Why is that? As stated there is no explanation as to why mankind is hairless, but there are some speculations. The most widely held theory about mankind’s evolution is that they “are descended from apes which moved out of the forest onto the grassland of the open Savannah” (Morgan). Naked mammals are known to live in only two places: a subterranean one or a wet one. A speculation is that humans became hairless to keep from overheating in the Savannah, but no other mammal does this. A covering of hair would defend the animal against the heat of the sun; this is why even in the hottest deserts, the desert-dwelling camel keeps its fur. Another speculation is it is to facilitate sweat-cooling, but many other species resort to sweat-cooling without losing their …show more content…
For example, humans “have a different way of sweating from other animals, using different skin glands. It is very wasteful of the body’s essential resources of water and salt” (Morgan). Humans often mate face-to-face, the reason being the mode of “locomotion in which the spine and hind legs are in a straight line, and that affects the position of the sex organs” (Morgan). The only other animals that mate like humans are aquatic mammals, not the primates that humans are linked with. Another difference is the brain size; this would be an advantage to early man, and to chimpanzees, but what would force them to acquire a larger brain? Scientists explain this brain growth by saying that mankind’s ancestors had an abundant source of food with an adequate supply of omega-3 fatty acid, but that acid is mainly found in the sea, not in forests. Humans have million of sebaceous glands which disperse oil over their head, face, and torso. The chimpanzee’s sebaceous glands are said to be vestigial, whereas the humans are described as enormous. No one can quite explain the purpose of sebaceous glands, the only known reason is waterproofing of the skin or