How to Compare Animal & Human Hair

Growth

• Human hair grows and sheds continuously. Its length and style are maintained through regular haircuts. Most animal hair, in contrast, in self-limiting and sheds seasonally. Its length is regulated biologically, meaning that it grows to a specific length, determined genetically, and then ceases to grow.

Indentification

• According to Web MD, strands of human hair carry chemical information which is specific to an indivudual, and which can be used for indentification. Animal hair, however, is indistinct, meaning that hair from two different animals of the same breed have no distinct difference, and cannot be used to identify an individual. In either case, according to the FBI, genetic information can only be accessed if the hair follicle is still attached to the root of the hair.

Layers

• Human hairs are all the same type of strand. Many animals, however, have two distinct layers of fur made up of hairs with different properties. The top layer is long and coarse, and the undercoat is short and fine. This two-layer coat type helps animal coats repel water, and protects the skin from extreme temperatures.

Specialization

• Many animals have specialized hair types that serve specific biological functions. For example, whiskers are a specialized hair which are connected to the nervous system, and which receives sensory information. They affect an animal's balance, sense of direction and depth perception. Similarly, porcupines and hedgehogs have modified hair strands called quills or spines, which act as defense mechanisms.