Showing papers on "Selection (genetic algorithm) published in 1973"
TL;DR: The number of comparisons required to select the i-th smallest of n numbers is shown to be at most a linear function of n by analysis of a new selection algorithm-PICK.
1,384 citations
TL;DR: Using data from human populations, this work has shown highly significant heterogeneity in F values for human polymorphic genes over the world, thus demonstrating that a significant fraction of human polymorphisms owe their current gene frequencies to the action of natural selection.
Abstract: The variation in gene frequency among populations or between generations within a population is a result of breeding structure and selection. But breeding structure should affect all loci and alleles in the same way. If there is significant heterogeneity between loci in their apparent inbreeding coefficients F=s(p) (2)/p(1-p), this heterogeneity may be taken as evidence for selection. We have given the statistical properties of F and shown how tests of heterogeneity can be made. Using data from human populations we have shown highly significant heterogeneity in F values for human polymorphic genes over the world, thus demonstrating that a significant fraction of human polymorphisms owe their current gene frequencies to the action of natural selection. We have also applied the method to temporal variation within a population for data on Dacus oleae and have found no significant evidence of selection.
1,216 citations
290 citations
TL;DR: The variation between the replicates was ascribed mainly to random drift, which may seriously influence the conclusions about the realized heritability and the asymmetry of response that would be drawn from a single experiment with the population size of one of these replicates.
Abstract: The variation in the response to selection was studied by replication of selected lines. A random-bred strain of mice was divided into six replicates. Two-way selection for 6-week weight was applied in an identical manner to each replicate, and each had an unselected control. Each line (6 large, 6 control, 6 small) was maintained by minimal inbreeding with 8 single-pair matings. The overall mean responses, both up and down, were linear and very regular for ten generations, with realized heritabilities of 40% upwards, 33% downwards and 37% for the divergence. The separate replicates, however, differed greatly in their realized heritabilities, with upward selection ranging from 25 to 46%, and downward selection from 16 to 50%. The theoretical prediction that, because of genetic drift, the standard error of a realized heritability is underestimated by the standard error of the regression of response on cumulated selection differential was borne out in this experiment. The empirical standard error, calculated from the observed variance between replicates, was more than twice as great as that of the regression. The empirical standard errors showed that the asymmetry between upward and downward responses was not significant. The variation between the replicates was ascribed mainly to random drift, which may seriously influence the conclusions about the realized heritability and the asymmetry of response that would be drawn from a single experiment with the population size of one of these replicates. After 23 generations of selection the large lines were approaching limits, and the limit appeared to be at the same level in all. The small lines showed an undiminished realized heritability after 23 generations, but the selection differentials were then so small that little progress was made. There was evidence of counter-acting natural selection. All aspects of productivity – proportion of fertile matings, litter size and weaning rate – declined in the control lines. The overall productivity of the large lines was a little below the controls, and that of the small lines was reduced to about half the level of the controls. The separate replicates differed from each other significantly in all the components of productivity.
214 citations
TL;DR: Seven methods for the selection of the most effective agents for the biological control of weeds are discussed and a scoring system proposed as a means of incorporating their best features.
Abstract: Little attention has been given to the selection of the most effective agents for the biological control of weeds. The consequence has been a needlessly high failure rate and cost. Seven methods for their selection are discussed and a scoring system proposed as a means of incorporating their best features.
184 citations
TL;DR: It is shown that migration from a more favorable regime to a less favorable regime is selected against and the ramifications for general modifier theory are discussed.
Abstract: Simple models for the genetic control of the tendency to migrate are considered. It is shown that migration from a more favorable regime to a less favorable regime is selected against. The ramifications for general modifier theory are discussed.
179 citations
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TL;DR: In this article, a new conditional probability model of fairness based on equal opportunity for potentially successful applicants is presented, which is an intuitively appealing and socially desirable model for use in many selection situations in employment and college admissions.
Abstract: Possible bias in selection procedures used for employment and college admissions is of crucial social and educational importance. However, there are many different definitions of what constitutes bias with each definition based on different values and with different implications for how selection should be accomplished. A number of these definitions of bias and their implications are examined, and a new conditional probability model of fairness based on equal opportunity for potentially successful applicants is presented. This conditional probability model is proposed as an intuitively appealing and socially desirable model for use in many selection situations in employment and college admissions.
176 citations
TL;DR: In this paper, the authors formulated the portfolio selection problem as a parametric quadratic programming problem and formulated the mean-variance assumption, which asserted that a portfolio is efficient if (and only if): (1) it has less variance than any other feasible portfolio with the same return and (2) it had more return than most feasible portfolio having the same variance.
Abstract: Almost two decades ago, Markowitz [12] formulated the portfolio selection problem as a parametric quadratic programming problem. The crux of his formulation was the mean-variance assumption which asserted that a portfolio is efficient if (and only if): (1) it has less variance than any other feasible portfolio with the same return and (2) it has more return than any other feasible portfolio with the same variance.
