Showing papers on "Selection (genetic algorithm) published in 1979"
TL;DR: A structural model of the demand for college attendance is derived from the theory of comparative advantage and recent statistical models of self-selection and unobserved components, which strongly support the theory as discussed by the authors.
Abstract: A structural model of the demand for college attendance is derived from the theory of comparative advantage and recent statistical models of self-selection and unobserved components. Estimates from NBEr-Thorndike data strongly support the theory. First, expected lifetime earnings gains influence the decision to attend college. Second, those who did not attend college would have earned less than measurably similar people who did attend, while those who attended college would have earned less as high school graduates than measurably similar people who stopped after high school. Positive selection in both groups implies no "ability bias" in these data.
1,115 citations
TL;DR: In this article, a synthesis of Bayesian and sample-reuse approaches to the problem of high structure model selection geared to prediction is presented. But this approach is not suitable for high-dimensional models.
Abstract: This article offers a synthesis of Bayesian and sample-reuse approaches to the problem of high structure model selection geared to prediction. Similar methods are used for low structure models. Nested and nonnested paradigms are discussed and examples given.
940 citations
TL;DR: The hypothesis regarding the importance of sexual selection could be tested by monitoring variation in individual fitness via pollen donation and via ovule maturation, and large PDU's may provide a means by which females can assess the relative masculinity of potential mates.
Abstract: The concept of sexual selection (intrasexual competition for mates and mate preference) is used in revising the classical explanation of dioecy in plants. Male and female functions of hermaphroditic flowers can be subject to different sexual selection pressures, which may conceivably lead to the separation of male and female structures. This suggestion does not exclude genetic advantages that may accrue from outcrossing; the two aspects of selection probably operated together in the evolution of dioecy. The hypothesis regarding the importance of sexual selection could be tested by monitoring variation in individual fitness via pollen donation and via ovule maturation. The evolution of pollinia and other large pollen dispersal units is also viewed in terms of sexual selection. Availability of a reliable pollen vector is a prerequisite to the evolution of pollen packages. From the point of view of a flower functioning as a male, large PDU's ensure fertilization of more ovules and possible preemption of stig...
483 citations
TL;DR: The chapter concludes that the most telling anatomical clues, probably, to the reproductive behavior of man and the Great Apes are the relative body sizes of the male and the female, and the relative sizes ofthe testis and the ovary.
Abstract: Publisher Summary Birds, in which, in the absence of lactation both sexes can play an equal role in feeding the young, monogamous mating systems are generally desirable, such that sexual dimorphisms in body size are unlikely to develop. This chapter describes the concept of sexual selection, reproduction in the gorilla, orangutan, chimpanzee, and man. Sexual selection can be subdivided into two components parts: somatic selection, the factors determining general body size, and genital selection, the factors determining the size of the gonads and external genitalia. While, somatic selection is apparently related to the mating system, and is concerned with successful competition for access to a mate, genital selection is far more complex; although influenced by mating type, it is ultimately a reflection of copulatory frequency. The chapter concludes that the most telling anatomical clues, probably, to the reproductive behavior of man and the Great Apes are the relative body sizes of the male and the female, and the relative sizes of the testis and the ovary. However, it remains to be seen whether the significance of these simple anatomical clues will be confirmed by the examination of a far wider range of species.
332 citations
TL;DR: The evidence for pervasive frequency-dependent selection is now very strong and can explain the maintenance not only of conventional polymorphism but also of continuous variation in both molecular and morphological characters.
Abstract: The existence within natural populations of large amounts of genetic variation in molecules and morphology presents an evolutionary problem. The ‘neutralist’ solution to this problem, that the variation is usually unimportant to the organisms displaying it, has now lost much of its strength. Interpretations that assume widespread heterozygous advantage also face serious difficulties. A resolution is possible in terms of frequency-dependent selection by predators, parasites and competitors. The evidence for pervasive frequency-dependent selection is now very strong. It appears to follow naturally from the behaviour of predators, from the evolutionary lability of parasites, from the ecology of competition and, at the molecular level, from the phenomena of enzyme kinetics. Such selection can explain the maintenance not only of conventional polymorphism but also of continuous variation in both molecular and morphological characters. It can account for the occurrence of diversity within groups of haploid and self-fertilizing organisms, and for the evolution of differences between individuals in their systems of genetic control.
264 citations
TL;DR: The selectivity coefficient (Wi) used by modelers in feeding constructs and the electivity index Ei*, derived here, are recommended instead because they do not suffer from the shortcomings described for Ei and Ei′.
Abstract: The electivity indices Ei and Ei′ of predator–prey interaction are currently used to quantify particle-size selection by grazers. Under conditions of passive, mechanical particle-size selection pre...
