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Anders Pape Moller - One of the best experts on this subject based on the ideXlab platform.
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genetic similarity breeding distribution range and Sexual Selection
Journal of Evolutionary Biology, 2008Co-Authors: Anders Pape Moller, Laszlo Zsolt Garamszegi, Claire N SpottiswoodeAbstract:Large populations with extensive breeding distributions may sustain greater genetic variability, thus producing a positive relationship between genetic variation and population size. Levels of genetic variability may also be affected by Sexual Selection, which could either reduce levels because a small fraction of males contribute to the following generation, or augment them by generating genetic variability through elevated rates of mutations. We investigated to what extent genetic variability, as estimated from band sharing coefficients for minisatellite markers, could be predicted by breeding distribution range, population size and intensity of Sexual Selection (as reflected by degree of polygyny and extra-pair paternity). Across a sample of 62 species of birds in the Western Palearctic, we found extensive interspecific variation in band sharing coefficients. High band sharing coefficients (implying low local genetic variability among individuals) were associated with restricted breeding distributions, a conclusion confirmed by analysis of statistically independent linear contrasts. Independently, species with large population sizes had small band sharing coefficients. Furthermore, bird species with a high richness of subspecies for their breeding distribution range had higher band sharing coefficients. Finally, bird species with high levels of polygyny and extra-pair paternity had small band sharing coefficients. These results suggest that breeding distribution range, population size and intensity of Sexual Selection are important predictors of levels of genetic variability in extant populations.
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protandry Sexual Selection and climate change
Global Change Biology, 2004Co-Authors: Anders Pape MollerAbstract:Protandry refers to the earlier appearance of males before females at sites of reproduction. Sexual Selection has been hypothesized to give rise to sex differences in benefits and costs of early arrival, thereby selecting for earlier appearance by the sex subject to more intense Sexual Selection. If Sexual Selection is more intense, there is a greater premium on early arrival among individuals of the chosen sex because of direct Selection for earlier arrival. This hypothesis leads to the prediction that changes in the costs and benefits of early arrival related to changes in environmental conditions should particularly affect the sex that arrives first and hence the degree of protandry. I tested this hypothesis using the Barn Swallow Hirundo rustica. During 1971‐2003, the degree of protandry increased significantly in a Danish population because males advanced arrival date while females did not. This earlier arrival by males compared with females was correlated with a significant increase by over 1.2 standard deviations in the length of the outermost tail feathers of males, a secondary Sexual character, suggesting direct Selection on both protandry and the secondary Sexual character. Environmental conditions during spring migration in Northern Africa, as reflected by the normalized difference vegetation index, have deteriorated since 1984, resulting in increased mortality among males during spring migration, but not among females, and this deterioration of climatic conditions was positively correlated with an increasing degree of protandry. Likewise, an increase in April temperatures at the breeding grounds during recent decades is positively correlated with increased protandry, apparently because males can arrive earlier without increasing the fitness cost of early arrival. Local population size did not predict changes in arrival date. These findings suggest that rapid changes in climate can cause a change in degree of protandry and secondary Sexual characters.
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allee effect Sexual Selection and demographic stochasticity
Oikos, 2001Co-Authors: Anders Pape Moller, Stephane LegendreAbstract:The negative frequency-dependent effect of reproductive success in animals on population growth refers to a category of phenomena termed the Allee effect. The mechanistic basis for this effect and hence an understanding of its consequences has been obscure. We suggest that Sexual Selection, in particular female mate preferences, is a previously neglected component giving rise to the Allee effect. Lack of breeding and reduced reproductive success of females at low population densities are commonly described in situations where females have little or no opportunity to choose a mate, consistent with this suggestion. We developed a demographic model that incorporated the effects of lack of female choice on rates of reproduction. Using either a mating system with incompatibility or a system with a directional mate preference, we show that commonly encountered levels of reproductive suppression in the absence of suitable mates in a population, where Sexual Selection still operates, may increase the effects of demographic stochasticity considerably.
