1
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Baur J, Zwoinska M, Koppik M, Snook RR, Berger D. Heat stress reveals a fertility debt owing to postcopulatory sexual selection. Evol Lett 2024; 8:101-113. [PMID: 38370539 PMCID: PMC10872150 DOI: 10.1093/evlett/qrad007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 01/21/2023] [Accepted: 02/21/2023] [Indexed: 02/20/2024] Open
Abstract
Climates are changing rapidly, demanding equally rapid adaptation of natural populations. Whether sexual selection can aid such adaptation is under debate; while sexual selection should promote adaptation when individuals with high mating success are also best adapted to their local surroundings, the expression of sexually selected traits can incur costs. Here we asked what the demographic consequences of such costs may be once climates change to become harsher and the strength of natural selection increases. We first adopted a classic life history theory framework, incorporating a trade-off between reproduction and maintenance, and applied it to the male germline to generate formalized predictions for how an evolutionary history of strong postcopulatory sexual selection (sperm competition) may affect male fertility under acute adult heat stress. We then tested these predictions by assessing the thermal sensitivity of fertility (TSF) in replicated lineages of seed beetles maintained for 68 generations under three alternative mating regimes manipulating the opportunity for sexual and natural selection. In line with the theoretical predictions, we find that males evolving under strong sexual selection suffer from increased TSF. Interestingly, females from the regime under strong sexual selection, who experienced relaxed selection on their own reproductive effort, had high fertility in benign settings but suffered increased TSF, like their brothers. This implies that female fertility and TSF evolved through genetic correlation with reproductive traits sexually selected in males. Paternal but not maternal heat stress reduced offspring fertility with no evidence for adaptive transgenerational plasticity among heat-exposed offspring, indicating that the observed effects may compound over generations. Our results suggest that trade-offs between fertility and traits increasing success in postcopulatory sexual selection can be revealed in harsh environments. This can put polyandrous species under immediate risk during extreme heat waves expected under future climate change.
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Affiliation(s)
- Julian Baur
- Department of Ecology and Genetics, Division of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Martyna Zwoinska
- Department of Ecology and Genetics, Division of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Mareike Koppik
- Department of Ecology and Genetics, Division of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- Department of Zoology, Animal Ecology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Rhonda R Snook
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - David Berger
- Department of Ecology and Genetics, Division of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
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2
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Di X, Yan B, Liu J, Wu C, Yu X, Smith CL, Yang M. Transgenerational effects of multiple mating in Spodoptera litura Fabricius (Lepidoptera: Noctuidae). Ecol Evol 2023; 13:e10189. [PMID: 37325727 PMCID: PMC10266576 DOI: 10.1002/ece3.10189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 05/14/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023] Open
Abstract
Polyandrous mating can result in sexual conflict and/or promote the evolution of mating patterns. Does multiple mating by females support the genetic benefits hypothesis and can it be validated as an evolutionary strategy? If we are to decipher the consequences of sexual interactions and understand the interplay of sexual conflict and multiple generational benefits, the transgenerational effects need to be followed over multiple generations. We investigated the effects of three mating patterns, single mating, repeated mating, and multiple mating, on parental Spodoptera litura copulation behavior, and then identified the impact on the development, survival, and fecundity of the F1 and F2 generations. Fecundity was not significantly affected in the F1 generation but was substantially enhanced in the F2 generation. There was a reversal of offspring fitness across the F2 generations from the F1 generations in progeny produced by multiple mating. In addition, the intrinsic rate of increase, finite rate of increase and net reproductive rate in the F1 generation the multiple mating treatment was significantly lower than in the single mating treatment, but there was no apparent effect on the F2 generation. Repeated mating had no significant effects on progeny fitness. We postulate that multiple mating imposes cross-transgenerational effects and may ultimately influence multigenerational fitness in S. litura.
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Affiliation(s)
- Xue‐yuan Di
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pest in Guiyang, Institute of Entomology, Guizhou UniversityMinistry of AgricultureGuiyangChina
| | - Bin Yan
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pest in Guiyang, Institute of Entomology, Guizhou UniversityMinistry of AgricultureGuiyangChina
| | - Jian‐feng Liu
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pest in Guiyang, Institute of Entomology, Guizhou UniversityMinistry of AgricultureGuiyangChina
| | - Cheng‐xu Wu
- College of ForestryGuizhou UniversityGuiyangChina
| | - Xiao‐fei Yu
- College of Tobacco ScienceGuizhou UniversityGuiyangChina
| | - Cecil L. Smith
- Georgia Museum of Natural HistoryUniversity of GeorgiaAthensGeorgiaUSA
| | - Mao‐fa Yang
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pest in Guiyang, Institute of Entomology, Guizhou UniversityMinistry of AgricultureGuiyangChina
- College of Tobacco ScienceGuizhou UniversityGuiyangChina
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3
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Matzke M, Toft S, Bechsgaard J, Pold Vilstrup A, Uhl G, Künzel S, Tuni C, Bilde T. Sperm competition intensity affects sperm precedence patterns in a polyandrous gift-giving spider. Mol Ecol 2022; 31:2435-2452. [PMID: 35178803 DOI: 10.1111/mec.16405] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 01/26/2022] [Accepted: 02/08/2022] [Indexed: 11/28/2022]
Abstract
Sperm competition drives traits that enhance fertilization success. The amount of sperm transferred relative to competitors is key for attaining paternity. Female reproductive morphology and male mating order may also influence fertilization, however the outcome for sperm precedence under intense sperm competition remains poorly understood. In the polyandrous spider Pisaura mirabilis, males offer nuptial gifts which prolong copulation and increase sperm transfer, factors proposed to alter sperm precedence patterns under strong sperm competition. First, we assessed the degree of female polyandry by genotyping wild broods. A conservative analysis identified up to 4 sires, with a mean of 2 sires per brood, consistent with an optimal mating female rate. Then we asked whether intense sperm competition shifts sperm precedence patterns from first male priority, as expected from female morphology, to last male advantage. We varied sexual selection intensity experimentally and determined competitive fertilization outcome by genotyping broods. In double matings, one male monopolised paternity regardless of mating order. A mating order effect with first male priority was revealed when females were mated to 4 males, however this effect disappeared when females were mated to 6 males, likely due to increased sperm mixing. The proportion of males that successfully sired offspring drastically decreased with the number of competitors. Longer copulations translated into higher paternity shares independently of mating order, reinforcing the advantage of traits that prolong copulation duration under intense competition, such as the nuptial gift. Sperm competition intensity enhances the impact of competitive sexual traits and imposes multiple effects on paternity.
