The cost of reproduction is well studied in females but only recently have the costs of mating been investigated in males. Research suggests that males allocate resources between subsequent mating events, resulting in differential success across mating bouts. Selection should favor allocation strategies that match the likelihood of successive matings. The complexity of the system, however, suggests that one fixed strategy is unlikely to be universally favored and thus I predict that genetic variation for different allocation strategies will be segregating in natural populations. To test this, I measured several components of reproductive performance in eight inbred genotypes of Drosophila melanogaster across three sequential mating events. As predicted, there was genetic variation for how previous experience affected a male's reproductive performance for both the proportion of matings that produced offspring and the proportion of offspring sired (P1). Some genotypes had the highest success in their first matings and declined in successive matings while other genotypes did best in later matings. Mating experience had consistent effects across genotypes on fertility and induced refractoriness to remating. On average, virgin matings produced the highest fertility and third matings most effectively induced refractoriness. Genotype also had a significant effect on fertility. These results have important implications for understanding how selection may be acting on males when there is variation in the likelihood of multiple mating events and could affect the evolution of male allocation strategies in the face of perceived competitors.
{"title":"Experience matters: genetic variation affects male reproductive success across sequential mating events in Drosophila melanogaster.","authors":"Anthony C Fiumera","doi":"10.1093/jeb/voae038","DOIUrl":"10.1093/jeb/voae038","url":null,"abstract":"<p><p>The cost of reproduction is well studied in females but only recently have the costs of mating been investigated in males. Research suggests that males allocate resources between subsequent mating events, resulting in differential success across mating bouts. Selection should favor allocation strategies that match the likelihood of successive matings. The complexity of the system, however, suggests that one fixed strategy is unlikely to be universally favored and thus I predict that genetic variation for different allocation strategies will be segregating in natural populations. To test this, I measured several components of reproductive performance in eight inbred genotypes of Drosophila melanogaster across three sequential mating events. As predicted, there was genetic variation for how previous experience affected a male's reproductive performance for both the proportion of matings that produced offspring and the proportion of offspring sired (P1). Some genotypes had the highest success in their first matings and declined in successive matings while other genotypes did best in later matings. Mating experience had consistent effects across genotypes on fertility and induced refractoriness to remating. On average, virgin matings produced the highest fertility and third matings most effectively induced refractoriness. Genotype also had a significant effect on fertility. These results have important implications for understanding how selection may be acting on males when there is variation in the likelihood of multiple mating events and could affect the evolution of male allocation strategies in the face of perceived competitors.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140186225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael D. Pointer, Lewis G. Spurgin, M. McMullan, Simon Butler, David S Richardson
Dispersal is an important facet of the life history of many organisms and is therefore subject to selective pressure, but does not evolve in isolation. Across nature there are examples of dispersal syndromes, life history strategies in which suites of traits coevolve and covary with dispersal in combinations that serve to maximise fitness in a given ecological context. The red rust flour beetle, Tribolium castaneum, is a model organism and globally significant post-harvest pest which relies on dispersal to reach new patches of ephemeral habitat. Dispersal behaviour in Tribolium has a strong genetic basis. However, a robust understanding of the relationship between dispersal and other life history components, which could elucidate evolutionary processes and allow pest managers to control their spread and reduce the impact of infestation, is currently lacking. Here we use highly replicated lines of T. castaneum previously artificially selected for divergent small-scale dispersal propensity, to robustly test several important life history components: reproductive strategy, development time and longevity. As predicted, we find that a suite of important change as result of our selection on dispersal; high dispersal propensity is associated with a lower number of longer mating attempts by males, lower investment in early-life reproduction by females, slower development of later-laid offspring and longer female lifespan. These findings indicate that correlated intraspecific variation in dispersal and related traits may represent alternative life history strategies in T. castaneum. We therefore suggest that pest management efforts to mitigate the species' agro-economic impact should consider the eco-evolutionary dynamics within multiple life-histories. The benefits of doing so could be felt both through improved targetting of efforts to reduce spread, and also in forecasting of how the selection pressures applied through pest management are likely to affect pest evolution.
