scholarly journals The effects of male harm vary with female quality and environmental complexity in Drosophila melanogaster

2018 ◽  
Vol 14 (8) ◽  
pp. 20180443 ◽  
Author(s):  
Alison MacPherson ◽  
Li Yun ◽  
Tania S. Barrera ◽  
Aneil F. Agrawal ◽  
Howard D. Rundle
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Natural Selection ◽  
Sexual Conflict ◽  
Mate Competition ◽  
Environmental Complexity ◽  
High Quality ◽  
Female Quality ◽  
Behavioural Interactions ◽  
Recent Attention

Mate competition provides the opportunity for sexual selection which often acts strongly on males, but also the opportunity for sexual conflict that can alter natural selection on females. Recent attention has focused on the potential of sexual conflict to weaken selection on females if male sexual attention, and hence harm, is disproportionately directed towards high- over low-quality females, thereby reducing the fitness difference between these females. However, sexual conflict could instead strengthen selection on females if low-quality females are more sensitive to male harm than high-quality females, thereby magnifying fitness differences between them. We quantify the effects of male exposure on low- versus high-quality females in Drosophila melanogaster in each of two environments (‘simple’ and ‘complex’) that are known to alter behavioural interactions. We show that the effects of male harm are greater for low- compared to high-quality females in the complex but not the simple environment, consistent with mate competition strengthening selection on females in the former but not in the latter environment.

scholarly journals The physical environment mediates male harm and its effect on selection in females

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170424 ◽  
Author(s):  
Li Yun ◽  
Patrick J. Chen ◽  
Amardeep Singh ◽  
Aneil F. Agrawal ◽  
Howard D. Rundle
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Physical Environment ◽  
Selective Advantage ◽  
Laboratory Studies ◽  
Male Choice ◽  
Female Fitness ◽  
High Quality ◽  
Evolutionary Consequences ◽  
Natural And Sexual Selection

Recent experiments indicate that male preferential harassment of high-quality females reduces the variance in female fitness, thereby weakening natural selection through females and hampering adaptation and purging. We propose that this phenomenon, which results from a combination of male choice and male-induced harm, should be mediated by the physical environment in which intersexual interactions occur. Using Drosophila melanogaster , we examined intersexual interactions in small and simple (standard fly vials) versus slightly more realistic (small cages with spatial structure) environments. We show that in these more realistic environments, sexual interactions are less frequent, are no longer biased towards high-quality females, and that overall male harm is reduced. Next, we examine the selective advantage of high- over low-quality females while manipulating the opportunity for male choice. Male choice weakens the viability advantage of high-quality females in the simple environment, consistent with previous work, but strengthens selection on females in the more realistic environment. Laboratory studies in simple environments have strongly shaped our understanding of sexual conflict but may provide biased insight. Our results suggest that the physical environment plays a key role in the evolutionary consequences of sexual interactions and ultimately the alignment of natural and sexual selection.

scholarly journals Sexual Selection Does Not Increase the Rate of Compensatory Adaptation to a Mutation Influencing a Secondary Sexual Trait in Drosophila melanogaster

2020 ◽  
Vol 10 (5) ◽  
pp. 1541-1551
Author(s):  
Christopher H. Chandler ◽  
Anna Mammel ◽  
Ian Dworkin
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Natural Selection ◽  
Spontaneous Mutation ◽  
Phenotypic Expression ◽  
Theoretical Work ◽  
Phenotypic Suppression ◽  
Compensatory Adaptation ◽  
Deleterious Alleles ◽  
Sex Comb

