ASN RSS https://amnat.org/ Latest press releases and announcements from the ASN en-us Tue, 10 Nov 2020 06:00:00 GMT 60 “Genetic variation in parental effects contributes to the evolutionary potential of prey responses to predation risk” https://amnat.org/an/newpapers/Feb-Tigreros-A.html Evolutionary potential of antipredator responses in a leaf beetle are driven by genetic parental effects Read the Article (Just Accepted) Abstract Despite the ubiquity of parental effects and their potential impact on evolutionary dynamics, their contribution to the evolution of predator-prey interactions remains poorly understood. Using quantitative genetics, here we demonstrate that parental effects substantially contribute to the evolutionary potential of larval antipredator responses in a leaf beetle (Leptinotarsa decemlineata). Previous research showed that larger L.&nbsp;decemlineata larvae elicit stronger antipredator responses, and mothers perceiving predators improved offspring responses by increasing intraclutch cannibalism –an extreme form of offspring provisioning. We now report substantial additive genetic variation underlying maternal ability to induce intraclutch cannibalism, indicating the potential of this adaptive maternal effect to evolve by natural selection. We also show that paternal size, a heritable trait, impacted larval responses to predation risk, but that larval responses themselves had little additive genetic variation. Together, these results demonstrate how larval responses to predation risk can evolve via two types of parental effects, both of which provide indirect sources of genetic variation for offspring traits. More forthcoming papers &raquo; <p><b>Evolutionary potential of antipredator responses in a leaf beetle are driven by genetic parental effects </b></p> <p><i><a href="https://dx.doi.org/10.1086/712341">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">D</span>espite the ubiquity of parental effects and their potential impact on evolutionary dynamics, their contribution to the evolution of predator-prey interactions remains poorly understood. Using quantitative genetics, here we demonstrate that parental effects substantially contribute to the evolutionary potential of larval antipredator responses in a leaf beetle (<i>Leptinotarsa decemlineata</i>). Previous research showed that larger <i>L.&nbsp;decemlineata</i> larvae elicit stronger antipredator responses, and mothers perceiving predators improved offspring responses by increasing intraclutch cannibalism –an extreme form of offspring provisioning. We now report substantial additive genetic variation underlying maternal ability to induce intraclutch cannibalism, indicating the potential of this adaptive maternal effect to evolve by natural selection. We also show that paternal size, a heritable trait, impacted larval responses to predation risk, but that larval responses themselves had little additive genetic variation. Together, these results demonstrate how larval responses to predation risk can evolve via two types of parental effects, both of which provide indirect sources of genetic variation for offspring traits. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 26 Oct 2020 05:00:00 GMT “Kin recognition in guppies uses self-referencing on olfactory cues” https://amnat.org/an/newpapers/Feb-Daniel-A.html Mitchel J. Daniel and F. Helen Rodd (Feb 2021) Kin recognition in guppies uses self-referencing based on olfactory cues Abstract Kin recognition plays an important role in social behavior and evolution, but the proximate mechanisms by which individuals recognize kin remain poorly understood. In many species, individuals form a “kin template” that they compare against conspecifics’ phenotypes to assess phenotypic similarity–and by association, relatedness. Individuals may form a kin template through self-inspection (i.e. self-referencing) and/or by observing their rearing associates (i.e. family-referencing). However, despite much interest, few empirical studies have successfully disentangled self- and family-referencing. Here, we employ a novel set of breeding crosses using the Trinidadian guppy (Poecilia reticulata) to disentangle referencing systems by manipulating exposure to kin from conception onwards. We show that guppies discriminate among their full- and maternal half-siblings, which can only be explained by self-referencing. Additional behavioral experiments revealed no evidence that guppies incorporate the phenotypes of their broodmates or mother into the kin template. Finally, by manipulating the format of our behavioral tests, we show that olfactory communication is both necessary and sufficient for kin discrimination. These results provide robust evidence that individuals recognize kin by comparing the olfactory phenotypes of conspecifics against their own. This study resolves key questions about the proximate mechanisms underpinning kin recognition, with implications for the ontogeny and evolution of social behavior. More forthcoming papers &raquo; <p>Mitchel J. Daniel and F. Helen Rodd (Feb 2021) </p> <p><b>Kin recognition in guppies uses self-referencing based on olfactory cues </b></p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">K</span>in recognition plays an important role in social behavior and evolution, but the proximate mechanisms by which individuals recognize kin remain poorly understood. In many species, individuals form a “kin template” that they compare against conspecifics’ phenotypes to assess phenotypic similarity–and by association, relatedness. Individuals may form a kin template through self-inspection (i.e. self-referencing) and/or by observing their rearing associates (i.e. family-referencing). However, despite much interest, few empirical studies have successfully disentangled self- and family-referencing. Here, we employ a novel set of breeding crosses using the Trinidadian guppy (<i>Poecilia reticulata</i>) to disentangle referencing systems by manipulating exposure to kin from conception onwards. We show that guppies discriminate among their full- and maternal half-siblings, which can only be explained by self-referencing. Additional behavioral experiments revealed no evidence that guppies incorporate the phenotypes of their broodmates or mother into the kin template. Finally, by manipulating the format of our behavioral tests, we show that olfactory communication is both necessary and sufficient for kin discrimination. These results provide robust evidence that individuals recognize kin by comparing the olfactory phenotypes of conspecifics against their own. This study resolves key questions about the proximate mechanisms underpinning kin recognition, with implications for the ontogeny and evolution of social behavior. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 26 Oct 2020 05:00:00 GMT “Revisiting the role of hyperparasitism in evolution of virulence” https://amnat.org/an/newpapers/Feb-Sandhu-A.html Simran K. Sandhu, Andrew Yu. Morozov, Robert D. Holt, and Michael Barfield (Feb 2021) Read the Article (Just Accepted) Abstract Hyperparasitism denotes the natural phenomenon where a parasite infecting a host is in turn infected by its own parasite. Hyperparasites can shape the dynamics of host-parasite interactions and often have a deleterious impact on pathogens, an important class of parasites, causing a reduction in their virulence and transmission rate. Hyperparasitism thus could be an important tool of biological control. However, host-parasite-hyperparasite systems have so far been outside the mainstream of modelling studies, especially those dealing with eco-evolutionary aspects of species interactions. Here we theoretically explore the evolution of life history traits in a generic host-parasite-hyperparasite system, focusing on parasite virulence and the positive impact hyperparasitism has on the host population. We also explore the co-evolution of life history traits of the parasite and hyperparasite, using adaptive dynamics and quantitative genetics frameworks to identify evolutionarily singular strategies. We find that in the presence of hyperparasites, the evolutionarily optimal pathogen virulence generally shifts towards more virulent strains. However, even in this case, the use of hyperparasites in biocontrol could be justified since overall host mortality decreases. An intriguing possible outcome of the evolution of the hyperparasite can be its evolutionary suicide. More forthcoming papers &raquo; <p>Simran K. Sandhu, Andrew Yu. Morozov, Robert D. Holt, and Michael Barfield (Feb 2021) </p> <p><i><a href="https://dx.doi.org/10.1086/712351">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">H</span>yperparasitism denotes the natural phenomenon where a parasite infecting a host is in turn infected by its own parasite. Hyperparasites can shape the dynamics of host-parasite interactions and often have a deleterious impact on pathogens, an important class of parasites, causing a reduction in their virulence and transmission rate. Hyperparasitism thus could be an important tool of biological control. However, host-parasite-hyperparasite systems have so far been outside the mainstream of modelling studies, especially those dealing with eco-evolutionary aspects of species interactions. Here we theoretically explore the evolution of life history traits in a generic host-parasite-hyperparasite system, focusing on parasite virulence and the positive impact hyperparasitism has on the host population. We also explore the co-evolution of life history traits of the parasite and hyperparasite, using adaptive dynamics and quantitative genetics frameworks to identify evolutionarily singular strategies. We find that in the presence of hyperparasites, the evolutionarily optimal pathogen virulence generally shifts towards more virulent strains. However, even in this case, the use of hyperparasites in biocontrol could be justified since overall host mortality decreases. An intriguing possible outcome of the evolution of the hyperparasite can be its evolutionary suicide. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 26 Oct 2020 05:00:00 GMT “Metapopulation structure predicts population dynamics in the <i>Cakile maritima–Alternaria brassicicola</i> host–pathogen interaction” https://amnat.org/an/newpapers/Feb-Papaix.html Julien Papaïx, Jeremy J. Burdon, Emily Walker, Luke G. Barrett, and Peter H. Thrall (Feb 2021) Read the Article (Just Accepted) Predicting disease dynamics in the wild is challenging because interdependent demographic dynamics between the host and its pathogen as well as heterogeneities in environmental conditions and genetic structure can result in extreme variability in population dynamics at local geographic scales. In such situations, the relative importance of biotic and abiotic factors in determining ecological processes is complicated to decipher. Researchers from CSIRO–Canberra and INRAE–Avignon developed a spatially explicit epidemiological model to better understand how environmental conditions (e.g. habitat quality, climatic conditions), the spatial structure of a population network and dispersal of interacting species jointly determine metapopulation dynamics in plant-pathogen interactions. Using a detailed multi-year survey of three metapopulations of the succulent plant Cakile maritima and the necrotrophic fungus Alternaria brassicicola located along the southeastern Australian coast, their research showed that climatic conditions are important drivers, likely explaining the high synchrony among populations. Host availability, landscape features facilitating dispersal, and local habitat conditions also impact the occurrence and spread of disease. Overall, this study demonstrates that the collection of longitudinal data on host and pathogen population dynamics, in combination with spatially explicit epidemiological modeling, makes it possible to accurately predict disease dynamics in wild systems. Abstract In symbiotic interactions, spatio-temporal variation in the distribution or population dynamics of one species represents spatial and temporal heterogeneity of the landscape for the other. Such interdependent demographic dynamics result in situations where the relative importance of biotic and abiotic factors in determining ecological processes is complicated to decipher. Using a detailed survey of three metapopulations of the succulent plant Cakile maritima and the necrotrophic fungus Alternaria brassicicola located along the southeastern Australian coast, we developed a series of statistical analyses, namely synchrony analysis, patch occupancy dynamics, and spatially explicit metapopulation model, to understand how habitat quality, weather conditions, dispersal, and spatial structure determine metapopulation dynamics. Climatic conditions are important drivers, likely explaining the high synchrony among populations. Host availability, landscape features facilitating dispersal, and habitat conditions also impact the occurrence and spread of disease. Overall, we show that the collection of extensive data on host and pathogen population dynamics, in combination with spatially explicit epidemiological modelling, makes it possible to accurately predict disease dynamics – even when there is extreme variability in host population dynamics. Finally, we discuss the importance