散布是许多生物生活史的一个重要方面,因此受到选择性压力的影响,但并不是孤立进化的。在整个自然界中,有一些散布综合征的例子,在这些生活史策略中,各种性状共同进化,并与散布结合在一起,从而在特定的生态环境中达到最大的适应性。红锈色面粉甲虫(Tribolium castaneum)是一种模式生物,也是全球重要的收获后害虫,它依靠扩散到达新的短暂栖息地。Tribolium的扩散行为有很强的遗传基础。然而,目前还缺乏对散布行为与其他生活史成分之间关系的有力了解,而这种了解可以阐明进化过程,并使害虫管理者能够控制其传播并减少虫害的影响。在这里,我们利用之前人工选择的具有不同小规模扩散倾向的高重复性 T. castaneum 品系,对几个重要的生活史组成部分进行了稳健的测试:繁殖策略、发育时间和寿命。正如我们所预测的那样,我们发现对散布倾向的选择导致了一系列重要的变化;高散布倾向与雄性较少的较长时间交配尝试、雌性较少的早期繁殖投资、晚产后代发育较慢以及雌性寿命较长有关。这些研究结果表明,分散性和相关性状的种内相关变异可能代表了 T. castaneum 的另一种生活史策略。因此,我们建议,为减轻该物种对农业经济的影响而开展的害虫管理工作应考虑多种生活史中的生态进化动态。这样做的好处是可以提高减少传播的针对性,还可以预测害虫管理所施加的选择压力可能会如何影响害虫的进化。
{"title":"Life history correlations and trade-offs resulting from selection for dispersal in Tribolium castaneum.","authors":"Michael D. Pointer, Lewis G. Spurgin, M. McMullan, Simon Butler, David S Richardson","doi":"10.1093/jeb/voae041","DOIUrl":"https://doi.org/10.1093/jeb/voae041","url":null,"abstract":"Dispersal is an important facet of the life history of many organisms and is therefore subject to selective pressure, but does not evolve in isolation. Across nature there are examples of dispersal syndromes, life history strategies in which suites of traits coevolve and covary with dispersal in combinations that serve to maximise fitness in a given ecological context. The red rust flour beetle, Tribolium castaneum, is a model organism and globally significant post-harvest pest which relies on dispersal to reach new patches of ephemeral habitat. Dispersal behaviour in Tribolium has a strong genetic basis. However, a robust understanding of the relationship between dispersal and other life history components, which could elucidate evolutionary processes and allow pest managers to control their spread and reduce the impact of infestation, is currently lacking. Here we use highly replicated lines of T. castaneum previously artificially selected for divergent small-scale dispersal propensity, to robustly test several important life history components: reproductive strategy, development time and longevity. As predicted, we find that a suite of important change as result of our selection on dispersal; high dispersal propensity is associated with a lower number of longer mating attempts by males, lower investment in early-life reproduction by females, slower development of later-laid offspring and longer female lifespan. These findings indicate that correlated intraspecific variation in dispersal and related traits may represent alternative life history strategies in T. castaneum. We therefore suggest that pest management efforts to mitigate the species' agro-economic impact should consider the eco-evolutionary dynamics within multiple life-histories. The benefits of doing so could be felt both through improved targetting of efforts to reduce spread, and also in forecasting of how the selection pressures applied through pest management are likely to affect pest evolution.","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140660321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantitative genetic theory on multivariate character evolution predicts that a population's response to directional selection is biased toward the major axis of the genetic covariance matrix G-the so-called genetic line of least resistance. Inferences on the genetic constraints in this sense have traditionally been made by measuring the angle of deviation of evolutionary trajectories from the major axis, or more recently by calculating the amount of genetic variance-the Hansen-Houle evolvability-available along the trajectories. However, there have not been clear practical guidelines on how these quantities can be interpreted, especially in a high-dimensional space. This study summarizes pertinent distribution theories for relevant quantities, pointing out that they can be written as ratios of quadratic forms in evolutionary trajectory vectors by taking G as a parameter. For example, a beta distribution with appropriate parameters can be used as a null distribution for squared cosine of the angle of deviation from a major axis or subspace. More general cases can be handled with the probability distribution of ratios of quadratic forms in normal variables. Apart from its use in hypothesis-testing, this latter approach could potentially be used as a heuristic tool for looking into various selection scenarios like directional and/or correlated selection as parameterized with mean and covariance of selection gradients.
