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ON THE PERSISTENCE AND PERVASIVENESS OF A NEW MUTATION
Author(s) -
GarciaDorado Aurora,
Caballero Armando,
Crow James F.
Publication year - 2003
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.0014-3820.2003.tb01507.x
Subject(s) - biology , heterozygote advantage , fixation (population genetics) , population , genetics , persistence (discontinuity) , mutation , allele , gene , demography , geotechnical engineering , sociology , engineering
It has frequently been assumed that the persistence of a deleterious mutation (the average number of generations before its loss) and its pervasiveness (the average number of individuals carrying the gene before its loss) are equal. This is true for a particular simple, widely used infinite model, but this agreement is not general. If hs > 1/(4 N e ), where hs is the selective disadvantage of mutant heterozygotes and N e is the effective population number, the contribution of homozygous mutants can be neglected and the simple approximate formula 1/ hs gives the mean pervasiveness. But the expected persistence is usually much smaller, 2(log e (1/2 hs ) + 1— y) where y = 0.5772. For neutral mutations, the total number of heterozygotes until fixation or loss is often the quantity of interest, and its expected value is 2N e , with remarkable generality for various population structures. In contrast, the number of generations until fixation or loss, 2(N e / N) (1 + log e 2 N ), is much smaller than the total number of heterozygotes. In general the number of generations is less than the number of individuals.