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Castano-Sanz V, Gomez-Mestre I, Rodriguez-Exposito E, Garcia-Gonzalez F. Pesticide exposure triggers sex-specific inter- and transgenerational effects conditioned by past sexual selection. Proc Biol Sci 2024; 291:20241037. [PMID: 39014998 PMCID: PMC11252676 DOI: 10.1098/rspb.2024.1037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/13/2024] [Accepted: 06/13/2024] [Indexed: 07/18/2024] Open
Abstract
Environmental variation often induces plastic responses in organisms that can trigger changes in subsequent generations through non-genetic inheritance mechanisms. Such transgenerational plasticity thus consists of environmentally induced non-random phenotypic modifications that are transmitted through generations. Transgenerational effects may vary according to the sex of the organism experiencing the environmental perturbation, the sex of their descendants or both, but whether they are affected by past sexual selection is unknown. Here, we use experimental evolution on an insect model system to conduct a first test of the involvement of sexual selection history in shaping transgenerational plasticity in the face of rapid environmental change (exposure to pesticide). We manipulated evolutionary history in terms of the intensity of sexual selection for over 80 generations before exposing individuals to the toxicant. We found that sexual selection history constrained adaptation under rapid environmental change. We also detected inter- and transgenerational effects of pesticide exposure in the form of increased fitness and longevity. These cross-generational influences of toxicants were sex dependent (they affected only male descendants), and intergenerational, but not transgenerational, plasticity was modulated by sexual selection history. Our results highlight the complexity of intra-, inter- and transgenerational influences of past selection and environmental stress on phenotypic expression.
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Affiliation(s)
- Veronica Castano-Sanz
- Department of Ecology and Evolution, Doñana Biological Station (CSIC), Seville, Spain
| | - Ivan Gomez-Mestre
- Department of Ecology and Evolution, Doñana Biological Station (CSIC), Seville, Spain
| | | | - Francisco Garcia-Gonzalez
- Department of Ecology and Evolution, Doñana Biological Station (CSIC), Seville, Spain
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
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2
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Rowe L, Rundle HD. The Alignment of Natural and Sexual Selection. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2021. [DOI: 10.1146/annurev-ecolsys-012021-033324] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sexual selection has the potential to decrease mean fitness in a population through an array of costs to nonsexual fitness. These costs may be offset when sexual selection favors individuals with high nonsexual fitness, causing the alignment of sexual and natural selection. We review the many laboratory experiments that have manipulated mating systems aimed at quantifying the net effects of sexual selection on mean fitness. These must be interpreted in light of population history and the diversity of ways manipulations have altered sexual interactions, sexual conflict, and sexual and natural selection. Theory and data suggest a net benefit is more likely when sexually concordant genetic variation is enhanced and that ecological context can mediate the relative importance of these different effects. Comparative studies have independently examined the consequences of sexual selection for population/species persistence. These provide little indication of a benefit, and interpreting these higher-level responses is challenging.
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Affiliation(s)
- Locke Rowe
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
| | - Howard D. Rundle
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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3
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Pilakouta N, Ålund M. Editorial: Sexual selection and environmental change: what do we know and what comes next? Curr Zool 2021; 67:293-298. [PMID: 34616921 PMCID: PMC8488989 DOI: 10.1093/cz/zoab021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2021] [Indexed: 12/02/2022] Open
Affiliation(s)
- Natalie Pilakouta
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3FX, UK
| | - Murielle Ålund
- Department of Ecology and Genetics, Animal Ecology, Evolutionary Biology Centre (EBC), Uppsala University, Norbyvägen 18D 75236 Uppsala, Sweden
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4
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Kyogoku D, Sota T. Sexual selection increased offspring production via evolution of male and female traits. J Evol Biol 2020; 34:501-511. [PMID: 33314378 DOI: 10.1111/jeb.13753] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/06/2020] [Accepted: 11/22/2020] [Indexed: 11/28/2022]
Abstract
Phenotypic evolution driven by sexual selection can impact the fitness of individuals and thus population performance through multiple mechanisms, but it is unresolved how and when sexual selection affects offspring production by females. We examined the effects of sexual selection on offspring production by females using replicated experimental evolutionary lines of Callosobruchus chinensis that were kept under polygamy (with sexual selection) or monogamy (without sexual selection) for 21 generations. We found that polygamous-line pairs produced more offspring than monogamous-line pairs, because polygamous-line beetles evolved to be larger than monogamous-line beetles, and larger females were more fecund. Egg hatchability did not differ between polygamous- and monogamous-line pairs, as a result of the positive and negative effects of sexual selection cancelling out. When mated with an individual from a common tester line, both polygamous-line females and males showed higher hatchability in resultant eggs than monogamous ones. Further, cohabitation with a male reduced egg hatchability, and this effect was more pronounced in polygamous-line than in monogamous-line males. These results demonstrate multiple mechanisms by which sexual selection affects female fitness, with the net effect being positive. Analyses of how development time, body size and male genital morphology were influenced by selection regime suggest that these results arose from both evolution via good-gene processes and sexually antagonistic selection. Our results are also consistent with the hypothesis that the fitness consequences of sexual selection for females are dependent on the evolutionary history of the population.
