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Title: Study of mathematical models of mutation and selection in multi-locus systems. Annual progress report, October 1, 1980-September 30, 1981

Abstract

During the past year, research has been devoted to two related studies of two-locus systems under natural selection and one on selection in haplo-diploid organisms. The principal results are: (1) Numerical studies were made of 2 locus selection models with asymmetric fitnesses. These were created by perturbing the fitness matrices of symmetric models whose results are known analytically. A complete classification of solved models has been made and all perturbations of these have been undertaken. The result is that all models lead to three classes of equilibrium structure. All are characterized by multiple equilbria with small linkage disequilibria under loose linkage and high complementarity equilibria under tight linkage. In some cases there is gene fixation at intermediate linkage. (2) It has been shown that selection may favor more recombination, contrary to the usual expectation, if multiple locus polymorphisms are maintained by a mechanism other than marginal overdominance. This may be the result of mutation-selection balance or frequency-dependent selection. (3) In a haplo-diploid system in which diploid males are lethal (as in bees and braconid wasps) the number of sex alleles that can be maintained depends both on breeding size and the number of colonies. Simulations show that the steady numbermore » is sensitive to the number of colonies but insensitive to the number of matings. Thirty-five to fifty colonies are sufficient to maintain very large numbers of sex alleles.« less

Authors:
Publication Date:
Research Org.:
Harvard Univ., Cambridge, MA (USA). Museum of Comparative Zoology
Sponsoring Org.:
USDOE
OSTI Identifier:
6503114
Report Number(s):
DOE/EV/02472-T1; COO-2472-07
DOE Contract Number:
AS02-76EV02472
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; BIOLOGICAL EVOLUTION; MATHEMATICAL MODELS; BIOLOGICAL EFFECTS; GENETIC VARIABILITY; POPULATION DYNAMICS; ANIMALS; ARTHROPODS; BIOLOGICAL VARIABILITY; INVERTEBRATES; 550400* - Genetics

Citation Formats

Lewontin, R C. Study of mathematical models of mutation and selection in multi-locus systems. Annual progress report, October 1, 1980-September 30, 1981. United States: N. p., 1981. Web. doi:10.2172/6503114.
Lewontin, R C. Study of mathematical models of mutation and selection in multi-locus systems. Annual progress report, October 1, 1980-September 30, 1981. United States. doi:10.2172/6503114.
Lewontin, R C. Thu . "Study of mathematical models of mutation and selection in multi-locus systems. Annual progress report, October 1, 1980-September 30, 1981". United States. doi:10.2172/6503114. https://www.osti.gov/servlets/purl/6503114.
@article{osti_6503114,
title = {Study of mathematical models of mutation and selection in multi-locus systems. Annual progress report, October 1, 1980-September 30, 1981},
author = {Lewontin, R C},
abstractNote = {During the past year, research has been devoted to two related studies of two-locus systems under natural selection and one on selection in haplo-diploid organisms. The principal results are: (1) Numerical studies were made of 2 locus selection models with asymmetric fitnesses. These were created by perturbing the fitness matrices of symmetric models whose results are known analytically. A complete classification of solved models has been made and all perturbations of these have been undertaken. The result is that all models lead to three classes of equilibrium structure. All are characterized by multiple equilbria with small linkage disequilibria under loose linkage and high complementarity equilibria under tight linkage. In some cases there is gene fixation at intermediate linkage. (2) It has been shown that selection may favor more recombination, contrary to the usual expectation, if multiple locus polymorphisms are maintained by a mechanism other than marginal overdominance. This may be the result of mutation-selection balance or frequency-dependent selection. (3) In a haplo-diploid system in which diploid males are lethal (as in bees and braconid wasps) the number of sex alleles that can be maintained depends both on breeding size and the number of colonies. Simulations show that the steady number is sensitive to the number of colonies but insensitive to the number of matings. Thirty-five to fifty colonies are sufficient to maintain very large numbers of sex alleles.},
doi = {10.2172/6503114},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1981},
month = {Thu Jan 01 00:00:00 EST 1981}
}

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