Albinism in humans all vertebrates, including humans. It is due to absence or defect of tyrosinase, a copper-containing enzyme involved in the production of melanin. It is the opposite of melanism. Unlike humans, other animals have multiple pigments and for these, albinism is considered to be a hereditary condition characterised by the absence of melanin in particular, in the eyes, skin, hair, scales, feathers or cuticle. While an organism with complete absence of melanin is called an albino, an organism with only a diminished amount of melanin is described as leucistic or albinoid. The term is from the Latin "albus", "white". There are
Reciprocal altruism in humans Reciprocal altruism in humans Reciprocal altruism in humans refers to an individual behavior that gives benefit conditionally upon receiving a returned benefit, which draws on the economic concept – ″gains in trade″. Human reciprocal altruism would include the following behaviors (but is not limited to): helping patients, the wounded, and the others when they are in crisis; sharing food, implement, knowledge. The concept of ″altruism″ was firstly coined by the French philosopher Auguete Comte in the 19th century, which was derived from the French word ″"altruisme"″. Comte believed that ″altruism″ is a moral doctrine, which is the opposite of egoism,