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Affiliation(s)
- Daisuke Kyogoku
- Ecological Integration, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.,Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Teiji Sota
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
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5
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Gibson Vega A, Kennington WJ, Tomkins JL, Dugand RJ. Experimental evidence for accelerated adaptation to desiccation through sexual selection on males. J Evol Biol 2020; 33:1060-1067. [PMID: 32315476 DOI: 10.1111/jeb.13634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/26/2020] [Accepted: 04/13/2020] [Indexed: 11/26/2022]
Abstract
The impact of sexual selection on the adaptive process remains unclear. On the one hand, sexual selection might hinder adaptation by favouring costly traits and preferences that reduce nonsexual fitness. On the other hand, condition dependence of success in sexual selection may accelerate adaptation. Here, we used replicate populations of Drosophila melanogaster to artificially select on male desiccation resistance while manipulating the opportunity for precopulatory sexual selection in a factorial design. Following five generations of artificial selection, we measured the desiccation resistance of males and females to test whether the addition of sexual selection accelerated adaptation. We found a significant interaction between the effects of natural selection and sexual selection: desiccation resistance was highest in populations where sexual selection was allowed to operate. Despite only selecting on males, we also found a correlated response in females. These results provide empirical support for the idea that sexual selection can accelerate the rate of adaptation.
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Affiliation(s)
- Aline Gibson Vega
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - W Jason Kennington
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Joseph L Tomkins
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Robert J Dugand
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia
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6
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Rai JK, Amendt J, Bernhardt V, Pasquerault T, Lindström A, Perotti MA. Mites (Acari) as a Relevant Tool in Trace Evidence and Postmortem Analyses of Buried Corpses. J Forensic Sci 2020; 65:2174-2183. [PMID: 32717143 DOI: 10.1111/1556-4029.14506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/13/2020] [Accepted: 06/16/2020] [Indexed: 11/30/2022]
Abstract
This report interprets the presence of mite species in three clandestine graves in Europe, evaluating their potential use as trace evidence or markers. Grave 1 (Sweden): Two mite species Rhizoglyphus robini Claparède, 1869 and Parasitus loricatus (Wankel, 1861) were recovered from the surface of a body buried in a shallow grave in an area surrounded by trees, in close vicinity to house gardens. Grave 2 (Germany): Phoretic deutonymphs of Gamasodes spiniger (Trägårdh, 1910) were attached to an adult fly (Diptera: Sphaeroceridae) found within a shallow grave containing two human bodies covered in soil and dung. Grave 3 (France): P. loricatus were recovered from the soil around a body buried in a deep grave (80 cm under). In graves 1 and 3 both corpses were undergoing advanced decay and skeletization, the locations match with the subterranean habit of P. loricatus, highlighting the value of this species as a marker of graves or burials in soil and during late decomposition. R. robini is a soil mite that feeds on decayed roots and bulbs; this mite species confirms the location of the corpse within top soil, agreeing with a more specific type of superficial burial, a shallow grave. In case 2, the presence of both coprophiles, the mite G. spiniger and the carrier fly confirm association of remains with dung or animal feces. The three mite species are reported for the first time in human graves. There are no previous records of R. robini from Sweden.
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Affiliation(s)
- Jas K Rai
- Ecology and Evolutionary Biology Section, School of Biological Sciences, Reading University, Whiteknights, Reading, RG6 6AS, U.K
| | - Jens Amendt
- Institut für Rechtsmedizin, Goethe University, Frankfurt am Main, 60596, Germany
| | - Victoria Bernhardt
- Institut für Rechtsmedizin, Goethe University, Frankfurt am Main, 60596, Germany
| | - Thierry Pasquerault
- Institut de Recherche Criminelle de la Gendarmerie Nationale Department Faune - Flore - Forensiques, Pontoise, 95000, France
| | - Anders Lindström
- Department of Microbiology, National Veterinary Institute SVA, Uppsala, 751 89, Sweden
| | - M Alejandra Perotti
- Ecology and Evolutionary Biology Section, School of Biological Sciences, Reading University, Whiteknights, Reading, RG6 6AS, U.K
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7
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Sexual conflict drives male manipulation of female postmating responses in Drosophila melanogaster. Proc Natl Acad Sci U S A 2019; 116:8437-8444. [PMID: 30962372 PMCID: PMC6486729 DOI: 10.1073/pnas.1821386116] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In species with males and females, reproduction requires contributions from both sexes and therefore some degree of cooperation. At the same time, antagonistic interactions can evolve because of the differing goals of males and females. We aligned the interests of the sexes in the naturally promiscuous fruit fly Drosophila melanogaster by enforcing randomized monogamy for more than 150 generations. Males repeatedly evolved to manipulate females less, a pattern visible in both the timing of female reproductive effort and gene expression changes after mating. Male investment in expression of genes encoding seminal fluid proteins, which shape the female postmating response, declined concurrently. Our results confirm the presence of sexually antagonistic selection on postcopulatory interactions that can be reversed by monogamy. In many animals, females respond to mating with changes in physiology and behavior that are triggered by molecules transferred by males during mating. In Drosophila melanogaster, proteins in the seminal fluid are responsible for important female postmating responses, including temporal changes in egg production, elevated feeding rates and activity levels, reduced sexual receptivity, and activation of the immune system. It is unclear to what extent these changes are mutually beneficial to females and males or instead represent male manipulation. Here we use an experimental evolution approach in which females are randomly paired with a single male each generation, eliminating any opportunity for competition for mates or mate choice and thereby aligning the evolutionary interests of the sexes. After >150 generations of evolution, males from monogamous populations elicited a weaker postmating stimulation of egg production and activity than males from control populations that evolved with a polygamous mating system. Males from monogamous populations did not differ from males from polygamous populations in their ability to induce refractoriness to remating in females, but they were inferior to polygamous males in sperm competition. Mating-responsive genes in both the female abdomen and head showed a dampened response to mating with males from monogamous populations. Males from monogamous populations also exhibited lower expression of genes encoding seminal fluid proteins, which mediate the female response to mating. Together, these results demonstrate that the female postmating response, and the male molecules involved in eliciting this response, are shaped by ongoing sexual conflict.
