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Leigh W Simmons - One of the best experts on this subject based on the ideXlab platform.
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state dependent changes in risk taking behaviour as a result of age and residual reproductive value
Animal Behaviour, 2018Co-Authors: Joe A Moschilla, Joseph L Tomkins, Leigh W SimmonsAbstract:Animals are able to modify their behaviour in response to changes in their internal and environmental state. The asset protection principle predicts that an animal's risk-taking behaviour should vary as a result of its residual reproductive value (RRV); animals with greater RRV would incur a greater cost if injured or killed and should therefore take fewer risks than those with low RRV. Despite the intuitive appeal of this hypothesis, few studies have effectively separated the effects of RRV on behaviour from those of age. We addressed this weakness in the widely invoked hypothesis by measuring the risk-taking behaviour of female Australian field crickets, Teleogryllus oceanicus, at various points in the animal's lifetime. We found significant effects of age on risk-taking behaviour: older females emerged from a shelter sooner after a simulated predation threat and exhibited greater mobility in an open arena. Importantly, there was also a significant marginal effect of RRV on risk-taking behaviour. Females with lower RRV displayed greater levels of risk taking than females with high RRV. Our results thereby offer support for the asset protection principle as an explanation for state-dependent variation in risk-taking behaviour.
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socially cued seminal fluid gene expression mediates responses in ejaculate quality to sperm competition risk
Proceedings of The Royal Society B: Biological Sciences, 2017Co-Authors: Leigh W Simmons, Maxine LovegroveAbstract:There is considerable evidence that males will increase the number of sperm ejaculated in response to sperm competition risk. However, whether they have the capacity to adjust seminal fluid components of the ejaculate has received less attention. Male crickets ( Teleogryllus oceanicus ) have been shown to adjust the viability of sperm in their ejaculate in response to sperm competition risk. Here we show that socially mediated plasticity in sperm viability is probably due, at least in part, to male adjustments in the protein composition of the seminal fluid. Seven seminal fluid protein genes were found to have an increased expression in males exposed to rival calls. Increased expression of these genes was correlated with increased sperm viability in whole ejaculates, and gene knockdown confirmed that at least one of these proteins promotes sperm viability. Our results lend support for recent theoretical models that predict complex responses in male allocation to seminal fluid composition in response to sperm competition risk.
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acoustic cues alter perceived sperm competition risk in the field cricket Teleogryllus oceanicus
Behavioral Ecology, 2013Co-Authors: Brian Gray, Leigh W SimmonsAbstract:Sperm competition game theory predicts that males should respond to increasing sperm competition risk by increasing ejaculate expenditure. There is considerable support for this prediction from a diverse range of taxa. However, the cues males use to assess risk and the fitness returns for strategic ejaculation are less well understood. We explored the role of acoustic cues in the assessment of sperm competition risk by manipulating male experience of acoustically signaling conspecifics in the field cricket Teleogryllus oceanicus. Compared with males reared in acoustic isolation, males reared in song-dense environments mimicking a high sperm competition risk produced ejaculates with a greater percentage of viable sperm. However, acoustic experience had only a weak and nonsignificant effect on competitive fertilization success. We argue that female influences on paternity are likely to have a strong moderating effect on male fitness returns from prudent allocation and call for more studies that address the consequences of strategic ejaculation for male fitness.
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female crickets assess relatedness during mate guarding and bias storage of sperm towards unrelated males
Journal of Evolutionary Biology, 2013Co-Authors: Cristina Tuni, Maxine Beveridge, Leigh W SimmonsAbstract:Recent evidence shows that females exert a post-copulatory fertilization bias in favour of unrelated males to avoid the genetic incompatibilities derived from inbreeding. One of the mechanisms suggested for fertilization biases in insects is female control over transport of sperm to the sperm-storage organs. We investigated post-copulatory inbreeding-avoidance mechanisms in females of the cricket Teleogryllus oceanicus. We assessed the relative contribution of related and unrelated males to the sperm stores of double-mated females. To demonstrate unequivocally that biased sperm storage results from female control rather than cryptic male choice, we manipulated the relatedness of mated males and of males performing post-copulatory mate guarding. Our results show that when guarded by a related male, females store less sperm from their actual mate, irrespective of the relatedness of the mating male. Our data support the notion that inhibition of sperm storage by female crickets can act as a form of cryptic female choice to avoid the severe negative effects of inbreeding.