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Affiliation(s)
- Magdalena Matzke
- Department of Biology, Ludwig Maximilian University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Søren Toft
- Department of Biology, Aarhus University, Ny Munkegade 116, DK-8000, Aarhus C, Denmark
| | - Jesper Bechsgaard
- Department of Biology, Aarhus University, Ny Munkegade 116, DK-8000, Aarhus C, Denmark
| | - Astrid Pold Vilstrup
- Department of Biology, Aarhus University, Ny Munkegade 116, DK-8000, Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Gabriele Uhl
- General and Systematic Zoology, University of Greifswald, Zoological Institute and Museum, Loitzer Straße 26, D-17489, Greifswald, Germany
| | - Sven Künzel
- Department for Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, August-Thienemann Straße 2, D-24306, Plön, Germany
| | - Cristina Tuni
- Department of Biology, Ludwig Maximilian University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Trine Bilde
- Department of Biology, Aarhus University, Ny Munkegade 116, DK-8000, Aarhus C, Denmark
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4
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Rosenthal GG, Ryan MJ. Sexual selection and the ascent of women: Mate choice research since Darwin. Science 2022; 375:eabi6308. [PMID: 35050648 DOI: 10.1126/science.abi6308] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Darwin's theory of sexual selection fundamentally changed how we think about sex and evolution. The struggle over mating and fertilization is a powerful driver of diversification within and among species. Contemporaries dismissed Darwin's conjecture of a "taste for the beautiful" as favoring particular mates over others, but there is now overwhelming evidence for a primary role of both male and female mate choice in sexual selection. Darwin's misogyny precluded much analysis of the "taste"; an increasing focus on mate choice mechanisms before, during, and after mating reveals that these often evolve in response to selection pressures that have little to do with sexual selection on chosen traits. Where traits and preferences do coevolve, they can do so whether fitness effects on choosers are positive, neutral, or negative. The spectrum of selection on traits and preferences, and how traits and preferences respond to social effects, determine how sexual selection and mate choice influence broader-scale processes like reproductive isolation and population responses to environmental change.
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Affiliation(s)
- Gil G Rosenthal
- Department of Biology, University of Padova, Padova, Italy.,Centro de Investigaciones Científicas de las Huastecas "Aguazarca," Calnali, Hidalgo, Mexico
| | - Michael J Ryan
- Department of Integrative Biology, University of Texas, Austin, TX, USA.,Smithsonian Tropical Research Institute, Balboa, Republic of Panama
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5
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Grieshop K, Maurizio PL, Arnqvist G, Berger D. Selection in males purges the mutation load on female fitness. Evol Lett 2021; 5:328-343. [PMID: 34367659 PMCID: PMC8327962 DOI: 10.1002/evl3.239] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 11/26/2022] Open
Abstract
Theory predicts that the ability of selection and recombination to purge mutation load is enhanced if selection against deleterious genetic variants operates more strongly in males than females. However, direct empirical support for this tenet is limited, in part because traditional quantitative genetic approaches allow dominance and intermediate-frequency polymorphisms to obscure the effects of the many rare and partially recessive deleterious alleles that make up the main part of a population's mutation load. Here, we exposed the partially recessive genetic load of a population of Callosobruchus maculatus seed beetles via successive generations of inbreeding, and quantified its effects by measuring heterosis-the increase in fitness experienced when masking the effects of deleterious alleles by heterozygosity-in a fully factorial sex-specific diallel cross among 16 inbred strains. Competitive lifetime reproductive success (i.e., fitness) was measured in male and female outcrossed F1s as well as inbred parental "selfs," and we estimated the 4 × 4 male-female inbred-outbred genetic covariance matrix for fitness using Bayesian Markov chain Monte Carlo simulations of a custom-made general linear mixed effects model. We found that heterosis estimated independently in males and females was highly genetically correlated among strains, and that heterosis was strongly negatively genetically correlated to outbred male, but not female, fitness. This suggests that genetic variation for fitness in males, but not in females, reflects the amount of (partially) recessive deleterious alleles segregating at mutation-selection balance in this population. The population's mutation load therefore has greater potential to be purged via selection in males. These findings contribute to our understanding of the prevalence of sexual reproduction in nature and the maintenance of genetic variation in fitness-related traits.
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Affiliation(s)
- Karl Grieshop
- Animal Ecology, Department of Ecology and GeneticsUppsala UniversityUppsalaSE‐75236Sweden
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONM5S 3B2Canada
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSE‐10691Sweden
| | - Paul L. Maurizio
- Section of Genetic Medicine, Department of MedicineUniversity of ChicagoChicagoIllinois60637
| | - Göran Arnqvist
- Animal Ecology, Department of Ecology and GeneticsUppsala UniversityUppsalaSE‐75236Sweden
| | - David Berger
- Animal Ecology, Department of Ecology and GeneticsUppsala UniversityUppsalaSE‐75236Sweden
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6
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Arnqvist G, Grieshop K, Hotzy C, Rönn J, Polak M, Rowe L. Direct and indirect effects of male genital elaboration in female seed beetles. Proc Biol Sci 2021; 288:20211068. [PMID: 34229496 PMCID: PMC8261210 DOI: 10.1098/rspb.2021.1068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/09/2021] [Indexed: 11/12/2022] Open
Abstract
Our understanding of coevolution between male genitalia and female traits remains incomplete. This is perhaps especially true for genital traits that cause internal injuries in females, such as the spiny genitalia of seed beetles where males with relatively long spines enjoy a high relative fertilization success. We report on a new set of experiments, based on extant selection lines, aimed at assessing the effects of long male spines on females in Callosobruchus maculatus. We first draw on an earlier study using microscale laser surgery, and demonstrate that genital spines have a direct negative (sexually antagonistic) effect on female fecundity. We then ask whether artificial selection for long versus short spines resulted in direct or indirect effects on female lifetime offspring production. Reference females mating with males from long-spine lines had higher offspring production, presumably due to an elevated allocation in males to those ejaculate components that are beneficial to females. Remarkably, selection for long male genital spines also resulted in an evolutionary increase in female offspring production as a correlated response. Our findings thus suggest that female traits that affect their response to male spines are both under direct selection to minimize harm but are also under indirect selection (a good genes effect), consistent with the evolution of mating and fertilization biases being affected by several simultaneous processes.
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Affiliation(s)
- Göran Arnqvist
- Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Karl Grieshop
- Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Cosima Hotzy
- Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Johanna Rönn
- Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Michal Polak
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Locke Rowe
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Swedish Collegium for Advanced Study, Uppsala University, 752 38 Uppsala, Sweden
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7
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Abstract
Abstract
Females mate multiply despite numerous costs. It is well established that polyandry can result in sexual conflict, favoring male adaptations that prevent sperm competition often to the disadvantage of the female. Such adaptations are extreme in spiders with one-shot genitalia of which parts break off and act as mating plugs, rendering them dysfunctional. In the spider Argiope bruennichi, mating plugs effectively prevent further males from inseminating and males that inseminate and plug both genital openings of a female secure exclusive paternity. However, females frequently prevent monopolization by attacking and cannibalizing males during their first copulation, leaving their second spermatheca free for another male. Here, we test whether the high frequency of sexual cannibalism evolved as a female adaptation to resist monopolization and secure indirect benefits of polyandry. To standardize conditions, we double-mated females either with the same or two different males and prevented male consumption. Using a split-brood design, we raised offspring to maturity under poor and rich food conditions and measured their survival, duration of juvenile phase, and adult body mass. Under low food, daughters of polyandrous mothers matured later but slightly heavier than daughters of monandrous females. Since the adaptive value of this combination is unclear, these findings lend no conclusive support to our hypothesis. We discuss the stereotypic nature of the female attack in the context of antagonistic co-evolution considering previous studies that found modest direct benefits of cannibalism as well as a potential for non-additive benefits.