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8
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Walsh CB, McGuigan K. Do slower movers have lower reproductive success and higher mutation load? Evol Lett 2018; 2:590-598. [PMID: 30564442 PMCID: PMC6292707 DOI: 10.1002/evl3.87] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 10/18/2018] [Indexed: 02/01/2023] Open
Abstract
Deleterious mutations occur frequently in eukaryotes, resulting in individuals carrying multiple alleles that decrease their fitness. At a population level, if unchecked, accumulation of this mutation load can ultimately lead to extinction. How selection counters the accumulation of mutation load, limiting declines in population fitness, is not well understood. Here, we use manipulative experiments in zebrafish (Danio rerio) to investigate the opportunities for selection on mutation load. Inducing high mutation load through mutagenesis, we applied one generation of within‐family selection on locomotor performance and characterized both the direct response to this selection and the indirect response of reproductive success. Offspring of slow swimming parents exhibited age‐dependent declines in swimming speed, whereas their cousins, with faster swimming parents, did not. This pattern mimics previously documented differences between high and low mutation load populations of zebrafish, suggesting that slow swimming siblings inherited (and transmitted) more mutations than their faster swimming siblings. Crosses among offspring of slow swimming fish had, on average, <75% of the reproductive success of crosses among offspring of fast swimming parents, or crosses of offspring of slow swimmers with offspring of fast swimmers. This evidence of mutationally correlated swimming speed and reproductive success reveals the potential for concordant selection on mutation load through different fitness components. There was no evidence that crosses within families (where parents potentially shared the same mutations inherited from their common ancestor) had lower reproductive success than crosses among families, suggesting that viability selection was not acting predominantly through lethal recessive homozygotes. Rather, patterns of reproductive success are suggestive of effects of mutation number per se on embryo viability. Overall, our results highlight the potential for early life mortality to remove deleterious mutations, and the need to account for this mortality when investigating the evolutionary dynamics of mutation load.
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Affiliation(s)
- Carly B Walsh
- School of Biological Sciences The University of Queensland Brisbane 4072 Australia
| | - Katrina McGuigan
- School of Biological Sciences The University of Queensland Brisbane 4072 Australia
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9
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Abstract
Competition for mates can be a major source of selection, not just on secondary sexual traits but across the genome. Mate competition strengthens selection on males via sexual selection, which typically favors healthy, vigorous individuals and, thus, all genetic variants that increase overall quality. However, recent studies suggest another major effect of mate competition that could influence genome-wide selection: Sexual harassment by males can drastically weaken selection on quality in females. Because of these conflicting effects, the net effect of mate competition is uncertain, although perhaps not entirely unpredictable. We propose that the environment in which mate competition occurs mediates the importance of sexual selection relative to sexual conflict and, hence, the net effect of mate competition on nonsexual fitness. To test this, we performed experimental evolution with 63 fruit fly populations adapting to novel larval conditions where each population was maintained with or without mate competition. In half the populations with mate competition, adults interacted in simple, high-density environments. In the remainder, adults interacted in more spatially complex environments in which male-induced harm is reduced. Populations evolving with mate competition in the complex environment adapted faster to novel larval environments than did populations evolving without mate competition or with mate competition in the simple environment. Moreover, mate competition in the complex environment caused a substantial reduction in inbreeding depression for egg-to-adult viability relative to the other two mating treatments. These results demonstrate that the mating environment has a substantial and predictable effect on nonsexual fitness through adaptation and purging.
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10
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Singh A, Agrawal AF, Rundle HD. Environmental complexity and the purging of deleterious alleles. Evolution 2017; 71:2714-2720. [DOI: 10.1111/evo.13334] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/26/2017] [Accepted: 07/27/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Amardeep Singh
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto ON Canada M5S 3B2
| | - Aneil F. Agrawal
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto ON Canada M5S 3B2
| | - Howard D. Rundle
- Department of Biology; University of Ottawa; Ottawa ON Canada K1N 6N5
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11
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Savic Veselinovic M, Pavkovic-Lucic S, Kurbalija Novicic Z, Jelic M, Stamenkovic-Radak M, Andjelkovic M. Mating behavior as an indicator of quality of Drosophila subobscura males? INSECT SCIENCE 2017; 24:122-132. [PMID: 26235310 DOI: 10.1111/1744-7917.12257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/05/2015] [Indexed: 06/04/2023]
Abstract
According to current theoretical predictions, any deleterious mutations that reduce nonsexual fitness may have a negative influence on mating success. This means that sexual selection may remove deleterious mutations from the populations. Males of good genetic quality should be more successful in mating, compared to the males of lower genetic quality. As mating success is a condition dependent trait, large fractions of the genome may be a target of sexual selection and many behavioral traits are likely to be condition dependent. We manipulated the genetic quality of Drosophila subobscura males by inducing mutations with ionizing radiation and observed the effects of the obtained heterozygous mutations on male mating behavior: courtship occurrence, courtship latency, mating occurrence, latency to mating and duration of mating. We found possible effects of mutations. Females mated more frequently with male progeny of nonirradiated males and that these males courted females faster compared to the male progeny of irradiated males. Our findings indicate a possible important role of sexual selection in purging deleterious mutations.