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sperm and seminal fluid proteomes of the field cricket Teleogryllus oceanicus identification of novel proteins transferred to females at mating
Insect Molecular Biology, 2013Co-Authors: Leigh W Simmons, Yewfoon Tan, A H MillarAbstract:Reproductive proteins are amongst the most evolutionarily divergent proteins known, and research on genetically well-characterized species suggests that postcopulatory sexual selection might be important in their evolution; however, we lack the taxonomic breadth of information on reproductive proteins that is required to determine the general importance of sexual selection for their evolution. We used transcriptome sequencing and proteomics to characterize the sperm and seminal fluid proteins of a cricket, Teleogryllus oceanicus, that has been widely used in the study of postcopulatory sexual selection. We identified 57 proteins from the sperm of these crickets. Many of these had predicted function in glycolysis and metabolism, or were structural, and had sequence similarity to sperm proteins found across taxa ranging from flies to humans. We identified 21 seminal fluid proteins, some of which resemble those found to be involved in postmating changes to female reproduction in other species. Some 27% of sperm proteins and 48% of seminal fluid proteins were of unknown function. The characterization of seminal fluid proteins in this species will allow us to explore their adaptive significance, and to contribute comparative data that will facilitate a general appreciation of the evolution of reproductive proteins within and among animal taxa.
Marlene Zuk - One of the best experts on this subject based on the ideXlab platform.
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direct and indirect effects of sexual signal loss on female reproduction in the pacific field cricket Teleogryllus oceanicus
Journal of Evolutionary Biology, 2019Co-Authors: Justa L Heinenkay, Susan L Balenger, Daina B Strub, Marlene ZukAbstract:Sexual signal evolution may present fitness consequences for the non-signaling sex due to shared genes and altered social conditions, but this is rarely studied in natural populations. On the Hawaiian Island of Kauai, most male Teleogryllus oceanicus (Pacific field crickets) lack the ability to sing because of a novel wing mutation (flatwing) that arose and spread in <20 generations. Obligately silent flatwing males have been highly successful because they avoid detection by a deadly, acoustically-orienting parasitoid fly. Little is known about how the flatwing mutation and resulting song-less acoustic environment affects female fitness. We found that Kauai females carrying the flatwing allele invested less in reproductive tissues and experienced more instances of mating failure than normal-wing-carrying females, though total offspring production did not differ between female genotypes. Females from Oahu (HI, where the parasitoid and flatwing also occur) and Mangaia (an island in the Cook Islands which harbors neither the parasitoid nor flatwing) invested less in reproductive tissues when reared in a song-less acoustic environment. Kauai females did not exhibit this plasticity, perhaps because they have experienced nearly song-less conditions for the past ~15 years following the establishment of flatwing. We show that female T. oceanicus experience a mix of costly and beneficial effects of sexual signal loss, which should help maintain the wing polymorphism in the wild. Our results demonstrate that the non-signaling sex can experience a nuanced set of phenotypic consequences resulting from signal evolution, which can further shape dynamics of sexual signal evolution.