of genetic information for predicting demographic dynamics in this pathosystem. More forthcoming papers &raquo; <p>Julien Papaïx, Jeremy J. Burdon, Emily Walker, Luke G. Barrett, and Peter H. Thrall (Feb 2021) </p> <p><i><a href="https://dx.doi.org/10.1086/712248">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">P</span>redicting disease dynamics in the wild is challenging because interdependent demographic dynamics between the host and its pathogen as well as heterogeneities in environmental conditions and genetic structure can result in extreme variability in population dynamics at local geographic scales. In such situations, the relative importance of biotic and abiotic factors in determining ecological processes is complicated to decipher. Researchers from CSIRO–Canberra and INRAE–Avignon developed a spatially explicit epidemiological model to better understand how environmental conditions (e.g. habitat quality, climatic conditions), the spatial structure of a population network and dispersal of interacting species jointly determine metapopulation dynamics in plant-pathogen interactions. </p><p>Using a detailed multi-year survey of three metapopulations of the succulent plant <i>Cakile maritima</i> and the necrotrophic fungus <i>Alternaria brassicicola</i> located along the southeastern Australian coast, their research showed that climatic conditions are important drivers, likely explaining the high synchrony among populations. Host availability, landscape features facilitating dispersal, and local habitat conditions also impact the occurrence and spread of disease. Overall, this study demonstrates that the collection of longitudinal data on host and pathogen population dynamics, in combination with spatially explicit epidemiological modeling, makes it possible to accurately predict disease dynamics in wild systems. </p> <hr /><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">I</span>n symbiotic interactions, spatio-temporal variation in the distribution or population dynamics of one species represents spatial and temporal heterogeneity of the landscape for the other. Such interdependent demographic dynamics result in situations where the relative importance of biotic and abiotic factors in determining ecological processes is complicated to decipher. Using a detailed survey of three metapopulations of the succulent plant <i>Cakile maritima</i> and the necrotrophic fungus <i>Alternaria brassicicola</i> located along the southeastern Australian coast, we developed a series of statistical analyses, namely synchrony analysis, patch occupancy dynamics, and spatially explicit metapopulation model, to understand how habitat quality, weather conditions, dispersal, and spatial structure determine metapopulation dynamics. Climatic conditions are important drivers, likely explaining the high synchrony among populations. Host availability, landscape features facilitating dispersal, and habitat conditions also impact the occurrence and spread of disease. Overall, we show that the collection of extensive data on host and pathogen population dynamics, in combination with spatially explicit epidemiological modelling, makes it possible to accurately predict disease dynamics – even when there is extreme variability in host population dynamics. Finally, we discuss the importance of genetic information for predicting demographic dynamics in this pathosystem. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 23 Oct 2020 05:00:00 GMT “Soil microbes generate stronger fitness differences than stabilization among California annual plants” https://amnat.org/an/newpapers/Jan-Kandlikar-A.html Gaurav S. Kandlikar (गौरव कांडलिकर), Xinyi Yan (严心怡), Jonathan M. Levine, and Nathan J. B. Kraft (Jan 2021) Soil microbes can both promote and hinder plant diversity in California grasslands Read the Article (Just Accepted)Abstract Soil microorganisms influence a variety of processes in plant communities. Many theoretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequency-dependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among fifteen pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequency-dependent dynamics that stabilize plant interactions, they simultaneously generate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is to often favor species exclusion over coexistence, a result that only becomes evident by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity. 土壤微生物在加利福尼亚一年生植物间产生超过其稳定化机制的适合度差异 土壤微生物影响植物种群的多种生态过程。许多理论和实验研究已表明,植物和土壤微生物之间的动态反馈,可以引起植物种群的负频率制约,从而稳定物种的共存关系。然而,推断土壤微生物对于植物种共存的实际影响,还需要量化它们给予共存种平均适合度的相对优势。然而,以前很少有研究关注这个效应。 我们通过一个温室实验,测量微生物在15对共生于南加州草原一年生植物之间产生的稳定化机制和适合度差异。结果表明,尽管土壤微生物经常引起有助于稳定植物共生关系的负频率制约,它们同时也导致植物物种之间出现较大的适合度差异。综合两者,假设这些共存的植物种在其他方面的竞争优势相同,植物-土壤反馈往往促进物种间的竞争排斥,而不是共存。这一结论只有通过量化微生物介导的适合度差异才能做出。本研究强调,比较植物-土壤微生物反馈引起的稳定化机制和适合度差异,对于理解土壤微生物对植物多样性的影响具有重要的意义。 More forthcoming papers &raquo; <p>Gaurav S. Kandlikar (गौरव कांडलिकर), Xinyi Yan (严心怡), Jonathan M. Levine, and Nathan J. B. Kraft (Jan 2021)</p> <p><b>Soil microbes can both promote and hinder plant diversity in California grasslands </b></p> <p><i><a href="https://dx.doi.org/10.1086/711662">Read the Article</a></i> (Just Accepted)</p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>oil microorganisms influence a variety of processes in plant communities. Many theoretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequency-dependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among fifteen pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequency-dependent dynamics that stabilize plant interactions, they simultaneously generate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is to often favor species exclusion over coexistence, a result that only becomes evident by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity. </p> <h4>土壤微生物在加利福尼亚一年生植物间产生超过其稳定化机制的适合度差异 </h4> <p>土壤微生物影响植物种群的多种生态过程。许多理论和实验研究已表明,植物和土壤微生物之间的动态反馈,可以引起植物种群的负频率制约,从而稳定物种的共存关系。然而,推断土壤微生物对于植物种共存的实际影响,还需要量化它们给予共存种平均适合度的相对优势。然而,以前很少有研究关注这个效应。 我们通过一个温室实验,测量微生物在15对共生于南加州草原一年生植物之间产生的稳定化机制和适合度差异。结果表明,尽管土壤微生物经常引起有助于稳定植物共生关系的负频率制约,它们同时也导致植物物种之间出现较大的适合度差异。综合两者,假设这些共存的植物种在其他方面的竞争优势相同,植物-土壤反馈往往促进物种间的竞争排斥,而不是共存。这一结论只有通过量化微生物介导的适合度差异才能做出。本研究强调,比较植物-土壤微生物反馈引起的稳定化机制和适合度差异,对于理解土壤微生物对植物多样性的影响具有重要的意义。 </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 23 Oct 2020 05:00:00 GMT “Tradeoffs with growth limit host range in complex life cycle helminths” https://amnat.org/an/newpapers/Feb-Benesh.html Daniel Benesh, Geoff Parker, James C. Chubb, and Kevin D. Lafferty (Feb 2021) Host availability, tradeoffs, or both – why do complex life cycle worms infect more host species at some life stages? Read the Article (Just Accepted) Is a worm of all trades a master of none? Some worms have mastered living in whales, but they are unable to live in other mammals. This is important because it means that a whale worm can’t mature in you after you eat its coiled larva hidden in your sashimi (though it might live long enough to make you sick). The coiled larva in your sashimi is a jack of all trades, being able to infect dozens of fish species. So the whale worm is a generalist in fish then a specialist in whales. Why? A new study finds that parasitic worms are generalists when they have the opportunity (there are lots of fish in the sea), but generalist worms don’t grow as much as their specialist relatives. And this is not just for whale worms, it seems to be the case for hundreds of parasitic roundworms, tapeworms, and spiny-headed worms. A parasite that lives in a host eaten by different predators has many opportunities to be a generalist. By analyzing food webs with parasites in them, the authors discovered that ‘middle’ (e.g., second) stage parasitic larvae have more host opportunities, and this matched what parasites do – ‘middle’ life stages infect more host species than early or late life stages. Regardless, parasites usually infect fewer host species than they could, suggesting generalism also has costs. In some stages, parasites grow a lot, like tapeworms that start out the size of this period “.”, but grow to be longer than an average human is tall. In contrast, less industrious stages simply encyst as they wait to be passed to their next host. The stages that grow a lot tend to infect a narrower range of hosts, hinting that worms must specialize to grow large. Overall, this study suggests that a worm of all trades is indeed a master of none. Abstract Parasitic worms with complex life cycles have several developmental stages, with each stage creating opportunities to infect additional host species. Using a dataset for 973 species of trophically transmitted acanthocephalans, cestodes, and nematodes, we confirmed that worms with longer life cycles (i.e. more successive hosts) infect a greater diversity of host species and taxa (after controlling for study effort). Generalism at the stage level was highest for ‘middle’ life stages, the second and third intermediate hosts of long life cycles. By simulating life cycles in real food webs, we found that middle stages had more potential host species to infect, suggesting that opportunity constrains generalism. However, parasites usually infected fewer host species than expected from simulated cycles, suggesting generalism also has costs. There was no tradeoff in generalism from one stage to the next, but worms spent less time growing and developing in stages where they infected more taxonomically diverse hosts. Our results demonstrate that life cycle complexity favors high generalism, and host use across life stages is determined by both ecological opportunity and life history tradeoffs. More forthcoming papers &raquo; <p>Daniel Benesh, Geoff Parker, James C. Chubb, and Kevin D. Lafferty (Feb 2021) </p> <p><b>Host availability, tradeoffs, or both – why do complex life cycle worms infect more host species at some life stages? </b></p> <p><i><a href="https://dx.doi.org/10.1086/712249">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">I</span>s a worm of all trades a master of none? Some worms have mastered living in whales, but they are unable to live in other mammals. This is important because it means that a whale worm can’t mature in you after you eat its coiled larva hidden in your sashimi (though it might live long enough to make you sick). The coiled larva in your sashimi is a jack of all trades, being able to infect dozens of fish species. So the whale worm is a generalist in fish then a specialist in whales. Why? A new study finds that parasitic worms are generalists when they have the opportunity (there are lots of fish in the sea), but generalist worms don’t grow as much as their specialist relatives. And this is not just for whale worms, it seems to be the case for hundreds of parasitic roundworms, tapeworms, and spiny-headed worms. </p><p>A parasite that lives in a host eaten by different predators has many opportunities to be a generalist. By analyzing food webs with parasites in them, the authors discovered that ‘middle’ (e.g., second) stage parasitic larvae have more host opportunities, and this matched what parasites do – ‘middle’ life stages infect more host species than early or late life stages. Regardless, parasites usually infect fewer host species than they could, suggesting generalism also has costs. </p><p>In some stages, parasites grow a lot, like tapeworms that start out the size of this period “.”, but grow to be longer than an average human is tall. In contrast, less industrious stages simply encyst as they wait to be passed to their next host. The stages that grow a lot tend to infect a narrower range of hosts, hinting that worms must specialize to grow large. Overall, this study suggests that a worm of all trades is indeed a master of none. </p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">P</span>arasitic worms with complex life cycles have several developmental stages, with each stage creating opportunities to infect additional host species. Using a dataset for 973 species of trophically transmitted acanthocephalans, cestodes, and nematodes, we confirmed that worms with longer life cycles (i.e. more successive hosts) infect a greater diversity of host species and taxa (after controlling for study effort). Generalism at the stage level was highest for ‘middle’ life stages, the second and third intermediate hosts of long life cycles. By simulating life cycles in real food webs, we found that middle stages had more potential host species to infect, suggesting that opportunity constrains generalism. However, parasites usually infected fewer host species than expected from simulated cycles, suggesting generalism also has costs. There was no tradeoff in generalism from one stage to the next, but worms spent less time growing and developing in stages where they infected more taxonomically diverse hosts. Our results demonstrate that life cycle complexity favors high generalism, and host use across life stages is determined by both ecological opportunity and life history tradeoffs. