1
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Balfour V, Armand M, Shuker D. Post-Copulatory Sexual Selection in an Insect With High Levels of Mating Failure. Ecol Evol 2024; 14:e70407. [PMID: 39421326 PMCID: PMC11483530 DOI: 10.1002/ece3.70407] [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: 06/18/2024] [Revised: 09/09/2024] [Accepted: 09/22/2024] [Indexed: 10/19/2024] Open
Abstract
Sexual selection is not a single process. Instead, multiple processes of sexual selection can interact with respect to a given phenotype, in either reinforcing, independent, or conflicting directions. Here we consider how different processes of sexual selection interact in the seed bug Lygaeus simulans. This species is characterised by limited pre-copulatory sexual selection, but the potential for rather strong post-copulatory sexual selection. In particular, mating failure is common in this species, with around 40%-60% of copulations failing to result in the successful transfer of sperm. Mating failure is negatively correlated with female size, with smaller females being less likely to end up inseminated. We have recently argued that this pattern is best explained by cryptic male mate choice for large, more fecund females. Males therefore preferentially inseminate larger females. Here we explore how this potential cryptic male choice interacts with another component of post-copulatory sexual selection: sperm competition. We first manipulated male and female size variation, generating large and small, male and female, size classes. Using a visible mutant marker to assign paternity, we then double-mated females with males, in all combinations of male and female size. Our results showed that sperm competition outcomes were primarily driven by copulation duration, with longer copulations leading to greater paternity share for a male. We also confirmed that larger females are more likely to produce offspring than smaller females, as predicted by cryptic male choice for large females. This effect was again linked to copulation duration, with longer copulations less likely to lead to mating failure. While larger males tended to be more successful in sperm competition, especially if copulating second, female size had little effect on paternity, suggesting that cryptic male choice and sperm competition are acting relatively independently in this species.
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Affiliation(s)
| | - Mélissa Armand
- School of BiologyUniversity of St AndrewsSt AndrewsUK
- Animal Comparative Economics Laboratory, Department of Zoology and Evolutionary BiologyUniversity of RegensburgRegensburgGermany
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2
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Schmidt M, Martin I, Melzer RR. Just a matter of size? Evaluating allometry and intersexual heterometry in Pagurus bernhardus using ratios and indices (Decapoda, Anomura). Integr Zool 2024; 19:807-823. [PMID: 38123465 DOI: 10.1111/1749-4877.12794] [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] [Indexed: 12/23/2023]
Abstract
Heterochely denotes the presence of dissimilarly sized chelipeds on opposite sides of the body, a prevalent occurrence in diverse crustaceans. Conversely, heterometry pertains to the quantifiable disparities in size between these chelipeds. Both chelipeds hold pivotal roles in activities such as foraging, mating, and defense. Consequently, individuals of both genders in heterochelic species exhibit this morphological pattern. Previous studies have identified sexual dimorphism in cheliped size, with males displaying larger major chelipeds compared to females, albeit solely relying on propodus length as a size proxy and focusing solely on the major cheliped. In our study, we meticulously examined 190 specimens of the common European hermit crab Pagurus bernhardus from two collections. We sought to elucidate allometric relationships and assess whether heterometry exhibited sex-based differences when adjusting for body size by using ratios. Our findings revealed that male chelipeds displayed hyperallometric growth relative to females, and all three calculated heterometry indices exhibited significant disparities between the sexes. Consequently, male specimens exhibited larger major and minor chelipeds, even when theoretically matched for body size with females. This phenomenon may be attributed, among other factors, to male-male contests. Should indirect mate selection favor males with larger chelipeds in proportion to their body size, this dynamic could potentiate sexual selection in their favor.
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Affiliation(s)
- Michel Schmidt
- Bavarian State Collection of Zoology, Bavarian Natural History Collections, Munich, Germany
- Faculty of Biology, Biocenter, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Munich, Germany
| | | | - Roland R Melzer
- Bavarian State Collection of Zoology, Bavarian Natural History Collections, Munich, Germany
- Faculty of Biology, Biocenter, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Munich, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, Germany
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3
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Petersdorf M, Weyher AH, Heistermann M, Gunson JL, Govaerts A, Siame S, Mustill RL, Hillegas ME, Winters S, Dubuc C, Higham JP. Multimodal sexual signals are not precise indicators of fertility in female Kinda baboons. Horm Behav 2024; 165:105632. [PMID: 39244874 DOI: 10.1016/j.yhbeh.2024.105632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 08/26/2024] [Accepted: 08/27/2024] [Indexed: 09/10/2024]
Abstract
Female fertility signals are found across taxa, and the precision of such signals may be influenced by the relative strength of different sexual selection mechanisms. Among primates, more precise signals may be found in species with stronger direct male-male competition and indirect female mate choice, and less precise signals in species with stronger indirect male-male competition (e.g. sperm competition) and direct female mate choice. We tested this hypothesis in a wild population of Kinda baboons in Zambia, combining data on female signals with reproductive hormones (estrogen and progesterone metabolites) and intra- and inter-cycle fertility. We predicted that Kinda baboons will exhibit less precise fertility signals than other baboon species, as they experience weaker direct and stronger indirect male-male competition. The frequency of copulation calls and proceptive behavior did not vary with hormones or intra- or inter-cycle fertility in almost all models. Sexual swelling size was predicted by the ratio of estrogen to progesterone metabolites, and was largest in the fertile phase, but differences in size across days were small. Additionally, there was variability in the timing of ovulation relative to the day of sexual swelling detumescence across cycles and swelling size did not vary with inter-cycle fertility. Our results suggest that female Kinda baboon sexual swellings are less precise indicators of fertility compared to other baboon species, while signals in other modalities do not reflect variation in intra- and inter-cycle fertility. Female Kinda baboon sexual signals may have evolved as a strategy to reduce male monopolizability, allowing for more female control over reproduction by direct mate choice.
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Affiliation(s)
- Megan Petersdorf
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States.
| | - Anna H Weyher
- Department of Anthropology, University of Massachusetts Amherst, 240 Hicks Way, Amherst, MA 01003, United States
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany.
| | - Jessica L Gunson
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States.
| | - Alison Govaerts
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland, 7602 Stellenbosch, South Africa
| | - Simon Siame
- Kasanka National Park, P.O. Box 850073, Serenje, Zambia
| | - Ruby L Mustill
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States; Department of Anthropology, Columbia University, 1200 Amsterdam Ave, Schermerhorn Extension, New York, NY 10027, United States.
| | - Madison E Hillegas
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States.
| | - Sandra Winters
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, United Kingdom.
| | - Constance Dubuc
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States
| | - James P Higham
- Department of Anthropology, New York University, 25 Waverly Pl., New York, NY 10003, United States.
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4
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Backhouse F, Welbergen JA, Robinson BW, Dalziell AH. Performative Manipulation of the Environment by Displaying Albert's Lyrebirds. Am Nat 2024; 204:181-190. [PMID: 39008842 DOI: 10.1086/730523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
AbstractWhere dramatic sexual displays are involved in attracting a mate, individuals can enhance their performances by manipulating their physical environment. Typically, individuals alter their environment either in preparation for a performance by creating a "stage" or during the display itself by using discrete objects as "props." We examined an unusual case of performative manipulation of an entire stage by male Albert's lyrebirds (Menura alberti) during their complex song and dance displays. We found that males from throughout the species' range shake the entangled forest vegetation of their display platforms, creating a highly conspicuous and stereotypical movement external to their bodies. This "stage shaking" is performed in two different rhythms, with the second rhythm an isochronous beat that matches the beat of the coinciding vocalizations. Our results provide evidence that stage shaking is an integral, and thus likely functional, component of male Albert's lyrebird sexual displays and so highlight an intriguing but poorly understood facet of complex communication.