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limited flexibility in female pacific field cricket Teleogryllus oceanicus exploratory behaviors in response to perceived social environment
Ethology, 2018Co-Authors: Justa L Heinenkay, Daina B Strub, Marlene ZukAbstract:How populations adapt, or not, to rapid evolution of sexual signals has important implications for population viability, but is difficult to assess due to the paucity of examples of sexual signals evolving in real time. In Hawaiian populations of the Pacific field cricket (Teleogryllus oceanicus), selection from a deadly parasitoid fly has driven the rapid loss of a male acoustic signal, calling song, that females use to locate and evaluate potential mates. In this newly quiet environment where many males are obligately silent, how do phonotactic females find mates? Previous work has shown that the acoustic rearing environment (presence or absence of male calling song) during late juvenile stages and early adulthood exposes adaptive flexibility in locomotor behaviors of males, as well as mating behaviors in both sexes that helps facilitate the spread of silent (flatwing) males. Here, we tested whether females also show acoustically induced plasticity in walking behaviors using laboratory‐reared populations of T. oceanicus from Kauai (HI; >90% flatwings), Oahu (HI; ~50% flatwings), and Mangaia (Cook Islands; no flatwings or parasitoid fly). Though we predicted that females reared without song exposure would increase walking behaviors to facilitate mate localization when song is rare, we discovered that, unlike males, female T. oceanicus showed relatively little plasticity in exploratory behaviors in response to an acoustic rearing environment. Across all three populations, exposure to male calling song during development did not affect latency to begin walking, distance walked, or general activity of female crickets. However, females reared in the absence of song walked slower and showed a marginally non‐significant tendency to walk for longer durations of time in a novel environment than those reared in the presence of song. Overall, plasticity in female walking behaviors appears unlikely to have facilitated sexual signal loss in this species.
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Preexisting behavior facilitated the loss of a sexual signal in the field cricket
2015Co-Authors: Teleogryllus Oceanicus, Janelle R Mcnabb, Nathan W. Bailey, Marlene ZukAbstract:Behavioral preadaptations can provide an accommodating environment in which novel morphological characters may be se-lected. A very recent morphological mutation, flatwing, has caused the loss of male song in field crickets (Teleogryllus oceanicus) from the Hawaiian island of Kauai. Previous studies in this and related species have shown that females require male courtship song to mount males, but flatwing T. oceanicus males still achieve matings. Females from Kauai may have a relaxed requirement for male courtship song, or flatwing males may compensate for their inability to sing by altering other courtship behaviors. We tested whether male courtship and female responses to male courtship were preadapted in a way that facilitated the spread of the male wing mutation or if parallel changes in male courtship and female responses accompanied the mutation. We performed mating trials in 2 captive-bred populations to assess how mating behavior varied depending on the presence or absence of courtship song playback. The first was an ancestral population from Kauai established prior to the emergence of the flatwing mutation, and the second was derived from Kauai after the mutation became prevalent. Mating behaviors did not differ qualitatively or quantitatively between the ancestral and current populations, and females from both accepted males for mating in the absence of courtship song. Our results provide direct evidence that a mechanism allowing flatwing males to mate with females was in place before the mutation actually arose on Kauai and demonstrate how preexisting behavior facilitated the rapid spread of a novel morphological mutation. Key words: behavioral preadaptation, courtship song, field cricket, playback experiment, rapid evolution, Teleogryllus oceanicus. [Behav Ecol 19:202–207 (2008)] Behavioral attributes have long been recognized to influ-ence the evolution of novel morphological character
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quantitative genetic variation in courtship song and its covariation with immune function and sperm quality in the field cricket Teleogryllus oceanicus
Behavioral Ecology, 2010Co-Authors: Leigh W Simmons, Robin M Tinghitella, Marlene ZukAbstract:Acoustic signals used by males to attract females are among the most prominent examples of secondary sexual traits, yet we have only limited understanding of their genetic architecture. Male crickets produce a calling song to attract females and then switch to a courtship song that incites mounting by females once they are at close range. Although we know much about the genetics of cricket calling song, no study has yet examined the quantitative genetics of courtship song. Here, we conduct a quantitative genetic analysis of courtship song using the Australian cricket Teleogryllus oceanicus. We find substantial levels of additive genetic variation in courtship song parameters and genetic covariances between courtship song parameters that reflect female preferences. We also found evidence for a negative relationship between the amount of trill in the courtship song and the ability of males to mount an immune response and to produce an ejaculate containing a high proportion of viable sperm. Trade-offs between immunity and sexual signaling are a prerequisite for immunocompetence handicap models of preference evolution, whereas a trade-off between gaining matings and fertilizations is a fundamental assumption underlying sperm competition theory. These life-history trade-offs are likely to constrain evolutionary responses to selection from female choice, and to maintain additive genetic variance in courtship song. Copyright 2010, Oxford University Press.