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 23 Oct 2020 05:00:00 GMT “Coping with danger and deception: lessons from signal detection theory” https://amnat.org/an/newpapers/Feb-Holen.html Øistein Haugsten Holen and Thomas N. Sherratt (Feb 2021) Many signal detection models of repeated encounters share fundamental similarities and counterintuitive predictions Read the Article (Just Accepted) Evolutionary ecologists often use signal detection theory to model how animals discriminate between desirable and undesirable events or items. The standard model has the limitation that it assumes that signal receivers behave so as to maximize payoff for a single encounter, and that undesirability is a fixed, absolute property of the items themselves. The standard model therefore cannot represent many common ecological scenarios in which the signal receivers benefit from rejecting low-quality items (e.g. mates, food items, resources) if high-quality alternatives are common but yet benefit from accepting them if high-quality alternatives are rare (in this case making the best of a bad situation). In this study, Øistein Holen (researcher at the University of Oslo, Norway) and Tom Sherratt (professor at Carleton University, Canada) have reviewed and reanalyzed a number of previously published signal detection models that were originally constructed to study prey choice, mimicry, mate search, and the aiding of kin. These signal detection models feature repeated encounters and have earlier been studied on a case-by-case basis. Holen and Sherratt show that they have a common mathematical form that allow them to be analyzed in a unified framework. This repeated-encounter framework provides a convenient and versatile alternative to the standard signal detection model: It is flexible enough to allow the undesirability of an item (e.g. a low-quality mate or food item) to be relative and dependent on the availability of better alternatives. In such cases, the repeated-encounter framework makes different predictions than the standard model. For example, the standard signal detection model has frequently been used to model Batesian mimicry, in which harmless prey gain protection from predators by resembling undesirable model prey. The authors show that if model prey are protected by low profitability rather than by harmful defense, counter-intuitive forms of Batesian mimicry may exist in which the predator is less likely to attack model prey upon encounter if the Batesian mimics are more abundant or more profitable. Two recent signal detection models of the building up of reserves under predation risk found that prey should sometimes respond to an increased probability of danger by being bolder and more willing to risk predation. Holen and Sherratt show that similar counter-intuitive predictions are common in the repeated-encounter models they review: If undesirable events are undesirable in a relative rather than an absolute sense, an increased probability of events being undesirable may lead to increased acceptance rates. Holen and Sherratt also identify ecological conditions under which the standard signal detection model remains a reasonable model of stimulus discrimination. Abstract Signal detection theory (SDT) has been used to model optimal stimulus discrimination for over four decades within evolutionary ecology. A popular standard model that maximizes payoff per encounter was recently criticized for being too simplistic, leading to erroneous predictions. We review a number of SDT models that have received less attention but have explicitly taken repeated encounters into account, focusing on prey choice, mate search, aggressive mimicry, and the aiding of kin. We show how these models can be seen as variants of a second standard model that can be analyzed in a unified framework. In contrast to the simpler model, in this second model a higher probability of an undesirable or dangerous event occurring may either decrease or increase the receiver's acceptance rates. In each instance, the latter outcome requires undesirable events to be undesirable in a relative rather than absolute sense. Increasing the abundance of desirable signalers or the payoff from accepting them may also either raise or reduce acceptance rates. Our synthesis highlights fundamental similarities among models previously studied on a case-by-case basis, and challenges some long-held beliefs. For example, some classic predictions of Batesian mimicry can be reversed when model prey are protected by low profitability rather than harmful defense. More forthcoming papers &raquo; <p>Øistein Haugsten Holen and Thomas N. Sherratt (Feb 2021) </p> <p><b>Many signal detection models of repeated encounters share fundamental similarities and counterintuitive predictions </b></p> <p><i><a href="https://dx.doi.org/10.1086/712246">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>volutionary ecologists often use signal detection theory to model how animals discriminate between desirable and undesirable events or items. The standard model has the limitation that it assumes that signal receivers behave so as to maximize payoff for a single encounter, and that undesirability is a fixed, absolute property of the items themselves. The standard model therefore cannot represent many common ecological scenarios in which the signal receivers benefit from rejecting low-quality items (e.g. mates, food items, resources) if high-quality alternatives are common but yet benefit from accepting them if high-quality alternatives are rare (in this case making the best of a bad situation). </p><p>In this study, Øistein Holen (researcher at the University of Oslo, Norway) and Tom Sherratt (professor at Carleton University, Canada) have reviewed and reanalyzed a number of previously published signal detection models that were originally constructed to study prey choice, mimicry, mate search, and the aiding of kin. These signal detection models feature repeated encounters and have earlier been studied on a case-by-case basis. Holen and Sherratt show that they have a common mathematical form that allow them to be analyzed in a unified framework. </p><p>This repeated-encounter framework provides a convenient and versatile alternative to the standard signal detection model: It is flexible enough to allow the undesirability of an item (e.g. a low-quality mate or food item) to be relative and dependent on the availability of better alternatives. In such cases, the repeated-encounter framework makes different predictions than the standard model. For example, the standard signal detection model has frequently been used to model Batesian mimicry, in which harmless prey gain protection from predators by resembling undesirable model prey. The authors show that if model prey are protected by low profitability rather than by harmful defense, counter-intuitive forms of Batesian mimicry may exist in which the predator is less likely to attack model prey upon encounter if the Batesian mimics are more abundant or more profitable. Two recent signal detection models of the building up of reserves under predation risk found that prey should sometimes respond to an increased probability of danger by being bolder and more willing to risk predation. Holen and Sherratt show that similar counter-intuitive predictions are common in the repeated-encounter models they review: If undesirable events are undesirable in a relative rather than an absolute sense, an increased probability of events being undesirable may lead to increased acceptance rates. Holen and Sherratt also identify ecological conditions under which the standard signal detection model remains a reasonable model of stimulus discrimination. </p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>ignal detection theory (SDT) has been used to model optimal stimulus discrimination for over four decades within evolutionary ecology. A popular standard model that maximizes payoff per encounter was recently criticized for being too simplistic, leading to erroneous predictions. We review a number of SDT models that have received less attention but have explicitly taken repeated encounters into account, focusing on prey choice, mate search, aggressive mimicry, and the aiding of kin. We show how these models can be seen as variants of a second standard model that can be analyzed in a unified framework. In contrast to the simpler model, in this second model a higher probability of an undesirable or dangerous event occurring may either decrease or increase the receiver's acceptance rates. In each instance, the latter outcome requires undesirable events to be undesirable in a relative rather than absolute sense. Increasing the abundance of desirable signalers or the payoff from accepting them may also either raise or reduce acceptance rates. Our synthesis highlights fundamental similarities among models previously studied on a case-by-case basis, and challenges some long-held beliefs. For example, some classic predictions of Batesian mimicry can be reversed when model prey are protected by low profitability rather than harmful defense. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 23 Oct 2020 05:00:00 GMT “Evolutionary and plastic phenotypic change can be just as fast as changes in population densities” https://amnat.org/an/newpapers/Jan-Grosklos-A.html Guenchik Grosklos and Michael H. Cortez (Jan 2021) In 30 empirical studies, plastic and evolving morphological traits change as fast as changes in population densities Read the Article (Just Accepted) Abstract Evolution and plasticity can drive population-level phenotypic change (e.g., changes in the mean phenotype) on time scales comparable to changes in population densities. However, it is unclear if phenotypic change has the potential to be just as fast as changes in densities, or if comparable rates of change only occur when densities are changing slow enough for phenotypes to keep pace. Moreover, it is unclear if this depends on the mode of adaptation. Using scaling theory and fast-slow dynamical systems theory, we develop a method for comparing maximum rates of density and phenotypic change estimated from population-level time series data. We apply our method to 30 published empirical studies where changes in morphological traits are caused by evolution, plasticity, or an unknown combination. For every study, the maximum rate of phenotypic change was 0.5 to 2.5 times faster than the maximum rate of change in density. Moreover, there were no systematic differences between systems with different modes of adaptation. Our results show that plasticity and evolution can drive phenotypic change just as fast as changes in densities. We discuss the implications of our results in terms of the strengths of feedbacks between population densities and traits. More forthcoming papers &raquo; <p>Guenchik Grosklos and Michael H. Cortez (Jan 2021) </p> <p><b>In 30 empirical studies, plastic and evolving morphological traits change as fast as changes in population densities </b></p> <p><i><a href="https://dx.doi.org/10.1086/711928">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>volution and plasticity can drive population-level phenotypic change (e.g., changes in the mean phenotype) on time scales comparable to changes in population densities. However, it is unclear if phenotypic change has the potential to be just as fast as changes in densities, or if comparable rates of change only occur when densities are changing slow enough for phenotypes to keep pace. Moreover, it is unclear if this depends on the mode of adaptation. Using scaling theory and fast-slow dynamical systems theory, we develop a method for comparing maximum rates of density and phenotypic change estimated from population-level time series data. We apply our method to 30 published empirical studies where changes in morphological traits are caused by evolution, plasticity, or an unknown combination. For every study, the maximum rate of phenotypic change was 0.5 to 2.5 times faster than the maximum rate of change in density. Moreover, there were no systematic differences between systems with different modes of adaptation. Our results show that plasticity and evolution can drive phenotypic change just as fast as changes in densities. We discuss the implications of our results in terms of the strengths of feedbacks between population densities and traits. