melanism


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melanosis

 [mel″ah-no´sis]
1. disordered melanin production, with darkening of the skin; called also melanism.
2. a disorder of pigment metabolism.
melanosis co´li brown-black discoloration of the mucosa of the colon.
melanosis i´ridis (melanosis of the iris) abnormal pigmentation of the iris by infiltration of melanoblasts.

mel·a·nism

(mel'ă-nizm),
Unusually marked, diffuse, melanin pigmentation of body hair and skin (usually not affecting the iris).
See also: melanosis.

melanism

(mĕl′ə-nĭz′əm)
n.
1. See melanosis.
2. Dark coloration of the skin, hair, fur, or feathers because of a high concentration of melanin.

mel′a·nis′tic adj.

mel·a·nism

(mel'ă-nizm)
Unusually marked, diffuse melanin pigmentation of body hair and skin (usually not affecting the iris).
See also: melanosis

melanism

a condition in which excessive production of MELANIN produces unusual dark colour or blackness in scales, skin or plumage. see INDUSTRIAL MELANISM.
References in periodicals archive ?
1946: The role of natural selection in distribution and dynamics of melanism in common hamster (Cricetus cricetus L.).
Industrial and non-industrial melanism in the peppered moth Biston betularia (L.).
The back-wingtip score was doubled because plumage melanism is considered the best way to visually distinguish hybrids from pure birds (Bell 1996).
Sargent (1985) suggested that some melanic moths may be adapted to exploit white backgrounds that are variegated with black, rather than the uniformly dark backgrounds suggested by the traditional explanation of industrial melanism (Kettlewell 1958a).
She also considers the reasons 20th century race researchers placed Asians at the summit of the intelligence racial hierarchy, describes the equally pseudoscientific (if far less celebrated) response of "melanism" researchers who ascribe superior qualities to those with greater melanin, and presents a new way of thinking about intelligence that holistically includes those qualities that race and intelligence researchers tend to ignore.
Ecology becomes central in the second and longest chapter, "A Green Machine," in which a cryptic discussion of the concept of an ecosystem precedes a treatment of standard ecological topics, including adaptation, industrial melanism, the Galapagos finches, niches, and food webs.
Insect melanism has long been a case study in evolutionary biology, providing some of the most conspicuous examples of natural selection (Kettlewell, 1973), genetic regulation (Wittkopp et al., 2002b) and pleiotropic effects (Wittkopp & Beldade, 2009).
This single supergene also appears important in melanism in other species, including moths.
Thus, while thermal melanism may be important for warming the body in some terrestrial organisms (King-solver, 1996; Clusella-Trullas et al, 2007), the importance to gastropods in intertidal systems is less clear.
Insularity and the evolution of melanism, sexual dichromaticsm and body size in the worldwide-distributed barn owl.