Natural Selection for an Intermediate Optimum

Latter, B. D. H.

doi:10.1071/bi9600030

Cited by 73 publications

(51 citation statements)

References 5 publications

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“…the equilibrium genetic variance is independent of the effects of mutants on the trait, but depends only on the total number occurring per generation. This result of Turelli with a 'House of Cards' approximation (Kingman, 1978) was obtained earlier for a two-allele model by Latter (1960) and Bulmer (1972), and a similar answer has been subsequently obtained for a five-allele model by Slatkin (1987). Burger (1986, see also Burger, Wagner & Stettinger, 1988 has generalized the analysis of the KL continuum of alleles model, and shown that Turelli's 'House of Cards' result is a very good approximation for the KL model over a very wide range of parameters.…”

Section: Grh52mentioning

confidence: 59%

“…We have concentrated on a model where the mutation rate is sufficiently low or the population size sufficiently small that two alleles segregate at each locus. The consequences of such a model with infinite population size have been investigated previously (Latter, 1960;Bulmer, 1972) and an important conclusion was that the equilibrium genetic variance, V g , is essentially independent of the effects of mutants on the trait, but depends only on the number of new mutants per generation. As a consequence of its independence of the effects of mutants, in an infinite population V g is independent of the shape of the mutational distribution.…”

Section: Discussionmentioning

confidence: 98%

“…As JV becomes infinite, (10) reduces to (11) the well-known result of Latter (1960), Bulmer (1972) and Turelli (1984). (An alternative derivation is given by Hill & Keightley (1988).)…”

Section: Methodsmentioning

confidence: 93%

“…Insight into the behaviour of a new mutant allele can be gained from extending Latter's (1960) two-allele treatment. The variance contributed by a mutant allele is given by V g = a 2 q{\ -q)/2.…”

Section: Methodsmentioning

confidence: 99%

“…In this respect it is similar to the models of Latter (1960) and Bulmer (1972) and to Turelli's (1984) 'House of Cards' approximation (henceforth referred to as the LBT models), with the additional assumption that mutant effects are randomly sampled.…”

Section: (Ii) Multi-allele Modelmentioning

confidence: 97%

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Quantitative genetic variability maintained by mutation-stabilizing selection balance in finite populations

Keightley

Hill

1988

Genet. Res.

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Models of variability in quantitative traits maintained by a balance between mutation and stabilizing selection are investigated. The effects of mutant alleles are assumed to be additive and to be randomly sampled from a stationary distribution. With a two-allele model the equilibrium genetic variance in an infinite population is independent of the distribution of mutant effects, and dependent only on the total number of mutants appearing per generation. In a finite population, however, both the shape and standard deviation of the distribution of mutant effects are important. The equilibrium variance is lower when most of the mutational variance is contributed by few genes of large effect. Genes of small effect can eventually contribute substantially to the variance with increasing population size (N). The equilibrium variance can be higher in a finite than an infinite population since near-neutral alleles can drift to intermediate frequencies where selection is weakest. Linkage leads to a reduction in the maintained variance which is small unless linkage is very tight and selection is strong, but the reduction becomes greater with increasing N since more mutants segregate. A multi-allele model is simulated and it is concluded that the two-allele model gives a good approximation of its behaviour. It is argued that the total number of loci capable of influencing most quantitative traits is large, and that the distribution of mutant effects is highly leptokurtic with the effects of most mutants very small, and such mutants are important in contributing to the maintained variance since selection against them is slight. The weakness of the simple optimum model is discussed in relation to the likely consequences of pleiotropy.

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Section: Grh52mentioning

confidence: 59%

Section: Discussionmentioning

confidence: 98%

“…As JV becomes infinite, (10) reduces to (11) the well-known result of Latter (1960), Bulmer (1972) and Turelli (1984). (An alternative derivation is given by Hill & Keightley (1988).)…”

Section: Methodsmentioning

confidence: 93%

Section: Methodsmentioning

confidence: 99%