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Showing papers on "Selection (genetic algorithm) published in 1991"


Book ChapterDOI
01 Jan 1991
TL;DR: A number of selection schemes commonly used in modern genetic algorithms are compared on the basis of solutions to deterministic difference or differential equations, verified through computer simulations to provide convenient approximate or exact solutions and useful convergence time and growth ratio estimates.
Abstract: This paper considers a number of selection schemes commonly used in modern genetic algorithms. Specifically, proportionate reproduction, ranking selection, tournament selection, and Genitor (or “steady state”) selection are compared on the basis of solutions to deterministic difference or differential equations, which are verified through computer simulations. The analysis provides convenient approximate or exact solutions as well as useful convergence time and growth ratio estimates. The paper recommends practical application of the analyses and suggests a number of paths for more detailed analytical investigation of selection techniques.

2,531 citations


Journal ArticleDOI
TL;DR: This paper reviews, annotates, and classfies 74 related articles which have appeared since 1966 and specific attention is given to the criteria and analytical methods used in the vendor selection process.

2,089 citations


Journal ArticleDOI
TL;DR: In this paper, the authors develop and longitudinally test a model to understand and predict behavior in organizations, considering both person and situation factors, and how these factors interact with each other.
Abstract: Understanding and predicting behavior in organizations requires a consideration of person and situation factors, and how these factors interact. This paper develops and longitudinally tests a model...

2,034 citations


Journal ArticleDOI
TL;DR: The degree to which adaptation to a uniform environment among independently evolving asexual populations is associated with increasing divergence of those populations is assessed, consistent with theoretical expectations that do not invoke divergence due to multiple fitness peaks in a Wrightian evolutionary landscape.
Abstract: We assess the degree to which adaptation to a uniform environment among independently evolving asexual populations is associated with increasing divergence of those populations. In addition, we are concerned with the pattern of adaptation itself, particularly whether the rate of increase in mean fitness tends to decline with the number of generations of selection in a constant environment. The correspondence between the rate of increase in mean fitness and the within-population genetic variance of fitness, as expected from Fisher's fundamental theorem, is also addressed. Twelve Escherichia coli populations were founded from a single clonal ancestor and allowed to evolve for 2,000 generations. Mean fitness increased by about 37%. However, the rate of increase in mean fitness was slower in later generations. There was no statistically significant within-population genetic variance of fitness, but there was significant between-population variance. Although the estimated genetic variation in fitness within po...

1,523 citations


Journal ArticleDOI
TL;DR: The model allows us to compare the relative contribution of different types of habitats to a species' growth rate and population size and predict how the loss of habitat of a particular type may affect a population.
Abstract: In the model described, we attempt to link breeding-site selection to population dynamics for situations in which there is more than one distinct type of habitat. The distribution of individuals between habitat types depends on the selective abilities of the species. This distribution, in turn, influences the population dynamics of the species as a whole. We show that the consequences of habitat selection on population dynamics for an ideal free distribution of individuals across habitats is predictably different from what would be predicted if habitat selection were preemptive, that is, if individuals, upon selecting a site, prevented others from sharing the site. If preemptive selection is ideal, average reproductive success declines with increasing density because each individual selects the best site available from those sites not yet occupied. The model allows us to compare the relative contribution of different types of habitats to a species' growth rate and population size. Furthermore, we can also...

1,197 citations


Journal ArticleDOI
01 Nov 1991-Genetics
TL;DR: It is argued that the bias in synonymous codon usage observed in unicellular organisms is due to a balance between the forces of selection and mutation in a finite population, with greater bias in highly expressed genes reflecting stronger selection for efficiency of translation.
Abstract: It is argued that the bias in synonymous codon usage observed in unicellular organisms is due to a balance between the forces of selection and mutation in a finite population, with greater bias in highly expressed genes reflecting stronger selection for efficiency of translation. A population genetic model is developed taking into account population size and selective differences between synonymous codons. A biochemical model is then developed to predict the magnitude of selective differences between synonymous codons in unicellular organisms in which growth rate (or possibly growth yield) can be equated with fitness. Selection can arise from differences in either the speed or the accuracy of translation. A model for the effect of speed of translation on fitness is considered in detail, a similar model for accuracy more briefly. The model is successful in predicting a difference in the degree of bias at the beginning than in the rest of the gene under some circumstances, as observed in Escherichia coli, but grossly overestimates the amount of bias expected. Possible reasons for this discrepancy are discussed.