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 20 Oct 2020 05:00:00 GMT “Infection status as the basis for habitat choices in a wild amphibian” https://amnat.org/an/newpapers/Jan-Barrile.html Gabriel M. Barrile, Anna D. Chalfoun, and Annika W. Walters (Jan 2021) Infection status shapes habitat choices in a wild amphibian; boreal toads clear chytrid infection by switching habitats Read the Article (Just Accepted) Infectious diseases pose a serious threat to the health of people, domestic animals, and wildlife alike. The chytrid fungus, for example, has already caused the extinction of over 100 amphibian species and continues to plague hundreds more across the globe. Boreal toads, once common in high-elevation habitats across the Rocky Mountain West, have suffered severe declines due to the chytrid fungus in recent decades. Boreal toads in western Wyoming, however, persist despite high infection rates with the fungus. Gabe Barrile, a graduate researcher from the University of Wyoming, along with faculty advisors Anna Chalfoun and Annika Walters, study the lives of boreal toads in the mountains of western Wyoming. Toads usually take refuge under riparian willows or in small mammal burrows. Occasionally, however, the researchers observe toads in open environments, often basking in the exposed sunlight. They hypothesized that use of sheltered habitats, which are cool and moist, versus the use of open habitats, which are warm and dry, may be related to whether an individual toad is infected with the chytrid fungus. To test this idea, they obtained disease samples and recorded body temperatures of radio-tracked toads during the summer of 2016. They then matched disease and thermal data to the habitats that toads used through time. The researchers found that wild boreal toads use moist, sheltered habitats when disease-free but move to warmer, more open habitats when infected. Switching habitats in response to infection appears to be advantageous, as increased warmth in open habitats is associated with the clearing of infection, likely via the elevation of body temperature. These findings suggest small-scale microhabitat manipulation to create warm patches may comprise an effective mitigation action against the chytrid fungus, and possibly other amphibian diseases. More broadly, a deeper understanding of disease dynamics better equips us to improve human and animal health in the face on infectious onslaughts. Abstract Animals challenged with disease may select specific habitat conditions that help prevent or reduce infection. Whereas pre-infection avoidance of habitats with a high risk of disease exposure has been documented in both captive and free-ranging animals, evidence of post-infection habitat switching to conditions that promote the clearing of infection is limited to laboratory experiments. The extent to which wild animals proximately modify habitat choices in response to infection status therefore remains unclear. We investigated pre-infection behavioral avoidance and post-infection habitat switching using wild, radio-tracked boreal toads (Anaxyrus boreas boreas) in a population challenged with Batrachochytrium dendrobatidis (Bd); a pathogenic fungus responsible for a catastrophic panzootic affecting hundreds of amphibian species worldwide. Boreal toads did not preemptively avoid microhabitats with conditions conducive to Bd growth. Infected individuals, however, selected warmer, more open habitats, which were associated with elevated body temperature and the subsequent clearing of infection. Our results suggest that disease can comprise an important selective pressure on animal habitat and space use. Habitat selection models therefore may be greatly improved by including variables that quantify infection risk and/or the infection status of individuals through time. More forthcoming papers &raquo; <p>Gabriel M. Barrile, Anna D. Chalfoun, and Annika W. Walters (Jan 2021) </p> <p><b>Infection status shapes habitat choices in a wild amphibian; boreal toads clear chytrid infection by switching habitats </b></p> <p><i><a href="https://dx.doi.org/10.1086/711927">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">I</span>nfectious diseases pose a serious threat to the health of people, domestic animals, and wildlife alike. The chytrid fungus, for example, has already caused the extinction of over 100 amphibian species and continues to plague hundreds more across the globe. Boreal toads, once common in high-elevation habitats across the Rocky Mountain West, have suffered severe declines due to the chytrid fungus in recent decades. Boreal toads in western Wyoming, however, persist despite high infection rates with the fungus. </p><p>Gabe Barrile, a graduate researcher from the University of Wyoming, along with faculty advisors Anna Chalfoun and Annika Walters, study the lives of boreal toads in the mountains of western Wyoming. Toads usually take refuge under riparian willows or in small mammal burrows. Occasionally, however, the researchers observe toads in open environments, often basking in the exposed sunlight. They hypothesized that use of sheltered habitats, which are cool and moist, versus the use of open habitats, which are warm and dry, may be related to whether an individual toad is infected with the chytrid fungus. To test this idea, they obtained disease samples and recorded body temperatures of radio-tracked toads during the summer of 2016. They then matched disease and thermal data to the habitats that toads used through time. </p><p>The researchers found that wild boreal toads use moist, sheltered habitats when disease-free but move to warmer, more open habitats when infected. Switching habitats in response to infection appears to be advantageous, as increased warmth in open habitats is associated with the clearing of infection, likely via the elevation of body temperature. These findings suggest small-scale microhabitat manipulation to create warm patches may comprise an effective mitigation action against the chytrid fungus, and possibly other amphibian diseases. More broadly, a deeper understanding of disease dynamics better equips us to improve human and animal health in the face on infectious onslaughts. </p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">A</span>nimals challenged with disease may select specific habitat conditions that help prevent or reduce infection. Whereas pre-infection avoidance of habitats with a high risk of disease exposure has been documented in both captive and free-ranging animals, evidence of post-infection habitat switching to conditions that promote the clearing of infection is limited to laboratory experiments. The extent to which wild animals proximately modify habitat choices in response to infection status therefore remains unclear. We investigated pre-infection behavioral avoidance and post-infection habitat switching using wild, radio-tracked boreal toads (<i>Anaxyrus boreas boreas</i>) in a population challenged with <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>); a pathogenic fungus responsible for a catastrophic panzootic affecting hundreds of amphibian species worldwide. Boreal toads did not preemptively avoid microhabitats with conditions conducive to <i>Bd</i> growth. Infected individuals, however, selected warmer, more open habitats, which were associated with elevated body temperature and the subsequent clearing of infection. Our results suggest that disease can comprise an important selective pressure on animal habitat and space use. Habitat selection models therefore may be greatly improved by including variables that quantify infection risk and/or the infection status of individuals through time. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 20 Oct 2020 05:00:00 GMT “Ageing and senescence across reproductive traits and survival in superb fairy-wrens (<i>Malurus cyaneus</i>)” https://amnat.org/an/newpapers/Jan-Cooper-A.html Eve B. Cooper, Timothée Bonnet, Helen L. Osmond, Andrew Cockburn, and Loeske E. B. Kruuk (Jan 2021) Dramatically different patterns of reproductive and survival senescence in a cooperatively breeding bird Read the Article (Just Accepted) Abstract Why do senescence rates of fitness-related traits often vary dramatically? By considering the full ageing trajectories of multiple traits we can better understand how a species’ life-history shapes the evolution of senescence within a population. Here, we examined age-related changes in sex-specific survival, reproduction, and several components of reproduction using a long-term study of a cooperatively-breeding songbird, the superb fairy-wren (Malurus cyaneus). We compared ageing patterns between traits by estimating standardized rates of maturation, the age of onset of senescence, and rates of senescence, while controlling for confounding factors reflecting individual variability in life-history. We found striking differences in ageing and senescence patterns between survival and reproduction, as well as between reproductive traits. In both sexes, survival started to decline from maturity onwards. In contrast, all reproductive traits showed improvements into early adulthood, and many showed little or no evidence of senescence. In females, despite senescence in clutch size, number of offspring surviving to independence did not decline in late life, possibly due to improvements in maternal care with age. Superb fairy-wrens have exceptionally high levels of extra-group paternity, and while male within-group reproductive success did not change with age, extra-group reproductive success showed a dramatic increase in early ages, followed by a senescent decline, suggesting that male reproductive ageing is driven by sexual selection. We discuss how the superb fairy-wrens’ complex life history may contribute to the disparate ageing patterns across different traits. More forthcoming papers &raquo; <p>Eve B. Cooper, Timothée Bonnet, Helen L. Osmond, Andrew Cockburn, and Loeske E. B. Kruuk (Jan 2021) </p> <p><b>Dramatically different patterns of reproductive and survival senescence in a cooperatively breeding bird </b></p> <p><i><a href="https://dx.doi.org/10.1086/711755">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">W</span>hy do senescence rates of fitness-related traits often vary dramatically? By considering the full ageing trajectories of multiple traits we can better understand how a species’ life-history shapes the evolution of senescence within a population. Here, we examined age-related changes in sex-specific survival, reproduction, and several components of reproduction using a long-term study of a cooperatively-breeding songbird, the superb fairy-wren (<i>Malurus cyaneus</i>). We compared ageing patterns between traits by estimating standardized rates of maturation, the age of onset of senescence, and rates of senescence, while controlling for confounding factors reflecting individual variability in life-history. We found striking differences in ageing and senescence patterns between survival and reproduction, as well as between reproductive traits. In both sexes, survival started to decline from maturity onwards. In contrast, all reproductive traits showed improvements into early adulthood, and many showed little or no evidence of senescence. In females, despite senescence in clutch size, number of offspring surviving to independence did not decline in late life, possibly due to improvements in maternal care with age. Superb fairy-wrens have exceptionally high levels of extra-group paternity, and while male within-group reproductive success did not change with age, extra-group reproductive success showed a dramatic increase in early ages, followed by a senescent decline, suggesting that male reproductive ageing is driven by sexual selection. We discuss how the superb fairy-wrens’ complex life history may contribute to the disparate ageing patterns across different traits. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 20 Oct 2020 05:00:00 GMT Applications for the 2021 Student Research Awards https://amnat.org/announcements/AWAStuResearch.html The ASN Student Research Awards support research by student members that advances the goals of the society: the conceptual unification of ecology, evolution, or behavior. Each award consists of a $2,000 check to the candidate. An applicant must must hold a bachelor’s degree or equivalent, must have passed to candidacy in a Ph.D. program or equivalent, and must be at least one year from completing the Ph.D at the time of the award. Projects in all types of research (i.e., laboratory, field, theory) are encouraged. A total of ten proposals will receive awards. Proposals will be judged on originality, strength, and significance of the questions being addressed, prospects for significant results, and the match between the proposed research and the ASN mission. If not already a member of the ASN (student membership is international and US$20), awardees are expected to join ASN at the time of the award. Applications include four elements: 1) A two-page proposal describing the research project for which support is requested; 2) A budget with justification (one page); 3) a short curriculum vitae (two pages); 4) a statement from the Ph.D. supervisor that verifies that the applicant meets the eligibility requirements, and confirms the supervisor’s support for the proposed project (one page). Detailed Instructions: The two-page proposal should describe a specific research project for which support is requested.&nbsp; While some background and context is appropriate, the proposal should not be a general overview of the applicant’s complete dissertation.&nbsp; The proposal should have a title at the top of the first page.&nbsp; The proposal should be single-spaced, have 1-inch (2.5cm) margins all around, and be written in a 12-point standard font on letter-sized paper (e.g., 8.5 x 11 inch).&nbsp; A list of references should follow but is not included in the 2-page limit. The budget and budget justification should clearly support the specific proposed project. If total costs of the project exceed $2000, some indication of how the applicant intends to find support for remaining costs should be given. The CV should meet the same formatting requirements as the project description. All materials should be compiled into one PDF.