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sperm competition and Sexual Selection
Sperm Competition and Sexual Selection, 1998Co-Authors: T R Birkhead, Anders Pape MollerAbstract:General Themes: G.A. Parker, Sperm Competition and the Evolution of Ejaculates: Towards a Theory Base. A.P. Moller, Sperm Competition and Sexual Selection. W.G. Eberhard, Female Roles in Sperm Competition. J. Wright, Paternity and Paternal Care. Taxonomic Treatments: L.F. Delph and K. Havens, Pollen Competition in Flowering Plants. D.R. Levitan, Sperm Limitation, Gamete Competition and Sexual Selection in External Fertilizers. N.K. Michiels, Mating Conflicts and Sperm Competition in Simultaneous Hermaphrodites. B. Baur, Sperm Competition in Molluscs. M.A. Elgar, Sperm Competition and Sexual Selection in Spiders and Other Arachnids. L.W. Simmons and M.T. Siva-Jothy, Sperm Competition in Insects: Mechanisms and the Potential for Selection. C.W. Petersen and R.R. Warner, Sperm Competition in Fishes. T.R. Halliday, Sperm Competition in Amphibians. M. Olsson and T. Madsen, Sexual Selection and Sperm Competition in Reptiles. T.R. Birkhead, Sperm Competition in Birds: Mechanisms and Function. D.A. Taggart, W.G. Breed, P.D. Temple-Smith, A. Purvis, and G. Shimmin, Reproduction, Mating Strategies and Sperm Competition in Marsupials and Monotremes. M. Gomendio, A.H. Harcourt, and E.R.S. Roldan, Sperm Competition in Mammals. T.R. Birkhead and A.P. Moller, Sperm Competition, Sexual Selection and Different Routes to Fitness. Index.
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Sexual Selection and the barn swallow
1994Co-Authors: Anders Pape MollerAbstract:Models of Sexual Selection and monogamy the study organism male mating advantages benefits of mate choice determinants of tail ornament size advantages of early arrival options for unmated males parasites and Sexual Selection parental care and male ornamentation sperm competition and Sexual Selection Sexual size dimorphism and female ornaments geographic variation in ornament size synthesis.
J. Hunt - One of the best experts on this subject based on the ideXlab platform.
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Sexual Selection and experimental evolution of chemical signals in Drosophila pseudoobscura
Journal of Evolutionary Biology, 2012Co-Authors: J. Hunt, C. Mitchell, Helen S. Crudgington, Rhonda R. Snook, A. J. MooreAbstract:Our expectations for the evolution of chemical signals in response to Sexual Selection are uncertain. How are chemical signals elaborated? Does Sexual Selection result in complexity of the composition or in altered quantities of expression? We addressed this in Drosophila pseudoobscura by examining male and female cuticular hydrocarbons (CHs) after 82 generations of elevated (E) Sexual Selection or relaxed Sexual Selection through monogamy (M). The CH profile consisted of 18 different components. We extracted three eigenvectors using principal component analysis that explained 72% of the variation. principal component (PC)1 described the amount of CHs produced, PC2 the trade-off between short- and long-chain CHs and PC3 the trade-off between apparently arbitrary CHs. In both sexes, the amount of CHs produced was greater in flies from the E treatment. PC3 was also higher, indicating that Sexual Selection also influenced the evolution of CH composition. The sexes differed in all three PCs, indicating substantial Sexual dimorphism in this species, although the magnitude of this dimorphism was not increased as a result of our experimental evolution. Collectively, our work provides direct evidence that Sexual Selection plays an important role in the evolution of CHs in D. pseudoobscura and that both increased quantity and overall composition are targeted.
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male male competition female mate choice and their interaction determining total Sexual Selection
Journal of Evolutionary Biology, 2009Co-Authors: J. Hunt, Casper J Breuker, Jennifer A Sadowski, Allen J MooreAbstract:Empirical studies of Sexual Selection typically focus on one of the two mechanisms of Sexual Selection without integrating these into a description of total Sexual Selection, or study total Sexual Selection without quantifying the contributions of all of the mechanisms of Sexual Selection. However, this can provide an incomplete or misleading view of how Sexually selected traits evolve if the mechanisms of Sexual Selection are opposing or differ in form. Here, we take a two-fold approach to advocate a direction for future studies of Sexual Selection. We first show how a quantitative partitioning and examination of Sexual Selection mechanisms can inform by identifying illustrative studies that describe both male-male competition and female mate choice acting on the same trait. In our sample, the most common trait where this occurred was body size, and Selection was typically linear. We found that male-male competition and female mate choice can be reinforcing or opposing, although the former is most common in the literature. The mechanisms of Sexual Selection can occur simultaneously or sequentially, and we found they were more likely to be opposing when the mechanisms operated sequentially. The degree and timing that these mechanisms interact have important implications for the operation of Sexual Selection and needs to be considered in designing studies. Our examples highlight where empirical data are needed. We especially lack standardized measures of the form and strength of Selection imposed by each mechanism of Sexual Selection and how they combine to determine total Sexual Selection. Secondly, using quantitative genetic principles, we outline how the Selection imposed by individual mechanisms can be measured and combined to estimate the total strength and form of Sexual Selection. We discuss the evolutionary consequences of combining the mechanisms of Sexual Selection and interpreting total Sexual Selection. We suggest how this approach may result in empirical progress in the field of Sexual Selection.