Significance statement
Sexual conflict is extreme in spiders where sexual cannibalism impairs male mating rates. Males of the spider Argiope bruennichi possess one-shot genitalia which they break off to plug female genital openings. They gain exclusive paternity with a female if two copulations are achieved and both genital openings plugged. Females, however, stereotypically attack every male at the onset of copulation, limiting most males to single copulation but retaining the option to secure potential benefits of polyandry. Previous studies revealed weak direct and non-additive indirect benefits of multiple mating. In this study, we tested for the presence of additive genetic benefits but again found only inconclusive evidence for adaptive differences in offspring quality between monandrous and polyandrous females. All results combined, we here speculate that the stereotypic female attack might be a ghost of a past antagonistic co-evolution.
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8
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Achorn AM, Rosenthal GG. It’s Not about Him: Mismeasuring ‘Good Genes’ in Sexual Selection. Trends Ecol Evol 2020; 35:206-219. [DOI: 10.1016/j.tree.2019.11.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 11/24/2019] [Accepted: 11/26/2019] [Indexed: 01/18/2023]
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9
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Sayadi A, Martinez Barrio A, Immonen E, Dainat J, Berger D, Tellgren-Roth C, Nystedt B, Arnqvist G. The genomic footprint of sexual conflict. Nat Ecol Evol 2019; 3:1725-1730. [DOI: 10.1038/s41559-019-1041-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/15/2019] [Indexed: 12/28/2022]
Abstract
AbstractGenes with sex-biased expression show a number of unique properties and this has been seen as evidence for conflicting selection pressures in males and females, forming a genetic ‘tug-of-war’ between the sexes. However, we lack studies of taxa where an understanding of conflicting phenotypic selection in the sexes has been linked with studies of genomic signatures of sexual conflict. Here, we provide such a link. We used an insect where sexual conflict is unusually well understood, the seed beetle Callosobruchus maculatus, to test for molecular genetic signals of sexual conflict across genes with varying degrees of sex-bias in expression. We sequenced, assembled and annotated its genome and performed population resequencing of three divergent populations. Sex-biased genes showed increased levels of genetic diversity and bore a remarkably clear footprint of relaxed purifying selection. Yet, segregating genetic variation was also affected by balancing selection in weakly female-biased genes, while male-biased genes showed signs of overall purifying selection. Female-biased genes contributed disproportionally to shared polymorphism across populations, while male-biased genes, male seminal fluid protein genes and sex-linked genes did not. Genes showing genomic signatures consistent with sexual conflict generally matched life-history phenotypes known to experience sexually antagonistic selection in this species. Our results highlight metabolic and reproductive processes, confirming the key role of general life-history traits in sexual conflict.
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10
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Fox RJ, Fromhage L, Jennions MD. Sexual selection, phenotypic plasticity and female reproductive output. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180184. [PMID: 30966965 PMCID: PMC6365872 DOI: 10.1098/rstb.2018.0184] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2018] [Indexed: 01/17/2023] Open
Abstract
In a rapidly changing environment, does sexual selection on males elevate a population's reproductive output? If so, does phenotypic plasticity enhance or diminish any such effect? We outline two routes by which sexual selection can influence the reproductive output of a population: a genetic correlation between male sexual competitiveness and female lifetime reproductive success; and direct effects of males on females' breeding success. We then discuss how phenotypic plasticity of sexually selected male traits and/or female responses (e.g. plasticity in mate choice), as the environment changes, might influence how sexual selection affects a population's reproductive output. Two key points emerge. First, condition-dependent expression of male sexual traits makes it likely that sexual selection increases female fitness if reproductively successful males disproportionately transfer genes that are under natural selection in both sexes, such as genes for foraging efficiency. Condition-dependence is a form of phenotypic plasticity if some of the variation in net resource acquisition and assimilation is attributable to the environment rather than solely genetic in origin. Second, the optimal allocation of resources into different condition-dependent traits depends on their marginal fitness gains. As male condition improves, this can therefore increase or, though rarely highlighted, actually decrease the expression of sexually selected traits. It is therefore crucial to understand how condition determines male allocation of resources to different sexually selected traits that vary in their immediate effects on female reproductive output (e.g. ornaments versus coercive behaviour). In addition, changes in the distribution of condition among males as the environment shifts could reduce phenotypic variance in certain male traits, thereby reducing the strength of sexual selection imposed by females. Studies of adaptive evolution under rapid environmental change should consider the possibility that phenotypic plasticity of sexually selected male traits, even if it elevates male fitness, could have a negative effect on female reproductive output, thereby increasing the risk of population extinction. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.
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Affiliation(s)
- Rebecca J. Fox
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Lutz Fromhage
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, Jyvaskyla 40014, Finland
| | - Michael D. Jennions
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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11
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Boulton RA, Zuk M, Shuker DM. An Inconvenient Truth: The Unconsidered Benefits of Convenience Polyandry. Trends Ecol Evol 2018; 33:904-915. [PMID: 30376988 DOI: 10.1016/j.tree.2018.10.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 09/19/2018] [Accepted: 10/02/2018] [Indexed: 12/22/2022]
Abstract
Polyandry, or multiple mating by females with different males, is commonplace. One explanation is that females engage in convenience polyandry, mating multiple times to reduce the costs of sexual harassment. Although the logic underlying convenience polyandry is clear, and harassment often seems to influence mating outcomes, it has not been subjected to as thorough theoretical or empirical attention as other explanations for polyandry. We re-examine here convenience polyandry in the light of new studies demonstrating previously unconsidered benefits of polyandry. We suggest that true convenience polyandry is likely to be a fleeting phenomenon, even though it can profoundly shape mating-system evolution via potential feedback loops between resistance to males and the costs and benefits of mating.