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acoustic experience shapes alternative mating tactics and reproductive investment in male field crickets
Current Biology, 2010Co-Authors: Nathan W. Bailey, Brian Gray, Marlene ZukAbstract:Summary Developmental plasticity allows juvenile animals to assess environmental cues and adaptively shape behavioral and morphological traits to maximize fitness in their adult environment [1]. Sexual signals are particularly conspicuous cues, making them likely candidates for mediating such responses. Plasticity in male reproductive traits is a common phenomenon, but empirical evidence for signal-mediated plasticity in males is lacking. We tested whether experience of acoustic sexual signals during juvenile stages influences the development of three adult traits in the continuously breeding field cricket Teleogryllus oceanicus : male mating tactics, reproductive investment, and condition. All three traits were affected by juvenile acoustic experience. Males of this species produce a long-range calling song to attract receptive females, but they can also behave as satellites by parasitizing other males' calls [2]. Males reared in an environment mimicking a population with many calling males were less likely to exhibit satellite behavior, invested more in reproductive tissues, and attained higher condition than males reared in a silent environment. These results contrast with other studies [3] and demonstrate how the effects of juvenile social experience on adult male morphology, reproductive investment, and behavior may subsequently influence sexual selection and phenotypic evolution.
Nathan W. Bailey - One of the best experts on this subject based on the ideXlab platform.
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rapid parallel adaptation despite gene flow in silent crickets
Nature Communications, 2021Co-Authors: Xiao Zhang, Mark Blaxter, Jack G Rayner, Nathan W. BaileyAbstract:Gene flow is predicted to impede parallel adaptation via de novo mutation, because it can introduce pre-existing adaptive alleles from population to population. We test this using Hawaiian crickets (Teleogryllus oceanicus) in which ‘flatwing’ males that lack sound-producing wing structures recently arose and spread under selection from an acoustically-orienting parasitoid. Morphometric and genetic comparisons identify distinct flatwing phenotypes in populations on three islands, localized to different loci. Nevertheless, we detect strong, recent and ongoing gene flow among the populations. Using genome scans and gene expression analysis we find that parallel evolution of flatwing on different islands is associated with shared genomic hotspots of adaptation that contain the gene doublesex, but the form of selection differs among islands and corresponds to known flatwing demographics in the wild. We thus show how parallel adaptation can occur on contemporary timescales despite gene flow, indicating that it could be less constrained than previously appreciated. Gene flow is classically thought to impede local adaptation via parallel evolution. However, a genomic study on Hawaiian crickets from different island populations finds evidence of parallel adaptation to the same lethal parasitoid in spite of strong ongoing gene flow.
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Electronic Supplementary Material from: "Vestigial singing behaviour persists after the evolutionary loss of song in crickets"
2018Co-Authors: Will T. Schneider, Christian Rutz, Berthold Hedwig, Nathan W. BaileyAbstract:The evolutionary loss of sexual traits is widely predicted. Because sexual signals can arise from the coupling of specialized motor activity with morphological structures, disruption to a single component could lead to overall loss of function. Opportunities to observe this process and characterize any remaining signal components are rare, but could provide insight into the mechanisms, indirect costs, and evolutionary consequences of signal loss. We investigated the recent evolutionary loss of a long-range acoustic sexual signal in the Hawaiian field cricket Teleogryllus oceanicus. Flatwing males carry mutations that remove sound-producing wing structures, eliminating all acoustic signalling and affording protection against an acoustically-orientating parasitoid fly. We show that flatwing males produce wing movement patterns indistinguishable from those that generate sonorous calling song in normal-wing males. Evolutionary song loss caused by the disappearance of structural components of the sound-producing apparatus has left behind the energetically-costly motor behaviour underlying normal singing. These results provide a rare example of a vestigial behaviour and raise the possibility that such traits could be co-opted for novel functions
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Preexisting behavior facilitated the loss of a sexual signal in the field cricket
