Abstract
Weak selection in a monoecious population is studied in two multiallelic panmictic models. In the first, a single locus is considered with continuous time and age-independent fertilities and mortalities. If the fertilities of the various matings and the genotypic mortalities may be expressed with an error at most of the second order in s (i.e., O(s 2)), where s is the intensity of selection, as sums of terms corresponding to the different genotypes and alleles, respectively, then after several generations the deviations from Hardy-Weinberg proportions are of O(s2). In the second model, two loci are treated with discrete nonoverlapping generations. It is shown that if the epistatic parameters are of O(s2), then after several generations the linkage disequilibria are reduced to O(s2). Assuming only weak selection, it is proved that in both models, after several generations, the total change in mean fitness is generally positive. It is likely that the exclusion of the initial period is usually unnecessary in natural populations. Exceptions are discussed.
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Selected References
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- Karlin S., Feldman M. W. Linkage and selection: two locus symmetric viability model. Theor Popul Biol. 1970 May;1(1):39–71. doi: 10.1016/0040-5809(70)90041-9. [DOI] [PubMed] [Google Scholar]
- Kimura M. Attainment of Quasi Linkage Equilibrium When Gene Frequencies Are Changing by Natural Selection. Genetics. 1965 Nov;52(5):875–890. doi: 10.1093/genetics/52.5.875. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Langley C. H., Tobari Y. N., Kojima K. I. Linkage disequilibrium in natural populations of Drosophila melanogaster. Genetics. 1974 Nov;78(3):921–936. doi: 10.1093/genetics/78.3.921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li W. H., Nei M. Stable linkage disequilibrium without epistasis in subdivided populations. Theor Popul Biol. 1974 Oct;6(2):173–183. doi: 10.1016/0040-5809(74)90022-7. [DOI] [PubMed] [Google Scholar]
- MORAN P. A. ON THE NONEXISTENCE OF ADAPTIVE TOPOGRAPHIES. Ann Hum Genet. 1964 Jun;27:383–393. doi: 10.1111/j.1469-1809.1963.tb01535.x. [DOI] [PubMed] [Google Scholar]