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 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 A link between heritable parasite resistance and mate choice in dung beetles

2019 ◽  
Vol 30 (5) ◽  
pp. 1382-1387 ◽  
Author(s):  
Bruno A Buzatto ◽  
Janne S Kotiaho ◽  
Larissa A F Assis ◽  
Leigh W Simmons
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Female Choice ◽  
Additive Genetic Variance ◽  
Dung Beetle ◽  
Mite Infestation ◽  
Adult Survival ◽  
Parasite Resistance ◽  
Onthophagus Taurus ◽  
Sexual Selection Theory

AbstractParasites play a central role in the adaptiveness of sexual reproduction. Sexual selection theory suggests a role for parasite resistance in the context of mate choice, but the evidence is mixed. The parasite-mediated sexual selection (PMSS) hypothesis derives a number of predictions, among which that resistance to parasites is heritable, and that female choice favors parasite resistance genes in males. Here, we tested the PMSS hypothesis using the dung beetle Onthophagus taurus, a species that can be heavily parasitized by Macrocheles merdarius mites, which are known to affect adult survival. We investigated the heritability of resistance to M. merdarius, as well as whether female O. taurus impose a mating bias against males susceptible to mite infestation. Female choice for parasite resistance is difficult to disentangle from the possibility that females are simply choosing less parasitized males due to naturally selected benefits of avoiding contracting those parasites. This is especially likely for ectoparasites, such as mites. We tackled this problem by performing a mate choice trial first, and then measuring a male’s resistance to mite infestation. Resistance to mite infestation exhibited significant levels of additive genetic variance. Although we found no relationship between mating success and parasite resistance, males with greater resistance to infestation mated for longer. If females control copula duration, given that short copulations often result in mating failure, female choice could act on parasite resistance.

scholarly journals A model of the interaction between ‘good genes’ and direct benefits in courtship-feeding animals: when do males of high genetic quality invest less?

2002 ◽  
Vol 357 (1419) ◽  
pp. 309-317 ◽  
Author(s):  
L. F. Bussière
Keyword(s):  
Sexual Selection ◽  
Simple Model ◽  
Parental Investment ◽  
Good Genes ◽  
High Quality ◽  
Genetic Quality ◽  
Individual Female ◽  
Female Partners ◽  
Direct Benefits ◽  
Courtship Feeding

Conflict between mates over the amount of parental investment by each partner is probably the rule except in rare cases of genetic monogamy. In systems with parental care, males may frequently benefit by providing smaller investments than are optimal for individual female partners. Females are therefore expected to choose males that will provide the largest amounts of parental investment. In some species, however, the preferred males provide less care than their rivals. Focusing on species in which males invest by feeding their mates, I use a simple model to demonstrate the conditions under which males preferred by females may have optimal donations that are smaller than those of less–preferred rivals. Pre–mating female choice may sufficiently bias the perception of mate availability of preferred males relative to their rivals such that preferred males gain by conserving resources for future matings. Similarly, ‘cryptic’ biases in favour of high–quality ejaculates by females can compensate for smaller than average donations received from preferred males. However, post–fertilization cryptic choice should not change the optimal donations of preferred males relative to their rivals. I discuss the implications of this work for understanding sexual selection in courtship–feeding animals, and the relevance of these systems to understanding patterns of investment for animals in general.

scholarly journals Sexual selection can reduce mutational load in Drosophila subobscura

Genetika ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. 537-552 ◽  
Author(s):  
Marija Savic-Veselinovic ◽  
Sofija Pavkovic-Lucic ◽  
Zorana Kurbalija-Novicic ◽  
Mihailo Jelic ◽  
Marko Andjelkovic
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Male Mating ◽  
Mutational Load ◽  
Genetic Quality ◽  
Genetic Structure Of Populations ◽  
Deleterious Alleles ◽  
Theoretical Predictions ◽  
Set Up ◽  
Genetic Pool

According to theoretical predictions sexual selection can reduce mutational load through male mating success. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality, thus in this way females can prevent deleterious alleles to be transmitted to the next generation. We tested this hypothesis through set up of two experimental groups from same genetic pool, where in one group genetic quality was manipulated by ionizing radiation. Within each group opportunity for choosing mates was imposed: males and females had no choice or had multiple choice. Mutational load was measured through the variability of different fitness components: fecundity and egg-to-adult viability. Our results indicate that sexual selection can reduce mutational load, only for fecundity. Group with the presence of female choice exhibited higher fecundity than group in which sexual selection was experimentally eliminated, but only in ?irradiated? group. There was no overall difference in egg-to-adult viability between different sexual selection regimes in any of the group. It should be considered that sexual selection can cause sexual conflict, and potential opposite effects of sexual selection and sexual conflict on fitness. Genetic structure of populations, in terms of the level of mutational load, is an important factor which can determinate the role of sexual selection.