2015Co-Authors: Teleogryllus Oceanicus, Janelle R Mcnabb, Nathan W. Bailey, Marlene ZukAbstract:Behavioral preadaptations can provide an accommodating environment in which novel morphological characters may be se-lected. A very recent morphological mutation, flatwing, has caused the loss of male song in field crickets (Teleogryllus oceanicus) from the Hawaiian island of Kauai. Previous studies in this and related species have shown that females require male courtship song to mount males, but flatwing T. oceanicus males still achieve matings. Females from Kauai may have a relaxed requirement for male courtship song, or flatwing males may compensate for their inability to sing by altering other courtship behaviors. We tested whether male courtship and female responses to male courtship were preadapted in a way that facilitated the spread of the male wing mutation or if parallel changes in male courtship and female responses accompanied the mutation. We performed mating trials in 2 captive-bred populations to assess how mating behavior varied depending on the presence or absence of courtship song playback. The first was an ancestral population from Kauai established prior to the emergence of the flatwing mutation, and the second was derived from Kauai after the mutation became prevalent. Mating behaviors did not differ qualitatively or quantitatively between the ancestral and current populations, and females from both accepted males for mating in the absence of courtship song. Our results provide direct evidence that a mechanism allowing flatwing males to mate with females was in place before the mutation actually arose on Kauai and demonstrate how preexisting behavior facilitated the rapid spread of a novel morphological mutation. Key words: behavioral preadaptation, courtship song, field cricket, playback experiment, rapid evolution, Teleogryllus oceanicus. [Behav Ecol 19:202–207 (2008)] Behavioral attributes have long been recognized to influ-ence the evolution of novel morphological character
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mate choice plasticity in the field cricket Teleogryllus oceanicus effects of social experience in multiple modalities
Behavioral Ecology and Sociobiology, 2011Co-Authors: Nathan W. BaileyAbstract:Social experience can elicit phenotypically plastic changes in mate choice, but little is known about the degree to which social information from one modality can influence mating decisions based on information from a different modality. I used the field cricket Teleogryllus oceanicus to test whether experience of chemical cues mimicking a high density of sexually mature males causes changes in mate choice based on acoustic signals. T. oceanicus males produce long-range calling songs to attract females for mating, but they also produce waxy, non-volatile hydrocarbons on their cuticle (CHCs) which, when deposited on a substrate, can be detected by females and may provide demographic information. I manipulated female experience of substrate-bound male CHCs and then performed acoustic mate choice trials. When CHCs were present on the substrate during trials, females showed greater motivation to respond to male calling song. This effect diminished with repeated exposure to male songs, demonstrating that the importance of olfactory cues in altering acoustic mate choice decreased with increasing exposure to acoustic signals. However, the temporal nature of CHC experience mattered: previous experience of CHCs did not alter subsequent female choice for male calling song traits. Exposure to male song increased the threshold of mate acceptance over time, and individuals varied considerably in overall levels of responsiveness. Taken together, the results demonstrate that mate choice is dependent on social context mediated by multiple modalities in T. oceanicus, but they do not support the idea that prior experience of social cues in one modality necessarily influences later mating decisions based on other signalling modalities.
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acoustic experience shapes alternative mating tactics and reproductive investment in male field crickets
Current Biology, 2010Co-Authors: Nathan W. Bailey, Brian Gray, Marlene ZukAbstract:Summary Developmental plasticity allows juvenile animals to assess environmental cues and adaptively shape behavioral and morphological traits to maximize fitness in their adult environment [1]. Sexual signals are particularly conspicuous cues, making them likely candidates for mediating such responses. Plasticity in male reproductive traits is a common phenomenon, but empirical evidence for signal-mediated plasticity in males is lacking. We tested whether experience of acoustic sexual signals during juvenile stages influences the development of three adult traits in the continuously breeding field cricket Teleogryllus oceanicus : male mating tactics, reproductive investment, and condition. All three traits were affected by juvenile acoustic experience. Males of this species produce a long-range calling song to attract receptive females, but they can also behave as satellites by parasitizing other males' calls [2]. Males reared in an environment mimicking a population with many calling males were less likely to exhibit satellite behavior, invested more in reproductive tissues, and attained higher condition than males reared in a silent environment. These results contrast with other studies [3] and demonstrate how the effects of juvenile social experience on adult male morphology, reproductive investment, and behavior may subsequently influence sexual selection and phenotypic evolution.
