scholarly journals Digest: Sexual conflict as a novel hypothesis for the evolution of gynodioecy

Evolution ◽  
2021 ◽  
Author(s):  
Jeanne Tonnabel
Keyword(s):  
Sexual Conflict

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.

scholarly journals A unique mating pattern of Panorpodes kuandianensis (Mecoptera: Panorpodidae)

2017 ◽  
Vol 86 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Xin Tong ◽  
Lu Jiang ◽  
Bao-Zhen Hua
Keyword(s):  
Mating Behavior ◽  
Sexual Conflict ◽  
Sperm Transfer ◽  
Nuptial Gift ◽  
Mating Pattern ◽  
End To End ◽  
Mating Behaviors ◽  
First Time

Sexually reproductive insects exhibit diverse mating behaviors. However, the mating pattern remains unknown for Panorpodes of Panorpodidae to date. In this study, we investigated the mating behavior and copulatory mechanism of the short-faced scorpionfly Panorpodes kuandianensis Zhong, Zhang and Hua, 2011 for the first time. The results show that the male provides a salivary mass as a nuptial gift to the female and starts to copulate with the female in a V-shaped position, then changes to an end-to-end position by temporarily twisting the female abdominal segments VII−IX by 180°. During mating the basal processes and the basal teeth of the gonostyli and the hypandrium are used to obtain copulation and sustain the coupling of genitalia to secure successful sperm transfer. This unique mating pattern is greatly different from that of other Mecoptera reported and is likely evolved as an adaptation in the context of sexual conflict.

scholarly journals The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict?

2020 ◽  
Vol 75 (1) ◽  
Author(s):  
Julia A. Kunz ◽  
Guilhem J. Duvot ◽  
Maria A. van Noordwijk ◽  
Erik P. Willems ◽  
Manuela Townsend ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Sexual Coercion ◽  
High Association ◽  
Sexual Swellings ◽  
Fecal Cortisol ◽  
Habitat Productivity ◽  
Pongo Pygmaeus Wurmbii ◽  
Males And Females ◽  
Study Sites ◽  
The Cost

Abstract Sexual coercion, in the form of forced copulations, is relatively frequently observed in orangutans and generally attributed to their semi-solitary lifestyle. High ecological costs of association for females may be responsible for this lifestyle and may have prevented the evolution of morphological fertility indicators (e.g., sexual swellings), which would attract (male) associates. Therefore, sexual conflict may arise not only about mating per se but also about associations, because males may benefit from associations with females to monitor their reproductive state and attempt to monopolize their sexual activities. Here, we evaluate association patterns and costs for females when associating with both males and females of two different orangutan species at two study sites: Suaq, Sumatra (Pongo abelii), and Tuanan, Borneo (Pongo pygmaeus wurmbii). Female association frequency with both males and females was higher in the Sumatran population, living in more productive habitat. Accordingly, we found that the cost of association, in terms of reduced feeding to moving ratio and increased time being active, is higher in the less sociable Bornean population. Males generally initiated and maintained such costly associations with females, and prolonged associations with males led to increased female fecal cortisol metabolite (FCM) levels at Tuanan, the Bornean population. We conclude that male-maintained associations are an expression of sexual conflict in orangutans, at least at Tuanan. For females, this cost of association may be responsible for the lack of sexual signaling, while needing to confuse paternity. Significance statement Socioecological theory predicts a trade-off between the benefits of sociality and the ecological costs of increased feeding competition. Orangutans’ semi-solitary lifestyle has been attributed to the combination of high association costs and low predation risk. Previous work revealed a positive correlation between association frequencies and habitat productivity, but did not measure the costs of association. In this comparative study, we show that females likely incur costs from involuntary, male-maintained associations, especially when they last for several days and particularly in the population characterized by lower association frequencies. Association maintenance therefore qualifies as another expression of sexual conflict in orangutans, and especially prolonged, male-maintained associations may qualify as an indirect form of sexual coercion.

scholarly journals Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Basabi Bagchi ◽  
Quentin Corbel ◽  
Imroze Khan ◽  
Ellen Payne ◽  
Devshuvam Banerji ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Mating System ◽  
Sexual Conflict ◽  
Experimental Evolution ◽  
Parasitic Infections ◽  
Pathogen Dynamics ◽  
Trade Offs ◽  
Host Pathogen ◽  
Seed Beetles

