In the English language, Black sheep is an idiom used to describe an odd or disreputable member of a group, especially within one's family. The term has typically been given negative implications, implying waywardness.
white sheep
It derived from the atypical and unwanted presence of black individuals in herds of white sheep. The idiom is also found in other languages, e.g., French, Serbian, Bulgarian, Hebrew, Portuguese, Turkish, Dutch, Spanish, Czech and Polish. There is an expression "white crow" ("белая ворона", "belaya vorona") in Russian.
sheep pictures
The term originated from the occasional black sheep which are born into a herd of white sheep due to a genetic process of recessive traits. Black wool was considered commercially undesirable because it could not be dyed.
Sheep
In 18th and 19th century England, the black color of the sheep was seen as the mark of the devil.In modern usage, the expression has lost some of its negative connotations, and the term is usually given to the member of a group who has certain characteristics or lack thereof deemed undesirable by that group.
black and white sheep
In sheep, whiteness is not albinism but a dominant gene that actively switches color production off. As a result, sheep blackness is recessive, and if a white ram and a white ewe are parents of a black lamb, both must be heterozygous for black, and then there is a 25% chance that the lamb will be black. A recent study done by the Agricultural University of Norway, and the Vollum Institute of the Oregon Health Sciences University believe the black color is created by an allele E D at the extension locus.