Theoretical work predicts that sexual selection can enhance natural selection, increasing the rate of adaptation to new environments and helping purge harmful mutations. While some experiments support these predictions, remarkably little work has addressed the role of sexual selection on compensatory adaptation—populations’ ability to compensate for the costs of deleterious alleles that are already present. We tested whether sexual selection, as well as the degree of standing genetic variation, affect the rate of compensatory evolution via phenotypic suppression in experimental populations of Drosophila melanogaster. These populations were fixed for a spontaneous mutation causing mild abnormalities in the male sex comb, a structure important for mating success. We fine-mapped this mutation to an ∼85 kb region on the X chromosome containing three candidate genes, showed that the mutation is deleterious, and that its phenotypic expression and penetrance vary by genetic background. We then performed experimental evolution, including a treatment where opportunity for mate choice was limited by experimentally enforced monogamy. Although evolved populations did show some phenotypic suppression of the morphological abnormalities in the sex comb, the amount of suppression did not depend on the opportunity for sexual selection. Sexual selection, therefore, may not always enhance natural selection; instead, the interaction between these two forces may depend on additional factors.

scholarly journals Offspring viability benefits but no apparent costs of mating with high quality males

2010 ◽  
Vol 7 (3) ◽  
pp. 419-421 ◽  
Author(s):  
Leigh W. Simmons ◽  
Rebecca Holley
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Alternative Hypothesis ◽  
Dung Beetle ◽  
Male Courtship ◽  
High Quality ◽  
Female Resistance ◽  
Genetic Quality ◽  
Onthophagus Taurus ◽  
Courtship Signals

Traditional models of sexual selection posit that male courtship signals evolve as indicators of underlying male genetic quality. An alternative hypothesis is that sexual conflict over mating generates antagonistic coevolution between male courtship persistence and female resistance. In the scarabaeine dung beetle Onthophagus taurus , females are more likely to mate with males that have high courtship rates. Here, we examine the effects of exposing females to males with either high or low courtship rates on female lifetime productivity and offspring viability. Females exposed to males with high courtship rates mated more often and produced offspring with greater egg–adult viability. Female productivity and lifespan were unaffected by exposure to males with high courtship rates. The data are consistent with models of sexual selection based on indirect genetic benefits, and provide little evidence for sexual conflict in this system.

scholarly journals Endless forms of sexual selection

2019 ◽  
Author(s):  
Willow R Lindsay ◽  
Staffan Andersson ◽  
Badreddine Bererhi ◽  
Jacob Höglund ◽  
Arild Johnsen ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Mate Choice ◽  
Sexual Conflict ◽  
Genetic Architecture ◽  
Mating Systems ◽  
Population Divergence ◽  
Trait Evolution ◽  
Mating Competition ◽  
Mhc Genes

The field of sexual selection has burgeoned with research into trait evolution in the context of ecology, sociality, phylogeny, natural selection, and sexual conflict. This paper is the product of a “stock-taking” workshop; our aim is to stimulate discussion, not to provide an exhaustive review. We identify outstanding questions organized into four thematic sections. 1) Evolution of mate choice and mating systems. Variation in mate quality can generate mating competition and choice in either sex with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems. Specifically, polyandry evolves in response to the strength of pre- vs. post-copulatory selection. The evolution of polyandry may be related to diversity of pathogens and Major Histocompatibility Complex (MHC) genes. MHC genes are also potential cues of kinship in avoidance of inbreeding. The balance between inbreeding avoidance and inclusive fitness in mating decisions deserves greater attention. 2) Sender and receiver mechanisms shaping signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are a challenge to measure. The neuroethology of sensory and cognitive receiver biases is the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both start and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection. 3) Genetic architecture of sexual selection. Despite advances in modern molecular techniques, the number and identity of genes underlying performance remain largely unknown. A combination of genomic techniques and long-term field studies that reveal ecological correlates of reproductive success is warranted. In-depth investigations into the genetic basis of sexual dimorphism will reveal constraints and trajectories of sexually selected trait evolution. 4) Sexual selection and conflict as drivers of speciation. Population divergence and speciation is often driven by an interplay between sexual and natural selection. To what extent sexual selection promotes or counteracts population divergence may differ depending on the genetic architecture of traits as well as covariance between mating competition and local adaptation, if traits have multiple functions and if sensory systems used in mate choice are locally adapted. Also, post-copulatory processes, e.g. selection against heterospecific sperm, may influence the importance of sexual selection. Sexual conflict can shape speciation processes, since mate choice selection on females can restrict gene flow whereas selection on males is permissive. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection.