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Affiliation(s)
| | | | | | - Mihailo Jelic
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Marina Stamenkovic-Radak
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
- Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Marko Andjelkovic
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
- Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
- Serbian Academy of Sciences and Arts, Belgrade, Serbia
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12
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Prokop ZM, Prus MA, Gaczorek TS, Sychta K, Palka JK, Plesnar-Bielak A, Skarboń M. Do males pay for sex? Sex-specific selection coefficients suggest not. Evolution 2017; 71:650-661. [PMID: 27943275 DOI: 10.1111/evo.13151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 10/31/2016] [Accepted: 11/11/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Zofia M. Prokop
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Monika A. Prus
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Tomasz S. Gaczorek
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Karolina Sychta
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Joanna K. Palka
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Agata Plesnar-Bielak
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
| | - Magdalena Skarboń
- Institute of Environmental Sciences; Jagiellonian University; Gronostajowa 7 30-387 Krakow Poland
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13
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Vega‐Trejo R, Head ML, Keogh JS, Jennions MD. Experimental evidence for sexual selection against inbred males. J Anim Ecol 2017; 86:394-404. [DOI: 10.1111/1365-2656.12615] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/24/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Regina Vega‐Trejo
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - Megan L. Head
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - J. Scott Keogh
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - Michael D. Jennions
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
- Wissenschaftskolleg zu Berlin Wallotstraße 19 14193 Berlin Germany
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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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Herdegen M, Radwan J. Effect of induced mutations on sexually selected traits in the guppy, Poecilia reticulata. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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16
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Collet JM, Blows MW, McGuigan K. Transcriptome-wide effects of sexual selection on the fate of new mutations. Evolution 2015; 69:2905-16. [DOI: 10.1111/evo.12778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Julie M. Collet
- School of Biological Sciences; The University of Queensland; Queensland 4072 Australia
| | - Mark W. Blows
- School of Biological Sciences; The University of Queensland; Queensland 4072 Australia
| | - Katrina McGuigan
- School of Biological Sciences; The University of Queensland; Queensland 4072 Australia
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17
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Power DJ, Holman L. Assessing the alignment of sexual and natural selection using radiomutagenized seed beetles. J Evol Biol 2015; 28:1039-48. [DOI: 10.1111/jeb.12625] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 12/01/2022]
Affiliation(s)
- D. J. Power
- Division of Evolution, Ecology & Genetics; Research School of Biology; Australian National University; Canberra ACT Australia
| | - L. Holman
- Division of Evolution, Ecology & Genetics; Research School of Biology; Australian National University; Canberra ACT Australia
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18
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Cabral LG, Holland B. Courtship song does not increase the rate of adaptation to a thermally stressful environment in a Drosophila melanogaster laboratory population. PLoS One 2014; 9:e111148. [PMID: 25365209 PMCID: PMC4218839 DOI: 10.1371/journal.pone.0111148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 09/29/2014] [Indexed: 11/18/2022] Open
Abstract
Courtship song in D. melanogaster contributes substantially to male mating success through female selection. We used experimental evolution to test whether this display trait is maintained through adaptive female selection because it indicates heritable male quality for thermal stress tolerance. We used non-displaying, outbred populations of D. melanogaster (nub1) mutants and measured their rate of adaptation to a new, thermally stressful environment, relative to wild-type control populations that retained courtship song. This design retains sexually selected conflict in both treatments. Thermal stress should select across genomes for newly beneficial alleles, increasing the available genetic and phenotypic variation and, therefore, the magnitude of female benefit derived from courtship song. Following introduction to the thermally stressful environment, net reproductive rate decreased 50% over four generations, and then increased 19% over the following 16 generations. There were no differences between the treatments. Possible explanations for these results are discussed.
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Affiliation(s)
- Larry G. Cabral
- Department of Biological Sciences, California State University, Sacramento, California, United States of America
| | - Brett Holland
- Department of Biological Sciences, California State University, Sacramento, California, United States of America
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19
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Pélabon C, Larsen LK, Bolstad GH, Viken Å, Fleming IA, Rosenqvist G. The effects of sexual selection on life-history traits: an experimental study on guppies. J Evol Biol 2014; 27:404-16. [PMID: 24417444 DOI: 10.1111/jeb.12309] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 11/18/2013] [Accepted: 11/24/2013] [Indexed: 11/26/2022]
Abstract
Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To better understand the effect of sexual selection on the fitness of small populations, we compared components of female fitness and the expression of male secondary sexual characters in 19 experimental populations of guppies (Poecilia reticulata) maintained under polygamous or monogamous mating regimes over nine generations. In order to generate treatments that solely differed by their level of sexual selection, the middle-class neighbourhood breeding design was enforced in the monogamous populations, while in the polygamous populations, all females contributed similarly to the next generation with one male and one female offspring. This experimental design allowed potential sexual conflicts to increase in the polygamous populations because selection could not operate on adult-female traits. Clutch size and offspring survival showed a weak decline from generation to generation but did not differ among treatments. Offspring size, however, declined across generations, but more in monogamous than polygamous populations. By generation eight, orange- and black-spot areas were larger in males from the polygamous treatment, but these differences were not statistically significant. Overall, these results suggest that neither sexual conflict nor the purging of deleterious mutation had important effects on the fitness of our experimental populations. However, only few generations of enforced monogamy in a benign environment were sufficient to negatively affect offspring size, a trait potentially crucial for survival in the wild. Sexual selection may therefore, under certain circumstances, be beneficial over enforced monogamy during captive breeding.
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Affiliation(s)
- C Pélabon
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
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20
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Holman L, Kokko H. The consequences of polyandry for population viability, extinction risk and conservation. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120053. [PMID: 23339244 DOI: 10.1098/rstb.2012.0053] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Polyandry, by elevating sexual conflict and selecting for reduced male care relative to monandry, may exacerbate the cost of sex and thereby seriously impact population fitness. On the other hand, polyandry has a number of possible population-level benefits over monandry, such as increased sexual selection leading to faster adaptation and a reduced mutation load. Here, we review existing information on how female fitness evolves under polyandry and how this influences population dynamics. In balance, it is far from clear whether polyandry has a net positive or negative effect on female fitness, but we also stress that its effects on individuals may not have visible demographic consequences. In populations that produce many more offspring than can possibly survive and breed, offspring gained or lost as a result of polyandry may not affect population size. Such ecological 'masking' of changes in population fitness could hide a response that only manifests under adverse environmental conditions (e.g. anthropogenic change). Surprisingly few studies have attempted to link mating system variation to population dynamics, and in general we urge researchers to consider the ecological consequences of evolutionary processes.