Abstract Background Sexual dimorphism in immunity is believed to reflect sex differences in reproductive strategies and trade-offs between competing life history demands. Sexual selection can have major effects on mating rates and sex-specific costs of mating and may thereby influence sex differences in immunity as well as associated host–pathogen dynamics. Yet, experimental evidence linking the mating system to evolved sexual dimorphism in immunity are scarce and the direct effects of mating rate on immunity are not well established. Here, we use transcriptomic analyses, experimental evolution and phylogenetic comparative methods to study the association between the mating system and sexual dimorphism in immunity in seed beetles, where mating causes internal injuries in females. Results We demonstrate that female phenoloxidase (PO) activity, involved in wound healing and defence against parasitic infections, is elevated relative to males. This difference is accompanied by concomitant sex differences in the expression of genes in the prophenoloxidase activating cascade. We document substantial phenotypic plasticity in female PO activity in response to mating and show that experimental evolution under enforced monogamy (resulting in low remating rates and reduced sexual conflict relative to natural polygamy) rapidly decreases female (but not male) PO activity. Moreover, monogamous females had evolved increased tolerance to bacterial infection unrelated to mating, implying that female responses to costly mating may trade off with other aspects of immune defence, an hypothesis which broadly accords with the documented sex differences in gene expression. Finally, female (but not male) PO activity shows correlated evolution with the perceived harmfulness of male genitalia across 12 species of seed beetles, suggesting that sexual conflict has a significant influence on sexual dimorphisms in immunity in this group of insects. Conclusions Our study provides insights into the links between sexual conflict and sexual dimorphism in immunity and suggests that selection pressures moulded by mating interactions can lead to a sex-specific mosaic of immune responses with important implications for host–pathogen dynamics in sexually reproducing organisms.

scholarly journals Is Sexual Conflict a Driver of Speciation? A Case Study With a Tribe of Brush-footed Butterflies

2020 ◽  
Author(s):  
Ana Paula S Carvalho ◽  
Ryan A St Laurent ◽  
Emmanuel F A Toussaint ◽  
Caroline Storer ◽  
Kelly M Dexter ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Abiotic Factors ◽  
Evolutionary Mechanisms ◽  
Diversification Rates ◽  
Exon Capture ◽  
Key Driver ◽  
Underlying Mechanisms ◽  
Analytical Approaches ◽  
Acting In Concert

Abstract Understanding the evolutionary mechanisms governing the uneven distribution of species richness across the tree of life is a great challenge in biology. Scientists have long argued that sexual conflict is a key driver of speciation. This hypothesis, however, has been highly debated in light of empirical evidence. Recent advances in the study of macroevolution make it possible to test this hypothesis with more data and increased accuracy. In the present study, we use phylogenomics combined with four different diversification rate analytical approaches to test whether sexual conflict is a driver of speciation in brush-footed butterflies of the tribe Acraeini. The presence of a sphragis, an external mating plug found in most species among Acraeini, was used as a proxy for sexual conflict. Diversification analyses statistically rejected the hypothesis that sexual conflict is associated with shifts in diversification rates in Acraeini. This result contrasts with earlier studies and suggests that the underlying mechanisms driving diversification are more complex than previously considered. In the case of butterflies, natural history traits acting in concert with abiotic factors possibly play a stronger role in triggering speciation than does sexual conflict. [Acraeini butterflies; arms race; exon capture phylogenomics; Lepidoptera macroevolution; sexual selection; sphragis.]

scholarly journals The limits of sexual conflict in the narrow sense: new insights from waterfowl biology

2012 ◽  
Vol 367 (1600) ◽  
pp. 2324-2338 ◽  
Author(s):  
Patricia L. R. Brennan ◽  
Richard O. Prum
Keyword(s):  
Sexual Conflict ◽  
Female Preference ◽  
Indirect Selection ◽  
Direct Selection ◽  
Sensory Bias ◽  
Indirect Benefits ◽  
Female Preferences ◽  
Male Display ◽  
Male Displays ◽  
Coercive Mating

Sexual conflict occurs when the evolutionary interests of the sexes differ and it broadly applies to decisions over mating, fertilization and parental investment. Recently, a narrower view of sexual conflict has emerged in which direct selection on females to avoid male-imposed costs during mating is considered the distinguishing feature of conflict, while indirect selection is considered negligible. In this view, intersexual selection via sensory bias is seen as the most relevant mechanism by which male traits that harm females evolve, with antagonistic coevolution between female preferences and male manipulation following. Under this narrower framework, female preference and resistance have been synonymized because both result in a mating bias, and similarly male display and coercion are not distinguished. Our recent work on genital evolution in waterfowl has highlighted problems with this approach. In waterfowl, preference and resistance are distinct components of female phenotype, and display and coercion are independent male strategies. Female preference for male displays result in mate choice, while forced copulations by unpreferred males result in resistance to prevent these males from achieving matings and fertilizations. Genital elaborations in female waterfowl appear to function in reinforcing female preference to maintain the indirect benefits of choice rather than to reduce the direct costs of coercive mating. We propose a return to a broader view of conflict where indirect selection and intrasexual selection are considered important in the evolution of conflict.

scholarly journals Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia

2009 ◽  
Vol 277 (1686) ◽  
pp. 1309-1314 ◽  
Author(s):  
Patricia L. R. Brennan ◽  
Christopher J. Clark ◽  
Richard O. Prum
Keyword(s):  
Functional Morphology ◽  
Sexual Conflict
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