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Affiliation(s)
- Rebecca A Boulton
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall TR10 9FE, UK; Department of Entomology, University of Minnesota, St Paul, MN 55108, USA; School of Biology, University of St Andrews, St Andrews KY16 9TH, UK.
| | - Marlene Zuk
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN 55108, USA
| | - David M Shuker
- School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
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12
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McNamara KB, Simmons LW. Experimental evolution reveals differences between phenotypic and evolutionary responses to population density. J Evol Biol 2017; 30:1763-1771. [PMID: 28675768 DOI: 10.1111/jeb.13139] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/16/2017] [Indexed: 11/29/2022]
Abstract
Group living can select for increased immunity, given the heightened risk of parasite transmission. Yet, it also may select for increased male reproductive investment, given the elevated risk of female multiple mating. Trade-offs between immunity and reproduction are well documented. Phenotypically, population density mediates both reproductive investment and immune function in the Indian meal moth, Plodia interpunctella. However, the evolutionary response of populations to these traits is unknown. We created two replicated populations of P. interpunctella, reared and mated for 14 generations under high or low population densities. These population densities cause plastic responses in immunity and reproduction: at higher numbers, both sexes invest more in one index of immunity [phenoloxidase (PO) activity] and males invest more in sperm. Interestingly, our data revealed divergence in PO and reproduction in a different direction to previously reported phenotypic responses. Males evolving at low population densities transferred more sperm, and both males and females displayed higher PO than individuals at high population densities. These positively correlated responses to selection suggest no apparent evolutionary trade-off between immunity and reproduction. We speculate that the reduced PO activity and sperm investment when evolving under high population density may be due to the reduced population fitness predicted under increased sexual conflict and/or to trade-offs between pre- and post-copulatory traits.
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Affiliation(s)
- K B McNamara
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, WA, Australia
| | - L W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, WA, Australia
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13
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Martinossi-Allibert I, Arnqvist G, Berger D. Sex-specific selection under environmental stress in seed beetles. J Evol Biol 2016; 30:161-173. [DOI: 10.1111/jeb.12996] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/21/2016] [Accepted: 10/13/2016] [Indexed: 01/15/2023]
Affiliation(s)
| | - G. Arnqvist
- Department of Ecology and Genetics; Animal Ecology; Uppsala University; Uppsala Sweden
| | - D. Berger
- Department of Ecology and Genetics; Animal Ecology; Uppsala University; Uppsala Sweden
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14
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Berger D, Martinossi-Allibert I, Grieshop K, Lind MI, Maklakov AA, Arnqvist G. Intralocus Sexual Conflict and the Tragedy of the Commons in Seed Beetles. Am Nat 2016; 188:E98-E112. [DOI: 10.1086/687963] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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15
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Mangels R, Young B, Keeble S, Ardekani R, Meslin C, Ferreira Z, Clark NL, Good JM, Dean MD. Genetic and phenotypic influences on copulatory plug survival in mice. Heredity (Edinb) 2015; 115:496-502. [PMID: 26103947 PMCID: PMC4806896 DOI: 10.1038/hdy.2015.50] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 04/23/2015] [Accepted: 04/27/2015] [Indexed: 02/07/2023] Open
Abstract
Across a diversity of animals, male seminal fluid coagulates upon ejaculation to form a hardened structure known as a copulatory plug. Previous studies suggest that copulatory plugs evolved as a mechanism for males to impede remating by females, but detailed investigations into the time course over which plugs survive in the female's reproductive tract are lacking. Here, we cross males from eight inbred strains to females from two inbred strains of house mice (Mus musculus domesticus). Plug survival was significantly affected by male genotype. Against intuition, plug survival time was negatively correlated with plug size: long-lasting plugs were small and relatively more susceptible to proteolysis. Plug size was associated with divergence in major protein composition of seminal vesicle fluid, suggesting that changes in gene expression may play an important role in plug dynamics. In contrast, we found no correlation to genetic variation in the protein-coding regions of five genes thought to be important in copulatory plug formation (Tgm4, Svs1, Svs2, Svs4 and Svs5). Our study demonstrates a complex relationship between copulatory plug characteristics and survival. We discuss several models to explain unexpected variation in plug phenotypes.
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Affiliation(s)
- R Mangels
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - B Young
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - S Keeble
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - R Ardekani
- Translational Imaging Center, University of Southern California, Los Angeles, CA, USA
| | - C Meslin
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Z Ferreira
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - N L Clark
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - J M Good
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - M D Dean
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
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16
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Alfaro-Núñez A, Jensen MP, Abreu-Grobois FA. Does polyandry really pay off? The effects of multiple mating and number of fathers on morphological traits and survival in clutches of nesting green turtles at Tortuguero. PeerJ 2015; 3:e880. [PMID: 25870773 PMCID: PMC4393808 DOI: 10.7717/peerj.880] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/17/2015] [Indexed: 11/30/2022] Open
Abstract
Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradictory results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity and number of sires in 12 clutches (240 hatchlings) of green turtles (Chelonia mydas) nests at Tortuguero, Costa Rica. Paternal alleles were inferred through comparison of maternal and hatchling genotypes, and indicated multiple paternity in at least 11 of the clutches (92%). The inferred average number of fathers was three (ranging from 1 to 5). Moreover, regression analyses were used to investigate for correlation of inferred clutch paternity with morphological traits of hatchlings fitness (emergence success, length, weight and crawling speed), the size of the mother, and an environmental variable (incubation temperature). We suggest and propose two different comparative approaches for evaluating morphological traits and clutch paternity, in order to infer greater offspring survival. First, clutches coded by the exact number of fathers and second by the exact paternal contribution (fathers who gives greater proportion of the offspring per nest). We found significant differences (P < 0.05) in clutches coded by the exact number of fathers for all morphological traits. A general tendency of higher values in offspring sired by two to three fathers was observed for the length and weight traits. However, emergence success and crawling speed showed different trends which unable us to reach any further conclusion. The second approach analysing the paternal contribution showed no significant difference (P > 0.05) for any of the traits. We conclude that multiple paternity does not provide any extra benefit in the morphological fitness traits or the survival of the offspring, when analysed following the proposed comparative statistical methods.
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Affiliation(s)
- Alonzo Alfaro-Núñez
- Center for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen , Copenhagen , Denmark
| | - Michael P Jensen
- Marine Mammal and Turtle Division, National Oceanic and Atmospheric Administration , La Jolla, CA , United States
| | - F Alberto Abreu-Grobois
- Laboratorio de Genética, Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México , México
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17
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Arnqvist G, Vellnow N, Rowe L. The effect of epistasis on sexually antagonistic genetic variation. Proc Biol Sci 2015; 281:rspb.2014.0489. [PMID: 24870040 DOI: 10.1098/rspb.2014.0489] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
There is increasing evidence of segregating sexually antagonistic (SA) genetic variation for fitness in laboratory and wild populations, yet the conditions for the maintenance of such variation can be restrictive. Epistatic interactions between genes can contribute to the maintenance of genetic variance in fitness and we suggest that epistasis between SA genes should be pervasive. Here, we explore its effect on SA genetic variation in fitness using a two locus model with negative epistasis. Our results demonstrate that epistasis often increases the parameter space showing polymorphism for SA loci. This is because selection in one locus is affected by allele frequencies at the other, which can act to balance net selection in males and females. Increased linkage between SA loci had more marginal effects. We also show that under some conditions, large portions of the parameter space evolve to a state where male benefit alleles are fixed at one locus and female benefit alleles at the other. This novel effect of epistasis on SA loci, which we term the 'equity effect', may have important effects on population differentiation and may contribute to speciation. More generally, these results support the suggestion that epistasis contributes to population divergence.