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Affiliation(s)
- Luke Holman
- Centre of Excellence in Biological Interactions, Division of Ecology, Evolution and Genetics, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
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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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22
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Anbesse S, Sumaya NH, Dörfler AV, Strauch O, Ehlers RU. Selective breeding for desiccation tolerance in liquid culture provides genetically stable inbred lines of the entomopathogenic nematode Heterorhabditis bacteriophora. Appl Microbiol Biotechnol 2012; 97:731-9. [DOI: 10.1007/s00253-012-4227-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/02/2012] [Accepted: 06/04/2012] [Indexed: 10/28/2022]
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The Effect of Sexual Selection on Offspring Fitness Depends on the Nature of Genetic Variation. Curr Biol 2012; 22:204-8. [DOI: 10.1016/j.cub.2011.12.020] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 10/28/2011] [Accepted: 12/01/2011] [Indexed: 11/22/2022]
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Abstract
Mutation load is a key parameter in evolutionary theories, but relatively little empirical information exists on the mutation load of populations, or the elimination of this load through selection. We manipulated the opportunity for sexual selection within a mutation accumulation divergence experiment to determine how sexual selection on males affected the accumulation of mutations contributing to sexual and nonsexual fitness. Sexual selection prevented the accumulation of mutations affecting male mating success, the target trait, as well as reducing mutation load on productivity, a nonsexual fitness component. Mutational correlations between mating success and productivity (estimated in the absence of sexual selection) were positive. Sexual selection significantly reduced these fitness component correlations. Male mating success significantly diverged between sexual selection treatments, consistent with the fixation of genetic differences. However, the rank of the treatments was not consistent across assays, indicating that the mutational effects on mating success were conditional on biotic and abiotic context. Our experiment suggests that greater insight into the genetic targets of natural and sexual selection can be gained by focusing on mutational rather than standing genetic variation, and on the behavior of trait variances rather than means.
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Affiliation(s)
- Katrina McGuigan
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia.
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25
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Hollis B, Houle D. Populations with elevated mutation load do not benefit from the operation of sexual selection. J Evol Biol 2011; 24:1918-26. [PMID: 21658188 DOI: 10.1111/j.1420-9101.2011.02323.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Theory predicts that if most mutations are deleterious to both overall fitness and condition-dependent traits affecting mating success, sexual selection will purge mutation load and increase nonsexual fitness. We explored this possibility with populations of mutagenized Drosophila melanogaster exhibiting elevated levels of deleterious variation and evolving in the presence or absence of male-male competition and female choice. After 60 generations of experimental evolution, monogamous populations exhibited higher total reproductive output than polygamous populations. Parental environment also affected fitness measures - flies that evolved in the presence of sexual conflict showed reduced nonsexual fitness when their parents experienced a polygamous environment, indicating trans-generational effects of male harassment and highlighting the importance of a common garden design. This cost of parental promiscuity was nearly absent in monogamous lines, providing evidence for the evolution of reduced sexual antagonism. There was no overall difference in egg-to-adult viability between selection regimes. If mutation load was reduced by the action of sexual selection in this experiment, the resultant gain in fitness was not sufficient to overcome the costs of sexual antagonism.
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Affiliation(s)
- B Hollis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.
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Firman RC, Cheam LY, Simmons LW. Sperm competition does not influence sperm hook morphology in selection lines of house mice. J Evol Biol 2011; 24:856-62. [PMID: 21306461 DOI: 10.1111/j.1420-9101.2010.02219.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R C Firman
- Centre for Evolutionary Biology, University of Western Australia, Australia.
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27
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Complex environmental effects on the expression of alternative reproductive phenotypes in the bulb mite. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9446-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Enders LS, Nunney L. Sex-specific effects of inbreeding in wild-caught Drosophila melanogaster under benign and stressful conditions. J Evol Biol 2010; 23:2309-23. [PMID: 20874846 DOI: 10.1111/j.1420-9101.2010.02085.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In animal populations, sib mating is often the primary source of inbreeding depression (ID). We used recently wild-caught Drosophila melanogaster to test whether such ID is amplified by environmental stress and, in males, by sexual selection. We also investigated whether increased ID because of stress (increased larval competition) persisted beyond the stressed stage and whether the effects of stress and sexual selection interacted. Sib mating resulted in substantial cumulative fitness losses (egg to adult reproduction) of 50% (benign) and 73% (stressed). Stress increased ID during the larval period (23% vs. 63%), but not during post-stress reproductive stages (36% vs. 31%), indicating larval stress may have purged some adult genetic load (although ID was uncorrelated across stages). Sexual selection exacerbated inbreeding depression, with inbred male offspring suffering a higher reproductive cost than females, independent of stress (57% vs. 14% benign, 49% vs. 11% stress).
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Affiliation(s)
- L S Enders
- Department of Ecology, Evolution and Organismal Biology, University of California, Riverside, CA 92507, USA.
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29
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Abstract
The hypothesis that adaptation to local environments can increase mating success was tested using ten replicate lines of Drosophila melanogaster adapted either to 16 degrees C or to 25 degrees C. Competitive mating trials at both temperatures were performed with males taken from a pair of lines, one adapted to each temperature. There was no average increase in mating success for males adapted to the local environment. Although one pair of lines showed the expected pattern, another pair showed the reverse pattern. More data are needed on this hypothesis, preferably with lines that have more strongly adapted to local environments.