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experimental evidence that Sexual conflict influences the opportunity form and intensity of Sexual Selection
Evolution, 2008Co-Authors: Matthew Hall, Luc F Bussiere, J. Hunt, Robert BrooksAbstract:Sexual interactions are often rife with conflict. Conflict between members of the same sex over opportunities to mate has long been understood to effect evolution via Sexual Selection. Although conflict between males and females is now understood to be widespread, such conflict is seldom considered in the same light as a general agent of Sexual Selection. Any interaction between males or females that generates variation in fitness, whether due to conflict, competition or mate choice, can potentially influence Sexual Selection acting on a range of male traits. Here we seek to address a lack of direct experimental evidence for how Sexual conflict influences Sexual Selection more broadly. We manipulate a major source of Sexual conflict in the black field cricket, Teleogryllus commodus, and quantify the resulting changes in the nature of Sexual Selection using formal Selection analysis to statistically compare multivariate fitness surfaces. In T. commodus, Sexual conflict occurs over the attachment time of an external spermatophore. By experimentally manipulating the ability of males and females to influence spermatophore attachment, we found that Sexual conflict significantly influences the opportunity, form, and intensity of Sexual Selection on male courtship call and body size. When males were able to harass females, the opportunity for Selection was smaller, the form of Selection changed, and Sexual Selection was weaker. We discuss the broader evolutionary implications of these findings, including the contributions of Sexual conflict to fluctuating Sexual Selection and the maintenance of additive genetic variation.
David Berger - One of the best experts on this subject based on the ideXlab platform.
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experimental evidence for effects of Sexual Selection on condition dependent mutation rates
Nature Ecology and Evolution, 2020Co-Authors: Julian Baur, David BergerAbstract:Sexual Selection depletes genetic variation but depleted genetic variation limits the efficacy of Sexual Selection—a long-standing enigma known as the lek paradox. Here we offer a twist to this paradox by showing that Sexual Selection and the generation of new genetic variation via mutation may be entangled in an evolutionary feedback loop. We induced DNA damage in the germline of male seed beetles evolved under regimes manipulating the opportunity for natural and Sexual Selection, and quantified de novo mutations in F2–F7 generations by measuring mutation load. Sexually selected males passed on smaller loads, suggesting that Selection for male quality not only purges segregating deleterious alleles, but can also reduce the rate at which such alleles originate de novo. However, when engaging in socio-Sexual interactions, males evolved exclusively under Sexual Selection transferred greater loads, suggesting that trade-offs between naturally and Sexually selected fitness components can increase mutation rate. These results offer causality to the widely observed male mutation bias and have implications for the maintenance of genetic variation in fitness. Experimental evolution in male seed beetles subjected to different levels of natural and Sexual Selection reveals that trade-offs between naturally and Sexually selected fitness components can increase mutation rate.
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Sexual Selection environmental robustness and evolutionary demography of maladapted populations a test using experimental evolution in seed beetles
Evolutionary Applications, 2019Co-Authors: Ivain Martinossiallibert, Goran Arnqvist, Emma Thilliez, David BergerAbstract:Whether Sexual Selection impedes or aids adaptation has become an outstanding question in times of rapid environmental change and parallels the debate about how the evolution of individual traits impacts on population dynamics. The net effect of Sexual Selection on population viability results from a balance between genetic benefits of "good-genes" effects and costs of Sexual conflict. Depending on how these facets of Sexual Selection are affected under environmental change, extinction of maladapted populations could be either avoided or accelerated. Here, we evolved seed beetles under three alternative mating regimes to disentangle the contributions of Sexual Selection, fecundity Selection, and male-female coevolution to individual reproductive success and population fitness. We compared these contributions between the ancestral environment and two stressful environments (elevated temperature and a host plant shift). We found evidence that Sexual Selection on males had positive genetic effects on female fitness components across environments, supporting good-genes Sexual Selection. Interestingly, however, when males evolved under Sexual Selection with fecundity Selection removed, they became more robust to both temperature and host plant stress compared to their conspecific females and males from the other evolution regimes that applied fecundity Selection. We quantified the population-level consequences of this sex-specific adaptation and found evidence that the cost of socioSexual interactions in terms of reduced offspring production was higher in the regime applying only Sexual Selection to males. Moreover, the cost tended to be more pronounced at the elevated temperature to which males from the regime were more robust compared to their conspecific females. These results illustrate the tension between individual-level adaptation and population-level viability in Sexually reproducing species and suggest that the relative efficacies of Sexual Selection and fecundity Selection can cause inherent sex differences in environmental robustness that may impact demography of maladapted populations.
