Hair vs Fur
Ever wondered why people refer to hair on the bodies of their dogs and cats as furs and switch to hair when they talk about their own? There must be some difference between hair on human body and hair on the body of primates as there would not have been two words for the same thing. Surprisingly, animals and mammals that do not have fur are called hairless and not furless. For example, whale is a mammal that is hairless. And apes that are closest to us humans are very hairy while we have hair mostly on our head and a small part of our face. Let us find out the difference between hair and fur.
Scientists say that the chemical composition of both hair and fur is same that is they are both made of protein (keratin). The difference, if any has to do with our usage of the word. Fur is reserved for hair on the body of cats and dogs (and other primates). Scientist have proposed a definition to solve this conundrum which says that fur stops growing after a certain length while hair keeps growing. While this satisfies me for facial hair (men) and hair on the head (both men and women), what would this definition say about hair on hands and legs that do not keep on growing though they are not cut periodically (at least by men). So are they fur and not hair? Biologically, this definition does not hold water. But yes, hair is a characteristic shared by mammals and the difference lies in the pattern of growth in different mammals. Whereas, there are some like whales that are hairless, there are some like cats, dogs and apes that are most hairy. It is human beings where there is only certain areas of body that have hair (like head in males and females) and face (only males).
Hair is classified into primary and secondary. Primary hair is longer and thicker and serves as a protection against insects and twigs. Secondary hair repels water and regulates body temperature. It is this hair that forms a fluffy coat known as fur in mammals. Polar bear has to live in freezing conditions and it is the thick fur that helps it in insulating against extreme weather conditions. There is no doubt that warm blooded animals have to expend energy to produce internal heat and it does not make sense to lose it through their skin. Hairs prove to be great insulators and they developed in the process of evolution for conservation of body temperatures of mammals. Hairs also prove to be a mechanism to prevent injuries. If you have seen the mane of a lion, you know what I mean. It is a great coat of fur that ostensibly does not serve any purpose. But it is this hair that saves a lion from the attack of other carnivores on its neck. Hairs also serve the purpose of carrying the scent inside the body to outside. The reduced growth of hair on body part of humans is a result of our reduced need of hair during the course of evolution.
Difference between Hair and Fur
• Biologically or chemically, there is no difference between hair and fur and both are made of keratin
• There is a definition that says that hair continue to grow whereas fur grows to a pre set limit.
• Hair refers to hair on the body, head and face of human beings whereas fur is hair that is thick and in the form of coat on the body of mammals.
• Fur is mostly for warmth and body protection whereas hair in human beings serves very few important functions.
• Mammals shed fur annually whereas hair on human body is not shed.