scholarly journals Assessing sexual conflict in the Drosophila melanogaster laboratory model system

2006 ◽  
Vol 361 (1466) ◽  
pp. 287-299 ◽  
Author(s):  
William R Rice ◽  
Andrew D Stewart ◽  
Edward H Morrow ◽  
Jodell E Linder ◽  
Nicole Orteiza ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Sexual Conflict ◽  
Graphical Model ◽  
Direct Costs ◽  
Model System ◽  
Laboratory Model ◽  
Laboratory Populations ◽  
Spatial Refuge ◽  
Sexually Antagonistic Coevolution

We describe a graphical model of interlocus coevolution used to distinguish between the interlocus sexual conflict that leads to sexually antagonistic coevolution, and the intrinsic conflict over mating rate that is an integral part of traditional models of sexual selection. We next distinguish the ‘laboratory island’ approach from the study of both inbred lines and laboratory populations that are newly derived from nature, discuss why we consider it to be one of the most fitting forms of laboratory analysis to study interlocus sexual conflict, and then describe four experiments using this approach with Drosophila melanogaster . The first experiment evaluates the efficacy of the laboratory model system to study interlocus sexual conflict by comparing remating rates of females when they are, or are not, provided with a spatial refuge from persistent male courtship. The second experiment tests for a lag-load in males that is due to adaptations that have accumulated in females, which diminish male-induced harm while simultaneously interfering with a male's ability to compete in the context of sexual selection. The third and fourth experiments test for a lag-load in females owing to direct costs from their interactions with males, and for the capacity for indirect benefits to compensate for these direct costs.

scholarly journals Male cognitive performance declines in the absence of sexual selection

2014 ◽  
Vol 281 (1781) ◽  
pp. 20132873 ◽  
Author(s):  
Brian Hollis ◽  
Tadeusz J. Kawecki
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Cognitive Ability ◽  
Cognitive Performance ◽  
Cognitive Abilities ◽  
Learning Ability ◽  
Cognitive Tasks ◽  
Mate Competition ◽  
Processing Information ◽  
Male Ornaments

Sexual selection is responsible for the evolution of male ornaments and armaments, but its role in the evolution of cognition—the ability to process, retain and use information—is largely unexplored. Because successful courtship is likely to involve processing information in complex, competitive sexual environments, we hypothesized that sexual selection contributes to the evolution and maintenance of cognitive abilities in males. To test this, we removed mate choice and mate competition from experimental populations of Drosophila melanogaster by enforcing monogamy for over 100 generations. Males evolved under monogamy became less proficient than polygamous control males at relatively complex cognitive tasks. When faced with one receptive and several unreceptive females, polygamous males quickly focused on receptive females, whereas monogamous males continued to direct substantial courtship effort towards unreceptive females. As a result, monogamous males were less successful in this complex setting, despite being as quick to mate as their polygamous counterparts with only one receptive female. This diminished ability to use past information was not limited to the courtship context: monogamous males (but not females) also showed reduced aversive olfactory learning ability. Our results provide direct experimental evidence that the intensity of sexual selection is an important factor in the evolution of male cognitive ability.

Sexual selection affects the evolution of contact pheromones in Drosophila melanogaster populations isolated by differential sexual conflict

2019 ◽  
Author(s):  
Rochishnu Dutta ◽  
Tejinder Singh Chechi ◽  
N. G. Prasad
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Reproductive Isolation ◽  
Sexual Conflict ◽  
Population Differentiation ◽  
Lipid Profiles ◽  
Mate Preference ◽  
Cuticular Lipid ◽  
Antagonistic Coevolution ◽  
Sexually Antagonistic Coevolution