&nbsp; The .pdf filename should be in the format Lastname_Firstname_SRA (example:&nbsp; Wright_Sewall_SRA.pdf). Send your application via e-mail to Anna Hargreaves (anna.hargreaves@mcgill.ca)&nbsp; with “ASN Student Research Award [last name]” in the subject line. Deadline for submission of all materials is January 31. Judging. Applications will be reviewed by a committee of six persons: three faculty-level researchers and three graduate students. Senior-level appointments are made by the President-Elect. Members each serve for three years; the longest-serving committee member serves as chair in her/his final year on the committee. Graduate student appointments are made from the Graduate Council, in consultation with the President-Elect. &nbsp; <p>The ASN Student Research Awards support research by student members that advances the goals of the society: the conceptual unification of ecology, evolution, or behavior. Each award consists of a $2,000 check to the candidate. An applicant must must hold a bachelor&rsquo;s degree or equivalent, must have passed to candidacy in a Ph.D. program or equivalent, and must be at least one year from completing the Ph.D at the time of the award. Projects in all types of research (i.e., laboratory, field, theory) are encouraged. A total of ten proposals will receive awards. Proposals will be judged on originality, strength, and significance of the questions being addressed, prospects for significant results, and the match between the proposed research and the ASN mission. If not already a member of the ASN (student membership is international and US$20), awardees are expected to join ASN at the time of the award.</p> <p>Applications include four elements: 1) A two-page proposal describing the research project for which support is requested; 2) A budget with justification (one page); 3) a short curriculum vitae (two pages); 4) a statement from the Ph.D. supervisor that verifies that the applicant meets the eligibility requirements, and confirms the supervisor&rsquo;s support for the proposed project (one page).</p> <p>Detailed Instructions:</p> <ol> <li>The two-page proposal should describe a specific research project for which support is requested.&nbsp; While some background and context is appropriate, the proposal should not be a general overview of the applicant&rsquo;s complete dissertation.&nbsp; The proposal should have a title at the top of the first page.&nbsp; The proposal should be single-spaced, have 1-inch (2.5cm) margins all around, and be written in a 12-point standard font on letter-sized paper (e.g., 8.5 x 11 inch).&nbsp; A list of references should follow but is not included in the 2-page limit.</li> <li>The budget and budget justification should clearly support the specific proposed project. If total costs of the project exceed $2000, some indication of how the applicant intends to find support for remaining costs should be given.</li> <li>The CV should meet the same formatting requirements as the project description.</li> <li>All materials should be compiled into one PDF.&nbsp; The .pdf filename should be in the format Lastname_Firstname_SRA (example:&nbsp; Wright_Sewall_SRA.pdf).</li> <li>Send your application via e-mail to Anna Hargreaves (<a href="mailto:anna.hargreaves@mcgill.ca">anna.hargreaves@mcgill.ca</a>)&nbsp; with &ldquo;ASN Student Research Award [last name]&rdquo; in the subject line.</li> <li><strong>Deadline for submission of all materials is January 31.</strong></li> </ol> <p><strong>Judging. </strong></p> <p>Applications will be reviewed by a committee of six persons: three faculty-level researchers and three graduate students. Senior-level appointments are made by the President-Elect. Members each serve for three years; the longest-serving committee member serves as chair in her/his final year on the committee. Graduate student appointments are made from the Graduate Council, in consultation with the President-Elect.</p> <p>&nbsp;</p> Fri, 16 Oct 2020 05:00:00 GMT Applications for the 2021 Jasper Loftus-Hills Young Investigator Awards https://amnat.org/announcements/NomYIAforms.html The Jasper Loftus-Hill Young Investigator’s Award of the American Society of Naturalists honors outstanding promise and accomplishments of young investigators who conduct integrative work in the fields of Ecology, Evolutionary Biology, Behavioral Ecology, and Genetics. Applicants working in any of these fields are encouraged to apply. The award honors outstanding promise and accomplishments of young investigators (3 years post-Ph.D., or in the final year of their Ph.D) who conduct integrative work in ecology, evolution, behavioral ecology, and genetics (see * below) . The award was established in 1984 to recognize exceptional work by investigators who received their doctorates in the three years preceding the application deadline, or who are in their final year of graduate school. The award commemorates Jasper Loftus-Hills (1946-1974), an Australian biologist of exceptional promise who died tragically during the course of fieldwork three years after receiving his degree. Winners of this award will present a research paper in the Young Investigator’s Symposium at the ASN annual meeting and receive a $700 prize, a travel allowance of $700, cost of registration for the meetings, and a supplement of $500 in case of intercontinental travel. Four awards are made annually. Recipients need not be members of the Society. In order to apply for this award, applicants should go to&nbsp;https://forms.gle/BJfjQN4xsvyHkmtf8 to the Google form, where they will be asked to answer a few questions and upload their application (see ** below). The application should consist of one pdf, with the following (in this exact order): - CV (no page limit) - Research statement (3 page limit, including figures) - 3 reprints Additionally, two letters by individuals familiar with the applicant’s work should be uploaded by referees to https://forms.gle/CMhhK9dKVAahJA948&nbsp; (a Google form).&nbsp;(see ** below).&nbsp; Applicants are responsible for ensuring their letter writers submit their letters before the deadline (this can be done before submitting an application), as applications will not be considered complete without these two letters. * The standard timeframe covers anyone who graduated in 2018, 2019, or 2020 or who plans to defend in 2021. Time since PhD degree can be extended by 1 year for each child born or adopted during this period if the applicant was a primary care giver. Other forms of exceptional care giving responsibility (e.g. partner, spouse, aged parent, etc.) will be considered on a case-by-case basis. **Applicants and letter writers will be required to sign into an account registered with Google (does not have to be a gmail address) to upload their applications and letters, respectively. If you or your letter writers do not have a google account, please send materials directly to Robin Hopkins.Jasper Loftus-Hills (1946-1974) was an Australian biologist of exceptional promise who lost his life doing fieldwork recording frog calls in Texas, three years after receiving his degree from the University of Melbourne. An obituary appeared in Copeia in 1974 (Alexander, Richard D. "Jasper Loftus-Hills." Copeia 1974:812-13). The Golden Coqu&iacute; (in the photo above) was discovered on Puerto Rico by George E. Drewry, Kirkland L. Jones, Julia R. Clark, and Jasper J. Loftus-Hills. They had planned to name the species for its color, but when Loftus-Hills was killed in 1974, his colleagues chose instead to name it in his honor: A further description of Jasper Loftus-Hills appeared in Copeia 2015 (103:467-475), which is a retrospective on his mentor, Murray John Littlejohn (doi:&nbsp;http://dx.doi.org/10.1643/OT-15-274) The most gifted graduate student Murray ever worked with (in his own estimation) was Jasper Loftus-Hills, whose Ph.D. thesis “Auditory function and acoustic communication in anuran amphibians” was completed in 1971. Jasper followed in Murray’s footsteps to Austin and then went on to Cornell University and the University of Michigan. He was tragically killed by a hit-and-run driver while doing night fieldwork on Gastrophryne in Texas in 1974. The 1992 Gastrophryne paper coauthored by Jasper and Murray is a lucid analysis of the state of the art in character displacement and reinforcement, two terms burdened with a long history of confusion. (Loftus-Hills, J. J., and M. J. Littlejohn.&nbsp;1992.&nbsp;Reinforcement and reproductive character displacement inGastrophryne carolinensis&nbsp;and&nbsp;G. olivacea&nbsp;(Anura: Microhylidae): a re-evaluation.&nbsp;Evolution 46:896–906.) &nbsp; <p>The Jasper Loftus-Hill Young Investigator&rsquo;s Award of the American Society of Naturalists honors outstanding promise and accomplishments of young investigators who conduct integrative work in the fields of Ecology, Evolutionary Biology, Behavioral Ecology, and Genetics. Applicants working in any of these fields are encouraged to apply.</p> <p>The award honors outstanding promise and accomplishments of young investigators (3 years post-Ph.D., or in the final year of their Ph.D) who conduct integrative work in ecology, evolution, behavioral ecology, and genetics <strong><a href="#time">(see * below</a></strong>) . The award was established in 1984 to recognize exceptional work by investigators who received their doctorates in the three years preceding the application deadline, or who are in their final year of graduate school. The award commemorates Jasper Loftus-Hills (1946-1974), an Australian biologist of exceptional promise who died tragically during the course of fieldwork three years after receiving his degree.</p> <p>Winners of this award will present a research paper in the Young Investigator&rsquo;s Symposium at the ASN annual meeting and receive a $700 prize, a travel allowance of $700, cost of registration for the meetings, and a supplement of $500 in case of intercontinental travel. Four awards are made annually. Recipients need not be members of the Society.</p> <p>In order to apply for this award, applicants should go to&nbsp;<span style="font-size: 11pt;"><span style="font-family: &quot;Calibri&quot;,sans-serif;"><a href="https://forms.gle/BJfjQN4xsvyHkmtf8" style="color:blue; text-decoration:underline">https://forms.gle/BJfjQN4xsvyHkmtf8</a> to the Google form, </span></span>where they will be asked to answer a few questions and upload their application <span style="font-size: 11pt;"><span style="font-family: &quot;Calibri&quot;,sans-serif;"><a href="#time">(<strong>see ** below</strong>)</a></span></span>. The application should consist of one pdf, with the following (in this exact order):<br /> - CV (no page limit)<br /> - Research statement (3 page limit, including figures)<br /> - 3 reprints</p> <p>Additionally, two letters by individuals familiar with the applicant&rsquo;s work should be uploaded by referees <span style="font-size: 11pt;"><span style="font-family: &quot;Calibri&quot;,sans-serif;">to <a href="https://forms.gle/CMhhK9dKVAahJA948" style="color:blue; text-decoration:underline">https://forms.gle/CMhhK9dKVAahJA948&nbsp;</a> (a Google form).&nbsp;<a href="#time">(<strong>see ** below</strong>)</a>.&nbsp; </span></span>Applicants are responsible for ensuring their letter writers submit their letters before the deadline (this can be done before submitting an application), as applications will not be considered complete without these two letters.</p> <hr /> <p id="time">* The standard timeframe covers anyone who graduated in 2018, 2019, or 2020 or who plans to defend in 2021. <strong>Time since PhD degree</strong> can be extended by 1 year for each child born or adopted during this period if the applicant was a primary care giver. Other forms of exceptional care giving responsibility (e.g. partner, spouse, aged parent, etc.) will be considered on a case-by-case basis.</p> <p>**<strong>Applicants and letter writers will be required to sign into an account registered with Google</strong> (does not have to be a gmail address) to upload their applications and letters, respectively. If you or your letter writers do not have a google account, please send materials directly to <a href="mailto:rhopkins@fas.harvard.edu?subject=YIA%20Application">Robin Hopkins.</a></p><p>Jasper Loftus-Hills (1946-1974) was an Australian biologist of exceptional promise who lost his life doing fieldwork recording frog calls in Texas, three years after receiving his degree from the University of Melbourne. <a href="/dam/jcr:50a091cd-227f-4bff-9f60-687a6679b1d8/JLH%20obituary.pdf">An obituary appeared in <i>Copeia</i></a> in 1974 (Alexander, Richard D. &quot;Jasper Loftus-Hills.&quot; <em>Copeia</em> 1974:812-13).</p> <p>The Golden Coqu&iacute; (in the photo above) was discovered on Puerto Rico by George E. Drewry, Kirkland L. Jones, Julia R. Clark, and Jasper J. Loftus-Hills. They had planned to name the species for its color, but when Loftus-Hills was killed in 1974, his colleagues chose instead to name it in his honor:</p> <p>A further description of Jasper Loftus-Hills appeared in <i>Copeia</i> 2015 (103:467-475), which is a retrospective on his mentor, Murray John Littlejohn (doi:&nbsp;<a href="http://dx.doi.org/10.1643/OT-15-274">http://dx.doi.org/10.1643/OT-15-274</a>)</p> <blockquote>The most gifted graduate student Murray ever worked with (in his own estimation) was Jasper Loftus-Hills, whose Ph.D. thesis &ldquo;Auditory function and acoustic communication in anuran amphibians&rdquo; was completed in 1971. Jasper followed in Murray&rsquo;s footsteps to Austin and then went on to Cornell University and the University of Michigan. He was tragically killed by a hit-and-run driver while doing night fieldwork on Gastrophryne in Texas in 1974. The 1992 Gastrophryne paper coauthored by Jasper and Murray is a lucid analysis of the state of the art in character displacement and reinforcement, two terms burdened with a long history of confusion.