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At least 19 recordsLinked to original sources
PubMed1985

Selecting mating pairs with linear programming techniques.

Mate selection can increase progency merit if overall merit is nonlinear for one or more component traits. An index of expected progeny merit could be calculated for all possible mating pairs, and the set of pairs with the highest progeny mean could be selected. There are serious computational problems for more than a few males and females. To select and mate f, females, and m, males, from n of each, with k0 females per male, would require (nf)(nm)f!/(k0!)m evaluations. Linear programming algorithms can determine the optimal strategy efficiently by considering only a subset of these possibilities. Let pi ij be the index of progency merit of the ith sire mated to the jth dam and Xij be the decision variable for that mating (restricted to 0 or 1). Then the problem of selecting mating pairs can be stated as: maximize sigma i sigma j pi ij Xij, subject to sigma i Xij less than or equal to 1, sigma j Xij less than or equal to k0, sigma i sigma j Xij = f, and Xij = 0 or 1. By including an artificial sire and an artificial dam and choosing appropriate merit values for the artificial matings, this problem can be solved by efficient "transportation" algorithms. These algorithms could be used to develop rational mating packages for dairy artificial insemination studs provided that an objective evaluation of progeny merit could be formulated, provided that merit is not simply additively inherited.

Animal Husbandry↗
PubMed2000

Use of computerized mate selection programs to control inbreeding of Holstein and Jersey cattle in the next generation.

The expected role of computerized mate selection programs with regard to inbreeding and lifetime profitability of Holstein and Jersey cattle was examined using data from 25 large registered herds of each breed. Sire selection and mate allocation were carried out using linear programming with the following objectives: 1) minimum inbreeding, 2) maximum net merit subject to a fixed inbreeding threshold, and 3) maximum expected lifetime profit after adjustment for inbreeding depression. Inbreeding of actual matings was similar to inbreeding from random matings, indicating that current inbreeding avoidance programs in these herds are ineffective. Inbreeding was reduced by 1.6 and 1.9% in Holsteins and Jerseys, respectively, when a mate allocation program was applied with service sires and usage levels fixed at the actual values. Benefits of mate selection programs increased when both sire selection and mate pair allocation were considered. Maximization of mean net merit with inbreeding restricted to a fixed level (5% in Holsteins and 8% in Jerseys) led to decreases in inbreeding of 0.9 and 1.4% and increases in lifetime profit of $16.66 and $26.86 in Holsteins and Jerseys, respectively, relative to programs that ignored inbreeding. Maximization of mean expected lifetime profit after adjustment for inbreeding depression decreased inbreeding by 1.8 and 2.8% and increased lifetime profit by $37.37 and $59.77 in Holsteins and Jerseys, respectively. Inbreeding coefficients estimated with pedigree traced to 1985 were inadequate predictors of inbreeding coefficients estimated with pedigrees traced to 1960. Mate selection programs cannot function optimally unless extensive historical pedigree data are available, particularly for service sires. Computerized mate selection programs can reduce inbreeding in the next generation, which will lead to an increase in farm profitability. However, if genetic diversity is to be maintained in the long term, procedures for selecting parents of AI sires must also be considered.

Algorithms↗
PubMed1998

Mate selection by groups.

The two key components in a breeding program can be described as the development of an objective function and the implementation of an algorithm for mate selection to target the objective function. However, mate selection is unacceptably slow for objective functions that involve longer term aims, such as engineering a good connection between herds. This paper proposes animal clustering to facilitate group mate selection, plus a step to refine mate selection for individual animals. Cluster analysis is used to form groups of animals within each sex based on nominated factors such as breed, herd, age, and EBV. Mate selection is then performed on groups, reducing the size of the problem considerably. The example used involved a three-breed crossbred population with a simple objective function to maximize predicted progeny merit. Twenty sires and 500 dams were to be selected from 816 and 1784 candidates. Group mate selection achieved 96.9% efficiency (random selection, 0%; full mate selection, 100%) and took 0.28 s to compute (394.2 s for full mate selection). Permitting more candidates to reach the individual mate selection stage increased efficiency to, for example, 98.9% at the cost of an extra 1.15 s. Efficiency was also improved by permitting more clusters.

Algorithms↗
PubMed1988

The "real" marriage squeeze: mate selection, mortality, and the mating gradient.

The nature and magnitude of the marriage squeeze in Canada is examined using vital statistics and census data. "Age differentials of brides and grooms in all marriages registered in 1981 are used to create 'availability indices' that estimate the number of unmarried persons of the opposite sex that are potentially available for every 100 unmarried persons. For men, availability indices are low in the 20s, and they increase with advancing age to about one-to-one in the 50s. For women, access to potential grooms is highest in the 20s and decreases with advancing age until, in the 50s, there are only 50 potential grooms per 100 unmarried women." The implications of unbalanced sex ratios are discussed with reference to changes in marriage and the family.

Age Factors↗
PubMed1977

The role of attractiveness and mate selection in phylogenetic adaptation with particular reference to early man.