多变量特征进化的定量遗传理论预测,种群对定向选择的反应偏向遗传协方差矩阵 G 的主轴,即所谓的遗传最小阻力线。对这种意义上的遗传限制的推断,传统上是通过测量进化轨迹偏离主轴的角度,或者最近通过计算沿轨迹可获得的遗传变异量--汉森-胡尔进化能力。然而,对于如何解释这些量,尤其是在高维空间中如何解释这些量,还没有明确的实用指南。本研究总结了相关数量的分布理论,指出可以通过将 G 作为参数,将它们写成进化轨迹向量中二次型的比率。例如,具有适当参数的贝塔分布可用作偏离主轴或子空间角度平方余弦的无效分布。更一般的情况可以用正态变量二次型之比的概率分布来处理。除了用于假设检验外,后一种方法还可以作为一种启发式工具,用于研究各种选择情况,如以选择梯度的均值和协方差为参数的定向选择和/或相关选择。
{"title":"Distribution theories for genetic line of least resistance and evolvability measures.","authors":"Junya Watanabe","doi":"10.1093/jeb/voae049","DOIUrl":"https://doi.org/10.1093/jeb/voae049","url":null,"abstract":"<p><p>Quantitative genetic theory on multivariate character evolution predicts that a population's response to directional selection is biased toward the major axis of the genetic covariance matrix G-the so-called genetic line of least resistance. Inferences on the genetic constraints in this sense have traditionally been made by measuring the angle of deviation of evolutionary trajectories from the major axis, or more recently by calculating the amount of genetic variance-the Hansen-Houle evolvability-available along the trajectories. However, there have not been clear practical guidelines on how these quantities can be interpreted, especially in a high-dimensional space. This study summarizes pertinent distribution theories for relevant quantities, pointing out that they can be written as ratios of quadratic forms in evolutionary trajectory vectors by taking G as a parameter. For example, a beta distribution with appropriate parameters can be used as a null distribution for squared cosine of the angle of deviation from a major axis or subspace. More general cases can be handled with the probability distribution of ratios of quadratic forms in normal variables. Apart from its use in hypothesis-testing, this latter approach could potentially be used as a heuristic tool for looking into various selection scenarios like directional and/or correlated selection as parameterized with mean and covariance of selection gradients.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140867354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katalin Krenhardt, Jesús Martínez-Padilla, David Canal, Mónika Jablonszky, G. Hegyi, Márton Herényi, Miklós Laczi, G. Markó, Gergely Nagy, B. Rosivall, Eszter Szász, Eszter Szöllősi, J. Török, Éva Vaskuti, Sándor Zsebők, L. Garamszegi
Temporal changes in environmental conditions may play a major role in the year-to-year variation in fitness consequences of behaviours. Identifying environmental drivers of such variation is crucial to understand the evolutionary trajectories of behaviours in natural contexts. However, our understanding of how environmental variation influences behaviours in the wild remains limited. Using data collected over 14 breeding seasons from a collared flycatcher (Ficedula albicollis) population, we examined the effect of environmental variation on the relationship between survival and risk-taking behaviour, a highly variable behavioural trait with great evolutionary and ecological significance. Specifically, using annual recapture probability as a proxy of survival, we evaluated the specific effect of predation pressure, food availability and mean temperature on the relationship between annual recapture probability and risk-taking behaviour (measured as flight initiation distance, FID). We found a negative trend, as the relationship between annual recapture probability and FID decreased over the study years, and changed from positive to negative. Specifically, in the early years of the study, risk-avoiding individuals exhibited a higher annual recapture probability, whereas in the later years, risk-avoiders had a lower annual recapture probability. However, we did not find evidence that any of the considered environmental factors mediated the variation in the relationship between survival and risk-taking behaviour.