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Affiliation(s)
- Göran Arnqvist
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, SE-752 36 Uppsala, Sweden
| | - Nikolas Vellnow
- Evolutionary Biology, Zoological Institute, University of Basel, CH-4051 Basel, Switzerland
| | - Locke Rowe
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada, M5S 3B2
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18
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Berger D, Berg EC, Widegren W, Arnqvist G, Maklakov AA. Multivariate intralocus sexual conflict in seed beetles. Evolution 2014; 68:3457-69. [DOI: 10.1111/evo.12528] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 09/01/2014] [Indexed: 12/22/2022]
Affiliation(s)
- David Berger
- Animal Ecology; Department of Ecology and Genetics; Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
| | - Elena C. Berg
- Ageing Research Group; Animal Ecology; Department of Ecology and Genetics; Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
- Department of Computer Science; Mathematics, and Environmental Science, The American University of Paris, Paris, France
| | - William Widegren
- Ageing Research Group; Animal Ecology; Department of Ecology and Genetics; Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
| | - Göran Arnqvist
- Animal Ecology; Department of Ecology and Genetics; Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
| | - Alexei A. Maklakov
- Ageing Research Group; Animal Ecology; Department of Ecology and Genetics; Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
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19
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Crean AJ, Bonduriansky R. What is a paternal effect? Trends Ecol Evol 2014; 29:554-9. [DOI: 10.1016/j.tree.2014.07.009] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 02/06/2023]
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20
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Reid JM, Arcese P, Keller LF, Losdat S. Female and male genetic effects on offspring paternity: additive genetic (co)variances in female extra-pair reproduction and male paternity success in song sparrows (Melospiza melodia). Evolution 2014; 68:2357-70. [PMID: 24724612 PMCID: PMC4285967 DOI: 10.1111/evo.12424] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 04/02/2014] [Indexed: 12/19/2022]
Abstract
Ongoing evolution of polyandry, and consequent extra-pair reproduction in socially monogamous systems, is hypothesized to be facilitated by indirect selection stemming from cross-sex genetic covariances with components of male fitness. Specifically, polyandry is hypothesized to create positive genetic covariance with male paternity success due to inevitable assortative reproduction, driving ongoing coevolution. However, it remains unclear whether such covariances could or do emerge within complex polyandrous systems. First, we illustrate that genetic covariances between female extra-pair reproduction and male within-pair paternity success might be constrained in socially monogamous systems where female and male additive genetic effects can have opposing impacts on the paternity of jointly reared offspring. Second, we demonstrate nonzero additive genetic variance in female liability for extra-pair reproduction and male liability for within-pair paternity success, modeled as direct and associative genetic effects on offspring paternity, respectively, in free-living song sparrows (Melospiza melodia). The posterior mean additive genetic covariance between these liabilities was slightly positive, but the credible interval was wide and overlapped zero. Therefore, although substantial total additive genetic variance exists, the hypothesis that ongoing evolution of female extra-pair reproduction is facilitated by genetic covariance with male within-pair paternity success cannot yet be definitively supported or rejected either conceptually or empirically.
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Affiliation(s)
- Jane M Reid
- Institute of Biological and Environmental Sciences, School of Biological Sciences, Zoology Building, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, Scotland.
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21
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van Lieshout E, McNamara KB, Simmons LW. Why do female Callosobruchus maculatus kick their mates? PLoS One 2014; 9:e95747. [PMID: 24752530 PMCID: PMC3994112 DOI: 10.1371/journal.pone.0095747] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/31/2014] [Indexed: 11/18/2022] Open
Abstract
Sexual conflict is now recognised as an important driver of sexual trait evolution. However, due to their variable outcomes and effects on other fitness components, the detection of sexual conflicts on individual traits can be complicated. This difficulty is exemplified in the beetle Callosobruchus maculatus, where longer matings increase the size of nutritious ejaculates but simultaneously reduce female future receptivity. While previous studies show that females gain direct benefits from extended mating duration, females show conspicuous copulatory kicking behaviour, apparently to dislodge mating males prematurely. We explore the potential for sexual conflict by comparing several fitness components and remating propensity in pairs of full sibling females where each female mated with a male from an unrelated pair of full sibling males. For one female, matings were terminated at the onset of kicking, whereas the other’s matings remained uninterrupted. While fecundity (number of eggs) was similar between treatments, uninterrupted matings enhanced adult offspring numbers and fractionally also longevity. However, females whose matings were interrupted at the onset of kicking exhibited an increased propensity to remate. Since polyandry can benefit female fitness in this species, we argue that kicking, rather than being maladaptive, may indicate that females prefer remating over increased ejaculate size. It may thus be difficult to assess the presence of sexual conflict over contested traits such as mating duration when females face a trade off between direct benefits gained from one mating and indirect benefits from additional matings.
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Affiliation(s)
- Emile van Lieshout
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, Australia
- * E-mail:
| | - Kathryn B. McNamara
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, Australia
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22
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Immler S, Hotzy C, Alavioon G, Petersson E, Arnqvist G. Sperm variation within a single ejaculate affects offspring development in Atlantic salmon. Biol Lett 2014; 10:20131040. [PMID: 24522632 DOI: 10.1098/rsbl.2013.1040] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
It is generally believed that variation in sperm phenotype within a single ejaculate has no consequences for offspring performance, because sperm phenotypes are thought not to reflect sperm genotypes. We show that variation in individual sperm function within an ejaculate affects the performance of the resulting offspring in the Atlantic salmon Salmo salar. We experimentally manipulated the time between sperm activation and fertilization in order to select for sperm cohorts differing in longevity within single ejaculates of wild caught male salmon. We found that within-ejaculate variation in sperm longevity significantly affected offspring development and hence time until hatching. Whether these effects have a genetic or epigenetic basis needs to be further evaluated. However, our results provide experimental evidence for transgenerational effects of individual sperm function.
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Affiliation(s)
- Simone Immler
- Department of Evolutionary Biology, Uppsala University, , Norbyvägen 18D, Uppsala 752 36, Sweden
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23
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Crean AJ, Dwyer JM, Marshall DJ. Adaptive paternal effects? Experimental evidence that the paternal environment affects offspring performance. Ecology 2014; 94:2575-82. [PMID: 24400509 DOI: 10.1890/13-0184.1] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The ability of females to adaptively influence offspring phenotype via maternal effects is widely acknowledged, but corresponding nongenetic paternal effects remain unexplored. Males can adjust sperm phenotype in response to local conditions, but the transgenerational consequences of this plasticity are unknown. We manipulated paternal density of a broadcast spawner (Styela plicata, a solitary ascidean) using methods shown previously to alter sperm phenotype in the field, then conducted in vitro fertilizations that excluded maternal effects and estimated offspring performance under natural conditions. Offspring sired by males from low-density experimental populations developed faster and had a higher hatching success than offspring sired by males living in high densities. In the field, offspring survived relatively better when their environment matched their father's, raising the possibility that fathers can adaptively influence the phenotype of their offspring according to local conditions. As the only difference between offspring is whether they were artificially fertilized by sperm from males kept in high- vs. low-density cages, we can unequivocally attribute any differences in offspring performance to an environmentally induced paternal effect. Males of many species manipulate the phenotype of their sperm in response to sperm competition: our results show this plasticity can influence offspring fitness, potentially in adaptive ways, raising the possibility that adaptive nongenetic paternal effects may be more common than previously thought.
