scholarly journals Female social preference for males that have evolved via monogamy: evidence of a trade-off between pre- and post-copulatory sexually selected traits?

2014 ◽  
Vol 10 (10) ◽  
pp. 20140659 ◽  
Author(s):  
Renée C. Firman
Keyword(s):  
Sperm Competition ◽  
Social Preference ◽  
A Priori ◽  
Early Life History ◽  
Trade Off ◽  
Competition Theory ◽  
Life History Stages ◽  
Fitness Advantage ◽  
Sexually Selected Traits ◽  
Selected Traits

When females mate with multiple males both pre- and post-copulatory sexual selections occur. It has been suggested that females benefit from polyandry when better-quality males are successful in sperm competition and sire high-quality offspring. Indeed, studies of experimental evolution have confirmed that sperm competition selects for both increased ejaculate quality and elevated offspring viability. Fewer investigations have explored whether these fitness benefits are evident beyond early life-history stages. Here, I used house mice ( Mus domesticus ) from selection lines that had been evolving for 25 generations under either polygamy or monogamy to test whether females preferred males from lines that had evolved with sperm competition. Males from the polygamous lines had previously been shown to achieve a fitness advantage under semi-natural conditions, deeming them to be of high genetic quality and leading to the a priori expectation that females would prefer males that had evolved with sperm competition compared with males that had not. Contrary to expectation, the data showed that sexually receptive females spent more time associating with males from the monogamous lines. This unexpected but interesting result is discussed in relation to sperm competition theory that predicts a trade-off between male investment in pre- and post-copulatory sexually selected traits.

scholarly journals Male-derived cuticular hydrocarbons signal sperm competition intensity and affect ejaculate expenditure in crickets

2008 ◽  
Vol 276 (1655) ◽  
pp. 383-388 ◽  
Author(s):  
Melissa L Thomas ◽  
Leigh W Simmons
Keyword(s):  
Sperm Competition ◽  
Chemical Cues ◽  
Relative Concentration ◽  
Virgin Female ◽  
Male Mating ◽  
Competition Intensity ◽  
Competition Theory ◽  
Fitness Advantage ◽  
First Time ◽  
Sexual Promiscuity

Female sexual promiscuity can have significant effects on male mating decisions because it increases the intensity of competition between ejaculates for fertilization. Because sperm production is costly, males that can detect multiple matings by females and allocate sperm strategically will have an obvious fitness advantage. The presence of rival males is widely recognized as a cue used by males to assess sperm competition. However, for species in which males neither congregate around nor guard females, other more cryptic cues might be involved. Here, we demonstrate unprecedented levels of sperm competition assessment by males, which is mediated via the use of chemical cues. Using the cricket Teleogryllus oceanicus , we manipulated male perception of sperm competition by experimentally coating live unmated females with cuticular compounds extracted from males. We found that males adjusted their ejaculate allocation in response to these compounds: the viability of sperm contained within a male's ejaculate decreased as the number of male extracts applied to his virgin female partner was increased. We further show that males do not respond to the relative concentration of male compounds present on females, but rather to the number of distinct signature odours of individual males. Our results conform to sperm competition theory, and show for the first time, to our knowledge, that males can detect different intensities of sperm competition by using distinct chemical cues of individual males present on females.

scholarly journals Cancer susceptibility and reproductive trade-offs: a model of the evolution of cancer defences

2015 ◽  
Vol 370 (1673) ◽  
pp. 20140220 ◽  
Author(s):  
Amy M. Boddy ◽  
Hanna Kokko ◽  
Felix Breden ◽  
Gerald S. Wilkinson ◽  
C. Athena Aktipis
Keyword(s):  
Cell Proliferation ◽  
Body Size ◽  
Cancer Susceptibility ◽  
Large Body ◽  
Large Body Size ◽  
Trade Off ◽  
Extrinsic Mortality ◽  
Sexually Selected Traits ◽  
Trade Offs ◽  
Selected Traits