258 citations
TL;DR: It is shown, for mutations affecting viability in Drosophila, that truncation selection or reasonable departures therefrom can reduce the mutation load greatly, and this may be one way to reconcile the very high mutation rate of such genes with a small mutation load.
Abstract: Truncation selection is known to be the most efficient form of directional selection. When this is modified so that the fitness increases linearly over a range of one or two standard deviations of the value of the selected character, the efficiency is reduced, but not greatly. When truncation selection is compared to a system in which fitness is strictly proportional to the character value, the relative efficiency of truncation selection is given by f(c)/σ, in which f(c) is the ordinate of the frequency distribution at the truncation point and σ is the standard deviation of the character. It is shown, for mutations affecting viability in Drosophila, that truncation selection or reasonable departures therefrom can reduce the mutation load greatly. This may be one way to reconcile the very high mutation rate of such genes with a small mutation load. The truncation model with directional selection is appropriate for this situation because of the approximate additivity of these mutations. On the other hand, it is doubtful that this simple model can be applied to all genes affecting fitness, for which there are intermediate optima and antagonistic selection among components with negative correlations. Whether nature ranks and truncates, or approximates this behavior, is an empirical question, yet to be answered.
182 citations
Book•
31 Dec 1979
169 citations
TL;DR: The analysis of inversion karyotypes in Drosophila pseudoobscura by Dobzhansky shows how genetic variation is affected by selection and by the size, dynamics, and degree of subdivision of populations.
Abstract: Ecological genetics is the investigation of the influence of ecological factors on the genetic properties of populations, and the influence of genetic structure on their ecological properties. Ideally, these studies should determine how genetic variation is affected by selection and by the size, dynamics, and degree of subdivision of populations; what ecological factors determine the relative fitness of genotypes; and what effect the genetic composition of a population has on such ecological parameters as its density, stability, and ecological amplitude. Many studies have demonstrated selection in natural populations; indeed, the widespread existence of selection is perhaps the only generalization that can be made about ecological genetics. But most studies are incomplete. A few, such as the analysis of inversion karyotypes in Drosophila pseudoobscura by Dobzhansky
155 citations
01 Jan 1979
TL;DR: This chapter is to develop a general framework in which to answer the question: What are the roles of individual, kin, and group selection in the evolution of social behavior?
Abstract: The main intent of this chapter is to develop a general framework in which to answer the question: What are the roles of individual, kin, and group selection in the evolution of social behavior? Evolution occurs when the gene frequencies in a population or species change. Natural selection in response to environmental conditions is the primary source of genetic change in most populations. But what is the unit of selection? Classically, the differential survival and reproduction of individuals, or individual selection, are regarded as the major cause of genie evolution. More recently, units larger than the individual have been proposed. The feasibility of the differential survival and reproduction of groups such as families, demes, trait groups, populations, and species has been examined qualitatively and quantitatively in theory, but few field data exist yet that prove the occurrence of these selection processes in nature.
TL;DR: These power functions show the relationship between the probability for rejection and the size of the analytical errors that are to be detected show some assessment of the quality available from present statistical control systems and provide some guidance in the selection of control rules and numbers of control observations when new control systems are designed.
Abstract: We have studied power functions for several control rules by use of a computer simulation program. These power functions show the relationship between the probability for rejection and the size of the analytical errors that are to be detected. They allow some assessment of the quality available from present statistical control systems and provide some guidance in the selection of control rules and numbers of control observations when new control systems are designed.
01 Jan 1979
TL;DR: In this article, the authors present a model based on the Wright-Fisher In.nitely Many Alleles Model and the Cannings (Exchangeable) Model: Two-Alleles 3.4.