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Affiliation(s)
- Angela J Crean
- School of Biological Sciences, University of Queensland, Brisbane, QLD 4072, Australia.
| | - John M Dwyer
- School of Biological Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Dustin J Marshall
- School of Biological Sciences, University of Queensland, Brisbane, QLD 4072, Australia
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24
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Female mating preferences determine system-level evolution in a gene network model. Genetica 2013; 141:157-70. [PMID: 23584953 DOI: 10.1007/s10709-013-9714-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 03/22/2013] [Indexed: 10/27/2022]
Abstract
Environmental patterns of directional, stabilizing and fluctuating selection can influence the evolution of system-level properties like evolvability and mutational robustness. Intersexual selection produces strong phenotypic selection and these dynamics may also affect the response to mutation and the potential for future adaptation. In order to to assess the influence of mating preferences on these evolutionary properties, I modeled a male trait and female preference determined by separate gene regulatory networks. I studied three sexual selection scenarios: sexual conflict, a Gaussian model of the Fisher process described in Lande (in Proc Natl Acad Sci 78(6):3721-3725, 1981) and a good genes model in which the male trait signalled his mutational condition. I measured the effects these mating preferences had on the potential for traits and preferences to evolve towards new states, and mutational robustness of both the phenotype and the individual's overall viability. All types of sexual selection increased male phenotypic robustness relative to a randomly mating population. The Fisher model also reduced male evolvability and mutational robustness for viability. Under good genes sexual selection, males evolved an increased mutational robustness for viability. Females choosing their mates is a scenario that is sufficient to create selective forces that impact genetic evolution and shape the evolutionary response to mutation and environmental selection. These dynamics will inevitably develop in any population where sexual selection is operating, and affect the potential for future adaptation.
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25
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Lange R, Reinhardt K, Michiels NK, Anthes N. Functions, diversity, and evolution of traumatic mating. Biol Rev Camb Philos Soc 2013; 88:585-601. [PMID: 23347274 DOI: 10.1111/brv.12018] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 12/17/2012] [Accepted: 12/19/2012] [Indexed: 11/28/2022]
Abstract
Copulation can involve the wounding of the mating partner by specialised devices. This type of mating, which we term traumatic mating, has been regarded as exceptional. Its prevalence, however, has not been compared across taxa, nor have its functions and putative evolutionary pathways. A categorisation has been lacking to date. We here show that traumatic mating is a widespread and diverse phenomenon that likely evolved via several pathways. Its putative functions include: (i) anchorage during mating; (ii) stimulation of short-term female reproductive investment; (iii) male paternity advantages; and (iv) enhanced fertilisation efficiency in transitions to internal fertilisation. Both natural and sexual selection have likely contributed to the parallel evolution of traumatic intromittent organs in phylogenetically distant taxa. These organs are sometimes remarkably similar in shape and often, but not always, inject sperm. The target sites of trauma infliction and the nature of secretions delivered alongside sperm are thus far poorly studied, but data on both are needed to elucidate the function of traumatic mating. The few existing studies that explicitly quantify fitness impacts of traumatic mating indicate that this strategy may often be costly to the party being wounded. However, a comprehensive approach to assess overall investments and returns for both sexes is a major target for future work. Finally, for the first time, we corroborate quantitatively the hypothesis that traumatic mating evolved relatively more often among hermaphroditic than among gonochoric taxa.
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Affiliation(s)
- Rolanda Lange
- Animal Evolutionary Ecology Group, Faculty of Sciences, University of Tuebingen, Auf der Morgenstelle 28, D-72076, Tuebingen, Germany.
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26
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Hotzy C, Polak M, Rönn J, Arnqvist G. Phenotypic Engineering Unveils the Function of Genital Morphology. Curr Biol 2012; 22:2258-61. [PMID: 23103188 DOI: 10.1016/j.cub.2012.10.009] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 07/30/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
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27
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Plesnar-Bielak A, Skrzynecka AM, Prokop ZM, Radwan J. Mating system affects population performance and extinction risk under environmental challenge. Proc Biol Sci 2012; 279:4661-7. [PMID: 22977151 PMCID: PMC3479737 DOI: 10.1098/rspb.2012.1867] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 08/17/2012] [Indexed: 11/12/2022] Open
Abstract
Failure of organisms to adapt to sudden environmental changes may lead to extinction. The type of mating system, by affecting fertility and the strength of sexual selection, may have a major impact on a population's chances to adapt and survive. Here, we use experimental evolution in bulb mites (Rhizoglyphus robini) to examine the effects of the mating system on population performance under environmental change. We demonstrate that populations in which monogamy was enforced suffered a dramatic fitness decline when evolving at an increased temperature, whereas the negative effects of change in a thermal environment were alleviated in polygamous populations. Strikingly, within 17 generations, all monogamous populations experiencing higher temperature went extinct, whereas all polygamous populations survived. Our results show that the mating system may have dramatic effects on the risk of extinction under environmental change.
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Affiliation(s)
| | | | | | - Jacek Radwan
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
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28
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Berg EC, Maklakov AA. Sexes suffer from suboptimal lifespan because of genetic conflict in a seed beetle. Proc Biol Sci 2012; 279:4296-302. [PMID: 22915670 PMCID: PMC3441075 DOI: 10.1098/rspb.2012.1345] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 07/27/2012] [Indexed: 01/25/2023] Open
Abstract
Males and females have different routes to successful reproduction, resulting in sex differences in lifespan and age-specific allocation of reproductive effort. The trade-off between current and future reproduction is often resolved differently by males and females, and both sexes can be constrained in their ability to reach their sex-specific optima owing to intralocus sexual conflict. Such genetic antagonism may have profound implications for evolution, but its role in ageing and lifespan remains unresolved. We provide direct experimental evidence that males live longer and females live shorter than necessary to maximize their relative fitness in Callosobruchus maculatus seed beetles. Using artificial selection in a genetically heterogeneous population, we created replicate long-life lines where males lived on average 27 per cent longer than in short-life lines. As predicted by theory, subsequent assays revealed that upward selection on male lifespan decreased relative male fitness but increased relative female fitness compared with downward selection. Thus, we demonstrate that lifespan-extending genes can help one sex while harming the other. Our results show that sexual antagonism constrains adaptive life-history evolution, support a novel way of maintaining genetic variation for lifespan and argue for better integration of sex effects into applied research programmes aimed at lifespan extension.
