scholarly journals Kin selection and sexual conflict: male relatedness and familiarity do not affect female fitness in seed beetles

2019 ◽  
Author(s):  
Elena C. Berg ◽  
Martin I. Lind ◽  
Shannon Monahan ◽  
Sophie Bricout ◽  
Alexei A. Maklakov
Keyword(s):  
Sexual Conflict ◽  
Kin Selection ◽  
Callosobruchus Maculatus ◽  
Lifetime Reproductive Success ◽  
Individual Fitness ◽  
Adaptive Mechanisms ◽  
Female Survival ◽  
Reproductive Part ◽  
Seed Beetles

SummaryTheory maintains that kin selection can mediate sexual conflict because within-group male relatedness should reduce male-male competition, thereby reducing collateral harm to females. We tested whether male relatedness and familiarity can lessen female harm in the seed beetle Callosobruchus maculatus. Neither male relatedness nor familiarity influenced female lifetime reproductive success or individual fitness. However, male relatedness, but not familiarity, marginally improved female survival. Because male relatedness improved female survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of kin selection in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies and suggest that cognitive error is a likely explanation.

scholarly journals Kin but less than kind: within-group male relatedness does not increase female fitness in seed beetles

2019 ◽  
Vol 286 (1910) ◽  
pp. 20191664 ◽  
Author(s):  
Elena C. Berg ◽  
Martin I. Lind ◽  
Shannon Monahan ◽  
Sophie Bricout ◽  
Alexei A. Maklakov
Keyword(s):  
Sexual Conflict ◽  
Callosobruchus Maculatus ◽  
Lifetime Reproductive Success ◽  
Cognitive Error ◽  
Individual Fitness ◽  
Adaptive Mechanisms ◽  
Female Survival ◽  
Reproductive Part ◽  
Seed Beetles

Theory maintains within-group male relatedness can mediate sexual conflict by reducing male–male competition and collateral harm to females. We tested whether male relatedness can lessen female harm in the seed beetle Callosobruchus maculatus . Male relatedness did not influence female lifetime reproductive success or individual fitness across two different ecologically relevant scenarios of mating competition. However, male relatedness marginally improved female survival. Because male relatedness improved female survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of within-group male relatedness in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of the female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies, and suggest that cognitive error is a likely explanation.

scholarly journals EvEel (evolutionary ecology-based model for eel): a model to explore the role of phenotypic plasticity as an adaptive response of three temperate eels to spatially structured environments

2014 ◽  
Vol 71 (10) ◽  
pp. 1561-1571 ◽  
Author(s):  
Hilaire Drouineau ◽  
Christian Rigaud ◽  
Françoise Daverat ◽  
Patrick Lambert
Keyword(s):  
Phenotypic Plasticity ◽  
Adaptive Response ◽  
Evolutionary Ecology ◽  
Anguilla Anguilla ◽  
Distribution Area ◽  
Heterogeneous Environments ◽  
Larval Drift ◽  
Individual Fitness ◽  
Adaptive Mechanisms

Anguilla anguilla, Anguilla japonica, and Anguilla rostrata are three widely distributed catadromous and semelparous species characterized by a long and passive oceanic larval drift between their marine spawning grounds and nursery areas in continental waters. Their large, spatially heterogeneous environments combined with population panmixia and long and passive larval drift impair the possibility of local adaptation and favour the development of phenotypic plasticity. In this context, we developed EvEel (evolutionary ecology-based model for eel), a model that aims to explore the role of phenotypic plasticity as an adaptive response of eels. Results suggest that the spatial patterns in terms of sex ratio, length-at-silvering, and habitat use observed at both the distribution area and river catchment scales may actually be the result of three adaptive mechanisms to maximize individual fitness in spatially structured environments. We believe that considering phenotypic plasticity as a paradigm is required to develop appropriate models for this species.

scholarly journals No evidence that relatedness or familiarity modulate male harm in wild Drosophila melanogaster

2021 ◽  
Author(s):  
Ana Marquez-Rosado ◽  
Clara García-Có ◽  
Claudia Londoño-Nieto ◽  
Pau Carazo
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Conflict ◽  
Kin Selection ◽  
Kin Recognition ◽  
Natural Populations ◽  
Male Competition ◽  
Natural Conditions ◽  
Population Average ◽  
In The Wild

