The biggest overt difference that one notices when comparing nonhuman primates to human primates is the loss of body hair in the modern human, to the extent even, that humans have been described as the “naked ape” in many contexts. The primates classified as old world apes that are closest in relation to humans are the Bonobos and Chimpanzees. Looking specifically at the Chimpanzees, we can compare and contrast the properties of the skin and hair between them and humans to get an idea of the evolutionary pressures that may have been in place. Notably, there are many different properties of the skin in the nonhuman and human primates. The dermis, or skin layer, contains various structures like nerve ending, sweat glands and hair follicles among other systems. Adrienne L. Zihlman and Debra A. Bolter state in the article “Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution” that chimpanzees, like humans, have eccrine sweat glands located on the body as well as limbs. While all primates have apocrine sweat glands and these eccrine glands located on their palms and the soles of their feet, the body and limb location for chimpanzee and humans are unique to those species. However, unlike the eccrine sweat glands in humans, chimpanzee glands do not actually respond to a hot environment …show more content…
Regarding this, the studies conducted by Schultz counted long dark terminal hairs and not the fine transparent vellus hairs. With the number of follicles in the skin being determined during the formation of the fetus, the number of hairs on the mammal is determined at birth. When the animal grows the larger ones gain more spacing between the hair follicles and the density decreases with the increased size (Sandel,