Melissa L Thomas - One of the best experts on this subject based on the ideXlab platform.
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no coolidge effect in the australian field cricket Teleogryllus oceanicus orthoptera gryllidae
Australian Journal of Entomology, 2015Co-Authors: Melissa L ThomasAbstract:A progressive decline in a male's propensity to mate with the same female, combined with a heightened sexual interest in new females, is known as the Coolidge effect. The Coolidge effect has been reported in a number of taxa and is thought to be adaptive, as males distribute sperm evenly across multiple females thereby maximising fitness. Here we looked for the Coolidge effect in the Australian field cricket, Teleogryllus oceanicus (Le Guillou). We found that males did not show greater sexual interest in novel females compared with their previous mates. Moreover, we did not find any decline in the quality of ejaculates transferred by males when mating sequentially with the same female, or an increase in ejaculate quality when males were presented with novel females. Our results are in contrast with findings investigating the Coolidge effect in other insects, which may reflect differences among species in the fitness benefits associated with mating repeatedly with the same female. We argue that examinations of the Coolidge effect need to be incorporated routinely into studies that examine the benefits of polyandry for females, because of the potential impact of reduced ejaculate expenditure by males in monandrous treatments.
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cuticular hydrocarbons influence female attractiveness to males in the australian field cricket Teleogryllus oceanicus
Journal of Evolutionary Biology, 2010Co-Authors: Melissa L ThomasAbstract:Sexual dimorphism is thought to result from directional sexual selection acting on male signal traits, with female signal traits given little, if any, attention. Here, we examine male mating preferences in the Australian field cricket, Teleogryllus oceanicus. Using a multivariate selection analysis approach, we found that male preferences have the potential to exert selection on female cuticular hydrocarbons, chemical compounds widely used as sexual signals in insects. In addition to finding both stabilizing and disruptive preference gradients, we also found weak negative directional preference for female cuticular hydrocarbons. We contrast our results with a recent study examining sexual selection via female choice on male T. oceanicus cuticular hydrocarbons and suggest that differences in the form and intensity of sexual selection between the genders may provide part of the net selection differential necessary for the evolution of sexual dimorphism in this species.
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male dominance influences pheromone expression ejaculate quality and fertilization success in the australian field cricket Teleogryllus oceanicus
Behavioral Ecology, 2009Co-Authors: Melissa L ThomasAbstract:The outcome of fights between males can often represent an honest signal of male quality and are therefore widely used by females in mate choice. Indeed, female preference for males that win fights has been demonstrated in numerous animal taxa, and many recent studies have focused attention on how subordinate males compensate for this disadvantage through postcopulatory mating strategies, such as increased investment in their ejaculates. Here, using the Australian field cricket, Teleogryllus oceanicus, we show that rather than investing more in postcopulatory strategies, subordinate males invest in an alternative precopulatory mating approach. We find that subordinate males produce ejaculates of lower quality than dominate males and sire less offspring when competing for fertilizations. However, subordinate males upregulate the quantity of a number of cuticular compounds that have previously been shown to increase male mating success. Our results suggest that male reproductive success is likely to result from the interaction of multiple traits in this species. Copyright 2009, Oxford University Press.