Adam Jones - One of the best experts on this subject based on the ideXlab platform.
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on the opportunity for Sexual Selection the bateman gradient and the maximum intensity of Sexual Selection
Evolution, 2009Co-Authors: Adam JonesAbstract:Bateman's classic paper on fly mating systems inspired quantitative study of Sexual Selection but also resulted in much debate and confusion. Here, I consider the meaning of Bateman's principles in the context of Selection theory. Success in precopulatory Sexual Selection can be quantified as a "mating differential," which is the covariance between trait values and relative mating success. The mating differential is converted into a Selection differential by the Bateman gradient, which is the least squares regression of relative reproductive success on relative mating success. Hence, a complete understanding of precopulatory Sexual Selection requires knowledge of two equally important aspects of mating patterns: the mating differential, which requires a focus on mechanisms generating covariance between trait values and mating success, and the Bateman gradient, which requires knowledge of the genetic mating system. An upper limit on the magnitude of the Selection differential on any Sexually selected trait is given by the product of the standard deviation in relative mating success and the Bateman gradient. This latter view of the maximum Selection differential provides a clearer focus on the important aspects of precopulatory Sexual Selection than other methods and therefore should be an important part of future studies of Sexual Selection.
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mate choice and Sexual Selection what have we learned since darwin
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Adam Jones, Nicholas L RattermanAbstract:Charles Darwin laid the foundation for all modern work on Sexual Selection in his seminal book The Descent of Man, and Selection in Relation to Sex. In this work, Darwin fleshed out the mechanism of Sexual Selection, a hypothesis that he had proposed in The Origin of Species. He went well beyond a simple description of the phenomenon by providing extensive evidence and considering the far-reaching implications of the idea. Here we consider the contributions of Darwin to Sexual Selection with a particular eye on how far we have progressed in the last 150 years. We focus on 2 key questions in Sexual Selection. First, why does mate choice evolve at all? And second, what factors determine the strength of mate choice (or intensity of Sexual Selection) in each sex? Darwin provided partial answers to these questions, and the progress that has been made on both of these topics since his time should be seen as one of the great triumphs of modern evolutionary biology. However, a review of the literature shows that key aspects of Sexual Selection are still plagued by confusion and disagreement. Many of these areas are complex and will require new theory and empirical data for complete resolution. Overall, Darwin's contributions are still surprisingly relevant to the modern study of Sexual Selection, so students of evolutionary biology would be well advised to revisit his works. Although we have made significant progress in some areas of Sexual Selection research, we still have much to accomplish.
Robert Brooks - One of the best experts on this subject based on the ideXlab platform.
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experimental evidence that Sexual conflict influences the opportunity form and intensity of Sexual Selection
Evolution, 2008Co-Authors: Matthew Hall, Luc F Bussiere, J. Hunt, Robert BrooksAbstract:Sexual interactions are often rife with conflict. Conflict between members of the same sex over opportunities to mate has long been understood to effect evolution via Sexual Selection. Although conflict between males and females is now understood to be widespread, such conflict is seldom considered in the same light as a general agent of Sexual Selection. Any interaction between males or females that generates variation in fitness, whether due to conflict, competition or mate choice, can potentially influence Sexual Selection acting on a range of male traits. Here we seek to address a lack of direct experimental evidence for how Sexual conflict influences Sexual Selection more broadly. We manipulate a major source of Sexual conflict in the black field cricket, Teleogryllus commodus, and quantify the resulting changes in the nature of Sexual Selection using formal Selection analysis to statistically compare multivariate fitness surfaces. In T. commodus, Sexual conflict occurs over the attachment time of an external spermatophore. By experimentally manipulating the ability of males and females to influence spermatophore attachment, we found that Sexual conflict significantly influences the opportunity, form, and intensity of Sexual Selection on male courtship call and body size. When males were able to harass females, the opportunity for Selection was smaller, the form of Selection changed, and Sexual Selection was weaker. We discuss the broader evolutionary implications of these findings, including the contributions of Sexual conflict to fluctuating Sexual Selection and the maintenance of additive genetic variation.
