Horizon Part Two

Hope you all passed a peaceful night, despite nakedness or woolly mammoths. I left you yesterday, still unable to prove for certain the link between sweating and hairlessness. To continue...

A study of the Patas monkey, in Kenya, has excited anthropologists because of similarities to its many attributes similar to our ancestors. Their body proportions are similar, with very long legs that enable them to range over vast distances of the open country on which they live, and, unlike other primates, they sweat copiously. It echoes steps in human evolution.

The monkey's fur is less dense, with finer hairs, but one simple fact prevents them from following the course of our early ancestor; they are not bi-pedal. Walking on all fours, their furry backs continue to give them protection from the sun on the open savannah. Upright humans had no need of furry backs, as in an upright position, the only major area exposed to the sun, was the top of their heads - hence the retention of hair on the scalp.

Another major impact of increased sweat production and cooling ability on the development of humans, was on the brain. One brain produces about 20kw of heat; a rise in temperature of 2-4 degrees can prove fatal, so our improved cooling system would have stopped this happening, and ensured our brains had the chance to develop further, unscathed.

But the one thing impossible to discover, was how far back this loss of hair first occurred. Skeletal remains aplenty have been found, but never skin. Then an unusual link was discovered: lice.
By research into the genetic evolution of lice, significant dates have been pinpointed.
Lice were the earliest common parasite to all furry mammals. By sequencing DNA extracted from lice, interesting facts emerged when it was correlated to evolutionary changes. Human head lice DNA sequence went back earlier than three million years, so it is safe to assume loss of hair was much earlier than at first thought.

Lice can only live once they have a suitable environment to inhabit. Each primate had their own species of lice, so scientists were able to pinpoint 3 million years ago as the date when there were changes in human body hair enough to support the crab louse. It needed a courser, more widely spaced hair for its habitat. Similarly for our third kind, the clothing louse. There had to have been clothing to supply it with its one and only habitat, so its appearance about half a million years ago, gives us the rough date at which our ancestors began dressing.

With the emergence of garments, come another set of questions. How does sexual attraction work, when all parts of the body naturally associated with it, are covered by clothes?

I think I will close the wardrobe doors now, and leave the speculations until tomorrow. My brain has had enough for one post, even if yours hasn't...