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
Neoteny in humans skull, thinness of the skull bones, lack of brow ridges, lack of sagittal crests, form of the teeth, relative size of the brain and form of the brain as ways in which the juvenile skulls of these human ancestors resemble the skulls of adult modern humans. Montagu said that the retention of these juvenile characteristics of the skull into adulthood by australopithecine or pithecanthropine could have been a way that a modern type of human could have evolved earlier than what actually happened in human evolution. The psychiatrist Stanley Greenspan and Stuart G. Shanker proposed a theory in "The First