The author hypothesizes on the roles of sexual selection and assortative mating in human evolution. Basing his argument on a theory, which views neurosis as a maladaptive vicious cycle, he argues that there is dovetailing of the actions of neurosis and mate selection in promoting the phylogenetic adaptation of early man. He sees both neurosis and assortative mating as magnifying existing differences in viability. This process would, by favoring the most viable, have accelerated human evolution. The relationship between movement patterns and neurosis is also discussed.

Adaptation, Psychological↗
PubMed1997

Models of selective mating and the initiation of the Fisherian process.

The effects of various rules of selective mating on the initial stages of Fisherian sexual selection are investigated. A comparison of three models of selective mating, fixed relative preference, best of N males and absolute preference is provided, with a special emphasis on their mathematical properties. Using a two-locus haploid model of sexual selection in a polygamous population, I show that the absolute preference rule of selective mating may lower the threshold frequency of the preference trait, required for the initiation of the Fisherian process, as low as zero. This was not observed in the previous analyses with fixed relative preference or best of N male rules. It is then argued that absolute preference may cause the initiations of the Fisherian process more easily without introducing additional assumptions such as pleiotropy or random genetic drift. Some problems associated with the mating rule are also discussed.

Animals↗
PubMed2006

Optimization of a crossing system using mate selection.

A simple model based on one single identified quantitative trait locus (QTL) in a two-way crossing system was used to demonstrate the power of mate selection algorithms as a natural means of opportunistic line development for optimization of crossbreeding programs over multiple generations. Mate selection automatically invokes divergent selection in two parental lines for an over-dominant QTL and increased frequency of the favorable allele toward fixation in the sire-line for a fully-dominant QTL. It was concluded that an optimal strategy of line development could be found by mate selection algorithms for a given set of parameters such as genetic model of QTL, breeding objective and initial frequency of the favorable allele in the base populations, etc. The same framework could be used in other scenarios, such as programs involving crossing to exploit breed effects and heterosis. In contrast to classical index selection, this approach to mate selection can optimize long-term responses.

Alleles↗
PubMed1992

Gender differences in mate selection preferences: a test of the parental investment model.

Evolutionary-related hypotheses about gender differences in mate selection preferences were derived from Triver's parental investment model, which contends that women are more likely than men to seek a mate who possesses nonphysical characteristics that maximize the survival or reproductive prospects of their offspring, and were examined in a meta-analysis of mate selection research (questionnaire studies, analyses of personal advertisements). As predicted, women accorded more weight than men to socioeconomic status, ambitiousness, character, and intelligence, and the largest gender differences were observed for cues to resource acquisition (status, ambitiousness). Also as predicted, gender differences were not found in preferences for characteristics unrelated to progeny survival (sense of humor, "personality"). Where valid comparisons could be made, the findings were generally invariant across generations, cultures, and research paradigms.

Female↗
PubMed1999

On sex, mate selection and the red queen.

The widespread occurrence of sexual reproduction despite the two-fold disadvantage of producing males, is still an unsolved mystery in evolutionary biology. One explanatory theory, called the "Red Queen" hypothesis, states that sex is an adaptation to escape from parasites. A more recent hypothesis, the mate selection hypothesis, assumes that non-random mating, possible only with sex, accelerates the evolution of beneficial traits. This paper tests these two hypotheses, using an agent-based or "micro-analytic" evolutionary algorithm where host-parasite interaction is simulated adhering to biological reality. While previous simpler models testing the "Red Queen" hypothesis considered mainly haploid hosts, stable population density, random mating and simplified expression of fitness, our more realistic model allows diploidy, mate selection, live history constraints and variable population densities. Results suggest that the Red Queen hypothesis is not valid for more realistic evolutionary scenarios and that each of the two hypotheses tested seem to explain partially but not exhaustively the adaptive value of sex. Based on the results we suggest that sexual populations in nature should avoid both, maximizing outbreeding or maximizing inbreeding and should acquire mate selection strategies which favour optimal ranges of genetic mixing in accordance with environmental challenges.

Animals↗
PubMed1995

Assortative mating: sex differences in mate selection for married and unmarried couples.

We studied assortative mating for age, nationality, educational level, and occupational level in married and unmarried parents to test evolutionary models explaining mate selection among humans. We used the marriage and birth registers of the Venezuelan population to compare recently married, fertile married, and fertile unmarried couples. The results show significant assortative mating for all variables, but the results are strongest for age and education. These data suggest that (1) selection criteria based on age vary along the life cycle and differ between married and unmarried couples; (2) male's socioeconomic status is more related to the availability of younger females among unmarried couples compared with married couples, except for young couples; and (3) female selection for better (more educated and/or better employed) mates is stronger among married couples, whereas male selection for younger females or those showing actual reproductive potential is stronger among unmarried couples.

Adolescent↗
PubMed1993

Is human mating adventitious or the result of lawful choice? A twin study of mate selection.