Sexual selection frequently promotes the evolution of aggressive behaviours that help males compete against their rivals, but which may harm females and hamper their fitness. Kin selection theory predicts that optimal male-male competition levels can be reduced when competitors are more genetically related to each other than to the population average, contributing to resolve this sexual conflict. Work in Drosophila melanogaster has spearheaded empirical tests of this idea, but studies so far have been conducted in lab-adapted populations in homogeneous rearing environments that may hamper kin recognition, and used highly skewed sex ratios that may fail to reflect average natural conditions. Here, we performed a fully factorial design with the aim of exploring how rearing environment (i.e. familiarity) and relatedness affect male-male aggression, male harassment, and overall male harm levels in a natural population of Drosophila melanogaster, under more natural conditions. Namely, we: a) manipulated relatedness and familiarity so that larvae reared apart were raised in different environments, as is common in the wild, and b) studied the effects of relatedness and familiarity under average levels of male-male competition in the field. We show that, contrary to previous findings, groups of unrelated-unfamiliar males were as likely to fight with each other and harass females than related-familiar males, and that overall levels of male harm to females were similar across treatments. Our results suggest that the role of kin selection in modulating sexual conflict is yet unclear in Drosophila melanogaster, and call for further studies that focus on natural populations and realistic socio-sexual and ecological environments.

scholarly journals Are flies kind to kin? The role of intra- and inter-sexual relatedness in mediating reproductive conflict

2015 ◽  
Vol 282 (1821) ◽  
pp. 20151991 ◽  
Author(s):  
Emily S. Martin ◽  
Tristan A. F. Long
Keyword(s):  
Sexual Conflict ◽  
Kin Selection ◽  
Alternative Explanation ◽  
Potential Role ◽  
Inclusive Fitness ◽  
Empirical Support ◽  
Cooperative Behaviour ◽  
Males And Females ◽  
Individual Success

As individual success often comes at the expense of others, interactions between the members of a species are frequently antagonistic, especially in the context of reproduction. In theory, this conflict may be reduced in magnitude when kin interact, as cooperative behaviour between relatives can result in increased inclusive fitness. Recent tests of the potential role of cooperative behaviour between brothers in Drosophila melanogaster have proved to be both exciting and controversial. We set out to replicate these experiments, which have profound implications for the study of kin selection and sexual conflict, and to expand upon them by also examining the potential role of kinship between males and females in reproductive interactions. While we did observe reduced fighting and courtship effort between competing brothers, contrary to previous studies we did not detect any fitness benefit to females as a result of the modification of male antagonistic behaviours. Furthermore, we did not observe any differential treatment of females by their brothers, as would be expected if the intensity of sexual conflict was mediated by kin selection. In the light of these results, we propose an alternative explanation for observed differences in male–male conflict and provide preliminary empirical support for this hypothesis.

scholarly journals Quantifying variation in female internal genitalia: no evidence for plasticity in response to sexual conflict risk in a seed beetle

2021 ◽  
Vol 288 (1954) ◽  
pp. 20210746
Author(s):  
Blake W. Wyber ◽  
Liam R. Dougherty ◽  
Kathryn McNamara ◽  
Andrew Mehnert ◽  
Jeremy Shaw ◽  
...  
Keyword(s):  
Social Environment ◽  
Sexual Conflict ◽  
Reproductive Tract ◽  
Callosobruchus Maculatus ◽  
Dimensional Space ◽  
Female Reproductive Tract ◽  
Female Resistance ◽  
The Social ◽  
Low Levels ◽  
Seed Beetles

Sexually antagonistic coevolution can drive the evolution of male traits that harm females, and female resistance to those traits. While males have been found to vary their harmfulness to females in response to social cues, plasticity in female resistance traits remains to be examined. Here, we ask whether female seed beetles Callosobruchus maculatus are capable of adjusting their resistance to male harm in response to the social environment. Among seed beetles, male genital spines harm females during copulation and females might resist male harm via thickening of the reproductive tract walls. We develop a novel micro computed tomography imaging technique to quantify female reproductive tract thickness in three-dimensional space, and compared the reproductive tracts of females from populations that had evolved under high and low levels of sexual conflict, and for females reared under a social environment that predicted either high or low levels of sexual conflict. We find little evidence to suggest that females can adjust the thickness of their reproductive tracts in response to the social environment. Neither did evolutionary history affect reproductive tract thickness. Nevertheless, our novel methodology was capable of quantifying fine-scale differences in the internal reproductive tracts of individual females, and will allow future investigations into the internal organs of insects and other animals.

scholarly journals Thermal Preferences of Cowpea Seed Beetles (Callosobruchus maculatus): Effects of Sex and Nuptial Gift Transfers

