Genetic mutation |
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Genetic mutations are irreversible changes in the DNA of cells, which are in some sense anomalous or irregular. Such changes are made deliberately in genetic engineering, but they can also occur naturally (e.g. through defective processes at cell level). They can be harmful, beneficial, or have no significant effect on the organism. Germ line mutations, which occur in reproductive cells or their precursors, can be inherited. Somatic mutations cannot. The former make evolution possible. Natural selection removes less favourable (deleterious) germ line mutations from the gene pool and allows more favourable (beneficial) ones to accumulate. In this limited sense we are all mutants. |
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Breeding has changed the exterior of hens (Jungle Fowl). Photo: Anette Wichman |
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Breeding has changed the exterior of hens (White Leghorn ). Photo: Anette Wichman |
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