The factors influencing cancer susceptibility and why it varies across species are major open questions in the field of cancer biology. One underexplored source of variation in cancer susceptibility may arise from trade-offs between reproductive competitiveness (e.g. sexually selected traits, earlier reproduction and higher fertility) and cancer defence. We build a model that contrasts the probabilistic onset of cancer with other, extrinsic causes of mortality and use it to predict that intense reproductive competition will lower cancer defences and increase cancer incidence. We explore the trade-off between cancer defences and intraspecific competition across different extrinsic mortality conditions and different levels of trade-off intensity, and find the largest effect of competition on cancer in species where low extrinsic mortality combines with strong trade-offs. In such species, selection to delay cancer and selection to outcompete conspecifics are both strong, and the latter conflicts with the former. We discuss evidence for the assumed trade-off between reproductive competitiveness and cancer susceptibility. Sexually selected traits such as ornaments or large body size require high levels of cell proliferation and appear to be associated with greater cancer susceptibility. Similar associations exist for female traits such as continuous egg-laying in domestic hens and earlier reproductive maturity. Trade-offs between reproduction and cancer defences may be instantiated by a variety of mechanisms, including higher levels of growth factors and hormones, less efficient cell-cycle control and less DNA repair, or simply a larger number of cell divisions (relevant when reproductive success requires large body size or rapid reproductive cycles). These mechanisms can affect intra- and interspecific variation in cancer susceptibility arising from rapid cell proliferation during reproductive maturation, intrasexual competition and reproduction.

scholarly journals Why are sexually selected weapons almost absent in females?

2013 ◽  
Vol 59 (4) ◽  
pp. 564-568 ◽  
Author(s):  
Anders Berglund
Keyword(s):  
Sex Roles ◽  
Sex Role ◽  
Sharp Contrast ◽  
Trade Off ◽  
Sexually Selected Traits ◽  
Direct Benefits ◽  
Female Ornaments ◽  
Males And Females ◽  
Selected Traits ◽  
Predator Defence

Abstract In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role reversed or not. However, sexually selected female weapons seem totally absent except for small wing spurs in three jacana species, present in both males and females. This poor female weaponry is in sharp contrast to the situation in species with conventional sex roles: males commonly have evolved sexually selected weapons as well as ornaments. At the same time, females in many taxa have naturally selected weapons, used in competition over resources or in predator defence. Why are sexually selected weapons then so rare, almost absent, in females? Here I briefly review weaponry in females and the function of these weapons, conclude that the near absence of sexually selected weapons begs an explanation, and suggest that costs of sexually selected weapons may exceed costs of ornaments. Females are more constrained when evolving sexually selected traits compared to males, at least compared to those males that do not provide direct benefits, as trait costs reduce a female’s fecundity. I suggest that this constraining trade-off between trait and fecundity restricts females to evolve ornaments but rarely weapons. The same may apply to paternally investing males. Whether sexually selected weapons actually are more costly than sexually selected ornaments remains to be investigated.

scholarly journals Intraspecific sperm competition genes enforce post-mating species barriers in Drosophila

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142050 ◽  
Author(s):  
Dean M. Castillo ◽  
Leonie C. Moyle
Keyword(s):  
Sexual Selection ◽  
Reproductive Isolation ◽  
Sperm Competition ◽  
Competitive Ability ◽  
Sexual Isolation ◽  
Theoretical Models ◽  
Sexually Selected Traits ◽  
Genetic Mechanisms ◽  
Selected Traits ◽  
Additional Role

Sexual selection and sexual conflict are considered important drivers of speciation, based on both theoretical models and empirical correlations between sexually selected traits and diversification. However, whether reproductive isolation between species evolves directly as a consequence of intrapopulation sexual dynamics remains empirically unresolved, in part because knowledge of the genetic mechanisms (if any) connecting these processes is limited. Here, we provide evidence of a direct mechanistic link between intraspecies sexual selection and reproductive isolation. We examined genes with known roles in intraspecific sperm competition (ISC) in D. melanogaster and assayed their impact on conspecific sperm precedence (CSP). We found that two such genes ( Acp36DE and CG9997 ) contribute to both offensive sperm competition and CSP; null/knockdown lines both had lower competitive ability against D. melanogaster conspecifics and were no longer able to displace heterospecific D. simulans sperm in competitive matings. In comparison, Sex Peptide ( Acp70A )—another locus essential for ISC—does not contribute to CSP. These data indicate that two loci important for sperm competitive interactions have an additional role in similar interactions that enforce post-mating reproductive isolation between species, and show that sexual selection and sexual isolation can act on the same molecular targets in a gene-specific manner.