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 310
Author(s):  
Dariusz Krzysztof Małek ◽  
Marcin Czarnoleski
Keyword(s):  
Water Balance ◽  
Callosobruchus Maculatus ◽  
Thermal Environment ◽  
Nuptial Gift ◽  
Thermal Preference ◽  
Nuptial Gifts ◽  
Insect Performance ◽  
Evaporative Water ◽  
Thermal Preferences ◽  
Seed Beetles

The thermal environment influences insect performance, but the factors affecting insect thermal preferences are rarely studied. We studied Callosobruchus maculatus seed beetles and hypothesized that thermal preferences are influenced by water balance, with individuals with limited water reserves preferring cooler habitats to reduce evaporative water loss. Adult C. maculatus, in their flightless morph, do not consume food or water, but a copulating male provides a female with a nuptial gift of ejaculate containing nutrients and water. We hypothesized that gift recipients would prefer warmer habitats than gift donors and that both sexes would plastically adjust their thermal preferences according to the size of the transferred gift. We measured the thermal preference in each sex in individuals that were mated once or were unmated. In the mated group, we measured the sizes of the nuptial gifts and calculated proportional body mass changes in each mate during copulation. Supporting the role of water balance in thermal preference, females preferred warmer habitats than males. Nevertheless, thermal preferences in either sex were not affected by mating status or gift size. It is likely that high rates of mating and gift transfers in C. maculatus living under natural conditions promoted the evolution of constitutive sex-dependent thermal preferences.

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 Family quarrels in seeds and rapid adaptive evolution in Arabidopsis

2019 ◽  
Vol 116 (19) ◽  
pp. 9463-9468 ◽  
Author(s):  
Katherine S. Geist ◽  
Joan E. Strassmann ◽  
David C. Queller
Keyword(s):  
Adaptive Evolution ◽  
Kin Selection ◽  
Conflicts Of Interest ◽  
A Priori ◽  
Flowering Plant ◽  
Rapid Adaptation ◽  
Arms Races ◽  
Evolutionary Conflict ◽  
Alternative Hypotheses

Evolutionary conflict can drive rapid adaptive evolution, sometimes called an arms race, because each party needs to respond continually to the adaptations of the other. Evidence for such arms races can sometimes be seen in morphology, in behavior, or in the genes underlying sexual interactions of host−pathogen interactions, but is rarely predicted a priori. Kin selection theory predicts that conflicts of interest should usually be reduced but not eliminated among genetic relatives, but there is little evidence as to whether conflict within families can drive rapid adaptation. Here we test multiple predictions about how conflict over the amount of resources an offspring receives from its parent would drive rapid molecular evolution in seed tissues of the flowering plant Arabidopsis. As predicted, there is more adaptive evolution in genes expressed in Arabidopsis seeds than in other specialized organs, more in endosperms and maternal tissues than in embryos, and more in the specific subtissues involved in nutrient transfer. In the absence of credible alternative hypotheses, these results suggest that kin selection and conflict are important in plants, that the conflict includes not just the mother and offspring but also the triploid endosperm, and that, despite the conflict-reducing role of kinship, family members can engage in slow but steady tortoise-like arms races.

scholarly journals Sex-biased dispersal, kin selection and the evolution of sexual conflict

2015 ◽  
Vol 28 (10) ◽  
pp. 1901-1910 ◽  
Author(s):  
Gonçalo S. Faria ◽  
Susana A. M. Varela ◽  
Andy Gardner
Keyword(s):  
Sexual Conflict ◽  
Kin Selection

scholarly journals Sex differences in helping effort reveal the effect of future reproduction on cooperative behaviour in birds

2018 ◽  
Vol 285 (1885) ◽  
pp. 20181164 ◽  
Author(s):  
Philip A. Downing ◽  
Ashleigh S. Griffin ◽  
Charlie K. Cornwallis
Keyword(s):  
Sex Differences ◽  
Reproductive Success ◽  
Kin Selection ◽  
Cooperative Behaviour ◽  
The Future ◽  
Helping Behaviour ◽  
Future Reproduction ◽  
Selection For ◽  
Family Groups

The evolution of helping behaviour in species that breed cooperatively in family groups is typically attributed to kin selection alone. However, in many species, helpers go on to inherit breeding positions in their natal groups, but the extent to which this contributes to selection for helping is unclear as the future reproductive success of helpers is often unknown. To quantify the role of future reproduction in the evolution of helping, we compared the helping effort of female and male retained offspring across cooperative birds. The kin selected benefits of helping are equivalent between female and male helpers—they are equally related to the younger siblings they help raise—but the future reproductive benefits of helping differ because of sex differences in the likelihood of breeding in the natal group. We found that the sex which is more likely to breed in its natal group invests more in helping, suggesting that in addition to kin selection, helping in family groups is shaped by future reproduction.

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