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Affiliation(s)
- Elena C Berg
- Ageing Research Group, Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
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29
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30
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Experimental evolution of a novel sexually antagonistic allele. PLoS Genet 2012; 8:e1002917. [PMID: 22956914 PMCID: PMC3431318 DOI: 10.1371/journal.pgen.1002917] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/06/2012] [Indexed: 11/22/2022] Open
Abstract
Evolutionary conflict permeates biological systems. In sexually reproducing organisms, sex-specific optima mean that the same allele can have sexually antagonistic expression, i.e. beneficial in one sex and detrimental in the other, a phenomenon known as intralocus sexual conflict. Intralocus sexual conflict is emerging as a potentially fundamental factor for the genetic architecture of fitness, with important consequences for evolutionary processes. However, no study to date has directly experimentally tested the evolutionary fate of a sexually antagonistic allele. Using genetic constructs to manipulate female fecundity and male mating success, we engineered a novel sexually antagonistic allele (SAA) in Drosophila melanogaster. The SAA is nearly twice as costly to females as it is beneficial to males, but the harmful effects to females are recessive and X-linked, and thus are rarely expressed when SAA occurs at low frequency. We experimentally show how the evolutionary dynamics of the novel SAA are qualitatively consistent with the predictions of population genetic models: SAA frequency decreases when common, but increases when rare, converging toward an equilibrium frequency of ∼8%. Furthermore, we show that persistence of the SAA requires the mating advantage it provides to males: the SAA frequency declines towards extinction when the male advantage is experimentally abolished. Our results empirically demonstrate the dynamics underlying the evolutionary fate of a sexually antagonistic allele, validating a central assumption of intralocus sexual conflict theory: that variation in fitness-related traits within populations can be maintained via sex-linked sexually antagonistic loci. Males and females are markedly different in many features, meaning that a trait that is beneficial for one sex may be detrimental for the other. Recent studies show that this type of sexual antagonism is abundant in natural populations; however, no study has tested the evolutionary fate of a sexually antagonistic allele. Using genetic manipulations to alter female fecundity and male mating success, we generated a novel sexually antagonistic allele in Drosophila melanogaster, allowing us to study whether such an allele can persist in populations. We show that the sexually antagonistic allele causes more harm to females than it provides benefits to males but—as predicted by theory—it is able to persist in the population. This is because the harmful effects to females are both recessive (it is only harmful when two copies of the allele are present) and linked to the X-chromosome, so females are rarely harmed when the allele is at low frequency. These results show how a sexually antagonistic allele can be maintained in populations and contribute to maintain variation in male and female reproductive success.
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31
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DROGE-YOUNG EM, MANIER MK, LÜPOLD S, BELOTE JM, PITNICK S. Covariance among premating, post-copulatory and viability fitness components in Drosophila melanogaster and their influence on paternity measurement. J Evol Biol 2012; 25:1555-63. [DOI: 10.1111/j.1420-9101.2012.02540.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Simmons LW. Resource allocation trade-off between sperm quality and immunity in the field cricket, Teleogryllus oceanicus. Behav Ecol 2011. [DOI: 10.1093/beheco/arr170] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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33
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Gasparini C, Devigili A, Pilastro A. CROSS-GENERATIONAL EFFECTS OF SEXUAL HARASSMENT ON FEMALE FITNESS IN THE GUPPY. Evolution 2011; 66:532-43. [PMID: 22276546 DOI: 10.1111/j.1558-5646.2011.01455.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Clelia Gasparini
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy.
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34
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Abstract
An enduring hypothesis for the proximal benefits of sex is that recombination increases the genetic variation among offspring and that this genetic variation increases offspring performance. A corollary of this hypothesis is that mothers that mate multiply increase genetic variation within a clutch and gain benefits due to genetic diversity alone. Many studies have demonstrated that multiple mating can increase offspring performance, but most attribute this increase to sexual selection and the role of genetic diversity has received less attention. Here, we used a breeding design to generate populations of full-siblings, half-siblings, and unrelated individuals of the solitary ascidian Ciona intestinalis. Importantly, we preclude the potentially confounding influences of maternal effects and sexual selection. We found that individuals in populations with greater genetic diversity had greater performance (metamorphic success, postmetamorphic survival, and postmetamorphic size) than individuals in populations with lower genetic diversity. Furthermore, we show that by mating with multiple males and thereby increasing genetic variation within a single clutch of offspring, females gain indirect fitness benefits in the absence of mate-choice. Our results show that when siblings are likely to interact, genetic variation among individuals can decrease competition for resources and generate substantial fitness benefits within a single generation.
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Affiliation(s)
- J David Aguirre
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
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35
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Slatyer RA, Mautz BS, Backwell PRY, Jennions MD. Estimating genetic benefits of polyandry from experimental studies: a meta-analysis. Biol Rev Camb Philos Soc 2011; 87:1-33. [PMID: 21545390 DOI: 10.1111/j.1469-185x.2011.00182.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rachel A Slatyer
- Evolution, Ecology & Genetics, Research School of Biology, The Australian National University, Canberra, Australia
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36
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Abstract
Recent documentations of sexually antagonistic genetic variation in fitness have spurred an interest in the mechanisms that may act to maintain such variation in natural populations. Using individual-based simulations, I show that positive assortative mating by fitness increases the amount of sexually antagonistic genetic variance in fitness, primarily by elevating the equilibrium frequency of heterozygotes, over most of the range of sex-specific selection and dominance. Further, although the effects of assortative mating by fitness on the protection conditions of polymorphism in sexually antagonistic loci were relatively minor, it widens the protection conditions under most reasonable scenarios (e.g., under heterozygote superiority when fitness is averaged across the sexes) but can also somewhat narrow the protection conditions under other circumstances. The near-ubiquity of assortative mating in nature suggests that it may contribute to upholding standing sexually antagonistic genetic variation in fitness.
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Affiliation(s)
- Göran Arnqvist
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden.
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37
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Good genes and sexual selection in dung beetles (Onthophagus taurus): genetic variance in egg-to-adult and adult viability. PLoS One 2011; 6:e16233. [PMID: 21267411 PMCID: PMC3022759 DOI: 10.1371/journal.pone.0016233] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 12/17/2010] [Indexed: 11/25/2022] Open
Abstract
Whether species exhibit significant heritable variation in fitness is central for sexual selection. According to good genes models there must be genetic variation in males leading to variation in offspring fitness if females are to obtain genetic benefits from exercising mate preferences, or by mating multiply. However, sexual selection based on genetic benefits is controversial, and there is limited unambiguous support for the notion that choosy or polyandrous females can increase the chances of producing offspring with high viability. Here we examine the levels of additive genetic variance in two fitness components in the dung beetle Onthophagus taurus. We found significant sire effects on egg-to-adult viability and on son, but not daughter, survival to sexual maturity, as well as moderate coefficients of additive variance in these traits. Moreover, we do not find evidence for sexual antagonism influencing genetic variation for fitness. Our results are consistent with good genes sexual selection, and suggest that both pre- and postcopulatory mate choice, and male competition could provide indirect benefits to females.