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5
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Zang C, Chung MHJ, Neeman T, Harrison L, Vinogradov IM, Jennions MD. Does losing reduce the tendency to engage with rivals to reach mates? An experimental test. Behav Ecol 2024; 35:arae037. [PMID: 38779595 PMCID: PMC11107846 DOI: 10.1093/beheco/arae037] [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: 11/27/2023] [Revised: 04/16/2024] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
Male-male contests for access to females or breeding resources are critical in determining male reproductive success. Larger males and those with more effective weaponry are more likely to win fights. However, even after controlling for such predictors of fighting ability, studies have reported a winner-loser effect: previous winners are more likely to win subsequent contests, while losers often suffer repeated defeats. While the effect of winning-losing is well-documented for the outcome of future fights, its effect on other behaviors (e.g. mating) remains poorly investigated. Here, we test whether a winning versus losing experience influenced subsequent behaviors of male mosquitofish (Gambusia holbrooki) toward rivals and potential mates. We housed focal males with either a smaller or larger opponent for 24 h to manipulate their fighting experience to become winners or losers, respectively. The focal males then underwent tests that required them to enter and swim through a narrow corridor to reach females, bypassing a cylinder that contained either a larger rival male (competitive scenario), a juvenile or was empty (non-competitive scenarios). The tests were repeated after 1 wk. Winners were more likely to leave the start area and to reach the females, but only when a larger rival was presented, indicating higher levels of risk-taking behavior in aggressive interactions. This winner-loser effect persisted for at least 1 wk. We suggest that male mosquitofish adjust their assessment of their own and/or their rival's fighting ability following contests in ways whose detection by researchers depends on the social context.
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Affiliation(s)
- Chenke Zang
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Meng-Han Joseph Chung
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Teresa Neeman
- Biological Data Science Institute, Australian National University, Canberra Australian Capital Territory, 2601, Australia
| | - Lauren Harrison
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Ivan M Vinogradov
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Michael D Jennions
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Centre at Stellenbosch University, Stellenbosch 7600, South Africa
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6
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Hopwood CJ, Zizer JN, Nissen AT, Dillard C, Thompkins AM, Graça J, Waldhorn DR, Bleidorn W. Paradoxical gender effects in meat consumption across cultures. Sci Rep 2024; 14:13033. [PMID: 38871837 DOI: 10.1038/s41598-024-62511-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 05/17/2024] [Indexed: 06/15/2024] Open
Abstract
Men tend to eat more meat than women, but it is not clear why. We tested three hypotheses in a cross-cultural design (20,802 individuals in 23 countries across four continents): that gender differences are (a) universal, (b) related to gender roles and thus weaker in countries with higher gender equality and human development, or (c) related to opportunities to express gender roles and thus stronger in countries with higher gender equality and human development. Across all countries, men tended to consume more meat than women. However, this difference increased significantly in countries with greater human development and gender equality. The paradoxical gender gap in meat consumption aligns with previous research that suggests greater differences in behavior across genders in contexts that are more developed and gender equal. We discuss implications for theories of culture and gender as well as practical implications for global meat reduction.
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Affiliation(s)
| | | | | | | | | | - Joāo Graça
- University of Groningen, Groningen, The Netherlands
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7
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Scott AM, Banes GL, Setiadi W, Saragih JR, Susanto TW, Mitra Setia T, Knott CD. Flanged males have higher reproductive success in a completely wild orangutan population. PLoS One 2024; 19:e0296688. [PMID: 38335166 PMCID: PMC10857694 DOI: 10.1371/journal.pone.0296688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/17/2023] [Indexed: 02/12/2024] Open
Abstract
Male orangutans (Pongo spp.) exhibit bimaturism, an alternative reproductive tactic, with flanged and unflanged males displaying two distinct morphological and behavioral phenotypes. Flanged males are larger than unflanged males and display secondary sexual characteristics which unflanged males lack. The evolutionary explanation for alternative reproductive tactics in orangutans remains unclear because orangutan paternity studies to date have been from sites with ex-captive orangutans, provisioning via feeding stations and veterinary care, or that lack data on the identity of mothers. Here we demonstrate, using the first long-term paternity data from a site free of these limitations, that alternative reproductive tactics in orangutans are condition-dependent, not frequency-dependent. We found higher reproductive success by flanged males than by unflanged males, a pattern consistent with other Bornean orangutan (Pongo pygmaeus) paternity studies. Previous paternity studies disagree on the degree of male reproductive skew, but we found low reproductive skew among flanged males. We compare our findings and previous paternity studies from both Bornean and Sumatran orangutans (Pongo abelii) to understand why these differences exist, examining the possible roles of species differences, ecology, and human intervention. Additionally, we use long-term behavioral data to demonstrate that while flanged males can displace unflanged males in association with females, flanged males are unable to keep other males from associating with a female, and thus they are unable to completely mate guard females. Our results demonstrate that alternative reproductive tactics in Bornean orangutans are condition-dependent, supporting the understanding that the flanged male morph is indicative of good condition. Despite intense male-male competition and direct sexual coercion by males, female mate choice is effective in determining reproductive outcomes in this population of wild orangutans.
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Affiliation(s)
- Amy M. Scott
- Department of Anthropology, Boston University, Boston, Massachusetts, United States of America
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Graham L. Banes
- Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- The Orang-Utan Conservation Genetics Project, Madison, Wisconsin, United States of America
| | - Wuryantari Setiadi
- Eijkman Research Center for Molecular Biology, National Agency for Research and Innovation (BRIN), The Science and Technology Center of Soekarno, Cibinong, West Java, Indonesia
| | - Jessica R. Saragih
- Eijkman Research Center for Molecular Biology, National Agency for Research and Innovation (BRIN), The Science and Technology Center of Soekarno, Cibinong, West Java, Indonesia
| | - Tri Wahyu Susanto
- Departemen of Biology, Faculty of Biology and Agricultural, Universitas Nasional, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta, Indonesia
| | - Tatang Mitra Setia
- Departemen of Biology, Faculty of Biology and Agricultural, Universitas Nasional, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta, Indonesia
| | - Cheryl D. Knott
- Department of Anthropology, Boston University, Boston, Massachusetts, United States of America
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
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8
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Sten TH, Li R, Hollunder F, Eleazer S, Ruta V. Male-male interactions shape mate selection in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.03.565582. [PMID: 37961193 PMCID: PMC10635267 DOI: 10.1101/2023.11.03.565582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Males of many species have evolved behavioral traits to both attract females and repel rivals. Here, we explore mate selection in Drosophila from both the male and female perspective to shed light on how these key components of sexual selection - female choice and male-male competition - work in concert to guide reproductive strategies. We find that male flies fend off competing suitors by interleaving their courtship of a female with aggressive wing flicks, which both repel competitors and generate a 'song' that obscures the female's auditory perception of other potential mates. Two higher-order circuit nodes - P1a and pC1x neurons - are coordinately recruited to allow males to flexibly interleave these agonistic actions with courtship displays, assuring they persistently pursue females until their rival falters. Together, our results suggest that female mating decisions are shaped by male-male interactions, underscoring how a male's ability to subvert his rivals is central to his reproductive success.