scholarly journals Natural and sexual selection on cuticular hydrocarbons: a quantitative genetic analysis

2019 ◽  
Vol 286 (1902) ◽  
pp. 20190677 ◽  
Author(s):  
Jacob D. Berson ◽  
Marlene Zuk ◽  
Leigh W. Simmons
Keyword(s):  
Cuticular Hydrocarbon ◽  
Field Cricket ◽  
Desiccation Resistance ◽  
Fitness Costs ◽  
Trade Off ◽  
Sexually Selected Traits ◽  
Quantitative Genetic ◽  
Selected Traits ◽  
Selected Functions ◽  
Natural And Sexual Selection

While the reproductive benefits of sexual displays have been widely studied, we have relatively limited evidence of the fitness costs associated with most display traits. Insect cuticular hydrocarbon (CHC) profiles are sexually selected traits that also protect against desiccation. These two functions are thought to oppose each other, with investment in particular compounds believed to increase attractiveness at the expense of compounds that protect against water loss. We investigated this potential trade-off in a quantitative genetic framework using the Australian field cricket, Teleogryllus oceanicus . Several compounds were significantly genetically correlated with either attractiveness or desiccation resistance. Of these compounds, one was negatively genetically correlated with attractiveness but positively genetically correlated with desiccation resistance. Furthermore, scoring each individual's overall CHC profile for its level of attractiveness and desiccation resistance indicated a negative genetic correlation between these multivariate phenotypes. Together, our results provide evidence for a genetic trade-off between sexually and naturally selected functions of the CHC profile. We suggest that the production of an attractive CHC profile may be costly for males, but highlight the need for further work to support this finding experimentally. Genetic covariation between the CHC profile and attractiveness suggests that females can gain attractive sons through female choice.

scholarly journals Greater sperm complexity in the Australasian old endemic rodents (Tribe: Hydromyini) is associated with increased levels of inter-male sperm competition

2017 ◽  
Vol 29 (5) ◽  
pp. 921 ◽  
Author(s):  
Hanna J. McLennan ◽  
Stefan Lüpold ◽  
Pete Smissen ◽  
Kevin C. Rowe ◽  
William G. Breed
Keyword(s):  
Sperm Competition ◽  
Sperm Morphology ◽  
Tail Length ◽  
Sperm Head ◽  
Sperm Tail ◽  
Apical Hook ◽  
Sexually Selected Traits ◽  
Male Sperm ◽  
Murid Rodents ◽  
Selected Traits

Spermatozoa exhibit considerable interspecies morphological variation across mammals, especially among murid rodents. In Australasia, most murids in the tribe Hydromyini have a spermatozoon with a highly complex head exhibiting an apical hook, characteristic of most murids, and two projections that extend from its upper concave surface, the ventral processes. In the present study we performed a phylogenetically controlled comparison of sperm morphology across 45 species of hydromyine rodents to test the hypothesis that the length and angle of both the apical hook and ventral processes, as well as the length of the sperm tail, increase with relative testes mass as a proxy for differences in levels of inter-male sperm competition. Although both sperm head protrusions exhibited considerable variation in their length and angle across species, only the angles increased significantly in relation to relative testes mass. Further, the length of the sperm flagellum was positively associated with relative testes mass. These results suggest that, in hydromyine rodents, the angle of the apical hook and ventral processes of the sperm head, as well as the sperm tail length, are likely to be sexually selected traits. The possible functional significance of these findings is briefly discussed.

scholarly journals Absence of reproduction-immunity trade-off in male Drosophila melanogaster evolving under differential sexual selection.