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male dominance influences pheromone expression ejaculate quality and fertilization success in the australian field cricket Teleogryllus oceanicus
Behavioral Ecology, 2009Co-Authors: Melissa L ThomasAbstract:The outcome of fights between males can often represent an honest signal of male quality and are therefore widely used by females in mate choice. Indeed, female preference for males that win fights has been demonstrated in numerous animal taxa, and many recent studies have focused attention on how subordinate males compensate for this disadvantage through postcopulatory mating strategies, such as increased investment in their ejaculates. Here, using the Australian field cricket, Teleogryllus oceanicus, we show that rather than investing more in postcopulatory strategies, subordinate males invest in an alternative precopulatory mating approach. We find that subordinate males produce ejaculates of lower quality than dominate males and sire less offspring when competing for fertilizations. However, subordinate males upregulate the quantity of a number of cuticular compounds that have previously been shown to increase male mating success. Our results suggest that male reproductive success is likely to result from the interaction of multiple traits in this species. Key words: cuticular hydrocarbons, paternity, social status, sperm quality, Teleogryllus oceanicus. [Behav Ecol]
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sexual dimorphism in cuticular hydrocarbons of the australian field cricket Teleogryllus oceanicus orthoptera gryllidae
Journal of Insect Physiology, 2008Co-Authors: Melissa L ThomasAbstract:Sexual dimorphism is presumed to reflect adaptive divergence in response to selection favouring different optimal character states in the two sexes. Here, we analyse patterns of sexual dimorphism in the cuticular hydrocarbons of the Australian field cricket Teleogryllus oceanicus using gas chromatography. Ten of the 25 peaks found in our chromatographs, differed in their relative abundance between the sexes. The presence of sexual dimorphism in T. oceanicus is discussed in reference to a review of sexual dimorphism in cuticular hydrocarbons of other insects. We found that this trait has been examined in 103 species across seven different orders. Seventy-six of these species (73%) displayed sex specificity of cuticular hydrocarbons, the presence/absence of which does not appear to be directly linked to phylogeny. The occurrence of sexual dimorphism in cuticular hydrocarbons of some but not other species, and the extent of variation within genera, suggest that this divergence has been driven primarily by sexual selection.
Bailey, Nathan W. - One of the best experts on this subject based on the ideXlab platform.
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Rapid parallel adaptation despite gene flow in silent crickets
'Springer Science and Business Media LLC', 2021Co-Authors: Zhang Xiao, Blaxter Mark, Rayner, Jack G., Bailey, Nathan W.Abstract:The work was funded by Natural Environment Research Council awards to N.W.B. [NE/I027800/1, NE/L011255/1]. Bioinformatics support was provided by a Wellcome Trust ISSF award [105621/Z/14/Z]. X.Z. was supported by a China Scholarship Council PhD studentship [201703780018].Gene flow is predicted to impede parallel adaptation via de novo mutation, because it can introduce pre-existing adaptive alleles from population to population. We test this using Hawaiian crickets (Teleogryllus oceanicus) in which ‘flatwing’ males that lack sound-producing wing structures recently arose and spread under selection from an acoustically-orienting parasitoid. Morphometric and genetic comparisons identify distinct flatwing phenotypes in populations on three islands, localized to different loci. Nevertheless, we detect strong, recent and ongoing gene flow among the populations. Using genome scans and gene expression analysis we find that parallel evolution of flatwing on different islands is associated with shared genomic hotspots of adaptation that contain the gene doublesex, but the form of selection differs among islands and corresponds to known flatwing demographics in the wild. We thus show how parallel adaptation can occur on contemporary timescales despite gene flow, indicating that it could be less constrained than previously appreciated.Publisher PDFPeer reviewe
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Sexual signal loss : the link between behaviour and rapid evolutionary dynamics in a field cricket
2019Co-Authors: Zuk Marlene, Bailey, Nathan W., Gray Brian, Rotenberry, John T.Abstract:N.W.B. received funding from Natural Environment Research Council fellowships (NE/G014906/1 and NE/L011255/1). M.Z. is supported by grants from the US National Science Foundation and by the University of Minnesota. Data used in these analyses (counts of crickets in survey plots and distances from playback speakers) have been placed in the Dryad Digital Repository and are accessible at https://doi.org/10.5061/dryad.bb384 (Zuk et al., 2018).1. Sexual signals may be acquired or lost over evolutionary time, and are tempered in their exaggeration by natural selection. 2. In the Pacific field cricket, Teleogryllus oceanicus, a mutation (“flatwing”) causing loss of the sexual signal, the song, spread in