{"title":"The effect of environmental variation on the relationship between survival and risk-taking behaviour in a migratory songbird.","authors":"Katalin Krenhardt, Jesús Martínez-Padilla, David Canal, Mónika Jablonszky, G. Hegyi, Márton Herényi, Miklós Laczi, G. Markó, Gergely Nagy, B. Rosivall, Eszter Szász, Eszter Szöllősi, J. Török, Éva Vaskuti, Sándor Zsebők, L. Garamszegi","doi":"10.1093/jeb/voae046","DOIUrl":"https://doi.org/10.1093/jeb/voae046","url":null,"abstract":"Temporal changes in environmental conditions may play a major role in the year-to-year variation in fitness consequences of behaviours. Identifying environmental drivers of such variation is crucial to understand the evolutionary trajectories of behaviours in natural contexts. However, our understanding of how environmental variation influences behaviours in the wild remains limited. Using data collected over 14 breeding seasons from a collared flycatcher (Ficedula albicollis) population, we examined the effect of environmental variation on the relationship between survival and risk-taking behaviour, a highly variable behavioural trait with great evolutionary and ecological significance. Specifically, using annual recapture probability as a proxy of survival, we evaluated the specific effect of predation pressure, food availability and mean temperature on the relationship between annual recapture probability and risk-taking behaviour (measured as flight initiation distance, FID). We found a negative trend, as the relationship between annual recapture probability and FID decreased over the study years, and changed from positive to negative. Specifically, in the early years of the study, risk-avoiding individuals exhibited a higher annual recapture probability, whereas in the later years, risk-avoiders had a lower annual recapture probability. However, we did not find evidence that any of the considered environmental factors mediated the variation in the relationship between survival and risk-taking behaviour.","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140696486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hélène Leroy, Rauri C K Bowie, Lucia Rubáčová, Beata Matysioková, Vladimír Remeš
Evolutionary radiations provide important insights into species diversification, which is especially true of adaptive radiations. New World wood warblers (Parulidae) are a family of small, insectivorous, forest-dwelling passerine birds, often considered an exemplar of adaptive radiation due to their rapid diversification followed by a slowdown. However, they deviate from the expectations of an adaptive radiation scenario due to the lack of conspicuous morphological and ecological differentiation. We fitted several macroevolutionary models to trait data in 105 species of wood warblers. We tested whether morphological traits underwent an early burst of evolution (suggesting adaptation to new ecological niches in adaptive radiations) and whether song and colour underwent a diversity-dependent acceleration of trait evolutionary rate (consistent with reproductive interference driving signal evolution). Morphology and song evolved gradually under stabilizing selection, suggesting niche conservatism, with morphology possibly acting as a constraint on song evolution. In contrast, many feather colour traits underwent a diversity-dependent burst of evolution occurring late in the clade's history. We suggest that a two-step process has led to the remarkable diversification of wood warblers. First, their early diversification probably proceeded by allopatric speciation. Second, feather colour divergence likely occurred during secondary contact after range expansion. This diversification of signalling traits might have facilitated species coexistence, in combination with behavioural niche partitioning. Wood warblers seem to present characteristics of both adaptive and non-adaptive radiations.