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Affiliation(s)
- Tom Hindmarsh Sten
- Laboratory of Neurophysiology and Behavior, The Rockefeller University and Howard Hughes Medical Institute, New York, NY, USA
- Present address: Department of Biology, Stanford University, Stanford, CA
| | - Rufei Li
- Laboratory of Neurophysiology and Behavior, The Rockefeller University and Howard Hughes Medical Institute, New York, NY, USA
| | - Florian Hollunder
- Laboratory of Neurophysiology and Behavior, The Rockefeller University and Howard Hughes Medical Institute, New York, NY, USA
| | - Shadé Eleazer
- Laboratory of Neurophysiology and Behavior, The Rockefeller University and Howard Hughes Medical Institute, New York, NY, USA
| | - Vanessa Ruta
- Laboratory of Neurophysiology and Behavior, The Rockefeller University and Howard Hughes Medical Institute, New York, NY, USA
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9
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Mitchell C, Wylde Z, Del Castillo E, Rapkin J, House CM, Hunt J. Beauty or function? The opposing effects of natural and sexual selection on cuticular hydrocarbons in male black field crickets. J Evol Biol 2023; 36:1266-1281. [PMID: 37534753 DOI: 10.1111/jeb.14198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/21/2023] [Accepted: 05/10/2023] [Indexed: 08/04/2023]
Abstract
Although many theoretical models of male sexual trait evolution assume that sexual selection is countered by natural selection, direct empirical tests of this assumption are relatively uncommon. Cuticular hydrocarbons (CHCs) are known to play an important role not only in restricting evaporative water loss but also in sexual signalling in most terrestrial arthropods. Insects adjusting their CHC layer for optimal desiccation resistance is often thought to come at the expense of successful sexual attraction, suggesting that natural and sexual selection are in opposition for this trait. In this study, we sampled the CHCs of male black field crickets (Teleogryllus commodus) using solid-phase microextraction and then either measured their evaporative water loss or mating success. We then used multivariate selection analysis to quantify the strength and form of natural and sexual selection targeting male CHCs. Both natural and sexual selection imposed significant linear and stabilizing selection on male CHCs, although for very different combinations. Natural selection largely favoured an increase in the total abundance of CHCs, especially those with a longer chain length. In contrast, mating success peaked at a lower total abundance of CHCs and declined as CHC abundance increased. However, mating success did improve with an increase in a number of specific CHC components that also increased evaporative water loss. Importantly, this resulted in the combination of male CHCs favoured by natural selection and sexual selection being strongly opposing. Our findings suggest that the balance between natural and sexual selection is likely to play an important role in the evolution of male CHCs in T. commodus and may help explain why CHCs are so divergent across populations and species.
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Affiliation(s)
- Christopher Mitchell
- Centre for Ecology & Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, UK
| | - Zachariah Wylde
- School of Science, Western Sydney University, Hawkesbury Campus, Penrith, New South Wales, Australia
| | - Enrique Del Castillo
- Department of Industrial & Manufacturing Engineering and Department of Statistics, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - James Rapkin
- Centre for Ecology & Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, UK
| | - Clarissa M House
- School of Science, Western Sydney University, Hawkesbury Campus, Penrith, New South Wales, Australia
| | - John Hunt
- Centre for Ecology & Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, UK
- School of Science, Western Sydney University, Hawkesbury Campus, Penrith, New South Wales, Australia
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10
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McCarthy MM. Neural Control of Sexually Dimorphic Social Behavior: Connecting Development to Adulthood. Annu Rev Neurosci 2023; 46:321-339. [PMID: 37001242 DOI: 10.1146/annurev-neuro-121522-110856] [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] [Indexed: 07/20/2023]
Abstract
Rapid advances in the neural control of social behavior highlight the role of interconnected nodes engaged in differential information processing to generate behavior. Many innate social behaviors are essential to reproductive fitness and therefore fundamentally different in males and females. Programming these differences occurs early in development in mammals, following gonadal differentiation and copious androgen production by the fetal testis during a critical period. Early-life programming of social behavior and its adult manifestation are separate but yoked processes, yet how they are linked is unknown. This review seeks to highlight that gap by identifying four core mechanisms (epigenetics, cell death, circuit formation, and adult hormonal modulation) that could connect developmental changes to the adult behaviors of mating and aggression. We further propose that a unique social behavior, adolescent play, bridges the preweaning to the postpubertal brain by engaging the same neural networks underpinning adult reproductive and aggressive behaviors.
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Affiliation(s)
- Margaret M McCarthy
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA;
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11
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Henske J, Saleh NW, Chouvenc T, Ramírez SR, Eltz T. Function of environment-derived male perfumes in orchid bees. Curr Biol 2023; 33:2075-2080.e3. [PMID: 37054713 DOI: 10.1016/j.cub.2023.03.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/01/2023] [Accepted: 03/21/2023] [Indexed: 04/15/2023]
Abstract
Perfume making in male orchid bees is a unique behavior that has given rise to an entire pollination syndrome in the neotropics.1,2 Male orchid bees concoct and store species-specific perfume mixtures in specialized hind-leg pockets3 using volatiles acquired from multiple environmental sources, including orchid flowers.4,5 However, the function and the ultimate causes of this behavior have remained elusive.2,6 Although previous observations suggested that male perfumes serve as chemical signals, the attractiveness for females has not be shown.7,8 Here, we demonstrate that the possession of perfume increases male mating success and paternity in Euglossa dilemma, a species of orchid bees recently naturalized in Florida. We supplemented males reared from trap-nests with perfume loads harvested from wild conspecifics. In dual-choice experiments, males supplemented with perfumes mated with more females, and sired more offspring, than untreated, equal-aged, control males. Although perfume supplementation had little effect on the intensity of male courtship display, it changed the dynamics of male-male interactions. Our results demonstrate that male-acquired perfumes are sexual signals that stimulate females for mating and suggest that sexual selection is key in shaping the evolution of perfume communication in orchid bees.
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Affiliation(s)
- Jonas Henske
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, Bochum, NRW 44801, Germany.
| | - Nicholas W Saleh
- Entomology and Nematology Department, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL 33314, USA
| | - Thomas Chouvenc
- Entomology and Nematology Department, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL 33314, USA
| | - Santiago R Ramírez
- Center for Population Biology, University of California, Davis, CA 95616, USA
| | - Thomas Eltz
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, Bochum, NRW 44801, Germany
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12
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Moyaho A, Salazar-Bautista JL, Beristain-Castillo E, Amira FU. Iridescent scales signal male fighting ability to access females in the jewelled splitfin Xenotoca variata. JOURNAL OF FISH BIOLOGY 2023; 102:794-802. [PMID: 36648014 DOI: 10.1111/jfb.15316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Jewelled splitfin males (Xenotoca variata) possess multi-colour iridescent scales (speckles) on the flanks. This study tested the hypothesis that the number of speckles could be a good proxy for predicting fighting ability in contests for access to females. The experiments consisted in observing and recording males' agonistic behaviour, courtship displays and mating attempts in mixed-sex groups. The data were analysed and presented based on a Bayesian approach, which revealed that the density (cm-2 ) of speckles was positively correlated with the increase observed in the proportional frequency of attacks. Similarly, the density of speckles was positively associated with the increase observed in the frequency of courtship behaviour and with the frequency of mating attempts. Male-male aggressions drastically diminished (by eightfold) when females were removed from the observation tanks. These results indicate that the number of speckles is a consistent predictor of successful access to females and therefore, speckled males are likely to be able to gain more mating opportunities. This finding highlights the ubiquitous role iridescent colours play in visual signalling.
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Affiliation(s)
- Alejandro Moyaho
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | - José Luis Salazar-Bautista
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | | | - Flores-Urbina Amira
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
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13
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Lindsay WR, Bererhi B, Ljungström G, Wapstra E, Olsson M. Quantitative genetics of breeding coloration in sand lizards; genic capture unlikely to maintain additive genetic variance. Heredity (Edinb) 2023; 130:329-334. [PMID: 36941410 PMCID: PMC10162981 DOI: 10.1038/s41437-023-00607-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
Sexual selection on fitness-determining traits should theoretically erode genetic variance and lead to low heritability. However, many sexually selected traits maintain significant phenotypic and additive genetic variance, with explanations for this "lek paradox" including genic capture due to condition-dependence, and breaks on directional selection due to environmental sources of variance including maternal effects. Here we investigate genetic and environmental sources of variance in the intrasexually selected green badge of the sand lizard (Lacerta agilis). The badge functions as a cue to male fighting ability in this species, and male-male interactions determine mate acquisition. Using animal models on a pedigree including three generations of males measured over an extensive 9-year field study, we partition phenotypic variance in both badge size and body condition into additive genetic, maternal, and permanent environmental effects experienced by an individual over its lifespan. Heritability of badge size was 0.33 with a significant estimate of underlying additive genetic variance. Body condition was strongly environmentally determined in this species and did not show either significant additive genetic variance or heritability. Neither badge size nor body condition was responsive to maternal effects. We propose that the lack of additive genetic variance and heritability of body condition makes it unlikely that genic capture mechanisms maintain additive genetic variance for badge size. That said, genic capture was originally proposed for male traits under female choice, not agonistic selection. If developmental pathways generating variance in body condition, and/or the covarying secondary sex trait, differ between inter- and intrasexual selection, or the rate at which their additive genetic variance or covariance is depleted, future work may show whether genic capture is largely restricted to intersexual selection processes.