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Simmons LW, Holley R. Offspring viability benefits but no apparent costs of mating with high quality males. Biol Lett 2010; 7:419-21. [PMID: 21123248 DOI: 10.1098/rsbl.2010.0976] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
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.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, School of Animal Biology, M092, The University of Western Australia, Crawley 6009, Australia.
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GARCIA-GONZALEZ F, SIMMONS LW. Male-induced costs of mating for females compensated by offspring viability benefits in an insect. J Evol Biol 2010; 23:2066-2075. [DOI: 10.1111/j.1420-9101.2010.02065.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Fricke C, Andersson C, Arnqvist G. Natural selection hampers divergence of reproductive traits in a seed beetle. J Evol Biol 2010; 23:1857-67. [PMID: 20646133 DOI: 10.1111/j.1420-9101.2010.02050.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Speciation is thought to often result from indirect selection for reproductive isolation. This will occur when reproductive traits that cause reproductive isolation evolve (i) as a by-product of natural selection on traits with which they are genetically correlated or (ii) as an indirect result of diversifying sexual selection. Here, we use experimental evolution to study the degree of divergent evolution of reproductive traits by manipulating the intensity of natural and sexual selection in replicated selection lines of seed beetles. Following 40 generations of selection, we assayed the degree of divergent evolution of reproductive traits between replicate selection lines experiencing the same selection regime. The evolution of reproductive traits was significantly divergent across selection lines within treatments. The evolution of reproductive traits was both slower and, more importantly, significantly less divergent among lines experiencing stronger directional natural selection. This suggests that reproductive traits did not evolve as an indirect by-product of adaptation. We discuss several ways in which natural selection may hamper divergent evolution among allopatric populations.
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Affiliation(s)
- C Fricke
- Evolutionary Biology Centre, Department of Ecology and Evolution, Animal Ecology, Uppsala University, Norbyvägen 18D, Uppsala, Sweden.
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Rodríguez-Muñoz R, Bretman A, Slate J, Walling CA, Tregenza T. Natural and Sexual Selection in a Wild Insect Population. Science 2010; 328:1269-72. [PMID: 20522773 DOI: 10.1126/science.1188102] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- R Rodríguez-Muñoz
- Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 EZ, UK
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Arnqvist G, Tuda M. Sexual conflict and the gender load: correlated evolution between population fitness and sexual dimorphism in seed beetles. Proc Biol Sci 2009; 277:1345-52. [PMID: 20031994 DOI: 10.1098/rspb.2009.2026] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Although males and females share much of the same genome, selection is often distinct in the two sexes. Sexually antagonistic loci will in theory cause a gender load in populations, because sex-specific selection on a given trait in one sex will compromise the adaptive evolution of the same trait in the other sex. However, it is currently not clear whether such intralocus sexual conflict (ISC) represents a transient evolutionary state, where conflict is rapidly resolved by the evolution of sexual dimorphism (SD), or whether it is a more chronic impediment to adaptation. All else being equal, ISC should manifest itself as correlated evolution between population fitness and SD in traits expressed in both sexes. However, comparative tests of this prediction are problematic and have been unfeasible. Here, we assess the effects of ISC by comparing fitness and SD across distinct laboratory populations of seed beetles that should be well adapted to a shared environment. We show that SD in juvenile development time, a key life-history trait with a history of sexually antagonistic selection in this model system, is positively related to fitness. This effect is due to a correlated evolution between population fitness and development time that is positive in females but negative in males. Loosening the genetic bind between the sexes has evidently allowed the sexes to approach their distinct adaptive peaks.
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Affiliation(s)
- Göran Arnqvist
- Evolutionary Biology Centre, Department of Ecology and Evolution, Animal Ecology, Uppsala University, Uppsala, Sweden.
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Dowling DK, Nystrand M, Simmons LW. Maternal effects, but no good or compatible genes for sperm competitiveness in Australian crickets. Evolution 2009; 64:1257-66. [PMID: 20002162 DOI: 10.1111/j.1558-5646.2009.00912.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Explanations for the evolution of polyandry often center on the idea that females garner genetic benefits for their offspring by mating multiply. Furthermore, postcopulatory processes are thought to be fundamental to enabling polyandrous females to screen for genetic quality. Much attention has focused on the potential for polyandrous females to accrue such benefits via a sexy- or good-sperm mechanism, whereby additive variation exists among males in sperm competitiveness. Likewise, attention has focused on an alternative model, in which offspring quality (in this context, the sperm competitiveness of sons) hinges on an interaction between parental haplotypes (genetic compatibility). Sperm competitiveness that is contingent on parental compatibility will exhibit nonadditive genetic variation. We tested these models in the Australian cricket, Teleogryllus oceanicus, using a design that allowed us to partition additive, nonadditive genetic, and parental variance for sperm competitiveness. We found an absence of additive and nonadditive genetic variance in this species, challenging the direct relevance of either model to the evolution of sperm competitiveness in particular, and polyandry in general. Instead, we found maternal effects that were possibly sex-linked or cytoplasmically linked. We also found effects of focal male age on sperm competitiveness, with small increments in age conferring more competitive sperm.
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Affiliation(s)
- Damian K Dowling
- School of Biological Sciences, Monash University, Clayton, 3800, Victoria, Australia.
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Maklakov AA, Cayetano L, Brooks RC, Bonduriansky R. The roles of life-history selection and sexual selection in the adaptive evolution of mating behavior in a beetle. Evolution 2009; 64:1273-82. [PMID: 19930453 DOI: 10.1111/j.1558-5646.2009.00904.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although there is continuing debate about whether sexual selection promotes or impedes adaptation to novel environments, the role of mating behavior in such adaptation remains largely unexplored. We investigated the evolution of mating behavior (latency to mating, mating probability and duration) in replicate populations of seed beetles Callosobruchus maculatus subjected to selection on life-history ("Young" vs. "Old" reproduction) under contrasting regimes of sexual selection ("Monogamy" vs. "Polygamy"). Life-history selection is predicted to favor delayed mating in "Old" females, but sexual conflict under polygamy can potentially retard adaptive life-history evolution. We found that life-history selection yielded the predicted changes in mating behavior, but sexual selection regime had no net effect. In within-line crosses, populations selected for late reproduction showed equally reduced early-life mating probability regardless of mating system. In between-line crosses, however, the effect of life-history selection on early-life mating probability was stronger in polygamous lines than in monogamous ones. Thus, although mating system influenced male-female coevolution, removal of sexual selection did not affect the adaptive evolution of mating behavior. Importantly, our study shows that the interaction between sexual selection and life-history selection can result in either increased or decreased reproductive divergence depending on the ecological context.
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Affiliation(s)
- Alexei A Maklakov
- Evolution & Ecology Research Centre and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, Sydney 2052, Australia.
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