According to evolutionary biologists, humans are so special not because they have so much hair but because they have so little. The story of how our body altered from being covered from head-to-toe to having hair in some random places has to do with climate change. Then, about three million years ago, a global cooling period dried out the regions of Central Africa where those early family members were living.\n
The fur that had once kept them warm became a nuisance, since their environment is not what it used to be. Grasslands succeded to forests and early hunters spent long hours walking or running across the landscape searching for food. From natural selection's point of view, the ability to sweat and quickly dissipate heat became daily routine. As a result,humans lost their hair.