{"title":"A late burst of colour evolution in a radiation of songbirds (Passeriformes: Parulidae) suggests secondary contact drives signal divergence.","authors":"Hélène Leroy, Rauri C K Bowie, Lucia Rubáčová, Beata Matysioková, Vladimír Remeš","doi":"10.1093/jeb/voae023","DOIUrl":"10.1093/jeb/voae023","url":null,"abstract":"<p><p>Evolutionary radiations provide important insights into species diversification, which is especially true of adaptive radiations. New World wood warblers (Parulidae) are a family of small, insectivorous, forest-dwelling passerine birds, often considered an exemplar of adaptive radiation due to their rapid diversification followed by a slowdown. However, they deviate from the expectations of an adaptive radiation scenario due to the lack of conspicuous morphological and ecological differentiation. We fitted several macroevolutionary models to trait data in 105 species of wood warblers. We tested whether morphological traits underwent an early burst of evolution (suggesting adaptation to new ecological niches in adaptive radiations) and whether song and colour underwent a diversity-dependent acceleration of trait evolutionary rate (consistent with reproductive interference driving signal evolution). Morphology and song evolved gradually under stabilizing selection, suggesting niche conservatism, with morphology possibly acting as a constraint on song evolution. In contrast, many feather colour traits underwent a diversity-dependent burst of evolution occurring late in the clade's history. We suggest that a two-step process has led to the remarkable diversification of wood warblers. First, their early diversification probably proceeded by allopatric speciation. Second, feather colour divergence likely occurred during secondary contact after range expansion. This diversification of signalling traits might have facilitated species coexistence, in combination with behavioural niche partitioning. Wood warblers seem to present characteristics of both adaptive and non-adaptive radiations.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139906814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Whether the heat and cold tolerance of endotherms evolve independently or correlatively remains unresolved. Both physiological trade-offs and natural selection can contribute to a coevolutionary pattern of heat and cold tolerance in endotherms. Using a published database, we tested the correlation between upper and lower thermal limits across endothermic species with multi-response generalized linear mixed models incorporating phylogenies. We found a positive correlation between upper and lower thermal limits, which suggested a coevolutionary pattern of heat and cold tolerance. Specifically, this relationship between heat and cold tolerance is phylogenetically constrained for tropical endotherms but not for temperate endotherms. The correlated evolution between heat and cold tolerance may have a significant influence on endotherms' evolution and ecology and needs to be further investigated.
{"title":"Coevolution between heat and cold tolerance in endotherms.","authors":"Hongtao Xiao, Jiale Li, Guozhi Yu, Yongfang Yao, Huailiang Xu","doi":"10.1093/jeb/voae018","DOIUrl":"10.1093/jeb/voae018","url":null,"abstract":"<p><p>Whether the heat and cold tolerance of endotherms evolve independently or correlatively remains unresolved. Both physiological trade-offs and natural selection can contribute to a coevolutionary pattern of heat and cold tolerance in endotherms. Using a published database, we tested the correlation between upper and lower thermal limits across endothermic species with multi-response generalized linear mixed models incorporating phylogenies. We found a positive correlation between upper and lower thermal limits, which suggested a coevolutionary pattern of heat and cold tolerance. Specifically, this relationship between heat and cold tolerance is phylogenetically constrained for tropical endotherms but not for temperate endotherms. The correlated evolution between heat and cold tolerance may have a significant influence on endotherms' evolution and ecology and needs to be further investigated.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139673488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The threshold public goods game is one of the best-known models of non-linear public goods dilemmas. Cooperators and defectors typically coexist in this game when the population is assumed to follow the so-called structured deme model. In this article, we develop a dynamical model of a general N-player game in which there is no deme structure: Individuals interact with randomly chosen neighbours and selection occurs between randomly chosen pairs of individuals. We show that in the deterministic limit, the dynamics in this model leads to the same replicator dynamics as in the structured deme model, i.e., coexistence of cooperators and defectors is typical in threshold public goods game even when the population is completely well mixed. We extend the model to study the effect of density dependence and density fluctuation on the dynamics. We show analytically and numerically that decreasing population density increases the equilibrium frequency of cooperators till the fixation of this strategy, but below a critical density cooperators abruptly disappear from the population. Our numerical investigations show that weak density fluctuations enhance cooperation, while strong fluctuations suppress it.