Abstract Background: The ability of sexual conflict to facilitate reproductive isolation is widely anticipated. However, very few experimental evolutionary studies have convincingly demonstrated the evolution of reproductive isolation due to sexual conflict. Recently a study on the replicates of Drosophila melanogaster populations under differential sexual conflict found that divergent mate preference evolved among replicates under high sexual conflict regime. The precopulatory isolating mechanism underlying such divergent mate preference could be sexual signals such as cuticular lipids since they evolve rapidly and are involved in D. melanogaster mate recognition. Using Drosophila melanogaster replicates used in the previous study, we investigate whether cuticular lipid divergence bears signatures of sexually antagonistic coevolution that led to reproductive isolation among replicates of high sexual conflict regime. Results: We found that their cuticular lipid profiles are sexually dimorphic. Although replicates with male biased sex ratio evolved isolation in reproductive traits due to high sexual conflict, the patterns of cuticular lipid divergence in high and low sexual conflict regimes suggest that sexual selection is the dominant selection pressure rather than sexual conflict affecting the cuticular lipid profile. We also find cuticular lipid divergence patterns to be suggestive of the Buridan’s Ass regime which is one of the six possible mechanism to resolve sexual conflict. Conclusions: Although reproductive isolation due to sexual conflict is anticipated, evolution of a sexually selected trait under sexual conflict may not lead to population differentiation in expected lines. This is because speciation due to sexually antagonistic coevolution is only one of the several outcomes of sexual conflict. This study indicates that population differentiation as a result of cuticular lipid divergence cannot be credited to sexual conflict despite high sexual conflict regime evolving divergent cuticular lipid profiles.

scholarly journals Evolutionary Consequences of Male Driven Sexual Selection and Sex-Biased Fitness Modifications in Drosophila melanogaster and Members of the simulans Clade

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Santosh Jagadeeshan ◽  
Wilfried Haerty ◽  
Monika Moglinicka ◽  
Abha Ahuja ◽  
Scot De Vito ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Natural Selection ◽  
Mating Strategies ◽  
Male Mating ◽  
Male Mating Strategies ◽  
Aggressive Male ◽  
Morphological And Physiological Traits ◽  
Evolutionary Consequences ◽  
Shed Light

Males have evolved a variety of behavioral, morphological, and physiological traits to manipulate their mates in order to maximize their chances of success. These traits are bound to influence how females respond to male behaviors and influence the nature of sexual selection/conflict. A common consequence of aggressive male mating strategies in Drosophila melanogaster is the reduction of female lifespan. Our study shows that this is common across members of the simulans clade. Reduced life expectancy of females implies that female contribution to a population is less than that of males per generation. Fitness differences between the sexes in every generation will invariably affect overall population fitness. How natural selection responds to the female deaths and thereby the unequal fitness of the sexes has rarely been addressed. We shed light on this issue and provide evidence, which suggests that additional gains of fitness by males due to their longevity and continued mating may provide one explanation as to why the loss of female fitness may be “invisible” (effectively neutral) to natural selection. Male driven sexual selection and additional, transgenerational gains of male fitness can be an important force of evolutionary change and need to be tested with other organisms.

scholarly journals The purging of deleterious mutations in simple and complex mating environments

2017 ◽  
Vol 13 (10) ◽  
pp. 20170518 ◽  
Author(s):  
Julie Colpitts ◽  
Darla Williscroft ◽  
Harmandeep Singh Sekhon ◽  
Howard D. Rundle
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Natural Selection ◽  
Experimental Evolution ◽  
The Other ◽  
Deleterious Mutations ◽  
Complex Environment ◽  
Net Benefit ◽  
Significant Difference ◽  
General Expectation

There is a general expectation that sexual selection should align with natural selection to aid the purging of deleterious mutations, yet experiments comparing purging under monogamy versus polygamy have provided mixed results. Recent studies suggest that this may be because the simplified mating environments used in these studies reduce the benefit of sexual selection through males and hamper natural selection through females by increasing costs associated with sexual conflict. To test the effect of the physical mating environment on purging, we use experimental evolution in Drosophila melanogaster to track the frequency of four separate deleterious mutations in replicate populations that experience polygamy under either a simple or structurally complex mating arena while controlling for arena size. Consistent with past results suggesting a greater net benefit of polygamy in a complex environment, two of the mutations were purged significantly faster in this environment. The other two mutations showed no significant difference between environments.

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