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Affiliation(s)
- Willow R Lindsay
- Department of Biological and Environmental Sciences, Göteborg University, Göteborg, Sweden
| | - Badreddine Bererhi
- Department of Biological and Environmental Sciences, Göteborg University, Göteborg, Sweden
| | | | - Erik Wapstra
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Mats Olsson
- Department of Biological and Environmental Sciences, Göteborg University, Göteborg, Sweden.
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14
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Guerrera AG, Daniel MJ, Hughes KA. Black and orange coloration predict success during male–male competition in the guppy. Behav Ecol 2022. [DOI: 10.1093/beheco/arac093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Investigating how intrasexual competition and intersexual mate choice act within a system is crucial to understanding the maintenance and diversity of sexually-dimorphic traits. These two processes can act in concert by selecting for the same trait, or in opposition by selecting for different extremes of the same trait; they can also act on different traits, potentially increasing trait complexity. We asked whether male–male competition and female mate choice act on the same male traits using Trinidadian guppies, which exhibit sexual size dimorphism and male-limited color patterns consisting of different colors arranged along the body and fins. We used behavioral assays to assess the relationship between color and competitive success and then compared our results to the plethora of data on female choice and color in our study population. Males initiated more contests if they were larger than their competitor. Males won contests more often if they had more black coloration than their competitor, and the effect of black was stronger when males had less orange than their competitor. Additionally, males won more often if they had either more structural color (iridescence) and more orange, or less structural color and less orange than their competitor, suggesting multiple combinations of color traits predict success. Females from our study population exhibit a strong preference for more orange coloration. Thus, traits favored in male contests differ from those favored by intersexual selection in this population. These results suggest that inter- and intrasexual selection, when acting concurrently, can promote increased complexity of sexually selected traits.
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Affiliation(s)
- Alexa G Guerrera
- Department of Biological Science, Florida State University , Tallahassee, FL , USA
| | - M J Daniel
- Department of Biological Science, Florida State University , Tallahassee, FL , USA
- Department of Ecology and Evolutionary Biology, University of Toronto , Toronto, ON , Canada
| | - K A Hughes
- Department of Biological Science, Florida State University , Tallahassee, FL , USA
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15
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Mitchem LD, Formica VA, Debray R, Homer DE, Brodie ED. Mycophagous beetle females do not behave competitively during intrasexual interactions in presence of a fungal resource. Ecol Evol 2022; 12:e8977. [PMID: 35784051 PMCID: PMC9163480 DOI: 10.1002/ece3.8977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/07/2022] [Accepted: 05/11/2022] [Indexed: 11/15/2022] Open
Abstract
Intrasexual interactions can determine which individuals within a population have access to limited resources. Despite their potential importance on fitness generally and mating success especially, female-female interactions are not often measured in the same species where male-male interactions are well-defined. In this study, we characterized female-female interactions in Bolitotherus cornutus, a mycophagous beetle species native to Northeastern North America. We used dyadic, behavioral assays to determine whether females perform directly aggressive or indirectly exclusionary competitive behaviors. Polypore shelf fungus, an important food and egg-laying resource for B. cornutus females, is patchily distributed and of variable quality, so we tested for competition over fungus as a resource. Behavior of females was assessed in three sets of dyadic trials with randomly paired female partners. Overall, females did not behave aggressively toward their female partner or perform exclusionary behaviors over the fungal resource. None of the behaviors performed by females were individually repeatable. Two scenarios may explain our lack of observed competition: our trial context may not induce competition, or female B. cornutus simply may not behave competitively in the wild. We compare our results to a similar study on male-male interactions in the same species and propose future studies on female-female interactions under different competitive contexts to expand the understanding of female competition.
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Affiliation(s)
- Lisa D. Mitchem
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | | | - Reena Debray
- Department of Integrative BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Dana E. Homer
- Department of BiologySwarthmore CollegeSwarthmorePennsylvaniaUSA
| | - Edmund D. Brodie
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
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16
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Cheng YC, Chen YH, Chang C, Chuang MF, Hsu Y. Endurance rivalry and female choice jointly influence male mating success in the emerald treefrog (Zhangixalus prasinatus), a lek-chorusing anuran. BMC ZOOL 2022; 7:17. [PMID: 37170165 PMCID: PMC10127438 DOI: 10.1186/s40850-022-00117-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/17/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Endurance rivalry and female choice are two important mechanisms of sexual selection in lek-breeding species. Endurance rivalry is when males compete for opportunities to mate by spending more time in leks than others (interaction-independent male-male competition). Because high-quality males can afford to have high lek attendance, females have a higher chance of mating with good-quality males even when they mate randomly. The good gene hypothesis proposes that females can pass good genes on to their offspring by choosing males that display elaborate morphological and/or behavioral traits that reflect the males’ genetic quality. The relative importance of lek attendance and female choice to males’ mating success in anurans is rarely evaluated. In this study, we investigated how these two mechanisms might jointly shape males’ morphological traits in the lek-chorusing emerald treefrog Zhangixalus prasinatus.
Results
Our results show that (1) male lek attendance is positively correlated with body size and condition, and males with higher lek attendance have higher mating success, (2) the dominant frequency of males’ advertisement calls are negatively correlated with body size and males producing lower frequency calls have higher mating success, (3) male body size, but not body condition, has a non-significant positive relationship with mating success and (4) females show preference for calls with lower dominant frequencies in two-choice playback.
Conclusions
Overall, both endurance rivalry and female choice play an important role in the mating success of male emerald treefrogs in the field and both are influenced by male body size/condition. By mating with males that have higher lek attendance and produce lower frequency calls, selection may indirectly favor larger males.
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17
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Villa SM, Kelly KP, Hollimon MG, Protil KJ, de Roode JC. Lack of inbreeding avoidance during mate selection in migratory monarch butterflies. Behav Processes 2022; 198:104630. [PMID: 35381312 PMCID: PMC10375862 DOI: 10.1016/j.beproc.2022.104630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/21/2022] [Accepted: 03/28/2022] [Indexed: 11/15/2022]
Abstract
Inbreeding is generally thought to have negative consequences for organismal health. However, despite the potential fitness effects, it remains surprisingly common among wild populations. In many cases, the complex factors that underlie mating dynamics make predicting whether individuals should or do avoid inbreeding quite challenging. One reason inbreeding may persist among species is that the likelihood of encountering relatives can be rare. Thus, even if inbreeding has severe consequences, selection to avoid mating with kin will be weak in species that are highly dispersed. Here we investigated if migratory monarch butterflies (Danaus plexippus), which are famous for their dispersal ability, actively avoid inbreeding. We found that neither female nor male monarchs choose mates based on relatedness. These results support the hypothesis that movement ecology can mask the deleterious effects of inbreeding and relax selection for active inbreeding avoidance behaviors. Overall, our data add to the growing list of studies showing that inbreeding avoidance is not the behavioral "default" for most species. We also highlight the implications that inbreeding may have on the declining populations of this iconic butterfly.
