Gene Duplication

Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene; it may occur as an error in homologous recombination, a retrotransposition event, or duplication of an entire chromosome. The second copy of the gene is often free from selective pressure — that is, mutations of it have no deleterious effects to its host organism. Thus it accumulates mutations faster than a functional single-copy gene, over generations of organisms.

A duplication is the opposite of a deletion. Duplications arise from an event termed unequal crossing-over that occurs during meiosis between misaligned homologous chromosomes. The chance of this happening is a function of the degree of sharing of repetitive elements between two chromosomes. The product of this recombination are a duplication at the site of the exchange and a reciprocal deletion.

Read more about Gene Duplication:  Gene Duplication As An Evolutionary Event, Gene Duplication As Amplification

Famous quotes containing the word duplication:

    A creative writer must study carefully the works of his rivals, including the Almighty. He must possess the inborn capacity not only of recombining but of re-creating the given world. In order to do this adequately, avoiding duplication of labor, the artist should know the given world.
    Vladimir Nabokov (1899–1977)