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Affiliation(s)
- L Correia
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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30
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Jarzebowska M, Radwan J. Sexual selection counteracts extinction of small populations of the bulb mites. Evolution 2009; 64:1283-9. [PMID: 19930452 DOI: 10.1111/j.1558-5646.2009.00905.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Genetic drift in small populations can increase frequency of deleterious recessives and consequently lead to inbreeding depression and population extinction. On the other hand, as homozygosity at deleterious recessives increases, they should be purged from populations more effectively by selection. Sexual selection has been postulated to strengthen selection against deleterious mutations, and should thus decrease extinction rate and intensify purging of inbreeding depression. We tested these predictions in the bulb mite Rhizoglyphus robini. We created 100 replicate lines of small populations (five males and five females) and in half of them experimentally removed sexual selection by enforcing monogamy. The lines were propagated for eight generations and then assayed for purging of inbreeding depression. We found that proportion of lines which went extinct was lower with sexual selection than without. We also found evidence for purging of inbreeding depression in the lines with sexual selection, but not in lines without sexual selection. Our results suggest that purging of inbreeding depression was more effective against mutations with relatively large deleterious effects. Thus, although our data clearly indicate a positive impact of sexual selection on short-term survival of bottlenecked populations, long-term consequences are less clear as they may be negatively impacted by accumulation of deleterious mutations of small effect.
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Affiliation(s)
- Magdalena Jarzebowska
- Institute of Environmental Studies, Jagiellonian University, Gronostajowa 7, Krakow 30387, Poland.
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32
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Firman RC, Simmons LW. Experimental evolution of sperm quality via postcopulatory sexual selection in house mice. Evolution 2009; 64:1245-56. [PMID: 19922447 DOI: 10.1111/j.1558-5646.2009.00894.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Individuals of many species copulate with multiple mates (polygamy). Multiple mating by females (polyandry) promotes sperm competition, which has broad implications for the evolution of the ejaculate. Multigenerational studies of polygamous insects have shown that the removal of sexual selection has profound fitness consequences for females, and can lead to an evolutionary divergence in ejaculate traits. However, the evolutionary implications of polygamous mating across successive generations have not before been demonstrated in a vertebrate. By manipulating the mating system we were able to reinstate postcopulatory sexual selection in a house mouse population that had a long history of enforced monogamy. Following eight generations of selection, we performed sperm quality assays on males from both the polygamous and monogamous selection lines. We applied a principal component analysis to summarize the variation among 12 correlated sperm traits, and found that males evolving under sperm competition had significantly larger scores on the first axis of variation, reflecting greater numbers of epididymal sperm and increased sperm motility, compared to males from lines under relaxed selection. Moreover, we found a correlated response in the size of litters born to females in lines subject to sperm competition. Thus, we present significant evidence that sperm competition has profound fitness consequences for both male and female house mice.
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Affiliation(s)
- Renée C Firman
- Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Nedlands WA 6009, Australia.
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33
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McGuigan K, Blows MW. Asymmetry of genetic variation in fitness-related traits: apparent stabilizing selection on g(max). Evolution 2009; 63:2838-47. [PMID: 19545265 DOI: 10.1111/j.1558-5646.2009.00759.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The maintenance of genetic variation in traits closely associated with fitness remains a key unresolved issue in evolutionary genetics. One important qualification on the observation of genetic variation in fitness-related traits is that such traits respond asymmetrically to selection, evolving to a greater extent in the direction of lower fitness. Here we test the hypothesis that standing genetic variation in fitness-related traits is principally maintained for unfit phenotypes. Male Drosophila bunnanda vary in mating success (the primary determinant of male fitness) due to female mate choice. We used competitive mating success to partitioning males into two groups: successful (high fitness) and unsuccessful (low fitness). Relative to successful males, unsuccessful males harbored considerably greater levels of additive genetic variation for sexual signaling traits. This genetic asymmetry was detected for a multivariate trait that we demonstrated was not directly under stabilizing sexual selection, leading us to conclude the trait was under apparent stabilizing selection. Consequently, our results suggest genetic variance might be biased toward low fitness even for traits that are not themselves the direct targets of selection. Simple metrics of genetic variance are unlikely to be adequate descriptors of the complex nature of the genetic basis of traits under selection.
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Affiliation(s)
- Katrina McGuigan
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
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34
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Abstract
The "middle-class neighborhood" is a breeding design intended to allow new mutations to accumulate by lessening the effects of purifying selection through the elimination of among-line fitness variation. We show that this design effectively applies soft selection to the experimental population, potentially causing biased estimates of mutational effects if social effects contribute to fitness.
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35
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Whitlock MC, Agrawal AF. Purging the genome with sexual selection: reducing mutation load through selection on males. Evolution 2008; 63:569-82. [PMID: 19154364 DOI: 10.1111/j.1558-5646.2008.00558.x] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Healthy males are likely to have higher mating success than unhealthy males because of differential expression of condition-dependent traits such as mate searching intensity, fighting ability, display vigor, and some types of exaggerated morphological characters. We therefore expect that most new mutations that are deleterious for overall fitness may also be deleterious for male mating success. From this perspective, sexual selection is not limited to influencing those genes directly involved in exaggerated morphological traits but rather affects most, if not all, genes in the genome. If true, sexual selection can be an important force acting to reduce the frequency of deleterious mutations and, as a result, mutation load. We review the literature and find various forms of indirect evidence that sexual selection helps to eliminate deleterious mutations. However, direct evidence is scant, and there are almost no data available to address a key issue: is selection in males stronger than selection in females? In addition, the total effect of sexual selection on mutation load is complicated by possible increases in mutation rate that may be attributable to sexual selection. Finally, sexual selection affects population fitness not only through mutation load but also through sexual conflict, making it difficult to empirically measure how sexual selection affects load. Several lines of enquiry are suggested to better fill large gaps in our understanding of sexual selection and its effect on genetic load.