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18
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19
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Nair A, Balakrishnan R. Ecological Constraints on Sexual Selection in a Human-Modified Landscape. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.802078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic activities are changing the sensory landscape, interfering with transmission and reception of sexual signals. These changes are leading to alterations in mating behaviour with consequences to fitness. In systems where mate-finding involves long-distance signalling by one sex and approach by the other sex, the spatial distribution of signallers can have implications for male and female fitness. Spatial distribution of signallers is typically determined by an interplay of multiple factors, both ecological and evolutionary, including male competition, female choice and resources, such as calling and oviposition sites. We investigated the possible influence of resource distribution (signalling sites) on the strength and direction of sexual selection acting on false-leaf katydid Onomarchus uninotatus males, signalling in a human-modified landscape in the Western Ghats, India, a biodiversity hotspot. The landscape has changed from evergreen forests to plantations owing to human settlements. We first determined the spatial distribution of calling males and of available calling sites, which are trees of the genus Artocarpus, in the landscape. Using the information on male spacing, call transmission and hearing thresholds, the perceptual spaces of male signals were computed to understand the acoustic environment of calling males and females. It was found that both calling males and females could hear calls of males from neighbouring trees with a probability of 0.76 and 0.59, respectively. Although calling males were found to be spaced apart more than predicted by chance, significant overlap was seen in their acoustic ranges. Clustering of males enables females to easily sample multiple males, facilitating mate choice, but is detrimental to males as it increases competition for females. Using simulations, we determined the optimal spatial distributions of O. uninotatus males for female choice, and for reduction of male competition, given the signalling site distribution. The observed distribution of signallers was then compared with the hypothetical optimal distributions to examine the drivers of signaller spacing. Spacing of calling males in the field was found to be not optimal for either males or females. Resource distribution was found to limit the effectiveness of sexual selection drivers in pushing male spacing toward fitness optima of males or females.
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20
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Siepielski AM, Gómez-Llano M, McPeek MA. Environmental Conditions during Development Affect Sexual Selection through Trait-Fitness Relationships. Am Nat 2022; 199:34-50. [DOI: 10.1086/717294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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21
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Kiat Y, Sapir N. Evolutionary trade-off between male colouration and feather moult extent also indirectly determines female moult. J Evol Biol 2021; 35:278-287. [PMID: 34935231 DOI: 10.1111/jeb.13977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 12/07/2021] [Accepted: 12/12/2021] [Indexed: 11/28/2022]
Abstract
Males and females are often influenced by different selective forces, frequently resulting in diverging phenotypes, for example in colouration. Since an animal's colouration may strongly influence its fitness, causes and consequences of sexual dichromatism in birds could aid in understanding important factors affecting sexual and natural selection. Variation in plumage ornamentation may affect mate attraction or intraspecific antagonistic behaviour. In most passerines, body plumage colouration of juveniles is obtained through the process of feather moult. The number of moulted wing and tail feathers, which also influences the bird's appearance, may affect its fitness. Here, we show that body plumage colouration of male, but not female, passerines is correlated with the number of moulted wing and tail feathers in the early stage of the bird's life for both sexes. Thus, the extent of wing and tail moult in females is not modulated by the female's colouration and can prevent females from reaching their sex-specific optima. This result could be explained by high intersexual genetic correlations, which might make it impossible for the sexes to reach their own trait fitness optima. Our findings may indicate that species-specific, rather than sex-specific, internal correlations shaped bird moult strategy, an important avian life-history trait.
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Affiliation(s)
- Yosef Kiat
- Animal Flight Laboratory, Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, 3498838, Israel
| | - Nir Sapir
- Animal Flight Laboratory, Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, 3498838, Israel
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22
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Dickerson AL, Rowland JA, Trama AJE, Wraith‐Franck D, Hall ML. Male and female Australian magpie‐larks respond differently to variation in song frequency (pitch). Ethology 2021. [DOI: 10.1111/eth.13254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Jessica A. Rowland
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Burwood Vic. Australia
| | - Asher J. E. Trama
- School of BioSciences The University of Melbourne Parkville Vic. Australia
| | | | - Michelle L. Hall
- School of BioSciences The University of Melbourne Parkville Vic. Australia
- Bush Heritage Australia Melbourne Vic. Australia
- School of Biological Sciences The University of Western Australia, Crawley WA Australia
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23
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Leese JM, Snekser JL, Itzkowitz M. Fighting can benefit both winning and losing male convict cichlid fish. Ethology 2021. [DOI: 10.1111/eth.13253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph M. Leese
- Department of Biology DeSales University Center Valley Pennsylvania USA
| | - Jennifer L. Snekser
- Department of Animal Behavior, Ecology, & Conservation Canisius College Buffalo New York USA
| | - Murray Itzkowitz
- Department of Biological Sciences Lehigh University Bethlehem Pennsylvania USA
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24
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Moore AJ, McGlothlin JW, Wolf JB. Runaway evolution from male-male competition. Ecol Lett 2021; 25:295-306. [PMID: 34784652 PMCID: PMC9299654 DOI: 10.1111/ele.13921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 11/29/2022]
Abstract
Wondrously elaborate weapons and displays that appear to be counter to ecological optima are widespread features of male contests for mates across the animal kingdom. To understand how such diverse traits evolve, here we develop a quantitative genetic model of sexual selection for a male signaling trait that mediates aggression in male‐male contests and show that an honest indicator of aggression can generate selection on itself by altering the social environment. This can cause selection to accelerate as the trait is elaborated, leading to runaway evolution. Thus, an evolving source of selection provided by the social environment is the fundamental unifying feature of runaway sexual selection driven by either male‐male competition or female mate choice. However, a key difference is that runaway driven by male‐male competition requires signal honesty. Our model identifies simple conditions that provide clear, testable predictions for empirical studies using standard quantitative genetic methods.
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Affiliation(s)
- Allen J Moore
- Department of Entomology, University of Georgia, Athens, Georgia, USA
| | - Joel W McGlothlin
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Jason B Wolf
- Milner Centre for Evolution and Department of Biology and Biochemistry, University of Bath, Bath, UK
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25
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Herdegen-Radwan M, Cattelan S, Buda J, Raubic J, Radwan J. What do orange spots reveal about male (and female) guppies? A test using correlated responses to selection. Evolution 2021; 75:3037-3055. [PMID: 34658022 PMCID: PMC9299167 DOI: 10.1111/evo.14384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 09/21/2021] [Accepted: 09/27/2021] [Indexed: 11/28/2022]
Abstract
Female preferences for male ornamental traits can arise from indirect benefits, such as increased attractiveness or better viability of progeny, but empirical evidence for such benefits is inconsistent. Artificial selection offers a powerful way to investigate indirect effects of male ornaments. Here, we selected for the area of orange spots on male guppies, a trait subject to female preferences in our population, in replicated up‐ and down‐selected lines. We found a significant direct response to selection, and a correlated response in female preferences, with females from down‐selected lines showing less interest in more orange males. Nevertheless, up‐selected males sired more offspring in direct competition with low‐selected males, irrespective of female origin. We did not find a significantly correlated response to selection among any other fitness correlates we measured. Our results imply that female preferences for orange spots can lead to increased reproductive success of their sons, with no effect on general viability of progeny. Furthermore, although we demonstrate that female preferences may evolve via linkage disequilibrium with the preferred trait, the potential for runaway selection by positive feedback may be constrained by the lack of corresponding linkage with male reproductive competitiveness.
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Affiliation(s)
- Magdalena Herdegen-Radwan
- Department of Behavioural Ecology, Faculty of Biology, Adam Mickiewicz University in Poznan, Poznan, 61-614, Poland
| | - Silvia Cattelan
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - Jakub Buda
- Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznan, Poznan, 61-614, Poland
| | - Jarosław Raubic
- Population Ecology Group, Faculty of Biology, Adam Mickiewicz University in Poznan, Poznan, 61-614, Poland
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznan, Poznan, 61-614, Poland
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26
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Schmidt M, Melzer RR, Bicknell RDC. Kinematics of whip spider pedipalps: a 3D comparative morpho-functional approach. Integr Zool 2021; 17:156-167. [PMID: 34532979 DOI: 10.1111/1749-4877.12591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/12/2021] [Accepted: 09/14/2021] [Indexed: 11/30/2022]
Abstract
Amblypygi are tropical and subtropical ambush predators that use elongated, raptorial pedipalps for different activities. Although pedipalp use in predation and courtship has been explored in videography in vivo analyses, kinematic ex vivo examination of these appendages has not been conducted. Here, we rectify this lack of data by using micro-CT scans to 3D-kinematically model the appendage morphology and the range of motion (ROM) of the joints for Damon medius and Heterophrynus elaphus. We illustrate the successful application of this technique to terrestrial euarthropods in determining the maximum ROM values for each pedipalp joint. We also note that, in life, these values would be lower due to motion restricting structures like tendons, arthrodial membranes, and muscles. We further compare our maximum values obtained here with data from video-based motion analyses. The ROM of each joint shows the greatest flexibility in the femur-tibia joint (140-150°), the lowest in the basitarsus-claw joint (35-40°). ROM in the tibia-basitarsus joint is markedly distinct (D. medius: 44°; H. elaphus: 105°). This disparity reflects how H. elaphus uses the joint in the capture basket, while D. medius uses the femur-tibia joint to form the capture basket. We further illustrate notable vertical motion of the H. elaphus pedipalp compared to D. medius. This difference reflects the retro-ventral trochanter apophysis of H. elaphus. Our study opens the possibility to further whip spider kinematic understanding. Examination of other taxa using this approach will result in a more comprehensive understanding of the ecological significance and ethological implications of this unique arachnid group.