Allometric relationships and character evolution in Onthophagus taurus (Coleoptera: Scarabaeidae)

2000 ◽  
Vol 78 (7) ◽  
pp. 1199-1206 ◽  
Author(s):  
Claudia Palestrini ◽  
Antonio Rolando ◽  
Paola Laiolo
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Small Body ◽  
Dung Beetle ◽  
Allometric Relationships ◽  
Secondary Sexual Traits ◽  
Onthophagus Taurus ◽  
Sexual Traits ◽  
External Body ◽  
Secondary Sexual

Allometric relationships in primary sexual traits (male and female genitalia), secondary sexual traits (male horns and female carinae), and non-sex-related traits (external body traits, epipharynx traits) were studied in the dung beetle Onthophagus taurus. Model II regressions of log-transformed data were used to quantify relationships, with pronotum width as regressor and indicator of overall body size. Slopes (allometric values) for the different trait categories were significantly different, with secondary sexual traits showing the highest values (higher than 1.0), followed by external body traits (slightly lower than 1.00) and epipharynx traits (around 0.2). Primary sexual traits and body size were mostly uncorrelated and genital sizes were virtually constant. Allometries of secondary sexual traits were quite different in the two sexes: the relationship between male horn length and pronotum width was approximately sigmoidal, while that between female carina length and pronotum width was linear. External body traits had significantly higher allometric values in females than in males. Our results suggest that traits in the different categories are under different kinds of selection. Genital allometries can be explained on the basis of sexual selection by cryptic female choice or by the lock-and-key hypothesis. Among secondary sexual characters, male horn morphology seems to be mostly "environmentally" determined and sexual selection would affect only a component of the developmental mechanism of horn expression. External body characters are likely under natural selection, even though a few traits could be sex-related. Finally, in both sexes, internal epipharynx traits seem to be subject to the same selective pressure, probably because males and females use the same feeding niche. The constancy of genital sizes in O. taurus suggests that in developmental processes, more is invested in primary sexual traits (to produce genitalia of the proper size) than in secondary sexual or body traits. Males receiving low quantities of food may incur costs associated with a small horn or small body size, but do not incur costs associated with small genitalia. Females probably share the same developmental pattern.

scholarly journals Can Sexual Selection Drive the Evolution of Sperm Cell Structure?

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1227
Author(s):  
Leigh W. Simmons ◽  
Francisco Garcia-Gonzalez
Keyword(s):  
Sexual Selection ◽  
Sperm Cell ◽  
Cell Structure ◽  
Dung Beetle ◽  
Divergent Evolution ◽  
Cell Phenotype ◽  
Sperm Cells ◽  
Sperm Length ◽  
Comparative Analyses ◽  
Onthophagus Taurus

Sperm cells have undergone an extraordinarily divergent evolution among metazoan animals. Parker recognized that because female animals frequently mate with more than one male, sexual selection would continue after mating and impose strong selection on sperm cells to maximize fertilization success. Comparative analyses among species have revealed a general relationship between the strength of selection from sperm competition and the length of sperm cells and their constituent parts. However, comparative analyses cannot address causation. Here, we use experimental evolution to ask whether sexual selection can drive the divergence of sperm cell phenotype, using the dung beetle Onthophagus taurus as a model. We either relaxed sexual selection by enforcing monogamy or allowed sexual selection to continue for 20 generations before sampling males and measuring the total length of sperm cells and their constituent parts, the acrosome, nucleus, and flagella. We found differences in the length of the sperm cell nucleus but no differences in the length of the acrosome, flagella, or total sperm length. Our data suggest that different sperm cell components may respond independently to sexual selection and contribute to the divergent evolution of these extraordinary cells.

Reproductive behavior

2018 ◽  
Author(s):  
Rachel Olzer ◽  
Rebecca L. Ehrlich ◽  
Justa L. Heinen-Kay ◽  
Jessie Tanner ◽  
Marlene Zuk
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Female Choice ◽  
Reproductive Behavior ◽  
Mating Systems ◽  
Insect Behavior ◽  
Sequential Approach ◽  
Evolutionary Mechanisms ◽  
Anatomy And Physiology ◽  
Males And Females

Sex and reproduction lie at the heart of studies of insect behavior. We begin by providing a brief overview of insect anatomy and physiology, followed by an introduction to the overarching themes of parental investment, sexual selection, and mating systems. We then take a sequential approach to illustrate the diversity of phenomena and concepts behind insect reproductive behavior from pre-copulatory mate signalling through copulatory sperm transfer, mating positions, and sexual conflict, to post-copulatory sperm competition, and cryptic female choice. We provide an overview of the evolutionary mechanisms driving reproductive behavior. These events are linked by the economic defendability of mates or resources, and how these are allocated in each sex. Under the framework of economic defendability, the reader can better understand how sexual antagonistic behaviors arise as the result of competing optimal fitness strategies between males and females.

Effect of Density and Extra Dung on Brood Parasitism in the Dung Beetle, Onthophagus Taurus

2012 ◽  
Vol 26 (2) ◽  
pp. 253-259 ◽  
Author(s):  
Mary Crowe ◽  
Erin Raspet ◽  
Jan Rychtar ◽  
Sat Gupta
Keyword(s):  
Brood Parasitism ◽  
Dung Beetle ◽  
Onthophagus Taurus
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