| 词条 | Negative selection (natural selection) |
| 释义 |
In natural selection, negative selection[1] or purifying selection is the selective removal of alleles that are deleterious. This can result in stabilizing selection through the purging of deleterious genetic polymorphisms that arise through random mutations.[2][3] Purging of deleterious alleles can be achieved on the population genetics level, with as little as a single point mutation being the unit of selection. In such a case, carriers of the harmful point mutation have fewer offspring each generation, reducing the frequency of the mutation in the gene pool. In the case of strong negative selection on a locus, the purging of deleterious variants will result in the occasional removal of linked variation, producing a decrease in the level of variation surrounding the locus under selection. The incidental purging of non-deleterious alleles due to such spatial proximity to deleterious alleles is called background selection.[4] This effect increases with lower mutation rate but decreases with higher recombination rate.[5] Purifying selection can be split into purging by non-random mating and purging by genetic drift. Purging by genetic drift can remove primarily deeply recessive alleles, whereas natural selection can remove any type of deleterious alleles.[6] See also
References1. ^{{cite journal |last1=Loewe |first1=Laurence | name-list-format = vanc |year=2008 |title=Negative selection |journal=Nature Education |volume=1 |issue=1 |pages=59 |url=https://www.nature.com/scitable/topicpage/Negative-Selection-1136 }} {{MolecularEvolution}}{{genetics-stub}}2. ^{{cite journal | vauthors = Tien NS, Sabelis MW, Egas M | title = Inbreeding depression and purging in a haplodiploid: gender-related effects | journal = Heredity | volume = 114 | issue = 3 | pages = 327–32 | date = March 2015 | pmid = 25407077 | pmc = 4815584 | doi = 10.1038/hdy.2014.106 }} 3. ^{{cite journal | vauthors = Gulisija D, Crow JF | title = Inferring purging from pedigree data | journal = Evolution; International Journal of Organic Evolution | volume = 61 | issue = 5 | pages = 1043–51 | date = May 2007 | pmid = 17492959 | doi = 10.1111/j.1558-5646.2007.00088.x }} 4. ^{{cite journal | vauthors = Charlesworth B, Morgan MT, Charlesworth D | title = The effect of deleterious mutations on neutral molecular variation | journal = Genetics | volume = 134 | issue = 4 | pages = 1289–303 | date = August 1993 | pmid = 8375663 | pmc = 1205596 }} 5. ^{{cite journal | vauthors = Hudson RR, Kaplan NL | title = Deleterious background selection with recombination | journal = Genetics | volume = 141 | issue = 4 | pages = 1605–17 | date = December 1995 | pmid = 8601498 | pmc = 1206891 }} 6. ^{{cite journal | vauthors = Glémin S | title = How are deleterious mutations purged? Drift versus nonrandom mating | journal = Evolution; International Journal of Organic Evolution | volume = 57 | issue = 12 | pages = 2678–87 | date = December 2003 | pmid = 14761049 | doi = 10.1111/j.0014-3820.2003.tb01512.x }} 2 : Selection|Classical genetics |
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