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Affiliation(s)
- Michael C Whitlock
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 Canada.
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36
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Morrow EH, Stewart AD, Rice WR. Assessing the extent of genome-wide intralocus sexual conflict via experimentally enforced gender-limited selection. J Evol Biol 2008; 21:1046-54. [PMID: 18462311 DOI: 10.1111/j.1420-9101.2008.01542.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intralocus sexual conflict, which occurs when a trait is selected in opposite directions in the two sexes, is a taxonomically widespread phenomenon. The strongest genetic evidence for a gender load due to intralocus sexual conflict comes from the Drosophila melanogaster laboratory model system, in which a negative genetic correlation between male and female lifetime fitness has been observed. Here, using a D. melanogaster model system, we utilize a novel modification of the 'middle class neighbourhood' design to relax selection in one sex, while maintaining selection in the other. After 26 generations of asymmetrical selection, we observed the expected drop in fitness of the non-selected sex compared to that of the selected sex, consistent with previous studies of intralocus sexual conflict in this species. However, the fitness of the selected sex also dropped compared to the base population. The overall decline in fitness of both the selected and the unselected sex indicates that most new mutations are harmful to both sexes, causing recurrent mutation to build a positive genetic correlation for fitness between the sexes. However, the steeper decay in the fitness of the unselected sex indicates that a substantial number of mutations are gender-limited in expression or sexually antagonistic. Our experiment cannot definitively resolve these two possibilities, but we use recent genomic data and results from previous studies to argue that sexually antagonistic alleles are the more likely explanation.
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Affiliation(s)
- E H Morrow
- Department of Ecology, Evolution & Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA.
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37
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Radwan J. Maintenance of genetic variation in sexual ornaments: a review of the mechanisms. Genetica 2007; 134:113-27. [PMID: 17874278 DOI: 10.1007/s10709-007-9203-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 08/08/2007] [Indexed: 10/22/2022]
Abstract
Female preferences for elaborate male sexual traits have been documented in a number of species in which males contribute only genes to the next generation. In such systems, mate choice has been hypothesised to benefit females genetically. For the genetic benefits to be possible there must be additive genetic variation (V A) for sexual ornaments, such that highly ornamented males can pass fitter genes on to the progeny of choosy females. Here, I review the mechanisms that can contribute to the maintenance of this variation. The variation may be limited to sexual ornaments, resulting in Fisherian benefits in terms of the increased reproductive success of male progeny produced by choosy females. Alternatively, ornaments may capture V A in other life-history traits. In the latter case, "good genes" benefits may apply in terms of improved performance of the progeny of either sex. Some mechanisms, however, such as negative pleiotropy, sexually antagonistic variation or overdominance, can maintain V A in ornaments and other life-history traits with little variation in total fitness, leaving little room for any genetic benefits of mate choice. Distinguishing between these mechanisms has consequences not only for the theory of sexual selection, but also for evolution of sex and for biological conservation. I discuss how the traditional ways of testing for genetic benefits can usefully be supplemented by tests detecting benefits resulting from specific mechanisms maintaining V A in sexual ornaments.
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Affiliation(s)
- Jacek Radwan
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Cracow, Poland.
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38
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Prokop ZM, Stuglik M, Żabińska I, Radwan J. Male age, mating probability, and progeny fitness in the bulb mite. Behav Ecol 2007. [DOI: 10.1093/beheco/arm012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Radwan J. Sexual selection and conflict in the bulb mite, Rhizoglyphus robini (Astigmata: Acaridae). EXPERIMENTAL & APPLIED ACAROLOGY 2007; 42:151-8. [PMID: 17611805 DOI: 10.1007/s10493-007-9086-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Accepted: 05/31/2007] [Indexed: 05/16/2023]
Abstract
Whether benefits of mate choice accrued by females outweigh costs associated with sexual selection remains largely unresolved. The 'good genes' perspective, posing that mate choice benefits females genetically has been challenged by the arguments that sexual selection is driven mostly by direct costs and inter-sexual conflict. Here, I present an overview of experimental tests of predictions of good genes and sexual conflict mechanisms in the bulb mite Rhizoglyphus robini.
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Affiliation(s)
- Jacek Radwan
- Institute of Nature Conservation, Polish Academy of Sciences, A. Mickiewicza 33, Krakow, 31-120, Poland.
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40
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Tilszer M, Antoszczyk K, Sałek N, Zajac E, Radwan J. Evolution under relaxed sexual conflict in the bulb mite Rhizoglyphus robini. Evolution 2006; 60:1868-73. [PMID: 17089971 DOI: 10.1554/06-060.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The experimental evolution under different levels of sexual conflict have been used to demonstrate antagonistic coevolution in muscids, but among other taxa a similar approach has not been employed. Here, we describe the results of 37 generations of evolution under either experimentally enforced monogamy or polygamy in the bulb mite Rhizoglyphus robini. Three replicates were maintained for each treatment. Monogamy makes male and female interests congruent; thus selection is expected to decrease harmfulness of males to their partners. Our results were consistent with this prediction in that females from monogamous lines achieved lower fecundity when housed with males from polygamous lines. Fecundity of polygamous females was not affected by mating system under which their partners evolved, which suggests that they were more resistant to male-induced harm. As predicted by the antagonistic coevolution hypothesis, the decrease in harmfulness of monogamous males was accompanied by a decline in reproductive competitiveness. In contrast, female fecundity and embryonic viability, which were not expected to be correlated with male harmfulness, did not differ between monogamous and polygamous lines. None of the fitness components assayed differed between individuals obtained from crosses between parents from the same line and those obtained from crosses between parents from different lines within the same mating system. This indicates that inbreeding depression did not confound our results. However, interpretation of our results is complicated by the fact that both males and females from monogamous lines evolved smaller body size compared to individuals from polygamous lines. Although a decrease in reproductive performance of males from monogamous lines was still significant when body size was taken into account, we were not able to separate the effects of male body size and mating system in their influence on fecundity of their female partners.
