Summary
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The genetic consequences of selection of intermediates or extremes for metric characters has been analysed- Selection of intermediates leads to fixation and selection of extremes (disassortative mating) will lead to a stable genetic situation with intermediate gene frequencies.
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The selection of intermediates is similar to the higher natural fitness of metric . intermediates often found in nature. The alternative model for the latter situation, in which the extremes hare a low fitness because they are homozygotes, was also analysed. It was found that several different phenomena could be interrelated on this model—the relationship of fitness to deviation both in the equilibrium population and after artificial selection, the decline in fitness after such selection and the rate of return to the equilibrium position when selection was suspended. The constant integrating these, called the homo-eostatic strength of the character, is related to the mean fitness of homozygotes compared to that of heterozygotes at the individual loci concerned.
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References
Falconer, D. S. (1953). Asymmetrical responses in selection experiments.Symp. Genetics of Population Structure, Pavia. pp. 16-41.
Falconer, D. S. &Pobertson, A. (1956). Selection for environmental variability of body size in. mice.Z. indukt. Abstamm.-u. VererbLehre.87, 385–391.
Haldane, J. B. S. (1927). A mathematical theory of natural and artificial selection. VII. Selection intensity as a function of mortality rate.Proc. Camb. Phil. Soc. 27, 131–6.
Haldane, J. B. S. (1953). The measurement of natural selection.Proc. IXth Int. Congr. Genet. part 1, pp. 480-7.
Lerner, I. M.(1950).Population Genetics and Animal Improvement. Pp.342. Cambridge: University Press.
Lerner, I. M. (1954).Genetic Homeostasis. Pp. 134. Edinburgh: Oliver and Boyd.
Moree, R. (1953). An. unexpected relation between negative assortative mating and gene frequency.Genetics,38, 677–8 (Abstract).
Wright, S. (1921). Systems of mating. III. Assortative mating based on somatic resemblance.Genetics,6, 143–61.
Wright, S. (1935). Evolution in populations in approximate equilibrium.J. Genet. 30, 257–66.
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Member of the Scientific Staff of the Agricultural Research Council.
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Robertson, A. The effect of selection against extreme deviants based on deviation or on homozygosis. J Genet 54, 236–248 (1956). https://doi.org/10.1007/BF02982779
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DOI: https://doi.org/10.1007/BF02982779