门槛公共物品博弈是最著名的非线性公共物品困境模型之一。当假定人口遵循所谓的结构化deme模型时,合作者和叛逃者通常在这个博弈中共存。在本文中,我们建立了一个一般 N 人博弈的动态模型,在这个模型中不存在 deme 结构:个体与随机选择的邻居互动,选择发生在随机选择的个体对之间。我们的研究表明,在确定性极限中,该模型中的动态会导致与结构化deme模型中相同的复制者动态,也就是说,即使在种群完全混合的情况下,合作者和叛逃者的共存也是阈值公共物品博弈中的典型现象。我们对模型进行了扩展,研究了密度依赖性和密度波动对动态的影响。我们用分析和数值方法证明,种群密度的降低会增加合作者的均衡频率,直到这种策略的衰减,但当密度低于临界值时,合作者会突然从种群中消失。我们的数值研究表明,弱密度波动会增强合作,而强密度波动则会抑制合作。
{"title":"Cooperation in public goods game does not require assortment and depends on population density.","authors":"Adél Károlyi, István Scheuring","doi":"10.1093/jeb/voae029","DOIUrl":"10.1093/jeb/voae029","url":null,"abstract":"<p><p>The threshold public goods game is one of the best-known models of non-linear public goods dilemmas. Cooperators and defectors typically coexist in this game when the population is assumed to follow the so-called structured deme model. In this article, we develop a dynamical model of a general N-player game in which there is no deme structure: Individuals interact with randomly chosen neighbours and selection occurs between randomly chosen pairs of individuals. We show that in the deterministic limit, the dynamics in this model leads to the same replicator dynamics as in the structured deme model, i.e., coexistence of cooperators and defectors is typical in threshold public goods game even when the population is completely well mixed. We extend the model to study the effect of density dependence and density fluctuation on the dynamics. We show analytically and numerically that decreasing population density increases the equilibrium frequency of cooperators till the fixation of this strategy, but below a critical density cooperators abruptly disappear from the population. Our numerical investigations show that weak density fluctuations enhance cooperation, while strong fluctuations suppress it.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140068886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Megan A M Kutzer, Beth Cornish, Michael Jamieson, Olga Zawistowska, Katy M Monteith, Pedro F Vale
Organismal health and survival depend on the ability to mount an effective immune response against infection. Yet immune defence may be energy-demanding, resulting in fitness costs if investment in immune function deprives other physiological processes of resources. While evidence of costly immunity resulting in reduced longevity and reproduction is common, the role of energy-producing mitochondria on the magnitude of these costs is unknown. Here we employed Drosophila melanogaster cybrid lines, where several mitochondrial genotypes (mitotypes) were introgressed onto a single nuclear genetic background, to explicitly test the role of mitochondrial variation on the costs of immune stimulation. We exposed female flies carrying one of nine distinct mitotypes to either a benign, heat-killed bacterial pathogen (stimulating immune deployment while avoiding pathology) or a sterile control and measured lifespan, fecundity, and locomotor activity. We observed mitotype-specific costs of immune stimulation and identified a positive genetic correlation between life span and the proportion of time cybrids spent moving while alive. Our results suggest that costs of immunity are highly variable depending on the mitochondrial genome, adding to a growing body of work highlighting the important role of mitochondrial variation in host-pathogen interactions.
{"title":"Mitochondrial background can explain variable costs of immune deployment.","authors":"Megan A M Kutzer, Beth Cornish, Michael Jamieson, Olga Zawistowska, Katy M Monteith, Pedro F Vale","doi":"10.1093/jeb/voae027","DOIUrl":"10.1093/jeb/voae027","url":null,"abstract":"<p><p>Organismal health and survival depend on the ability to mount an effective immune response against infection. Yet immune defence may be energy-demanding, resulting in fitness costs if investment in immune function deprives other physiological processes of resources. While evidence of costly immunity resulting in reduced longevity and reproduction is common, the role of energy-producing mitochondria on the magnitude of these costs is unknown. Here we employed Drosophila melanogaster cybrid lines, where several mitochondrial genotypes (mitotypes) were introgressed onto a single nuclear genetic background, to explicitly test the role of mitochondrial variation on the costs of immune stimulation. We exposed female flies carrying one of nine distinct mitotypes to either a benign, heat-killed bacterial pathogen (stimulating immune deployment while avoiding pathology) or a sterile control and measured lifespan, fecundity, and locomotor activity. We observed mitotype-specific costs of immune stimulation and identified a positive genetic correlation between life span and the proportion of time cybrids spent moving while alive. Our results suggest that costs of immunity are highly variable depending on the mitochondrial genome, adding to a growing body of work highlighting the important role of mitochondrial variation in host-pathogen interactions.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140061131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Group size is an important trait for many ecological and evolutionary processes. However, it is not a trait possessed by individuals but by social groups, and as many genomes contribute to group size understanding its genetic underpinnings and so predicting its evolution is a conceptual challenge. Here I suggest how group size can be modelled as a joint phenotype of multiple individuals, and so how models for evolution accounting for indirect genetic effects are essential for understanding the genetic variance of group size. This approach makes it clear that (a) group size should have a larger genetic variance than initially expected as indirect genetic effects always contribute exactly as much as direct genetic effects and (b) the response to selection of group size should be faster than expected based on direct genetic variance alone as the correlation between direct and indirect effects is always at the maximum positive limit of 1. Group size should therefore show relatively rapid evolved increases and decreases, the consequences of which and evidence for I discuss.