Pairs of middle-aged twins and their spouses provided data on 74 mainly psychological variables. Neither spousal similarity nor idiosyncratic criteria could account for specific mate selection in these 738 couples. Of the twins (and their spouses), 547 independently rated their initial attraction to their twin's mate (or to their spouse's twin): Findings suggest that characteristics both of the chooser and the chosen constrain mate selection only weakly. This article proposes that it is romantic infatuation that commonly determines the final choice from a broad field of potential eligibles and that this phenomenon is inherently random, in the same sense as is imprinting in precocial birds.

Adult↗
PubMed2006

The dilemma of female mate selection in the brown bear, a species with sexually selected infanticide.

Because of differential investment in gametes between sexes, females tend to be the more selective sex. Based on this concept, we investigate mate selection in a large carnivore: the brown bear (Ursus arctos). We hypothesize that, in this species with sexually selected infanticide (SSI), females may be faced with a dilemma: either select a high-quality partner based on phenotypic criteria, as suggested by theories of mate choice, or rather mate with future potentially infanticidal males as a counter-strategy to SSI. We evaluated which male characteristics were important in paternity assignment. Among males available in the vicinity of the females, the largest, most heterozygous and less inbred and also the geographically closest males were more often the fathers of the female's next litter. We suggest that female brown bears may select the closest males as a counter-strategy to infanticide and exercise a post-copulatory cryptic choice, based on physical attributes, such as a large body size, reflecting male genetic quality. However, male-male competition either in the form of fighting before copulation or during the post-copulatory phase, in the form of sperm competition, cannot entirely be ruled out.

Animals↗
PubMed1994

Mating-type differentiation and mate selection in the homothallic Chlamydomonas monoica.

By using combinations of phenotypically-distinct--but sexually-compatible--mutant strains of C. monoica (zym-1, zym-27, and nit-2) and assaying for zygote genotypes in genetically-mixed mating populations (where gametes of the two parental homothallic strains were present at similar frequencies), we have found that matings occur preferentially between cells of the same genotype. Additional support for an hypothesis of non-random mate selection was provided by using an easily-selectable genetic marker (sup-1) to verify the frequent occurrence of matings between cells of identical genotype in populations where the selectable genotype was present at very low relative frequency (10(-2) or 10(-3)) in a mixed mating population. Direct evidence for non-random mate selection was obtained by presenting nitrogen-starved cells with limiting nitrate to synchronize gametic differentiation in wild-type strains. Under these conditions, the four, eight, or 16 mitotic daughters released from the same mother sporangium often immediately established mating pairs within the group. Thus successive mitotic divisions of a single mother cell yielded progeny of opposite expressed mating-type.

Animals↗
PubMedDate not supplied

Assortative versus selective mating: is the distinction worthwhile?

The study examines the distinction between assortative and selective mating made by Lewontin, Kirk, and Crow in 1968 and finds it unproductive. Not only has the difference been ignored on many occasions even as it was invoked, but maintaining it obscures several useful properties of both nonrandom mating schemes and some formally equivalent systems such as fertility selection. The elucidation of these similarities could have accelerated the work of population biologists.

Alleles↗
PubMed1998

Factors and their origins in mate selection and choice among humans: implications for individual psychotherapy and counseling.

A mechanism of mate selection in humans is proposed and elaborated. It is further proposed that this mechanism constitutes one of the important factors for stability and the necessary longevity of the procreational dyad and therefore the procreational success of humans as a species. The concepts and mechanisms of assortative mating (homogamy) and that of complementarity of temperaments of the mates (heterogamy) which guide such selections are described, the relationships between the two are explored, and finally their possible early developmental origins are proposed. Evidence from a small study of 20 married couples' responses in temperament tests is offered as well as some illustrative case histories all pointing to those mechanisms. The argument is based mainly on principles of evolutionary psychology.

Adult↗
PubMed1976

Motivational and personality trait relationships in mate selection.

This article discusses the question of homogamy and/or heterogamy in human mate selection with particular emphasis on Winch's principles of type I and type II complementarity. The experiment was performed on 82 married couples, at least one spouse of which was a graduate student at the University of Illinois. All were given the 16PF, the Motivational Analysis Test (MAT), and the Marriage Role Questionnaire. The authors found that except for fear and pugnacity all husband-wife trait correlations were positive, in contrast to Winch's principle of type I complementarity. They also found that their data did not support Winch's principle of type II complementarity.

Aggression↗
PubMed2004

Warm and homely or cold and beautiful? Sex differences in trading off traits in mate selection.

Prior research and theory suggest that people use three main sets of criteria in mate selection: warmth/trustworthiness, attractiveness/vitality, and status/resources. In two studies, men and women made mating choices between pairs of hypothetical potential partners and were forced to make trade-offs among these three criteria (e.g., warm and homely vs. cold and attractive). As predicted, women (relative to men) placed greater importance on warmth/trustworthiness and status/resources in a potential mate but less importance on attractiveness/vitality. In addition, as expected (a) ratings of ideal standards partly mediated the link between sex and mate choices, (b) ideal standards declined in importance from long-term to short-term relationships, with the exception of attractiveness/vitality, and unexpectedly, (c) sex differences were higher for long-term (compared to short-term) mate choice. Explanations and implications are discussed.

Adolescent↗