Search results for "Sexual selectio"
showing 10 items of 255 documents
SEXUALLY SELECTED TRAITS EVOLVE POSITIVE ALLOMETRY WHEN SOME MATINGS OCCUR IRRESPECTIVE OF THE TRAIT
2014
Positive allometry of secondary sexual traits (whereby larger individuals have disproportionally larger traits than smaller individuals) has been called one of the most pervasive and poorly understood regularities in the study of animal form and function. Its widespread occurrence is in contrast with theoretical predictions that it should evolve only under rather special circumstances. Using a combination of mathematical modeling and simulations, here we show that positive allometry is predicted to evolve under much broader conditions than previously recognized. This result hinges on the assumption that mating success is not necessarily zero for males with the lowest trait values: for examp…
Do female leaf beetles Galerucella nymphaeae choose their mates and does it matter?
1998
The role of active female choice in sexual selection is frequently difficult to ascertain, and this is particularly the case for many insect species. Also, it is uncertain whether choosing between males would affect offspring viability. We designed an experiment to investigate the presence of female choice in a Coleoptera species (Galerucella nymphaeae). We also estimated whether mate choice would have any effect on offspring performance. Females were first placed with two males in a test arena to see which of the males copulated with the virgin female, and how quickly. Subsequently the loser male was offered a new virgin female to test for any change in latency time until mating. The two-m…
When are vomiting males attractive? Sexual selection on condition-dependent nuptial feeding in Drosophila subobscura
2009
Nuptial gifts are any nutritious items or inedible tokens transferred from the male to the female as a part of courtship or copulation. Although nuptial gift donation has been studied in a variety of taxa, this behavior has been largely overlooked in Drosophila. We studied nuptial feeding in Drosophila subobscura, where the gift is a regurgitated drop of liquid, in order to examine the importance of this behavior for male mating success and female fecundity. We varied male and female condition by dietary restriction to assess any condition dependence of male nuptial feeding ability and female feeding behavior and mate discrimination. Our results show that there was directional selection for…
Sexual signalling and viability in a wolf spider ( Hygrolycosa rubrofasciata ): measurements under laboratory and field conditions
1999
This study examined the crucial prediction of the conditional-handicap theory, the relationship between male sexual trait size and male viability, in the wolf spider Hygrolycosa rubrofasciata. In this species, males court females by drumming dry leaves with their abdomen, and males with the highest drumming rate enjoy highest mating success. We determined male drumming rate, body mass, and mobility, which reflects mate-searching activity, in relation to male survival. Because it is often difficult to know how results obtained from laboratory studies reflect the natural world, particularly when the measured variable is survival, we repeated our study in both laboratory and field conditions. …
Preference, Rationality and Interindividual Variation: The Persisting Debate About Female Choice
2015
Contemporary research on sexual selection remains deeply influenced by the controversy between Charles Darwin and Alfred Russel Wallace about the true nature and importance of female choice. After briefly reviewing the main points of disagreement between the two famous evolutionists, I discuss some methodological issues relevant to the contemporary study of female choice. I first use some recent controversy about sexual selection in the Indian Peafowl, Pavo cristatus, to illustrate several recurring problems and shortcomings in the empirical study of female preference for male characters. I then address the empirical evidence for rationality in female choice, and discuss how the recently em…
Variable mode of estrus affects female decision for multiple mating
2011
Investigating patterns of variation in mating strategies may shed light on their evolutionary importance as well as their impact on the strength and shape of sexual selection. Multimale mating (polyandry) and mate choice are intensely studied subjects in the area of sexual selection, but little is known about intraspecific patterns of variation that may respond to dynamic cost-benefit balances. In a laboratory study, we investigated the mating behavior of female bank voles (Myodes glareolus) with distinctly different time and energy budgets: They were either in cycling estrus (CE) or postpartum estrus (PPE) shortly after delivery. Postpartum mating is highly constrained by time and energy d…
Can sexual selection theory inform genetic management of captive populations? A review
2014
International audience; Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the co…
Sexual and natural selection on body mass and metabolic rates in free-living bank voles
2010
Summary 1. Because energy is a crucial resource, adaptive significance of variation in the rate of energy metabolism, and especially in basal (BMR) and maximum aerobic (VO2max) metabolic rates, is a popular theme in evolutionary and ecological physiology. However, little is known about the association of these traits with fitness components in populations of free-living animals. 2. We studied the association between body size, the metabolic rates, and reproductive success in bank voles (Myodes glareolus) in an isolated, small island population. Correlation analyses were performed for two measures of reproductive performance: mating success (the number of partners with which an individual ha…
Behavior adaptation and selection.
2010
6 pages; The evolutionary approach to behavior is concerned with the evolutionary origin and adaptive function of behavioral traits. Like any other part of the phenotype, behavior can be shaped by natural selection to produce adaptations. However, behavior often shows large phenotypic variation and flexibility, and can be both – subject to selection and a major agent of selection. Therefore, the study of adaptation and evolution of behavior is a particularly complex one, involving a wide range of methodologies and techniques, including mathematical modeling, comparative methods, phenotypic engineering, quantitative genetics, genetic dissection, and artificial selection.
Do Women Prefer More Complex Music around Ovulation?
2012
The evolutionary origins of music are much debated. One theory holds that the ability to produce complex musical sounds might reflect qualities that are relevant in mate choice contexts and hence, that music is functionally analogous to the sexually-selected acoustic displays of some animals. If so, women may be expected to show heightened preferences for more complex music when they are most fertile. Here, we used computer-generated musical pieces and ovulation predictor kits to test this hypothesis. Our results indicate that women prefer more complex music in general; however, we found no evidence that their preference for more complex music increased around ovulation. Consequently, our f…