The story of how we lost our fur is actually pretty interesting.
We used to have fur, but after we moved out of the jungle and onto the sunny savanna, it got hotter. To expose as little as possible of our body to the sun's rays, we started walking upright. To improve the cooling of the body, we shed our fur which then allowed us to sweat from the skin's surface. Being able to cool off through sweating allowed us to move faster and for longer periods of time, improving our ability to hunt stuff.
To protect our hairless bodies from the sun's rays (in addition to causing sunburns, they break down folic acid which lowers sperm quality), we developed a darker skin pigmentation. As we moved up north into colder climates, we were less exposed to the sun, which meant less D-vitamin absorbed. When we started raising and eating livestock, our intake of D-vitamin was lowered even more. To counter it, we lost the darker skin pigmentation.
After we invented beer and started drinking it a lot, we developed body hair again
Okay, the last one is my own theory. I don't know why some people (as in: populations) in warmer climates are still hairy. Scientists speculate that it's a balance between protecting against parasites and protecting against the cold.
Edited, Mar 26th 2013 3:24pm by Mazra
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