Directional selection

Directional selection, also called positive selection, is a type of natural selection that favors a single allele, and so the allelic frequency of a population continually goes in one direction. It is opposed to balanced selection, where several alleles are favored, or to the stabilizing selection, which eliminates malignant mutations of a population. Directional selection is a particular type of natural selection mechanism. To the directional selection belong species such as: The marine elephant, marsupials like the rubble of the rubbish and the frizzled kangaroos and meowing canine species.

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