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Affiliation(s)
- Magdalena Tilszer
- Institute of Environmental Sciences, Jagiellonian University, Cracow 30-387, Poland
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41
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Tilszer M, Antoszczyk K, Ssaek N, Zajaoc E, Radwan J. EVOLUTION UNDER RELAXED SEXUAL CONFLICT IN THE BULB MITE RHIZOGLYPHUS ROBINI. Evolution 2006. [DOI: 10.1111/j.0014-3820.2006.tb00530.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Fox CW, Scheibly KL, Wallin WG, Hitchcock LJ, Stillwell RC, Smith BP. The genetic architecture of life span and mortality rates: gender and species differences in inbreeding load of two seed-feeding beetles. Genetics 2006; 174:763-73. [PMID: 16888331 PMCID: PMC1602065 DOI: 10.1534/genetics.106.060392] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We examine the inbreeding load for adult life span and mortality rates of two seed beetle species, Callosobruchus maculatus and Stator limbatus. Inbreeding load differs substantially between males and females in both study populations of C. maculatus--life span of inbred females was 9-13% shorter than the life span of outbred females, whereas the life span of inbred males did not differ from the life span of outbred males. The effect of inbreeding on female life span was largely due to an increase in the slope of the mortality curve. In contrast, inbreeding had only a small effect on the life span of S. limbatus--life spans of inbred beetles were approximately 5% shorter than those of outbred beetles, and there was no difference in inbreeding load between the sexes. The inbreeding load for mean life span was approximately 0.4-0.6 lethal equivalents per haploid gamete for female C. maculatus and approximately 0.2-0.3 for both males and females of S. limbatus, all within the range of estimates commonly obtained for Drosophila. However, contrary to the predictions of mutation-accumulation models, inbreeding load for loci affecting mortality rates did not increase with age in either species, despite an effect of inbreeding on the initial rate of increase in mortality. This was because mortality rates decelerated with age and converged to a mortality plateau for both outbred and inbred beetles.
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Affiliation(s)
- Charles W Fox
- Department of Entomology, University of Kentucky, Lexington, Kentucky 40546-0091, USA.
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43
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Kokko H, Rankin DJ. Lonely hearts or sex in the city? Density-dependent effects in mating systems. Philos Trans R Soc Lond B Biol Sci 2006; 361:319-34. [PMID: 16612890 PMCID: PMC1569612 DOI: 10.1098/rstb.2005.1784] [Citation(s) in RCA: 440] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Two very basic ideas in sexual selection are heavily influenced by numbers of potential mates: the evolution of anisogamy, leading to sex role differentiation, and the frequency dependence of reproductive success that tends to equalize primary sex ratios. However, being explicit about the numbers of potential mates is not typical to most evolutionary theory of sexual selection. Here, we argue that this may prevent us from finding the appropriate ecological equilibria that determine the evolutionary endpoints of selection. We review both theoretical and empirical advances on how population density may influence aspects of mating systems such as intrasexual competition, female choice or resistance, and parental care. Density can have strong effects on selective pressures, whether or not there is phenotypic plasticity in individual strategies with respect to density. Mating skew may either increase or decrease with density, which may be aided or counteracted by changes in female behaviour. Switchpoints between alternative mating strategies can be density dependent, and mate encounter rates may influence mate choice (including mutual mate choice), multiple mating, female resistance to male mating attempts, mate searching, mate guarding, parental care, and the probability of divorce. Considering density-dependent selection may be essential for understanding how populations can persist at all despite sexual conflict, but simple models seem to fail to predict the diversity of observed responses in nature. This highlights the importance of considering the interaction between mating systems and population dynamics, and we strongly encourage further work in this area.
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Affiliation(s)
- Hanna Kokko
- Laboratory of Ecological and Evolutionary Dynamics, Department of Biological and Environmental Science, University of Helsinki, PO Box 65 (Vükinkaari 1), 00014 Helsinki, Finland.
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44
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45
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Tomkins JL, Radwan J, Kotiaho JS, Tregenza T. Genic capture and resolving the lek paradox. Trends Ecol Evol 2004; 19:323-8. [PMID: 16701278 DOI: 10.1016/j.tree.2004.03.029] [Citation(s) in RCA: 408] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The genic capture hypothesis offers a resolution to the question of how genetic variation in male sexually selected traits is maintained in the face of strong female preferences. The hypothesis is that male display traits are costly to produce and hence depend upon overall condition, which itself is dependent upon genes at many loci. Few attempts have been made to test the assumptions and predictions of the genic capture hypothesis rigorously and, in particular, little attention has been paid to determining the genetic basis of condition. Such tests are crucial to our understanding of the maintenance of genetic variation and in the evaluation of recent models that propose a role for sexual selection in the maintenance of sex. Here, we review approaches to testing the link between genetically determined condition and levels of sexual trait expression and consider the probable importance of deleterious mutations.
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Affiliation(s)
- Joseph L Tomkins
- Environmental and Evolutionary Biology, Dyer's Brae House, The Mitchell Building, University of St Andrews, Fife, UK, KY16 9TH
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