930 citations


Journal ArticleDOI
W.E. Nyquist1
TL;DR: A unified presentation, a synthesis, and an evaluation of the methods employed in the estimation of heritability in plants are presented, discussing the use of both collateral and lineal relatives and the biases present in the estimators.
Abstract: A unified presentation, a synthesis, and an evaluation of the methods employed in the estimation of heritability in plants are presented. Asexual, cross‐fertilizing, and self‐fertilizing diploid species, as well as annual and perennial ones, are considered. All broad‐ and narrow‐sense heritabilities are defined on individual and family bases for prediction of response to selection for a target population of environments in space and time. Narrow‐sense heritabilities are defined in cross‐fertilizing species for expected response to variations of mass, half‐sib, and full‐sib family selection for the next generation and the long term, and similarly in self‐fertilizing species. The use of both collateral and lineal relatives to estimate heritability is discussed, and the biases present in the estimators are given. Many departures and variations of the common procedures are discussed. The standard errors of heritability estimators and confidence intervals are presented.

795 citations


Journal ArticleDOI

581 citations


Journal ArticleDOI
TL;DR: The results imply that the evolution of specialization and phenotypic plasticity may not only depend on selection regimes within habitats, but also on contingent, historical events (migration, mutation).
Abstract: Quantitative genetic models are used to investigate the evolution of generalists and specialists in a coarse-grained environment with two habitat types when there are costs attached to being a generalist. The outcomes for soft and hard selection models are qualitatively different. Under soft selection (e.g., for juvenile or male-reproductive traits) the population evolves towards the single peak in the adaptive landscape. At equilibrium, the population mean phenotype is a compromise between the reaction that would be optimal in both habitats and the reaction with the lowest cost. Furthermore, the equilibrium is closer to the optimal phenotype in the most frequent habitat, or the habitat in which selection on the focal trait is stronger. A specialist genotype always has a lower fitness than a generalist, even when the costs are high. In contrast, under hard selection (e.g., for adult or female-reproductive traits) the adaptive landscape can have one, two, or three peaks; a peak represents a population specialized to one habitat, equally adapted to both habitats, or an intermediate. One peak is always found when the reaction with the lowest cost is not much different from the optimal reaction, and this situation is similar to the soft selection case. However, multiple peaks are present when the costs become higher, and the course of evolution is then determined by initial conditions, and the region of attraction of each peak. This implies that the evolution of specialization and phenotypic plasticity may not only depend on selection regimes within habitats, but also on contingent, historical events (migration, mutation). Furthermore, the evolutionary dynamics in changing environments can be widely different for populations under hard and soft selection. Approaches to measure costs in natural and experimental populations are discussed.

536 citations


Journal ArticleDOI
TL;DR: This paper describes how evolutionary techniques of variation and selection can be used to create complex simulated structures, textures, and motions for use in computer graphics and animation.
Abstract: This paper describes how evolutionary techniques of variation and selection can be used to create complex simulated structures, textures, and motions for use in computer graphics and animation. Int...

365 citations


Book ChapterDOI
01 Jan 1991
TL;DR: This work investigates the PGA with deceptive problems and the traveling salesman problem, a parallel search with information exchange between the individuals, and shows the correlation for thetraveling salesman problem by a configuration space analysis.
Abstract: The parallel genetic algorithm (PGA) uses two major modifications compared to the genetic algorithm. Firstly, selection for mating is distributed. Individuals live in a 2-D world. Selection of a mate is done by each individual independently in its neighborhood. Secondly, each individual may improve its fitness during its lifetime by e.g. local hill-climbing. The PGA is totally asynchronous, running with maximal efficiency on MIMD parallel computers. The search strategy of the PGA is based on a small number of active and intelligent individuals, whereas a GA uses a large population of passive individuals. We will investigate the PGA with deceptive problems and the traveling salesman problem. We outline why and when the PGA is succesful. Abstractly, a PGA is a parallel search with information exchange between the individuals. If we represent the optimization problem as a fitness landscape in a certain configuration space, we see, that a PGA tries to jump from two local minima to a third, still better local minima, by using the crossover operator. This jump is (probabilistically) successful, if the fitness landscape has a certain correlation. We show the correlation for the traveling salesman problem by a configuration space analysis. The PGA explores implicitly the above correlation.