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Affiliation(s)
- Michel Schmidt
- Bavarian State Collection of Zoology, Bavarian Natural History Collections, Munich, Germany.,Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Roland R Melzer
- Bavarian State Collection of Zoology, Bavarian Natural History Collections, Munich, Germany.,Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Russell D C Bicknell
- Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, Australia
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27
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Juarez BH, Adams DC. Evolutionary allometry of sexual dimorphism of jumping performance in anurans. Evol Ecol 2021. [DOI: 10.1007/s10682-021-10132-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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28
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Kwek BZW, Tan M, Yu L, Zhou W, Chang CC, Li D. Aggressive males are more attractive to females and more likely to win contests in jumping spiders. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Strategic adjustment of ejaculate quality in response to variation of the socio-sexual environment. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03032-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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30
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Vilella‐Pacheco Z, Mitchem LD, Formica VA, Brodie ED. Male competition reverses female preference for male chemical cues. Ecol Evol 2021; 11:4532-4541. [PMID: 33976828 PMCID: PMC8093714 DOI: 10.1002/ece3.7348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/28/2021] [Accepted: 02/10/2021] [Indexed: 11/10/2022] Open
Abstract
Females must choose among potential mates with different phenotypes in a variety of social contexts. Many male traits are inherent and unchanging, but others are labile to social context. Competition, for example, can cause physiological changes that reflect recent wins and losses that fluctuate throughout time. We may expect females to respond differently to males depending on the outcome of their most recent fight. In Bolitotherus cornutus (forked fungus beetles), males compete for access to females, but copulation requires female cooperation. In this study, we use behavioral trials to determine whether females use chemical cues to differentiate between males and whether the outcome of recent male competition alters female preference. We measured female association time with chemical cues of two size-matched males both before and after male-male competition. Females in our study preferred to associate with future losers before males interacted, but changed their preference for realized winners following male competitive interactions. Our study provides the first evidence of change in female preference based solely on the outcome of male-male competition.
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Affiliation(s)
| | - Lisa D. Mitchem
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
| | | | - Edmund D. Brodie
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
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31
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Blanckenhorn WU, Baur J, Roy J, Puniamoorthy N, Busso JP, Schäfer MA, Rohner PT. Comparative sexual selection in field and laboratory in a guild of sepsid dung flies. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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32
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Rueda-Zozaya P, Plasman M, Reynoso VH. Good alimentation can overcome the negative effects of climate change on growth in reptiles. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Climate change may lead to higher nest temperatures, which may increase embryo development rate but reduce hatchling size and growth. Larger body size permits better performance, making growth an important fitness trait. In ectotherms, growth is affected by temperature and food quality. To segregate the effects of incubation temperature vs. alimentation on the growth of the Mexican black spiny-tailed iguana, Ctenosaura pectinata, we incubated eggs at 29 or 32 °C, and hatchlings were kept at 30 °C and fed either high- or low-quality food for 1 year, with body size and mass being recorded every 2 weeks. Iguanas incubated at 29 °C grew faster than those incubated at 32 °C. However, food quality had a larger effect on growth than incubation temperature; iguanas fed with high-quality food reached larger body sizes. Growth models suggested that differences in growth between incubation temperatures and food types remain throughout their lives. We found that incubation temperature had long-lasting effects on an ectotherm, and higher incubation temperatures might lead to reduced growth and maturation at a later age. However, food might transcend the effect of increased incubation temperature; therefore, good alimentation might mitigate effects of climate change on growth.
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Affiliation(s)
- Pilar Rueda-Zozaya
- Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, Coyoacán, Ciudad de México, Mexico
| | - Melissa Plasman
- Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, Coyoacán, Ciudad de México, Mexico
| | - Víctor Hugo Reynoso
- Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, Coyoacán, Ciudad de México, Mexico
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33
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Measuring Pre- and Post-Copulatory Sexual Selection and Their Interaction in Socially Monogamous Species with Extra-Pair Paternity. Cells 2021; 10:cells10030620. [PMID: 33799610 PMCID: PMC7999480 DOI: 10.3390/cells10030620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 01/08/2023] Open
Abstract
When females copulate with multiple males, pre- and post-copulatory sexual selection may interact synergistically or in opposition. Studying this interaction in wild populations is complex and potentially biased, because copulation and fertilization success are often inferred from offspring parentage rather than being directly measured. Here, I simulated 15 species of socially monogamous birds with varying levels of extra-pair paternity, where I could independently cause a male secondary sexual trait to improve copulation success, and a sperm trait to improve fertilization success. By varying the degree of correlation between the male and sperm traits, I show that several common statistical approaches, including univariate selection gradients and paired t-tests comparing extra-pair males to the within-pair males they cuckolded, can give highly biased results for sperm traits. These tests should therefore be avoided for sperm traits in socially monogamous species with extra-pair paternity, unless the sperm trait is known to be uncorrelated with male trait(s) impacting copulation success. In contrast, multivariate selection analysis and a regression of the proportion of extra-pair brood(s) sired on the sperm trait of the extra-pair male (including only broods where the male sired ≥1 extra-pair offspring) were unbiased, and appear likely to be unbiased under a broad range of conditions for this mating system. In addition, I investigated whether the occurrence of pre-copulatory selection impacted the strength of post-copulatory selection, and vice versa. I found no evidence of an interaction under the conditions simulated, where the male trait impacted only copulation success and the sperm trait impacted only fertilization success. Instead, direct selection on each trait was independent of whether the other trait was under selection. Although pre- and post-copulatory selection strength was independent, selection on the two traits was positively correlated across species because selection on both traits increased with the frequency of extra-pair copulations in these socially monogamous species.
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Hund AK, Hubbard JK, Krausová S, Munclinger P, Safran RJ. Different underlying mechanisms drive associations between multiple parasites and the same sexual signal. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2020.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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House CM, Lewis Z, Sharma MD, Hodgson DJ, Hunt J, Wedell N, Hosken DJ. Sexual selection on the genital lobes of male Drosophila simulans. Evolution 2021; 75:501-514. [PMID: 33386741 DOI: 10.1111/evo.14158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/03/2020] [Accepted: 12/11/2020] [Indexed: 12/01/2022]
Abstract
Sexual selection is thought to be responsible for the rapid divergent evolution of male genitalia with several studies detecting multivariate sexual selection on genital form. However, in most cases, selection is only estimated during a single episode of selection, which provides an incomplete view of net selection on genital traits. Here, we estimate the strength and form of multivariate selection on the genitalia arch of Drosophila simulans when mating occurs in the absence of a competitor and during sperm competition, in both sperm defence and offense roles (i.e., when mating first and last). We found that the strength of sexual selection on the genital arch was strongest during noncompetitive mating and weakest during sperm offense. However, the direction of selection was similar across selection episodes with no evidence for antagonistic selection. Overall, selection was not particularly strong despite genitals clearly evolving rapidly in this species.