<br /> (<span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">Loftus-Hills, J. J., and M. J. Littlejohn.&nbsp;</span><span class="NLM_year" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">1992</span><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">.&nbsp;</span><span class="NLM_article-title" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">Reinforcement and reproductive character displacement in<i>Gastrophryne carolinensis</i>&nbsp;and&nbsp;<i>G. olivacea</i>&nbsp;(Anura: Microhylidae): a re-evaluation</span><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">.&nbsp;</span><span class="citation_source-journal" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px; font-style: italic;">Evolution </span><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">46:</span><span class="NLM_fpage" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">896</span><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">&ndash;</span><span class="NLM_lpage" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px;">906</span><span class="citation_source-journal" style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12.51px; font-style: italic;">.</span>)</blockquote> <p>&nbsp;</p> Fri, 16 Oct 2020 05:00:00 GMT Nominations for the Edward O. Wilson Naturalist Award https://amnat.org/announcements/NomEOWilson.html The Edward O. Wilson Naturalist Award is given to an active investigator in mid-career (within 20 years of completion of the PhD) who has made significant contributions to the knowledge of a particular ecosystem or group of organisms.&nbsp;Time since PhD degree can be extended in light of parental leave. Other forms of exceptional caregiving responsibility [e.g., partner, spouse, aged parent, etc]. or extenuating circumstances will be considered on a case-by-case basis. Individuals whose research and writing illuminate principles of evolutionary biology and an enhanced aesthetic appreciation of natural history will merit special consideration. The recipient need not be a member of the Society. The award will consist of an especially appropriate work of art and a prize of $2,000. The ASN strongly encourages its members to submit nominations of deserving people. The names of former recipients can be found here&nbsp;https://www.amnat.org/awards.html#Wilson Nominations will be held over for two years. The application packet should in the form of a single PDF consisting of a letter of nominations, curriculum vitae of the candidate including a publication list, and three key publications to be send electronically by January 15, 2021, to Joe Travis (travis@bio.fsu.edu). Please indicate "E. O. Wilson Award" in the subject line.&nbsp; <p>The Edward O. Wilson Naturalist Award is given to an active investigator in mid-career (within 20 years of completion of the PhD) who has made significant contributions to the knowledge of a particular ecosystem or group of organisms.&nbsp;Time since PhD degree can be extended in light of parental leave. Other forms of exceptional caregiving responsibility [e.g., partner, spouse, aged parent, etc]. or extenuating circumstances will be considered on a case-by-case basis.</p> <p>Individuals whose research and writing illuminate principles of evolutionary biology and an enhanced aesthetic appreciation of natural history will merit special consideration. <em>The recipient need not be a member of the Society</em>. The award will consist of an especially appropriate work of art and a prize of $2,000.</p> <p>The ASN strongly encourages its members to submit nominations of deserving people. The names of former recipients can be found here&nbsp;<a href="https://www.amnat.org/awards.html#Wilson">https://www.amnat.org/awards.html#Wilson</a></p> <p>Nominations will be held over for two years.</p> <p>The application packet should in the form of a single PDF consisting of a letter of nominations, curriculum vitae of the candidate including a publication list, and three key publications to be send electronically by January 15, 2021, to Joe Travis (<a href="mailto:travis@bio.fsu.edu">travis@bio.fsu.edu</a>). Please indicate &quot;E. O. Wilson Award&quot; in the subject line.&nbsp;</p> Thu, 15 Oct 2020 05:00:00 GMT Call for Nominations for ASN President, Vice President, and Secretary https://amnat.org/announcements/NomASNOfficersANN.html Members of the American Society of Naturalists are encouraged to submit nominations for the Executive Committee (EC). Elections will be held in 2021 for President, Vice President, and Secretary. The President serves on the EC from 2022-2026, acting as President in 2023 The Vice President serves on the EC from 2022-2024, acting as VP in 2023. The VP organizes a symposium to be presented at the meetings in 2023 and edits the symposium papers for publication in The American Naturalist. The Secretary serves on the EC from 2022-2027, acting as Secretary from 2022-2024 and Past Secretary from 2025-2027. Names of nominees for specific offices should be submitted by December 1, 2020, to Maria Orive (morive@ku.edu) Please indicate “ASN Nomination” in the subject line. As you contemplate nominations, you may want to check the current (https://www.amnat.org/about/governance/execcomm.html) and past officers (https://www.amnat.org/about/history/past-ec.html) for reference.The PRESIDENT leads the ASN Executive Council and selects the membership of the award and officer nomination committees. The President selects the President’s Award for the “best” paper in The American Naturalist in the past year, gives the ASN Presidential Address and presents the Society’s awards at the annual meeting, and represents the ASN in multiple other ways through the year. The President serves on the Executive Council for five years, including one year as President-Elect and three years as a Past-President. The VICE PRESIDENT organizes the Vice-President’s Symposium for the annual meeting and edits the special supplement to The American Naturalist that contains the papers derived from the VP Symposium. The Vice-President is also the Society’s liaison for the organizers of the annual meeting. The Vice-President serves as a member of the Executive Council for three years, two as a regular member and one as ex officio member. The SECRETARY records and publishes the minutes of the annual meeting of the Executive Committee and ensures that elections for Society offices are conducted in a timely manner. In addition, the Secretary works closely with the President with respect to the normal running of the Society, documents the Executive Committee’s actions, sees that the ASN Officer’s Handbook and website are up to date, and coordinates communication between the Executive Committee, other societies’ Executive Committees, the University of Chicago Press, and ASN membership. The Secretary serves for a three-year term, and then remains a voting member for three years as Past Secretary. <p>Members of the American Society of Naturalists are encouraged to submit nominations for the Executive Committee (EC). Elections will be held in 2021 for President, Vice President, and Secretary.</p> <ul> <li>The President serves on the EC from 2022-2026, acting as President in 2023</li> <li>The Vice President serves on the EC from 2022-2024, acting as VP in 2023. The VP organizes a symposium to be presented at the meetings in 2023 and edits the symposium papers for publication in <em>The American Naturalist</em>.</li> <li>The Secretary serves on the EC from 2022-2027, acting as Secretary from 2022-2024 and Past Secretary from 2025-2027.</li> </ul> <p>Names of nominees for specific offices should be submitted by December 1, 2020, to Maria Orive (<a href="mailto:morive@ku.edu">morive@ku.edu</a>)</p> <p>Please indicate &ldquo;ASN Nomination&rdquo; in the subject line.</p> <p>As you contemplate nominations, you may want to check the current (<a href="https://www.amnat.org/about/governance/execcomm.html">https://www.amnat.org/about/governance/execcomm.html</a>) and past officers (<a href="https://www.amnat.org/about/history/past-ec.html)">https://www.amnat.org/about/history/past-ec.html)</a> for reference.</p><p>The <strong>PRESIDENT </strong>leads the ASN Executive Council and selects the membership of the award and officer nomination committees. The President selects the President&rsquo;s Award for the &ldquo;best&rdquo; paper in <em>The American Naturalist </em>in the past year, gives the ASN Presidential Address and presents the Society&rsquo;s awards at the annual meeting, and represents the ASN in multiple other ways through the year. The President serves on the Executive Council for five years, including one year as President-Elect and three years as a Past-President.</p> <p>The <strong>VICE PRESIDENT </strong>organizes the Vice-President&rsquo;s Symposium for the annual meeting and edits the special supplement to <em>The American Naturalist </em>that contains the papers derived from the VP Symposium. The Vice-President is also the Society&rsquo;s liaison for the organizers of the annual meeting. The Vice-President serves as a member of the Executive Council for three years, two as a regular member and one as ex officio member.</p> <p>The <strong>SECRETARY</strong> records and publishes the minutes of the annual meeting of the Executive Committee and ensures that elections for Society offices are conducted in a timely manner. In addition, the Secretary works closely with the President with respect to the normal running of the Society, documents the Executive Committee&rsquo;s actions, sees that the ASN Officer&rsquo;s Handbook and website are up to date, and coordinates communication between the Executive Committee, other societies&rsquo; Executive Committees, the University of Chicago Press, and ASN membership. The Secretary serves for a three-year term, and then remains a voting member for three years as Past Secretary.</p> Thu, 15 Oct 2020 05:00:00 GMT Nominations for the Sewall Wright Award https://amnat.org/announcements/NomWright.html The American Society of Naturalists invites nominations for the 2021 Sewall Wright Award. The Sewall Wright Award was established in 1991 for a senior but highly active investigator who is making fundamental contributions to the Society’s goals in promoting the conceptual unification of the natural biological sciences. The winner of the 2021 Sewall Wright Award will be announced by the President during the annual meeting prior to the Presidential address.&nbsp; The recipient will be invited to write a paper for publication in a special section of the journal and will receive an honorarium of $1000. The recipient need not be a member of the Society. The ASN strongly encourages its members to submit nominations of deserving people, preferentially scientists in their prime period as active and influential researcher rather than nearing retirement, who have been successful at conceptually unifying the biological sciences in some way. Ideally, all areas of ecology, evolution, behavioral ecology, and genetics are represented among the nominees. Nominations will be held over for two years. The names of former recipients can be found here: https://www.amnat.org/awards.html#Wright For the 2021 Sewall Wright Award, the prize committee encourages nominations from the membership. A nomination should consist of a letter with a brief description of why the nominee is deserving of the award. Please send all nominations by January 15, 2021, via e-mail to Michael Antolin (antolin@rams.colostate.edu). Please indicate “Sewall Wright Award” in the subject line and let the filename of the nomination letter indicate the name of the nominee. <p>The American Society of Naturalists invites nominations for the 2021 Sewall Wright Award. The Sewall Wright Award was established in 1991 for a senior but highly active investigator who is making fundamental contributions to the Society&rsquo;s goals in promoting the conceptual unification of the natural biological sciences. The winner of the 2021 Sewall Wright Award will be announced by the President during the annual meeting prior to the Presidential address.&nbsp; The recipient will be invited to write a paper for publication in a special section of the journal and will receive an honorarium of $1000. The recipient need not be a member of the Society.</p> <p>The ASN strongly encourages its members to submit nominations of deserving people, preferentially scientists in their prime period as active and influential researcher rather than nearing retirement, who have been successful at conceptually unifying the biological sciences in some way. Ideally, all areas of ecology, evolution, behavioral ecology, and genetics are represented among the nominees. Nominations will be held over for two years.