Journal ArticleDOI
TL;DR: Measurements of opposing selection confirm that evolution of traits is governed by a balance of conflicting fitness advantages, and show how fluctuations in selection pressures lead to norms of reaction for life history traits in the absence of developmental plasticity.
Abstract: We review studies of natural selection in wild populations in which selection has acted in opposite directions at different stages of the life history. For example, the phenotype with highest probability of survival may have the lowest reproductive success. We discuss two important implications of these findings. First, measurements of opposing selection confirm that evolution of traits is governed by a balance of conflicting fitness advantages. Second, studies of opposing selection are informative about mechanisms underlying life history trade-offs. We outline difficulties in measuring opposing selection, particularly the problem that patterns of selection may be masked by the positive effects of nutrition on size of metric traits and fitness components. We discuss some solutions to these problems, and present a statistical technique to help disentangle direct selection from nutritional effects. Finally, we show how fluctuations in selection pressures lead to norms of reaction for life history traits in the absence of developmental plasticity.

Journal ArticleDOI
TL;DR: In this paper, the movement of pedestrians is assumed to be determined by an intended velocity, by several attractive and repulsive effects, and by fluctuations, which can be explicitly modeled.
Abstract: The movement of pedestrians is supposed to show certain regularities which can be best described by an “algorithm” for individual behavior and is easily simulated on computers. This behavior is assumed to be determined by an intended velocity, by several attractive and repulsive effects, and by fluctuations. The movement of pedestrians is dependent on decisions, which have the purpose of optimizing their behavior and can be explicitly modeled. Some interesting applications of the model to real situations are given, especially to formation of groups, behavior in queues, avoidance of collisions, and selection processes among behavioral alternatives.

Journal ArticleDOI
TL;DR: In this paper, a method for the selection of appropriate test case, an important issue for conformance testing of protocol implementations as well as software engineering, is presented, called the partial W-method, which is shown to have general applicability, full fault-detection power, and yields shorter test suites than the W-Method.
Abstract: A method for the selection of appropriate test case, an important issue for conformance testing of protocol implementations as well as software engineering, is presented. Called the partial W-method, it is shown to have general applicability, full fault-detection power, and yields shorter test suites than the W-method. Various other issues that have an impact on the selection of a suitable test suite including the consideration of interaction parameters, various test architectures for protocol testing and the fact that many specifications do not satisfy the assumptions made by most test selection methods (such as complete definition, a correctly implemented reset function, a limited number of states in the implementation, and determinism), are discussed. >

Journal ArticleDOI
01 Jan 1991-Genetics
TL;DR: The general results support the previous observation that these indirect selection forces are so weak that they are unlikely to dominate the evolution of preference-producing loci.
Abstract: A method is developed that describes the effects on an arbitrary number of autosomal loci of selection on haploid and diploid stages, of nonrandom mating between haploid individuals, and of recombination. We provide exact recursions for the dynamics of allele frequencies and linkage disequilibria (nonrandom associations of alleles across loci). When selection is weak relative to recombination, our recursions provide simple approximations for the linkage disequilibria among arbitrary combinations of loci. We show how previous models of sex-independent natural selection on diploids, assortative mating between haploids, and sexual selection on haploids can be analyzed in this framework. Using our weak-selection approximations, we derive new results concerning the coevolution of male traits and female preferences under natural and sexual selection. In particular, we provide general expressions for the intensity of linkage-disequilibrium induced selection experienced by loci that contribute to female preferences for specific male traits. Our general results support the previous observation that these indirect selection forces are so weak that they are unlikely to dominate the evolution of preference-producing loci.

01 Jan 1991
TL;DR: Common selection mechanisms used in Evolutionary Algorithms are combined to form some generalized variants of selection that are applied to a Genetic Algorithm and are subject to an experimental comparison.
Abstract: Common selection mechanisms used in Evolutionary Algorithms are combined to form some generalized variants of selection. These are applied to a Genetic Algorithm and are subject to an experimental comparison. The feature of extinctiveness as introduced in Evolution Strategies is identiied to be the main reason for a considerable speedup of the search in case of unimodal objective functions .

Journal ArticleDOI
TL;DR: By utilizing this decision algorithm, the decision-makers’ fuzzy assessments with various rating attitudes and the trade-off among various selection criteria can be taken into account in the aggregation process to asssure more convincing and accurate decision-making.
Abstract: In this paper, a facility site selection algorithm is proposed. The algorithm based on the concepts of fuzzy set theory and the hierarchical structure analysis to aggregate decision-makers’ linguistic assessments about criteria weightings and the suitability of facility sites versus various selection criteria to obtain fuzzy suitability indices. Then rank the suitability ratings to determine the best facility site selection. By utilizing this decision algorithm, the decision-makers’ fuzzy assessments with various rating attitudes and the trade-off among various selection criteria can be taken into account in the aggregation process to asssure more convincing and accurate decision-making.