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Increased socially mediated plasticity in gene expression accompanies rapid adaptive evolution
'Wiley', 2019Co-Authors: Pascoal Sonia, Zuk Marlene, Liu Xuan, Fang Yongxiang, Paterson Steve, Ritchie, Michael G, Rockliffe Nichola, Bailey, Nathan W.Abstract:This work was funded by Natural 524 Environment Research Council grants (NE/I027800/1, NE/G014906/1, NE/L011255/1).Recent theory predicts that increased phenotypic plasticity can facilitate adaptation as traits respond to selection. When genetic adaptation alters the social environment, socially mediated plasticity could cause co-evolutionary feedback dynamics that increase adaptive potential. We tested this by asking whether neural gene expression in a recently arisen, adaptive morph of the field cricket Teleogryllus oceanicus is more responsive to the social environment than the ancestral morph. Silent males (flatwings) rapidly spread in a Hawaiian population subject to acoustically orienting parasitoids, changing the population's acoustic environment. Experimental altering crickets’ acoustic environments during rearing revealed broad, plastic changes in gene expression. However, flatwing genotypes showed increased socially mediated plasticity, whereas normal-wing genotypes exhibited negligible expression plasticity. Increased plasticity in flatwing crickets suggests a coevolutionary process coupling socially flexible gene expression with the abrupt spread of flatwing. Our results support predictions that phenotypic plasticity should rapidly evolve to be more pronounced during early phases of adaptation.PostprintPeer reviewe
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Vestigial singing behaviour persists after the evolutionary loss of song in crickets
'The Royal Society', 2019Co-Authors: Schneider Will, Hedwig Berthold, Rutz Christian, Bailey, Nathan W.Abstract:This researchwas supported by Natural Environment Research Council grants to N.W.B. (NE/L011255/1 and NE/I027800/1).The evolutionary loss of sexual traits is widely predicted. Because sexual signals can arise from the coupling of specialized motor activity with morphological structures, disruption to a single component could lead to overall loss of function. Opportunities to observe this process and characterize any remaining signal components are rare, but could provide insight into the mechanisms, indirect costs and evolutionary consequences of signal loss. We investigated the recent evolutionary loss of a long-range acoustic sexual signal in the Hawaiian field cricket Teleogryllus oceanicus. Flatwing males carry mutations that remove sound-producing wing structures, eliminating all acoustic signalling and affording protection against an acoustically-orientating parasitoid fly. We show that flatwing males produce wing movement patterns indistinguishable from those that generate sonorous calling song in normal-wing males. Evolutionary song loss caused by the disappearance of structural components of the sound-producing apparatus has left behind the energetically costly motor behaviour underlying normal singing. These results provide a rare example of a vestigial behaviour and raise the possibility that such traits could be co-opted for novel functions.PostprintPeer reviewe
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Sexual selection and population divergence II. Divergence in different sexual traits and signal modalities in field crickets (Teleogryllus oceanicus)
'Wiley', 2018Co-Authors: Pascoal Sonia, Hunt John, Mendrok Magdalena, Wilson, Alastair J., Bailey, Nathan W.Abstract:Funding was provided by Natural Environment Research Council grants to N.W.B. (NE/G014906/1, NE/L011255/1, NE/I027800/1), a University of California Pacific Rim Research Grant to N.W.B. (08.T.PRRP.05.0029), an Erasmus exchange grant to support M.M., a University Royal Society Fellowship and Royal Society Equipment Grant to J.H., and a BBSRC David Phillips Fellowship to A.J.W.Sexual selection can target many different types of traits. However, the relative influence of different sexually selected traits during evolutionary divergence is poorly understood. We used the field cricket Teleogryllus oceanicus to quantify and compare how five traits from each of three sexual signal modalities and components diverge among allopatric populations: male advertisement song, cuticular hydrocarbon (CHC) profiles and forewing morphology. Population divergence was unexpectedly consistent: we estimated the among-population (genetic) variance-covariance matrix, D , for all 15 traits, and D max explained nearly two-thirds of its variation. CHC and wing traits were most tightly integrated, whereas song varied more independently. We modeled the dependence of among-population trait divergence on genetic distance estimated from neutral markers to test for signatures of selection versus neutral divergence. For all three sexual trait types, phenotypic variation among populations was largely explained by a neutral model of divergence. Our findings illustrate how phenotypic integration across different types of sexual traits might impose constraints on the evolution of mating isolation and divergence via sexual selection.PostprintPeer reviewe