Abstract: Contents Preface Introduction 1 Historical Background 1.1 Biometricians, Saltationists and Mendelians 1.2 The Hardy-Weinberg Law 1.3 The Correlation Between Relatives 1.4 Evolution 1.4.1 The Deterministic Theory 1.4.2 Non-Random-Mating Populations 1.4.3 The Stochastic Theory 1.5 Evolved Genetic Phenomena 1.6 Modelling 1.7 Overall Evolutionary Theories 2 Technicalities and Generalizations 2.1 Introduction 2.2 Random Union of Gametes 2.3 Dioecious Populations 2.4 Multiple Alleles 2.5 Frequency-Dependent Selection 2.6 Fertility Selection 2.7 Continuous-Time Models 2.8 Non-Random-Mating Populations 2.9 The Fundamental Theorem of Natural Selection 2.10 Two Loci 2.11 Genetic Loads 2.12 Finite Markov Chains 3 Discrete Stochastic Models 3.1 Introduction 3.2 Wright-Fisher Model: Two Alleles 3.3 The Cannings (Exchangeable) Model: Two Alleles 3.4 Moran Models: Two Alleles 3.5 K-Allele Wright-Fisher Models 3.6 Infinitely Many Alleles Models 3.6.1 Introduction 3.6.2 The Wright-Fisher In.nitely Many Alleles Model 3.6.3 The Cannings In.nitely Many Alleles Model 3.6.4 The Moran In.nitely Many Alleles Model 3.7 The Effective Population Size 3.8 Frequency-Dependent Selection 3.9 Two Loci 4 Diffusion Theory 4.1 Introduction 4.2 The Forward and Backward Kolmogorov Equations 4.3 Fixation Probabilities 4.4 Absorption Time Properties 4.5 The Stationary Distribution 4.6 Conditional Processes 4.7 Diffusion Theory 4.8 Multi-dimensional Processes 4.9 Time Reversibility 4.10 Expectations of Functions of Di.usion Variables 5 Applications of Diffusion Theory 5.1 Introduction 5.2 No Selection or Mutation 5.3 Selection 5.4 Selection: Absorption Time Properties 5.5 One-Way Mutation 5.6 Two-Way Mutation 5.7 Diffusion Approximations andBoundary Conditions 5.8 Random Environments 5.9 Time-Reversal and Age Properties 5.10 Multi-Allele Diffusion Processes 6 Two Loci 6.1 Introduction 6.2 Evolutionary Properties of Mean Fitness 6.3 Equilibrium Points 6.4 Special Models 6.5 Modifier Theory 6.6 Two-Locus Diffusion Processes 6.7 Associative Overdominance and Hitchhiking 6.8 The Evolutionary Advantage of Recombination 6.9 Summary 7 Many Loci 7.1 Introduction 7.2 Notation 7.3 The Random Mating Case 7.3.1 Linkage Disequilibrium, Means and Variances 7.3.2 Recurrence Relations for Gametic Frequencies 7.3.3 Components of Variance 7.3.4 Particular Models 7.4 Non-Random Mating 7.4.1 Introduction 7.4.2 Notation and Theory 7.4.3 Marginal Fitnesses and Average Effects 7.4.4 Implications 7.4.5 The Fundamental Theorem of Natural Selection 7.4.6 Optimality Principles 7.5 The Correlation Between Relatives 7.6 Summary 8 Further Considerations 8.1 Introduction 8.2 What is Fitness? 8.3 Sex Ratio 8.4 Geographical Structure 8.5 Age Structure 8.6 Ecological Considerations 8.7 Sociobiology 9 Molecular Population Genetics: Introduction 9.1 Introduction 9.2 Technical Comments 9.3 In.nitely Many Alleles Models: Population Properties 9.3.1 The Wright-Fisher Model 9.3.2 The Moran Model 9.4 In.nitely Many Sites Models: Population Properties 9.4.1 Introduction 9.4.2 The Wright-Fisher Model 9.4.3 The Moran Model 9.5 Sample Properties of In.nitely Many Alleles Models 9.5.1 Introduction 9.5.2 The Wright-Fisher Model 9.5.3 The Moran Model 9.6 Sample Properties of In.nitely Many Sites Models 9.6.1 Introduction 9.6.2 The Wright-Fisher Model 9.6.3 The Moran Model 9.7 Relation Between In.nitely Many Alleles and Infinitely Many Sites Models 9.8 Genetic Variation Within and Between
TL;DR: Nine generations of direct selection for ovulation rate (OR) were evaluated to determine the magnitude of the correlated response in three litter size and two litter weight traits and none of these estimates of correlated response was significantly different from zero.
Abstract: Nine generations of direct selection for ovulation rate (OR) were evaluated to determine the magnitude of the correlated response in three litter size and two litter weight traits. A total of 387 Select line and 394 Control line litters were included in the ten generations of data. Realized heritabili ty of OR was .42 -+ .06 based on the regression of response (SelectControl) on weighted cumulative selection differential. Regressions of line means on generation number were significant for lit ter birth weight in both lines (-.31 +.12 kg, Select ;.41 -+ .06 kg, Control) and for lit ter weaning weight (-3.4 -+ .8 kg) in the Control line. None of the other regressions of line means on generation number was significantly different from zero. Regressions of line difference (Select-Control) on generation number were .06 -+ .07, .07 -+ .07, .10 _+ .07, .10 +.10 kg and 1.2 -+ .8 kg for total number farrowed (TNF), number farrowed alive (NFA), number weaned (NW), l i t ter birth weight (LBW), and litter weaning weight (LWW), respectively. However, none of these estimates of correlated response was significantly different from zero. Estimates of realized genetic correlation obtained were .07 (OR-TNF), .11 (OR-NFA),
TL;DR: In this paper, a model for inheritance of continuous polygenic traits, similar to a model of Lande, is considered, and the equilibrium density of gametic types is found approximately, if the forces of mutation and selection are weak compared to recombination.
