not result in damaged or pink eyes . Leucistic animals appear much more often in the wild than albino ones . White squirrels are relatively common and are simply a version of the eastern grey squirrel . Clustered in specific areas of the eastern part of the United States , “ white ” squirrels have become quite the tourist attraction in some towns , including Brevard , North Carolina , a familiar summer retreat for South Carolinians .
Not all leucistic animals , birds , and insects are entirely white . Very often , they have patchy coloration of the skin , hair , feathers , and scales . One of the conditions considered a type of leucism is piebaldism . Even though this genetic abnormality is statistically rare , we see many piebald deer on Kiawah . Unfortunately , the same recessive gene that causes piebaldism has a variety of other defects attached to it . Piebald deer may have unusually short legs and an arching spine ( scoliosis ). They can also have internal organ deformities . Both fawns in a set of twins may have piebaldism , or only one twin may have it . Piebaldism often occurs in degrees so that only a few patches appear on a deer ’ s side or hind leg . If the deformities are not severe , piebald deer reach adulthood .
Melanism The term melanism refers to the increased development of the dark-colored pigment called melanin in the skin or hair . Melanistic animals are very dark or completely black , such as a black panther . Just as white squirrels are noticeable in areas
of the country , so are black squirrels , which are seen mainly in northern parts of the United States . They , like the white squirrel , are a subgroup of the eastern gray squirrel .
Erythrism Erythrism is another genetic condition that causes a reddish pigmentation of an animal ’ s outward appearance . Affected creatures may appear completely orange or pink or simply have patches of discoloration on the body .
Chimera Chimera refers to an animal or bird that has two distinct appearances on one body . For example , one side of a parakeet may be blue while the other side is green . This very unusual condition happens when two fertilized eggs merge into one .
Other than being interesting to observe , why are mutations in animal coloration important to scientists ? Researchers have long known piebaldism as a genetic condition , but now they know precisely which gene causes it and how that gene plays a part in the cell division of the developing embryo . Scientists have tracked the cells as they multiply and move either too slowly or too quickly from the back of the embryo to the front . Irregular migration of the cells responsible for pigment formation is random and results in unusual coloration . By mapping cell movement , biologists believe they can develop a mathematical model to understand various serious conditions that cause debilitating illnesses in humans . NK
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