Journal ArticleDOI
TL;DR: It is found that the plasticity of a character does respond to selection and this response is partially independent of the response to selection on the mean of the character.
Abstract: We selected on phenotypic plasticity of thorax size in response to temperature in Drosophila melanogaster using a family selection scheme. The results were compared to those of lines selected directly on thorax size. We found that the plasticity of a character does respond to selection and this response is partially independent of the response to selection on the mean of the character. One puzzling result was that a selection limit of zero plasticity was reached in the lines selected for decreased plasticity yet additive genetic variation for plasticity still existed in the lines. We tested the predictions of three models of the genetic basis of phenotypic plasticity: overdominance, pleiotropy, and epistasis. The results mostly support the epistasis model, that the plasticity of a character is determined by separate loci from those determining the mean of the character.

Journal ArticleDOI
TL;DR: An investigation into the application of the genetic algorithm in the optimization of structural design and the basic operations of selection, crossover, mutation and parameter scaling are presented.

Journal ArticleDOI
TL;DR: Simulations show that systematic selection in the poor environment is required, not merely trials of potential cultivars after selection in a good environment, and systematic exploitation of a GE interactions effect is proposed.
Abstract: Regressions of yields of cultivars upon means of sets of cultivars over diverse environments are often used as measures of stability/adaptability. Prolonged selection for performance in environments of high yield potential has generally led to unconscious selection for high regressions. If adaptation to poor environments is required (as it often is in Third World agriculture), common sense suggests that low regressions could be exploited for the purpose. Simulations show that systematic selection in the poor environment is required, not merely trials of potential cultivars after selection in a good environment. In effect, systematic exploitation of a GE interactions effect is proposed. The effects are large enough to reduce correlated responses in different environments to zero. Orderly experimental studies are needed but not available. What information there is does not disagree with the theory developed here.

Journal ArticleDOI
TL;DR: Using both multivariate and univariate regression techniques, selection acting through female reproductive success is measured in two hermaphroditic species with precise pollen placement but different pollinators: hummingbird‐pollinated Lobelia cardinalis and bumblebee‐ pollinated L. siphilitica.
Abstract: Using both multivariate and univariate regression techniques, I measured selection acting through female reproductive success in two hermaphroditic species with precise pollen placement but different pollinators: hummingbird-pollinated Lobelia cardinalis and bumblebee-pollinated L. siphilitica. Six traits were analyzed in two populations of L. cardinalis and one population of L. siphilitica: flower number, mean number of flowers open per day, inflorescence height, number of days in flower, median-flower date and nectar-stigma distance. In another study it was found that female reproductive success in one population of L. cardinalis was much less pollen limited than in the other two populations, and it was therefore expected that selection of female reproductive traits in this population would be weaker. In the univariate analyses correlations caused nearly all traits to have significant directional selection coefficients. However, in the multivariate analyses no traits in L. siphilitica experienced directional or quadratic selection. Selection acted differently in the two L. cardinalis populations. The less pollen-limited population experienced positive directional selection on flower number and median-flower date, while in the other L. cardinalis population there was positive directional selection on flower number and nectar-stigma distance and both positive directional and positive quadratic selection on height. The functional significance of floral traits in these two species and the probable effect of increased sample sizes are discussed.


Journal ArticleDOI
11 Jan 1991-Cell
TL;DR: Although constitutive CD8 expression does not affect thymic selection of CD4+ cells, selection of a class I-specific TCR in the CD8 subset is substantially improved, consistent with a model for positive selection in which selection occurs at a developmental stage in which both CD4 and CD8 are expressed.

Journal ArticleDOI
TL;DR: Patterns of change of genetic correlations are caused by differences in development and physiology, an understanding of which appears to be necessary to predict the response to selection in natural, heterogeneous environments.
Abstract: Recent theory suggests that genetic correlations should help to predict the simultaneous response to selection of two or more traits, and much recent research has been directed towards understanding the sources of variation in genetic correlations. Genetic correlations can change from sample to sample, from species to species, from population to population, during the course of development and — within a population, at a fixed stage of development — from one environment to another. These are changes not only in magnitude but also in sign. Theory suggests that genetic correlations should not change sign when the two traits are tightly integrated by physiology or development. Patterns of change of genetic correlations are caused by differences in development and physiology, an understanding of which appears to be necessary to predict the response to selection in natural, heterogeneous environments.