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Affiliation(s)
- Clarissa M House
- School of Science, Western Sydney University, Richmond, NSW, Australia
| | - Zenobia Lewis
- School of Life Sciences, University of Liverpool, Liverpool, UK
| | - Manmohan D Sharma
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hodgson
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - John Hunt
- School of Science, Western Sydney University, Richmond, NSW, Australia.,Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - Nina Wedell
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hosken
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
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Talavera JB, Collosi E, Clark MI, Robertson JM, Gray DA. Minimal prezygotic isolation between ecologically divergent sibling species. Biol J Linn Soc Lond 2021; 132:32-43. [PMID: 33390615 PMCID: PMC7761596 DOI: 10.1093/biolinnean/blaa178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/28/2020] [Indexed: 11/14/2022]
Abstract
Divergence in mating signals typically accompanies speciation. We examine two ecologically divergent sibling species of crickets to assess the degree and timing of the evolution of prezygotic reproductive isolation. Gryllus saxatilis occurs in rocky habitats throughout western North America with long-winged individuals capable of long-distance dispersal; Gryllus navajo is endemic to red-rock sandstone areas of south-eastern Utah and north-eastern Arizona and has short-winged individuals only capable of limited dispersal. Previous genetic work suggested some degree of introgression and/or incomplete lineage sorting is likely. Here we: (1) use restriction site associated DNA sequencing (RAD-seq) genetic data to describe the degree of genetic divergence among species and populations; (2) examine the strength of prezygotic isolation by (i) quantifying differences among male mating songs, and (ii) testing whether females prefer G. saxatilis or G. navajo calling songs. Our results show that genetically distinct "pure" species populations and genetically intermediate populations exist. Male mating songs are statistically distinguishable, but the absolute differences are small. In playback experiments, females from pure populations had no preference based on song; however, females from a genetically intermediate population preferred G. navajo song. Together these results suggest that prezygotic isolation is minimal, and mediated by female behaviour in admixed populations.
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Affiliation(s)
- Janelle B Talavera
- Department of Biology, California State University, Northridge, Northridge, CA, USA
| | - Emma Collosi
- Department of Biology, California State University, Northridge, Northridge, CA, USA
| | - Meaghan I Clark
- Department of Biology, California State University, Northridge, Northridge, CA, USA
| | - Jeanne M Robertson
- Department of Biology, California State University, Northridge, Northridge, CA, USA
| | - David A Gray
- Department of Biology, California State University, Northridge, Northridge, CA, USA
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Owens R, Driscoll H, Farrelly D. Variation in Women’s Mate Preferences over the Development of a Monogamous Relationship Corresponds with Changes in Men’s Life History Strategy. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2020. [DOI: 10.1007/s40806-020-00246-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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Yang Y, Richards-Zawacki CL. Male–male contest limits the expression of assortative mate preferences in a polymorphic poison frog. Behav Ecol 2020. [DOI: 10.1093/beheco/araa114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Codivergence of sexual traits and mate preferences can lead to assortative mating and subsequently reproductive isolation. However, mate choice rarely operates without intrasexual competition, and the effects of the latter on speciation are often overlooked. Maintaining trait polymorphisms despite gene flow and limiting assortative female preferences for less-competitive male phenotypes are two important roles that male–male competition may play in the speciation process. Both roles rely on the assumption that male–male competition limits the expression of divergent female preferences. We tested this assumption in the highly color-polymorphic strawberry poison frog (Oophaga pumilio). Females prefer males of the local color, suggesting that reproductive isolation may be evolving among color morphs. However, this inference does not account for male–male competition, which is also color-mediated. We housed females with two differently colored males, and compared reproductive patterns when the more attractive male was the territory holder versus when he was the nonterritorial male. Females mated primarily with the territory winner, regardless of coloration, suggesting that when a choice must be made between the two, male territoriality overrides female preferences for male coloration. Our results highlight the importance of considering the combined effects of mate choice and intrasexual competition in shaping phenotypic divergence and speciation.
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Affiliation(s)
- Yusan Yang
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Corinne L Richards-Zawacki
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Smithsonian Tropical Research Institute Tupper, Balboa, Ancon, Panama, Republic of Panama
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Burnett AD, Koprowski JL. Ultimate causes of antipredator vocalizations in a nonhibernating squirrel. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Saitta ET, Stockdale MT, Longrich NR, Bonhomme V, Benton MJ, Cuthill IC, Makovicky PJ. An effect size statistical framework for investigating sexual dimorphism in non-avian dinosaurs and other extinct taxa. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa105] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
Despite reports of sexual dimorphism in extinct taxa, such claims in non-avian dinosaurs have been rare over the last decade and have often been criticized. Since dimorphism is widespread in sexually reproducing organisms today, under-reporting in the literature might suggest either methodological shortcomings or that this diverse group exhibited highly unusual reproductive biology. Univariate significance testing, especially for bimodality, is ineffective and prone to false negatives. Species recognition and mutual sexual selection hypotheses, therefore, may not be required to explain supposed absence of sexual dimorphism across the grade (a type II error). Instead, multiple lines of evidence support sexual selection and variation of structures consistent with secondary sexual characteristics, strongly suggesting sexual dimorphism in non-avian dinosaurs. We propose a framework for studying sexual dimorphism in fossils, focusing on likely secondary sexual traits and testing against all alternate hypotheses for variation in them using multiple lines of evidence. We use effect size statistics appropriate for low sample sizes, rather than significance testing, to analyse potential divergence of growth curves in traits and constrain estimates for dimorphism magnitude. In many cases, estimates of sexual variation can be reasonably accurate, and further developments in methods to improve sex assignments and account for intrasexual variation (e.g. mixture modelling) will improve accuracy. It is better to compare estimates for the magnitude of and support for dimorphism between datasets than to dichotomously reject or fail to reject monomorphism in a single species, enabling the study of sexual selection across phylogenies and time. We defend our approach with simulated and empirical data, including dinosaur data, showing that even simple approaches can yield fairly accurate estimates of sexual variation in many cases, allowing for comparison of species with high and low support for sexual variation.
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Affiliation(s)
- Evan T Saitta
- Life Sciences Section, Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA
| | | | - Nicholas R Longrich
- Department of Biology and Biochemistry and Milner Centre for Evolution, University of Bath, Bath, UK
| | - Vincent Bonhomme
- Institut des sciences de l’évolution, Université de Montpellier, Montpellier, France
| | | | - Innes C Cuthill
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Peter J Makovicky
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
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Formica V, Donald H, Marti H, Irgebay Z, Brodie E. Social network position experiences more variable selection than weaponry in wild subpopulations of forked fungus beetles. J Anim Ecol 2020; 90:168-182. [PMID: 32808282 DOI: 10.1111/1365-2656.13322] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 06/17/2020] [Indexed: 12/19/2022]
Abstract
The phenotypic expression and fitness consequences of behaviours that are exhibited during social interactions are especially sensitive to their local social context. This context-dependence is expected to generate more variation in the sign and magnitude of selection on social behaviour than that experienced by static characters like morphology. Relatively few studies, however, have examined selection on behavioural traits in multiple populations. We estimated sexual selection in the wild to determine if the strength and form of selection on social phenotypes is more variable than that on morphology. We compared selection gradients on social network position, body size, and weaponry of male forked fungus beetles Bolitotherus cornutus as they influenced mating success across nine natural subpopulations. Male horn length consistently experienced positive sexual selection. However, the sign and magnitude of selection on individual measures of network centrality (strength and betweenness) differed significantly among subpopulations. Moreover, selection on social behaviours occurred at a local scale ('soft selection'), whereas selection on horn length occurred at the metapopulation scale ('hard selection'). These results indicate that an individual with a given social phenotype could experience different fitness consequences depending on the network it occupies. While individuals seem to be unable to escape the fitness effects of their morphology, they may have the potential to mediate the pressures of selection on behavioural phenotypes by moving among subpopulations or altering social connections within a network.