146 citations
TL;DR: In this paper, geometric programming is employed to optimize the constrained unit cost problem in turning, where the cutting power available from the machine tool and the permissible CLA value of surface roughness are used as the forced constraints in the primal program.
Abstract: The selection of economically optimal machining rate variables, i.e. cutting speed and feed rate, is of major importance in the field of metal cutting. In this paper, apart from the conventional methods used for optimization in machining economics, geometric programming, a relatively new non-linear programming technique, is employed to optimize the constrained unit cost problem in turning. The cutting power available from the machine tool and the permissible CLA value of surface roughness are used as the forced constraints in the primal programme. Initially, the primal and dual programmes are formulated. Furthermore, a numerical example is presented to illustrate the application of geometric programming which has been proved successful. It is pointed out that geometric programming may be also used for optimization of unit cost in machining processes other than turning under the assumption that the imposed restrictions, discussed in this paper, are valid.
135 citations
TL;DR: The heritabilities for number of plates and gill rakers are high, and so the values obtained for the increase in mean relative fitness show that natural selection is acting strongly on these traits.
Abstract: Selective predation and the intensity of selection acting upon the lateral plates of threespine sticklebacks
TL;DR: In this article, a probabilistic model of consumer purchase behavior for frequently purchased, low-cost items is presented. But, the model is based on the concept of maximum entropy and the only empirical data required are market shares; all other brand selection statistics, such as repeat and switch rates, are derived quantities.
Abstract: A probabilistic model of consumer purchase behavior for frequently purchased, low cost items. The concept of maximum entropy is used to specify the model. The only empirical data required are market shares; all other brand selection statistics, such as repeat and switch rates, are derived quantities.
TL;DR: This article found that repeated listening increases students' music discriminations, and repeated exposure to music during classroom contact was correlated with music selection in a non-music classroom setting, while repeated listening or familiarity was not associated with an influence on music selection.
Abstract: Many of the variables that influence music selecting behaviors of students are not amenable to influence by teachers.1 These nonschool variables include age, sex, socioeconomic status, and mass media exposure. However, one variable that may be manipulated by the teacher is repeated exposure to music during classroom contact. Much of the available evidence points to the importance of repeated listening or familiarity as an influence on music selection.2 When this evidence is related to learning theory, whether derived from laboratory research or from research in the nonmusic classroom, it seems that repeated listening increases students' music discriminations.
TL;DR: The process, well known to paleontologists and biogeographers, is responsible for the familiar patterns of dynastic succession of major groups such as ammonites, sharks, graptolites, and dinosaurs through geologic time.
Abstract: Selection can be said to operate at the group level and deserves to be called group selection, when it affects two or more members of a lineage group as a unit. Just above the level of the individual we can delimit various of these lineage groups: a set of sibs, parents, and their offspring, a close-knit tribe of families related by at least the degree of third cousin, and so on. If selection operates on any of the groups as a unit, the process is referred to as kin selection. At a higher level, an entire breeding population may be the unit, so that populations (i.e., demes) possessing different genotypes are diminished or extinguished differentially, in which case we speak of interdemic (or interpopulation) selection. The hierarchy of ascending levels of selection is visualized in Figure 1. The concept of group selection was introduced by Darwin in "The Origin of Species" to account for the evolution of sterile castes in social insects. The term intergroup selection, in the sense of interdemic selection defined here, was used by Sewall Wright in 1945. Essentially the same expression (Gruppenauslese), was used independently and with the same meaning by Olavi Kalela (1954, 1957), while the phrase kin selection was coined by J. Maynard Smith (1964). The classification adopted here is approximately that recommended by J. L. Brown (1966). Selection can also operate at the level of species or entire clusters of related species. The process, well known to paleontologists and biogeographers, is responsible for the familiar patterns of dynastic succession of major groups such as ammonites, sharks, graptolites, and dinosaurs through geologic time (Simpson 1953, P. J. Darlington 1971). It is even possible to conceive of the differential extinction of entire ecosystems, involving all trophic levels (Dunbar 1960). However, selection at these highest levels is not likely to be important in the evolution of altruism, for the following simple reason. In order to counteract individual
TL;DR: The results show that a higher proportion of heterozygotes than of homozygotes survive from seeding to adult stages and that viability selection accounts for the overall excess ofheterozygotes.
Abstract: Estimates of relative selective values of different genotypes in natural populations of predominantly self-pollinated plants have consistently shown a net heterozygote advantage. Heterozygote advantage is further analyzed in the present study by estimating components of selective values corresponding approximately to viability and fecundity. The results show that a higher proportion of heterozygotes than of homozygotes survive from seeding to adult stages and that this viability selection accounts for the overall excess of heterozygotes.
TL;DR: Correlated responses to selection for postweaning gain in mice were studied to determine the influence of population size and selection intensity: correlated responses in the body weight traits and litter size increased as (1) selection intensity increased and (2) effective population size increased.
Abstract: The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.
