patronizing of you to assume that malnourished
early humans might NOT think to eat every part of the animal they
could. Two words: "British Cuisine" They eat tongue, kidneys, blood,
liver, spleen, stomach, heart, 'haggis', etc. - by *tradition*. The
tradition arose locally; it wasn't imported by the Romans.
> This produces the question with
> regard to how long ago humans
> started wearing clothing in northern
> climates to protect against heat
> loss in winter, and possibly
> provide at least a temporary
> immediate short term protection
> against some, less powerful animal
> bites in some areas.
So far there have been no indications in the archaelogical record that
Neanderthals (who lived in northern Europe before the advent of
Cro-Magnons) ever produced clothing.
> a heavy skin might also reduce
> the speed of a human while
> running, and decrease protection
> against overheating during
> periods of high exertion, unless
> they are shedded (which if they
> were not highly treated skins,
> might also, still be eaten by
> predators if one does not return
> and recover them fast enough).
It would also be a liability when fishing. The high prevalence of fish
bones, the total inability of humans to synthesize their own
omega-fatty acids (essential for neurological development) which are
abundant in fish, and the use of perspeiration as a thermoregulation
mechanism would argue for early humans spending a lot of time in/near
water.
> Another fundamental problem with
> wearing at least animal skins, is
> the potential for attracting large
> predators from their smell if
> they are not treated in some
> fashion.
The body odor of unwashed humans would more than compensate. Even now,
only those predators (Bengal Tigers, wolves, cougars, etc.) that are
unable to find other food and are nearly starving will consider eating
a foul-smelling human.
> If a human were to wear a large
> amount of thick clothing, this
> would only leave part of the
> body available to to produce
> vitamin D from sunlight, disposing
> the wearer to possibly become more
> susceptible to rickets over time.
Duh!! Even humans accustomed to northern climes are likely to go nude
in the summer. They only dress against the cold when it *IS* cold.
> The question exists, with regard
> to how long, that might have presented
> an additional selection pressure upon
> humans in northern climates, and what
> effects that might have had
> upon human physiology among its
> different variants.
"Variants?" Do you mean "populations?" 25,000 years is only from 1000
to 2000 generations. Although this is more than enough to produce
changes in a population when deliberately selective breeding is
involved, it seems scarcely enough to produce a notable change in the
physiology of a species when the stochastic effects of 'natural'
selection are the only effective pressures - unless of course some
punctuated evolution as selective pressure on a single trait (such as
susceptibility to Yersina becteria) becomes predominant.
> How far
> back did clothing go, within
> the archaeological and
> paleontological record, as
> we now know it?
The earliest evidence (so far) for tools specifically used to make
clothing (i.e. needles) is Upper Paleolithic - about 25,000 years ago
(France):
http://anthro.palomar.edu/homo2/sapiens_culture.htm
The earliest fossil rag heap dates to 22,000 years ago (Russia).
This is substantially after the first appearance of Cro-Magnon
('modern') Man.
Tom Davidson
Richmond, VA
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