{"title":"Indirect genetic effects should make group size more evolvable than expected.","authors":"David N Fisher","doi":"10.1093/jeb/voae026","DOIUrl":"10.1093/jeb/voae026","url":null,"abstract":"<p><p>Group size is an important trait for many ecological and evolutionary processes. However, it is not a trait possessed by individuals but by social groups, and as many genomes contribute to group size understanding its genetic underpinnings and so predicting its evolution is a conceptual challenge. Here I suggest how group size can be modelled as a joint phenotype of multiple individuals, and so how models for evolution accounting for indirect genetic effects are essential for understanding the genetic variance of group size. This approach makes it clear that (a) group size should have a larger genetic variance than initially expected as indirect genetic effects always contribute exactly as much as direct genetic effects and (b) the response to selection of group size should be faster than expected based on direct genetic variance alone as the correlation between direct and indirect effects is always at the maximum positive limit of 1. Group size should therefore show relatively rapid evolved increases and decreases, the consequences of which and evidence for I discuss.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140061130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ecological theory suggests that a host organism's internal spatial structure can promote the persistence of mutualistic microbes by allowing for the turnover of tissue occupied by non-beneficial or cheating microbes. This type of regulation, whereby a host preferentially rewards tissue occupied by beneficial members of its microbiome but sanctions tissue occupied by non-beneficial cheaters, is expected to generate a competition-extinction trade-off by allowing beneficial microbes to experience a lower extinction rate than competitively dominant cheaters. Using an adaptive dynamics approach, we demonstrate that although ecologically stable, microbial regulation via sanctioning is not stable in any evolutionary sense, as each individual host will be under pressure to reduce the costs incurred from cheater suppression in order to maximize its own fitness at the expense of the rest of the host population. However, increasing the diversity of non-beneficial cheaters in the host population metamicrobiome can lead to an increase in the relative fitness of hosts that actively sanction non-performing tissue, thus facilitating the evolutionary emergence and persistence of such strategies in host-microbial systems. These counter-intuitive results demonstrate how diversity at multiple levels of biological organization and spatiotemporal scales can interact to facilitate the establishment and maintenance of mutualistic relationships.
{"title":"Metamicrobiome diversity promotes the evolution of host-microbial mutualisms.","authors":"Pradeep Pillai, Tarik C Gouhier","doi":"10.1093/jeb/voae019","DOIUrl":"10.1093/jeb/voae019","url":null,"abstract":"<p><p>Ecological theory suggests that a host organism's internal spatial structure can promote the persistence of mutualistic microbes by allowing for the turnover of tissue occupied by non-beneficial or cheating microbes. This type of regulation, whereby a host preferentially rewards tissue occupied by beneficial members of its microbiome but sanctions tissue occupied by non-beneficial cheaters, is expected to generate a competition-extinction trade-off by allowing beneficial microbes to experience a lower extinction rate than competitively dominant cheaters. Using an adaptive dynamics approach, we demonstrate that although ecologically stable, microbial regulation via sanctioning is not stable in any evolutionary sense, as each individual host will be under pressure to reduce the costs incurred from cheater suppression in order to maximize its own fitness at the expense of the rest of the host population. However, increasing the diversity of non-beneficial cheaters in the host population metamicrobiome can lead to an increase in the relative fitness of hosts that actively sanction non-performing tissue, thus facilitating the evolutionary emergence and persistence of such strategies in host-microbial systems. These counter-intuitive results demonstrate how diversity at multiple levels of biological organization and spatiotemporal scales can interact to facilitate the establishment and maintenance of mutualistic relationships.</p>","PeriodicalId":50198,"journal":{"name":"Journal of Evolutionary Biology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139747694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}