TL;DR: It was concluded that with antagonistic index selection, the pleiotropic effects of genes may be more powerful in retarding response in aggregate genotype than current theory would suggest.
Abstract: Heritability and genetic correlations realized from both single-trait and antagonistic index selection were compared with paternal half-sib estimates. Primary attention was focused on the genetic correlation between six-week body weight and six-week tail length. Parameters realized from single-trait selection were in excellent agreement with paternal half-sib estimates. However, the realized genetic correlation between six-week body weight and six-week tail length obtained from index selection was significantly greater than the other estimates. Differential inbreeding levels and realized selection intensities were considered and rejected as being causative factors for these results. Linkage disequilibrium probably was not a factor either, as the base population had been randomly mated and randomly selected with a large effective population size for many generations. It was concluded that with antagonistic index selection, the pleiotropic effects of genes may be more powerful in retarding response in aggregate genotype than current theory would suggest. Replication of all selected and control lines allowed the use of between-line estimators of sampling variances of realized genetic parameters in the above comparisons. Generally, standard errors of realized genetic parameters were much smaller than corresponding paternal half-sib standard errors. Thus, selection was an efficient method of estimation.
TL;DR: Equations are derived for the rate of increase under selection of a gene present at low frequency in a population with overlapping generations to support the idea that the evolution of life histories can be understood in terms of the relative effects on the intrinsic rate of increasing at different ages in the age-specific mortality and fecundity rates.
Abstract: Equations are derived for the rate of increase under selection of a gene present at low frequency in a population with overlapping generations. These equations are used to support the idea that the evolution of life histories can be understood in terms of the relative effects on the intrinsic rate of increase of changes at different ages in the age-specific mortality and fecundity rates. It is shown that an analogous idea can be applied to density-regulated populations. The results can also be used to determine sufficient conditions for the selective maintenance of a polymorphism in an age-structured population.
Journal Article•
TL;DR: In this paper, the authors focused on the manager's behavior within the international personnel selection decision process and found that managers play an active role in the process, and their behavior is influenced by their...
Abstract: This study is concerned with manager’s behavior within the international personnel selection decision process. Managers play an active role in the process, and their behavior is influenced by their...
TL;DR: No change was detected in the genetic correlation between selected traits even though the divergent two-trait selection was designed especially to ‘break’ the positive correlation of + 0·55 ± 0·12 present in the base population.
Abstract: Simultaneous selection by independent culling levels of two correlated traits in all four combinations of directions was investigated with Tribolium in a replicated experiment extending over nine generations. In addition to the two primary traits, 13-day larval weight and pupal weight, four secondary traits (pupation time, adult emergence time, adult weight and larval number) were observed.The observed responses for both selected and unselected traits agreed with theoretical expectations after the latter were adjusted for changes which occurred in genetic and phenotypic parameters. Phenotypio variances for the selected traits were correlated positively with population means, yet genetic variances and heritabilities declined in all selected populations. No change was detected in the genetic correlation between selected traits even though the divergent two-trait selection was designed especially to ‘break’ the positive correlation of + 0·55 ± 0·12 present in the base population.Striking changes in growth and developmental patterns resulting from the divergent selection were discussed in terms of metamorphic limits and ‘stabilizing’ genetic correlations.
Journal Article•
TL;DR: In this article, the relative importance of carrier selection determinants in the carrier selection situation in which the decision is made from one mode is investigated, i.e., the movement of household goods by industrial firms.
Abstract: Most works dealing with the problem of carrier selection are directed toward the evaluation of alternative modes of transportation. In this article, the problem of carrier selection from within one mode is considered; this is accomplished by determining the relative importance of carrier selection determinants in the carrier selection situation in which the decision is made from one mode. The movement of household goods by industrial firms was the commodity movement chosen for study. In addition, attention is given to the nature of the carrier selection decision and to a review of carrier selection determinants revealed in previous works.
TL;DR: A theoretical investigation is reported into the effects of overlapping generations on the prediction of genetic gain from repeated within-population truncation selection for a quantitative trait.
Abstract: A theoretical investigation is reported into the effects of overlapping generations on the prediction of genetic gain from repeated within-population truncation selection for a quantitative trait. The gain resulting from the selection process produces genetic differences between the groups of breeding animals of different ages, and between the means of their progeny. These differences are not allowed for in the usual prediction formula. The correct allowances to make for the genetic effects of maternal age are derived for a simple situation. The implications of these allowances on the overall rate of genetic progress, and on the optimum age structure for maximum progress, are shown in a model pig breeding programme. The normal prediction formula underestimates the genetic gain which can be achieved if females are kept for five litters by 10 to 12%, and overestimates the disadvantages of keeping females for more than one or two litters.
TL;DR: In this paper, a study on Breeding and Selection Schemes in Pigs is presented, with a focus on the selection of pigs for breeding and selection schemes in the wild.
Abstract: (1973). Studies on Breeding and Selection Schemes in Pigs. Acta Agriculturae Scandinavica: Vol. 23, No. 2, pp. 61-76.