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Affiliation(s)
- Vincent Formica
- Department of Biology, Swarthmore College, Swarthmore, PA, USA
| | - Hannah Donald
- Department of Biology, Swarthmore College, Swarthmore, PA, USA
| | - Hannah Marti
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Zhazira Irgebay
- Department of Biology, Swarthmore College, Swarthmore, PA, USA
| | - Edmund Brodie
- Mountain Lake Biological Station and Department of Biology, University of Virginia, Charlottesville, VA, USA
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Spermatophore retention may accommodate sexual signal loss in Pacific field crickets. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-020-02850-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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The Role of Sexual Selection in the Evolution of Facial Displays in Male Non-human Primates and Men. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2020. [DOI: 10.1007/s40750-020-00139-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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44
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Lehtonen TK, Kaitala A. Leave me alone: solitary females attract more mates in a nocturnal insect. Behav Ecol 2020. [DOI: 10.1093/beheco/araa049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Spatial distributions of sexual competitors and potential mating partners have a large impact on sexual selection and mating systems. Typically, such effects are investigated with regard to male aggregations. However, females may also need to compete for mating opportunities. Here, we investigated the consequences of clustering and rival attractiveness on female mate attraction success under field conditions in a nocturnal beetle, the common glowworm, Lampyrus noctiluca. We placed dummy females of two glow intensity (attractiveness) levels either alone or in clusters of varying attractiveness compositions. We found that, by displaying alone rather than in a cluster, females have a higher probability of mating and greater potential to exercise mate choice. Within clusters, females of both attractiveness levels had the highest probability of mating when having neighbors of only the less attractive type. These results show that both the presence and attractiveness of rivals can strongly influence females’ mate attraction. The findings also suggest that the typical distribution of glowing females in the wild is better explained by female than male benefits. Hence, the results highlight the important links between spatial distribution of females, male mate searching, and sexual selection.
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Affiliation(s)
- Topi K Lehtonen
- Department of Ecology and Genetics, University of Oulu, Oulu, Finland
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, Hanko, Finland
| | - Arja Kaitala
- Department of Ecology and Genetics, University of Oulu, Oulu, Finland
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, Hanko, Finland
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Joye P, Kawecki TJ. Sexual selection favours good or bad genes for pathogen resistance depending on males' pathogen exposure. Proc Biol Sci 2020; 286:20190226. [PMID: 31064300 DOI: 10.1098/rspb.2019.0226] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton-Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila-but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters' resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the 'general immunocompetence' hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.
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Affiliation(s)
- Patrick Joye
- Department of Ecology and Evolution, University of Lausanne , 1015 Lausanne , Switzerland
| | - Tadeusz J Kawecki
- Department of Ecology and Evolution, University of Lausanne , 1015 Lausanne , Switzerland
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46
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Pardo JCF, Stefanelli-Silva G, Christy JH, Costa TM. Fiddler crabs and their above-ground sedimentary structures: a review. J ETHOL 2020. [DOI: 10.1007/s10164-020-00647-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
AbstractFiddler crabs are abundant, semi-terrestrial crustaceans inhabiting tropical, subtropical and warm temperate coasts worldwide. Some species build above-ground sedimentary structures at or near the opening to their burrows. The functions and shapes of these constructions vary interspecifically and according to the sex of the builder. Here, we compile the dispersed reports on these structures, suggest uniform naming for different shapes, review explanations for their functions and explore associations between the attributes of builders and their structures. We found that 47 fiddler crab species build at least one type (or subtype) of structure, including chimneys, hoods, pillars, semidomes, mudballs, and rims. Sedimentary structures show a strong association with sediment type as well as builder front type, genus and sex, but not with fiddler crab clade. Experimental studies have revealed distinct, sometimes multiple functions for some of these structures (e.g., female attraction, reduction of aggressive behavior and/or landmark orientation); however, most studies have been observational leaving the proposed functions of these structures for many species untested. Both field and laboratory experiments as well as observational studies can help us to better understand these sedimentary structures and their role in fiddler crab behavior and ecology.
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Filice DCS, Dukas R. Winners have higher pre-copulatory mating success but losers have better post-copulatory outcomes. Proc Biol Sci 2020; 286:20182838. [PMID: 30940060 DOI: 10.1098/rspb.2018.2838] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In many animals, the outcomes of competitive interactions can have lasting effects that influence an individual's reproductive success and have important consequences for the strength and direction of evolution via sexual selection. In the fruit fly, Drosophila melanogaster, males that have won previous contests are more likely to win in subsequent conflicts and losers are more likely to lose (winner-loser effects), but the direct fitness consequences and genetic underpinnings of this plasticity are poorly understood. Here, we tested how male genotype and the outcomes of previous male-male conflicts influence male pre- and post-copulatory success. We quantified pre-copulatory success in a choice and no-choice context, and post-copulatory success by quantifying ejaculate offensive and defensive ability. We found that winners have higher reproductive success compared to losers in both pre-copulatory scenarios. However, losers consistently mated for a longer duration, boosted female fecundity and had an increased paternity share when they were the first males to mate, suggesting increased investment into post-copulatory mechanisms. Finally, by using clonal hybrids from the Drosophila Genetic Reference Panel, we documented that genetic variation explained a sizeable proportion of the observed differences between lines, and of the interaction between line and winner and loser effects. Our results place the behavioural data on winner-loser effects in an evolutionary context by documenting the potential fitness gain to males from altering their reproductive strategy based on fighting experience. Our data may also explain the presence and maintenance of trade-offs between different male reproductive strategies.
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Affiliation(s)
- David C S Filice
- Department of Psychology, Neuroscience, and Behaviour, McMaster University , 1280 Main Street West, Hamilton, ON , Canada L8S 4K1
| | - Reuven Dukas
- Department of Psychology, Neuroscience, and Behaviour, McMaster University , 1280 Main Street West, Hamilton, ON , Canada L8S 4K1
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Okada K, Katsuki M, Kiyose K, Okada Y. Older males are more competitive in male fights and more aggressive toward females in the broad-horned flour beetle Gnatocerus cornutus. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-020-2815-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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49
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Wiens JJ, Tuschhoff E. Songs versus colours versus horns: what explains the diversity of sexually selected traits? Biol Rev Camb Philos Soc 2020; 95:847-864. [PMID: 32092241 DOI: 10.1111/brv.12593] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 01/25/2020] [Accepted: 02/10/2020] [Indexed: 01/14/2023]
Abstract
Papers on sexual selection often highlight the incredible diversity of sexually selected traits across animals. Yet, few studies have tried to explain why this diversity evolved. Animals use many different types of traits to attract mates and outcompete rivals, including colours, songs, and horns, but it remains unclear why, for example, some taxa have songs, others have colours, and others horns. Here, we first conduct a systematic survey of the basic diversity and distribution of different types of sexually selected signals and weapons across the animal Tree of Life. Based on this survey, we describe seven major patterns in trait diversity and distributions. We then discuss 10 unanswered questions raised by these patterns, and how they might be addressed. One major pattern is that most types of sexually selected signals and weapons are apparently absent from most animal phyla (88%), in contrast to the conventional wisdom that a diversity of sexually selected traits is present across animals. Furthermore, most trait diversity is clustered in Arthropoda and Chordata, but only within certain clades. Within these clades, many different types of traits have evolved, and many types appear to have evolved repeatedly. By contrast, other major arthropod and chordate clades appear to lack all or most trait types, and similar patterns are repeated at smaller phylogenetic scales (e.g. within insects). Although most research on sexual selection focuses on female choice, we find similar numbers of traits (among sampled species) are involved in male contests (44%) and female choice (55%). Overall, these patterns are largely unexplained and unexplored, as are many other fundamental questions about the evolution of these traits. We suggest that understanding the diversity of sexually selected traits may require a shift towards macroevolutionary studies at relatively deep timescales (e.g. tens to hundreds of millions of years ago).
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Affiliation(s)
- John J Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - E Tuschhoff
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
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50
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Offspring sired by subordinate red deer males under controlled conditions: did some females prefer not to mate with the alpha male? Acta Ethol 2020. [DOI: 10.1007/s10211-020-00336-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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