2019 ◽  
Author(s):  
Zeeshan Ali Syed ◽  
Vanika Gupta ◽  
Manas Geeta Arun ◽  
Aatashi Dhiman ◽  
Bodhisatta Nandy ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Post Infection ◽  
Reproductive Traits ◽  
Trade Off ◽  
Sexually Selected Traits ◽  
Naturally Occurring ◽  
Selection History ◽  
Selected Traits ◽  
Positive Correlations

Abstract Background: The theory of trade-off suggests that limited resources should lead to trade-off in resource intensive traits such as, immunity related and sexually selected traits in males. Alternatively, sexual exaggerations can also act as an honest indicator of underlying immunocompetence, leading to positive correlations between these traits. Evidences in support of either hypothesis in invertebrates is equivocal. Whereas several studies have addressed this question, few have used naturally occurring pathogens and realized post infection realized immunity (e.g., survivorship) to assay the fitness correlations between these two sets of traits. Results: Adopting an experimental evolution approach, we evolved replicate populations of Drosophila melanogaster under (high and low) sexual selection regimes for over a hundred generations and found the following in virgin and mated males in three separate assays: a. Post infection survivorship against two natural pathogens - Pseudomonas entomophila (Pe) and Staphylococcus succinus (Ss): Mated males survived better against Pe, but were no different than virgins against Ss. b. Bacterial clearance ability against a third natural pathogen Providencia rettgeri (Pr): Mated males had significantly lower CFUs than virgins. However, sexual selection history had no effect on realized immunity of either virgin or mated males. Conclusion: We show that while mating can affect realized immunity in a pathogen specific way, sexual selection did not affect the same. The results highlight that complex polygenic traits such as immunity and reproductive traits not necessarily evolve following a binary trade-off model. We also stress the importance natural pathogens while studying sexual selection-immunity correlations.

scholarly journals Female × male and male × male interactions have limited influence on competitive fertilization inDrosophila melanogaster

2019 ◽  
Author(s):  
Stefan Lüpold ◽  
Jonathan Bradley Reil ◽  
Mollie K. Manier ◽  
Valérian Zeender ◽  
John M. Belote ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Cryptic Female Choice ◽  
Complex Interactions ◽  
Sexually Selected Traits ◽  
Selected Traits ◽  
Reproductive Events

AbstractHow males and females contribute to joint reproductive success has been a long-standing question in sexual selection. Under postcopulatory sexual selection (PSS), paternity success is predicted to derive from complex interactions among females engaging in cryptic female choice and males engaging in sperm competition. Such interactions have been identified as potential sources of genetic variation in sexually selected traits but are also expected to inhibit trait diversification. To date, studies of interactions between females and competing males have focused almost exclusively on genotypes and not phenotypic variation in sexually selected traits. Here, we characterize within- and between-sex interactions inDrosophila melanogasterusing isogenic lines with heritable variation in both male and female traits known to influence competitive fertilization. We found surprisingly few genotypic interaction effects on various stages of PSS such as female remating interval, copulation duration, sperm transfer, or sperm storage. Only the timing of female sperm ejection depended on female × male genotypic interactions. By contrast, several reproductive events, including sperm transfer, female sperm ejection and sperm storage, were explained by two- and three-way interactions among sex-specific phenotypes. We also documented complex interactions between the lengths of competing males’ sperm and the female seminal receptacle, which are known to have experienced rapid female-male co-diversification. Our results highlight the non-independence of sperm competition and cryptic female choice and demonstrate that complex interactions between the sexes do not limit the ability of multivariate systems to respond to directional sexual selection.Significance statementFor species with internal fertilization and female promiscuity, postcopulatory sexual selection (PSS) is believed to depend, in part, on complex interactions between rival males and between the sexes. Although little investigated, clarifying such interactions is critical as they may limit the efficacy of PSS in the diversification of reproductive traits (e.g., ejaculate biochemistry and sperm, genitalia and female reproductive tract morphology). Here, we resolve how sex-specific traits and their interactions contribute to key reproductive events and outcomes related to competitive fertilization success, including traits known to have experienced rapid diversification. Our results provide novel insights into the operation and complexity of PSS and demonstrate that the processes of sperm competition and cryptic female choice are not independent selective forces.

Sign in / Sign up

Export Citation Format

Share Document