Re: Sweating hominids

Marc Verhaegen wrote:

> The patas monkey example (most-sweating non-human primate AFAWK) suggests
> that nakedness has not much to do with sweating.

This is a matter of physics. I already explained the patas
case. Nakedness is also good way to get rid of parasites.

Andrew Nowicki wrote:

> seem to be an oxymoron for three reasons: 1. Early hominids lived in a
> mosaic habitat close to wet habitats, usually a gallery forest surrounded
> by dry bushland.

Marc Verhaegen wrote:

> This is about apiths. No indication they were naked or not.

According to the The New York Times article that I
quoted in this thread, hominids became naked long
before they wore clothes. Nakedness is older than
1.2 million years. The first clothes were worn between
42,000 and 72,000 years ago -- about the same time
the first humans migrated from Africa. We do not
know if the apiths were naked and if they sweated,
but we know that their postcranial anatomy was similar
to our anatomy. Look at the gastrocnemius muscles
bulging in our calves. They are so massive that they
severely impede our ability to run. No other animal
has so prominent gastrocnemius muscles. It is obvious
that these massive gastrocnemius muscles were used to
help us haul heavy loads. When you combine the facts:
nakedness, huge gastrocnemius muscles, sweating, and
dexterous hands -- they fit like pieces of a puzzle.
The apiths sweated because they hauled heavy loads.

Andrew Nowicki wrote:

> How did they protect themselves from mosquitoes,
> biting flies, and predators?

Marc Verhaegen wrote:

> How do apes?

Apes have fur.
We do not know if the apiths had fur,
but their ability to walk enabled them
to walk away from the mosquito habitat
every evening. I believe that they slept
in dry, mosquito free places.

Andrew Nowicki wrote:

> Human sweat is made of water, salt, and about 350 different aromatic
> compounds which attract mosquitoes, biting flies, and predators. The naked
> human skin is extremely vulnerable to the biting insects. (Caribous have
> fur and yet they loose large amounts of blood to mosquitoes.)

Marc Verhaegen wrote:

> This is no problem if our furless ancestors were littoral
> http://www.onelist.com/community/AAT .

Mosquito larvae breed in lakes!

Seas, including tropical seas, are much colder than hominid
body, so they cool naked hominids efficiently. Mosquito
larvae do not breed in the seas, and they do not breed in
running water. A seaside devoid of lakes is relatively free
of mosquitoes. This really means dry or semi-dry seaside,
which is more suitable for bipedal creatures than for
arboreal monkeys. The only problem with this habitat is
that is was very small part of Africa. Similar habitat
(dry, salty, mosquito free area close to aquatic, food
rich habitat) existed on land and made up much larger area
of Africa.

It did not make sense for the apiths to spent all the
time in the water because they would get hypothermia.
It did not make sense to spend all the time in the baking
heat of dry bushland, because they would get heat stroke.
It did not make sense to live in a forest, because they
were more bipedal than arboreal. The best strategy for
the apiths was to sleep in a dry, mosquito free place,
walk in the morning to aquatic, food rich habitat, spend
the hot afternoon in the cool water, and return to the
dry, mosquito free place in the evening.

Note that some dogs like to take a swim on a hot
summer day, but they shake off the moisture as soon
as they are out of the water. Apparently the wet
fur is too cold for them. This raises the question:
was fur beneficial for the semi-aquatic apith
thermoregulation? Was fur better than subcutaneous
fat? Our nakedness suggests that overheating was
bigger problem for hominids than hypothermia. The
aboriginal population of Tasmania and Tierra del
Fuego did not use clothes. The aboriginal Tasmanians
did not built houses, only windbreaks, and yet they
survived occasional snow storms.
.

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