</p> <p>The names of former recipients can be found here:<br /> <a href="https://www.amnat.org/awards.html#Wright">https://www.amnat.org/awards.html#Wright</a></p> <p>For the 2021 Sewall Wright Award, the prize committee encourages nominations from the membership. A nomination should consist of a letter with a brief description of why the nominee is deserving of the award. Please send all nominations by January 15, 2021, via e-mail to Michael Antolin (<a href="mailto:antolin@rams.colostate.edu?subject=Wright%20Award">antolin@rams.colostate.edu</a>). Please indicate &ldquo;Sewall Wright Award&rdquo; in the subject line and let the filename of the nomination letter indicate the name of the nominee.</p> Thu, 15 Oct 2020 05:00:00 GMT Nominations for the IDEA Award https://amnat.org/announcements/NomIDEAaward.html The American Society of Naturalists, the Society for the Study of Evolution, and the Society of Systematic Biologists announce the call for nominations for the 2nd annual ASN/SSE/SSB Inclusiveness, Diversity, Equity, and Access (IDEA) Award. The IDEA Award will be given to a person at any career stage who has strengthened the ecology and evolutionary biology community by promoting inclusiveness and diversity in our fields. The award can also be presented to a group. The recipient(s) will each receive a plaque at the annual meeting of ASN/SSB/SSE and a $1000 honorarium (shared among recipients if more than one). ***Eligibility Note: No contemporary officer, editor, member of diversity committee, or meeting organizer of the three societies is eligible for the award.*** Nomination packages should include: Nomination Letter: A single letter of support (1-2 pages) including biographical information (name, title, organization) of the person or group being nominated, along with a short description of the activities supporting the nomination. The letter must also include a section on the nature of the impact the person or group has had on inclusivity, diversity, and equity in the field. For self-nominations, this letter should be written by someone familiar with the activities of the nominee. Biosketch: A brief biosketch or list of activities (maximum 3 pages) for the person/group nominated. Optional Supplementary Material: Any material you believe clarifies the activities of the nominee relevant to this award (maximum 3 pages) Nominations should be submitted by January 15, 2021 by going to the award nomination form: http://bit.ly/2021IDEA For more information about the ASN Diversity Committee, see https://www.amnat.org/about/governance/Diversity.html <p>The American Society of Naturalists, the Society for the Study of Evolution, and the Society of Systematic Biologists announce the call for nominations for the 2nd annual ASN/SSE/SSB Inclusiveness, Diversity, Equity, and Access (IDEA) Award. The IDEA Award will be given to a person at any career stage who has strengthened the ecology and evolutionary biology community by promoting inclusiveness and diversity in our fields. The award can also be presented to a group. The recipient(s) will each receive a plaque at the annual meeting of ASN/SSB/SSE and a $1000 honorarium (shared among recipients if more than one).</p> <p>***Eligibility Note: No contemporary officer, editor, member of diversity committee, or meeting organizer of the three societies is eligible for the award.***</p> <p><strong>Nomination packages should include:</strong></p> <ol> <li><em><strong>Nomination Letter</strong>:</em> A single letter of support (1-2 pages) including biographical information (name, title, organization) of the person or group being nominated, along with a short description of the activities supporting the nomination. The letter must also include a section on the nature of the impact the person or group has had on inclusivity, diversity, and equity in the field. For self-nominations, this letter should be written by someone familiar with the activities of the nominee.</li> <li><strong><em>Biosketch</em>:</strong> A brief biosketch or list of activities (maximum 3 pages) for the person/group nominated.</li> <li><strong><em>Optional Supplementary Material:</em></strong> Any material you believe clarifies the activities of the nominee relevant to this award (maximum 3 pages)</li> </ol> <p>Nominations should be submitted by January 15, 2021 by going to the award nomination form:<b id="docs-internal-guid-881ba0c7-7fff-e854-6486-ad7997e2f94e" style="font-weight:normal;"><span style="font-size:12pt;font-family:Arial;color:#292b2c;background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre;white-space:pre-wrap;"> <a href="http://bit.ly/2021IDEA">http://bit.ly/2021IDEA</a></span></b></p> <p><b style="font-weight:normal;"><span style="font-size:12pt;font-family:Arial;color:#292b2c;background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre;white-space:pre-wrap;">For more information about the ASN Diversity Committee, see </span></b><a href="https://www.amnat.org/about/governance/Diversity.html">https://www.amnat.org/about/governance/Diversity.html</a></p> Mon, 12 Oct 2020 05:00:00 GMT ASN Diversity Committee Call for Members https://amnat.org/announcements/NomDivCom.html The ASN Diversity Committee (DC) seeks to add 2-4 new members starting in January 2021. The DC works to promote diversity, equity, and inclusiveness to enhance the study of evolution, ecology, and behavior and to foster the career of its developing scientists. We pursue initiatives that support marginalized groups, which include helping to create an inclusive, accessible environment at the Evolution conference, the stand-alone ASN meeting, and our field in general. Members serve a 3-year term, and the committee typically meets about once a month. Many of the DC’s initiatives are created and operated with the DCs of our sister societies: the Society for the Study of Evolution and the Society for Systematic Biologists. Past or ongoing efforts of the ASN DC include: Data collection and analysis regarding the demographic composition of ASN Creation of guidelines on best practices for awards procedures Events at Society meetings including Story Collider and mixers to build community among LGBTQ+ biologists, biologists with disabilities, biologists of color, biologists at PUIs, and parents Improving accessibility at Society meetings for scientists with disabilities, scientists of marginalized genders, and scientists who are nursing/caretaking Creation of the joint society Inclusiveness, Diversity, Equity, and Access (IDEA) Award to recognize individuals who have strengthened the ecology and evolutionary biology community by promoting inclusiveness and diversity in our fields Applicants must be members of ASN (join or renew your membership here: https://amnat.org/membership/beamember.html) and have attended at least one Evolution conference or ASN stand-alone meeting in the past. &nbsp; We welcome participation from members of the community from all backgrounds and all countries, across all career stages (including graduate students and postdocs), and in all career paths. Applicants should submit an application (https://forms.gle/b1btKm6EZWNr3sEZ9) by Wednesday 25 November 2020. If you have any questions, feel free to contact us at ASNdiversity@gmail.com. For more information about the Diversity Committee, see https://www.amnat.org/about/governance/Diversity.html <p>The ASN Diversity Committee (DC) seeks to add 2-4 new members starting in January 2021. The DC works to promote diversity, equity, and inclusiveness to enhance the study of evolution, ecology, and behavior and to foster the career of its developing scientists. We pursue initiatives that support marginalized groups, which include helping to create an inclusive, accessible environment at the Evolution conference, the stand-alone ASN meeting, and our field in general. Members serve a 3-year term, and the committee typically meets about once a month.</p> <p>Many of the DC&rsquo;s initiatives are created and operated with the DCs of our sister societies: the Society for the Study of Evolution and the Society for Systematic Biologists. Past or ongoing efforts of the ASN DC include:</p> <ul> <li>Data collection and analysis regarding the demographic composition of ASN</li> <li>Creation of guidelines on best practices for awards procedures</li> <li>Events at Society meetings including Story Collider and mixers to build community among LGBTQ+ biologists, biologists with disabilities, biologists of color, biologists at PUIs, and parents</li> <li>Improving accessibility at Society meetings for scientists with disabilities, scientists of marginalized genders, and scientists who are nursing/caretaking</li> <li>Creation of the joint society Inclusiveness, Diversity, Equity, and Access (IDEA) Award to recognize individuals who have strengthened the ecology and evolutionary biology community by promoting inclusiveness and diversity in our fields</li> </ul> <p>Applicants must be members of ASN (join or renew your membership here: <a href="https://amnat.org/membership/beamember.html">https://amnat.org/membership/beamember.html</a>) and have attended at least one Evolution conference or ASN stand-alone meeting in the past.<br /> &nbsp;<br /> We welcome participation from members of the community from all backgrounds and all countries, across all career stages (including graduate students and postdocs), and in all career paths. Applicants should submit an application (<a href="https://forms.gle/b1btKm6EZWNr3sEZ9">https://forms.gle/b1btKm6EZWNr3sEZ9</a>) by <strong>Wednesday 25 November 2020</strong>. If you have any questions, feel free to contact us at <a href="mailto:ASNdiversity@gmail.com">ASNdiversity@gmail.com</a>.</p> <p><strong>For more information about the Diversity Committee, see <a href="https://www.amnat.org/about/governance/Diversity.html">https://www.amnat.org/about/governance/Diversity.html</a></strong></p> Mon, 12 Oct 2020 05:00:00 GMT “Ecological consequences of intraspecific variation in coevolutionary systems” https://amnat.org/an/newpapers/Jan-Senthilnathan.html Athmanathan Senthilnathan and Sergey Gavrilets (Jan 2021) Read the Article (Just Accepted) How species coexist is a fundamental question in ecology. Athmanathan Senthilnathan and Sergey Gavrilets attempt to answer this question using mathematical models of two-species interactions between competitors, mutualists, or a victim species and an exploiter species. In their model, species interactions depend on the similarity in traits like beak shape, body size, coloration, etc. These traits contribute to an individual’s fitness as they interact with individuals from the same species and the other species. The authors also assume that the traits have their own optimum values dependent on the environment. The authors show that strong interactions between similar individuals promote stable coexistence of competitors and exploiter-victim pair. In contrast, mutualists require weak interactions for stable coexistence. This study thus highlights the important role of individual differences for coexistence. Moreover, it provides an eco-evolutionary explanation for why we do not observe “the orgy of mutual benefaction” – the paradoxical situation where mutualism leads to an indefinite increase in population size. Abstract The patterns and outcomes of coevolution are expected to depend on intraspecific trait variation. Various evolutionary factors can change this variation in time. As a result, modeling coevolutionary processes solely in terms of mean trait values may not be sufficient; one may need to study the dynamics of the whole trait distribution. Here, we develop a theoretical framework for studying the effects of evolving intraspecific variation in two-species coevolutionary systems. In particular, we build and study mathematical models of competition, exploiter-victim interactions, and mutualism in which the strength of within- and between-species interactions depends on the difference in continuously varying traits between individuals reproducing asexually. We use analytical approximations based on the invasion analysis and supplement them with numerical results. We find that intraspecific variation can be maintained if stabilizing selection is weak in at least one species. When intraspecific variation is maintained under competition or mutualism, coexistence in a stable equilibrium is promoted when between-species interactions mostly happen between individuals similar in trait values. In contrast, in exploiter-victim systems coexistence typically requires strong interactions between dissimilar exploiters and victims. We show that trait distributions can become multimodal. Our approach and results contribute to the understanding of the ecological consequences of intraspecific variation in coevolutionary systems by exploring its effects on population densities and trait distributions. More forthcoming papers &raquo; <p>Athmanathan Senthilnathan and Sergey Gavrilets (Jan 2021) </p> <p><i><a href="https://dx.doi.org/10.1086/711886">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">H</span>ow species coexist is a fundamental question in ecology. Athmanathan Senthilnathan and Sergey Gavrilets attempt to answer this question using mathematical models of two-species interactions between competitors, mutualists, or a victim species and an exploiter species. In their model, species interactions depend on the similarity in traits like beak shape, body size, coloration, etc. These traits contribute to an individual&rsquo;s fitness as they interact with individuals from the same species and the other species. The authors also assume that the traits have their own optimum values dependent on the environment. The authors show that strong interactions between similar individuals promote stable coexistence of competitors and exploiter-victim pair. In contrast, mutualists require weak interactions for stable coexistence. This study thus highlights the important role of individual differences for coexistence. Moreover, it provides an eco-evolutionary explanation for why we do not observe &ldquo;the orgy of mutual benefaction&rdquo; &ndash; the paradoxical situation where mutualism leads to an indefinite increase in population size.