Abstract: A model for inheritance of continuous polygenic traits, similar to a model of Lande, is considered. The equilibrium density of gametic types is found approximately, if the forces of mutation and selection are weak compared to recombination.
TL;DR: The importance of aggression in acquisition of initial breeding territory by male Red-winged Blackbirds (Agelaius phoeniceus) is assessed.
Abstract: In this paper I assess the importance of aggression in acquisition of initial breeding territory by male Red-winged Blackbirds (Agelaius phoeniceus). The ability to acquire territory is expected to depend upon that portion of male quality determined primarily by intrasexual selection. Darwin (1859, 1871) formulated the theory of sexual selection to account for certain apparent exceptions to his concept of natural selection, but evolutionary biologists now realize that sexual selection is a special case of individual selection relating to the evolutionary implications of competitive mating. Most zoologists agree with Darwin that sexual selection has two phases: intrasexual, usually in the form of competition between males; and intersexual or epigamic, usually in the form of female choice of a mate (Selander 1972, Emlen 1973, Brown 1975, Wilson 1975, but see also Mayr 1972). In practice it is difficult to separate the effects of non-sexual and sexual selection
TL;DR: A continuous, graded form of group selection which does not involve extinction of demes can effectively oppose selection on the individual level against an altruistic allele under fluctuating environments in infinitely large demes among which uniform mixing occurs every generation.
TL;DR: This paper examined research relating to the selection of teachers into particular teaching positions, and their retention after obtaining a teaching position, and proposed a framework for viewing research on teacher selection, focusing on the conceptual and methodological problems that beset teacher selection.
Abstract: This chapter examines research relating to the selection of teachers into particular teaching positions, and their retention after obtaining a teaching position. Only studies involving a measure of teaching effectiveness as a dependent variable are included. Two lines of research have produced studies that meet this criterion. Firstly, teacher selection research that has focused on 'selection-work success', and secondly, teacher effectiveness research that has focused on 'process-product' studies. A proposed framework for viewing research on teacher selection is central to the chapter. The framework grew out of the research reviewed and serves to focus the discussion on the conceptual and methodological problems that beset research on teacher selection.
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TL;DR: The Qβ-polymerase-Qβ-RNA system is reviewed and it is suggested that this system provides a useful model of the evolution of haploid genomes under natural selection.
Abstract: The Qβ-polymerase-Qβ-RNA system is reviewed and the evolution of resistance to inhibitors is discussed. It is suggested that this system provides a useful model of the evolution of haploid genomes under natural selection. Consequences for theories of the origins of life are discussed.
TL;DR: Wade et al. as mentioned in this paper showed that both the group and individual selection treatments resulted in changes in the mean numbers of adult beetles, and that these changes in mean adult numbers occurred rapidly, often within two or three generations, and were large in magnitude, the population size in the group selection treatments differing from that of the control by over 50%.
Abstract: A recent experimental study of the effect of group and individual selection on population size in the flour beetle, Tribolium castaneum (Wade, 1976, 1977) showed that both the group and individual selection treatments resulted in changes in the mean numbers of adult beetles. These changes in mean adult numbers occurred rapidly, often within two or three generations, and were large in magnitude, the population size in the group selection treatments differing from that of the control by over 50%. In this paper I will elucidate the genetic and ecological mechanisms responsible for the observed changes in population size. I begin by reviewing briefly the major populational results and notation of the selection experiments, because all of the data reported here will be discussed in the context of the earlier study. The group selection experiment (Wade, 1976, 1977) consisted of four treatments (48 populations per treatment) labelled for purpose of discussion as follows: Treatment Aselection by the differential extinction and recolonization of populations, i.e., group selection, for greater numbers of adults per population; Treatment B-group selection for fewer numbers of adults per population; Treatment C-no group selection, individual selection within populations was allowed to determine the numbers of adults; Treatment D-random group selection, selection and recolonization of populations were carried out by means of a table of random numbers (cf. Wade, 1976, 1977, for details of the experimental design). After nine generations of selection, the average adult population sizes and the standard errors of the means were 178 ? 8.23 for the A treatment, 20 ? .58 for B, 49 + 5.92 for C, and 69 + 6.35 for D. The relationship among the means of A> D> C > B was highly significant (P < .005, Kruskal-Wallis rank sum test, 48 observations per treatment). In this paper I present the results of experiments designed to reveal treatment similarities and dissimilarities with respect to those "primary characteristics" (cf. 1 through 4 below) and "group interactions" (cf. 5 below) (Park et al., 1961) which are known to influence population size in Tribolium (cf. King and Dawson, 1972; Mertz, 1972; Sokoloff, 1974; for detailed and comprehensive reviews). The characteristics assayed from populations of each of the four treatments were as follows:
Book•
01 Jan 1979