Journal ArticleDOI
TL;DR: The actuator location selection problem is cast in the framework of a zero-one optimization problem and a genetic algorithmic approach is developed that involves three basic operations: reproduction, crossover, and mutation.
Abstract: The actuator location selection problem is cast in the framework of a zero-one optimization problem. A genetic algorithmic approach is developed. To obtain successive generations that yield the solution corresponding to the maximum fitness value, this approach involves three basic operations: reproduction, crossover, and mutation.

Proceedings ArticleDOI
01 Jun 1991
TL;DR: The results suggest that the "sugar flavor" of the “normal selection” of the Buchberger algorithm, implemented first in COCOA, then in AlPI, [14], [15] (up to now in the muLISP version, in a short time in the COMMON-LISp version, including the parallel version, [1]) and now in SCRATCHPAD-II, is the best choice for a selection strategy.
Abstract: In this paper redescribe some experimentti findings on selection strategies for Gr6bner basis computation with the Buchberger algorithm. In particular, the results suggest that the “sugar flavor” of the “normal selection”, implemented first in COCOA, then in AlPI, [14], [15] (up to now in the muLISP version, in a short time in the COMMON-LISP version, including the parallel version, [1]) and now in SCRATCHPAD-II, is the best choice for a selection strategy. It has to be combined with the “straightforward” simplification strategy and with a special form of the Gebauer-Moller criteria to obtain the best results. The idea of the “sugar flavor” is the following: the Buchberger algorithm for homogeneous ideals, with degreecompatible term ordering and normal selection strategy, usually works fine. Homogenizing the basis of the ideal is good for the strategy, but bad for the basis to be computed. The sugar flavor computes, for every polynomial in the course of the algorithm, ‘(the degree that it would have if computed with the homogeneous algorithm”, and uses this phantom degree (the sugar) only for the selection strategy. We have tested several examples with different selection strategies, and the sugar flavor has proved to be always the best choice or very near to it. The comparison between the different variants of the sugar flavor has been made, but the results are up to now inconclusive. We include a complete deterministic description of the Buchberger algorithm as it was used in our experiments.l

Journal ArticleDOI
TL;DR: An efficient approach for a computer-based solution to the problem of selection of an ‘optimum robot’ specifically to aid industries by applying Multiple Attribute Decision Making (MADM) ideology to equipment selection (robots).
Abstract: This paper presents an efficient approach for a computer-based solution to the problem of selection of an ‘optimum robot’ specifically to aid industries. The approach breaks new ground by applying Multiple Attribute Decision Making (MADM) ideology to equipment selection (robots) which is of consequence because selection is an implicit aspect of design. Indeed, the approach is also applicable to a robot design problem. The robot selection procedure allows rapid convergence from a very large number to a manageable shortlist of potentially suitable robots using an ‘elimination search’ routine based on a few pertinent attributes of the robots. Subsequently, the selection procedure proceeds to rank the alternatives in the shortlist by employing a MADM method termed TOPS1S (Technique for Order Preference by Similarity to Ideal Solution). An expert system has been developed as part of the software package to assist an inexperienced user to establish priorities, and to ‘oversee’ the selection process at ...

Journal ArticleDOI
TL;DR: This study addresses the question of how the expression of genetic variation for fledgling body size of Great Tits varies with the environment by manipulating brood sizes and interacting with natural temporal variation in food availability.
Abstract: Evolutionary change requires natural selection in the presence of heritable variation for the trait(s) under selection. Since heritabilities and selection pressures are known to vary with environmental conditions, it is crucial to know how much genetic variation is expressed under which conditions. This study addresses the question of how the expression of genetic variation for fledgling body size of Great Tits varies with the environment. Different environmental conditions were created experimentally by manipulating brood sizes. The treatment affected body size, measured as either fledging weight or tarsus length, and interacted with natural temporal variation in food availability. Both measurements show stabilizing selection. A cross-fostering design was carried out to separate genetic and environmental causes of variation. Heritabilities as measured from offspring-midparent regressions and from full-sib analyses were substantial for both traits, except that no heritability was found for weight under poor conditions. Instead, fledging weights were significantly correlated with the weights of their unrelated guardians’ ( = fosterparents’) weight under poor conditions. We propose that under poor conditions, when selection on fledging weights is expected to be directional and strong, only little genetic variance is expressed. Any evolutionary response to this selection on fledging weight might therefore be slow, if the increase in selection pressure is not greater than the decrease in heritability.