Any of a diverse group of polymers, derived from phenolic precursors, such as the amino acid tyrosine, that cause pigmentation of eyes, skin, and hair in vertebrates, and of various structures in plants and fungi. Vertebrate melanins are produced by specialized epidermal cells called melanophores (or melanocytes); their dispersion in these cells is controlled by melanocyte-stimulating hormone and melatonin. The photo-absorptive properties of melanins are important in protecting the skin against damage by UV light; they also scavenge harmful free radicals, and their pigmentation provides camouflage for many animals. Invertebrates, fungi, and microorganisms also produce melanin pigments: the ‘ink’ of the octopus and squid is a notable example. Hereditary albinism is caused by the absence of the enzyme tyrosinase, which is necessary for melanin production.