</p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">T</span>he patterns and outcomes of coevolution are expected to depend on intraspecific trait variation. Various evolutionary factors can change this variation in time. As a result, modeling coevolutionary processes solely in terms of mean trait values may not be sufficient; one may need to study the dynamics of the whole trait distribution. Here, we develop a theoretical framework for studying the effects of evolving intraspecific variation in two-species coevolutionary systems. In particular, we build and study mathematical models of competition, exploiter-victim interactions, and mutualism in which the strength of within- and between-species interactions depends on the difference in continuously varying traits between individuals reproducing asexually. We use analytical approximations based on the invasion analysis and supplement them with numerical results. We find that intraspecific variation can be maintained if stabilizing selection is weak in at least one species. When intraspecific variation is maintained under competition or mutualism, coexistence in a stable equilibrium is promoted when between-species interactions mostly happen between individuals similar in trait values. In contrast, in exploiter-victim systems coexistence typically requires strong interactions between dissimilar exploiters and victims. We show that trait distributions can become multimodal. Our approach and results contribute to the understanding of the ecological consequences of intraspecific variation in coevolutionary systems by exploring its effects on population densities and trait distributions.</p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 02 Oct 2020 05:00:00 GMT “Plasticity versus evolutionary divergence: what causes habitat partitioning in urban-adapted birds?” https://amnat.org/an/newpapers/Jan-Martin.html Paul R. Martin, Kevin W. Burke, and Frances Bonier (Jan 2021) A global study of urban birds suggests both plasticity and evolutionary divergence underlie habitat partitioning Read the Article (Just Accepted) Ecologically similar species often minimize competition and other costs of living together by occupying distinct habitats. The mechanisms that cause this habitat partitioning include plasticity, where subordinate species occupy different habitats to avoid or minimize competitive interactions with dominant species, and evolutionary divergence, where subordinate species evolve ecological differences from dominant species that lead them to occupy distinct habitats. How important is plasticity versus evolutionary divergence for habitat partitioning in nature? In this study, researchers from Queen’s University in Ontario, Canada use a global dataset on urban birds to provide one of the few tests of the relative importance of plasticity versus evolutionary divergence underlying habitat partitioning. They find evidence for both. Greater habitat partitioning was associated with increased range overlap among dominant and subordinate species – a factor that is expected to increase the intensity of selection favoring evolutionary divergence. For birds that thrive in cities, however, the greatest impact on habitat partitioning appears to result from subordinates actively shifting out of cities when dominant species occur there, consistent with plasticity in response to aggressive, dominant species. The study results suggest distinct ways to mitigate loss of biodiversity caused by urbanization. When dominant species thrive in cities, providing resources for subordinates that cannot be monopolized by the dominant (e.g., nest boxes with entrance holes too small for the dominant species to use) would help subordinates to persist. In the case of evolutionary divergence, adding distinct habitat refuges suited to subordinate species could help them colonize or persist in cities. Overall, this global study provides new insight into the importance of two distinct processes that shape patterns of diversity in an urbanizing landscape. Abstract Habitat partitioning can facilitate the coexistence of closely related species, and often results from competitive interference inducing plastic shifts of subordinate species in response to aggressive, dominant species (plasticity), or the evolution of ecological differences in subordinate species that reduce their ability to occupy habitats where the dominant species occurs (evolutionary divergence). Evidence consistent with both plasticity and evolutionary divergence exist, but the relative contributions of each to habitat partitioning have been difficult to discern. Here we use a global dataset on the breeding occurrence of birds in cities to test predictions of these alternative hypotheses to explain previously described habitat partitioning associated with competitive interference. Consistent with plasticity, the presence of behaviorally dominant congeners in a city was associated with a 65% reduction in occurrence of subordinate species, but only when the dominant was a widespread breeder in urban habitats. Consistent with evolutionary divergence, increased range-wide overlap with dominant congeners was associated with a 56% reduction in occurrence of subordinates in cities, even when the dominant was absent from the city. Overall, our results suggest that both plasticity and evolutionary divergence play important, concurrent roles in habitat partitioning among closely related species in urban environments. More forthcoming papers &raquo; <p>Paul R. Martin, Kevin W. Burke, and Frances Bonier (Jan 2021) </p> <p><b>A global study of urban birds suggests both plasticity and evolutionary divergence underlie habitat partitioning </b></p> <p><i><a href="https://dx.doi.org/10.1086/711753">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>cologically similar species often minimize competition and other costs of living together by occupying distinct habitats. The mechanisms that cause this habitat partitioning include <i>plasticity</i>, where subordinate species occupy different habitats to avoid or minimize competitive interactions with dominant species, and <i>evolutionary divergence</i>, where subordinate species evolve ecological differences from dominant species that lead them to occupy distinct habitats. </p><p>How important is plasticity versus evolutionary divergence for habitat partitioning in nature? In this study, researchers from Queen’s University in Ontario, Canada use a global dataset on urban birds to provide one of the few tests of the relative importance of plasticity versus evolutionary divergence underlying habitat partitioning. They find evidence for both. Greater habitat partitioning was associated with increased range overlap among dominant and subordinate species – a factor that is expected to increase the intensity of selection favoring evolutionary divergence. For birds that thrive in cities, however, the greatest impact on habitat partitioning appears to result from subordinates actively shifting out of cities when dominant species occur there, consistent with plasticity in response to aggressive, dominant species. </p><p>The study results suggest distinct ways to mitigate loss of biodiversity caused by urbanization. When dominant species thrive in cities, providing resources for subordinates that cannot be monopolized by the dominant (e.g., nest boxes with entrance holes too small for the dominant species to use) would help subordinates to persist. In the case of evolutionary divergence, adding distinct habitat refuges suited to subordinate species could help them colonize or persist in cities. </p><p>Overall, this global study provides new insight into the importance of two distinct processes that shape patterns of diversity in an urbanizing landscape.</p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">H</span>abitat partitioning can facilitate the coexistence of closely related species, and often results from competitive interference inducing plastic shifts of subordinate species in response to aggressive, dominant species (plasticity), or the evolution of ecological differences in subordinate species that reduce their ability to occupy habitats where the dominant species occurs (evolutionary divergence). Evidence consistent with both plasticity and evolutionary divergence exist, but the relative contributions of each to habitat partitioning have been difficult to discern. Here we use a global dataset on the breeding occurrence of birds in cities to test predictions of these alternative hypotheses to explain previously described habitat partitioning associated with competitive interference. Consistent with plasticity, the presence of behaviorally dominant congeners in a city was associated with a 65% reduction in occurrence of subordinate species, but only when the dominant was a widespread breeder in urban habitats. Consistent with evolutionary divergence, increased range-wide overlap with dominant congeners was associated with a 56% reduction in occurrence of subordinates in cities, even when the dominant was absent from the city. Overall, our results suggest that both plasticity and evolutionary divergence play important, concurrent roles in habitat partitioning among closely related species in urban environments. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 02 Oct 2020 05:00:00 GMT “Microgeography, not just latitude, drives climate overlap on mountains from tropical to polar ecosystems” https://amnat.org/an/newpapers/Jan-Klinges.html David H. Klinges and Brett R. Scheffers (Jan 2021) Revisiting Janzen 1967’s classic: we show that 🌳, ❄️, microhabitats drive 🌡️ overlap on 29 🏔️s more than latitude Read the Article (Just Accepted) Since the publication of Dan Janzen’s seminal 1967 paper, “Why mountain passes are higher in the tropics”, ecologists have pondered the role that mountains play in creating barriers to dispersal. Janzen suggested that tropical organisms, which oftentimes experience similar temperatures year-round, may have a tougher time crossing a cold mountain peak than temperate organisms, which are tolerant of a range of climates due to their cool winters and warm summers. This effectively makes tropical mountains thermally “taller” than temperate ones of similar height. Yet despite many works exploring the downstream implications of these findings, few have explored other possible drivers of mountain “thermal height” besides changes in latitude. For examples, forests shade out sunlight in the heat of the day and trap warm air at night, thereby offering more thermally stable conditions—might forested mountains be therefore taller than non-forested ones?Here, researchers at the University of Florida expand upon Janzen’s hypothesis using in-situ measurements globally, and for the first time account for many other geographic variables besides latitude that may influence how much temperature changes across mountains. Their findings suggest that mountains may be thermally “taller” for organisms that live within soils relative to those that live above the ground, as well as for forest-dwellers relative to species in open-air systems. Mountains situated at different latitudes, on the other hand, did not differ substantially in “thermal height”. Although this work does not discount Janzen’s idea that tropical mountains may act as more difficult barriers to dispersal than temperate mountains, it suggests that more emphasis should be placed on local considerations for determining dispersal. To accompany the classic gradients of latitude and altitude, the authors propose that “vertitude”—for lack of a better word to describe the change in climate from below ground, to the surface, to above any vegetation canopy—ought to be a worthy consideration for biogeography as well. Abstract An extension of the climate variability hypothesis is that relatively stable climate, such as that of the tropics, induces distinct thermal bands across elevation that render dispersal over tropical mountains difficult compared to temperate mountains. Yet, ecosystems are not thermally static in space-time, especially at small scales, which might render some mountains greater thermal isolators than others. Here, we provide an extensive investigation of temperature drivers from fine to coarse scales, and demonstrate that the degree of similarity in temperatures at high and low elevations on mountains is driven by more than just absolute mountain height and latitude. We compiled a database of 29 mountains spanning 6 continents to characterize “thermal overlap” by vertically stratified microhabitats, biomes, and owing to seasonal changes in foliage, demonstrating via mixed-effects modeling that micro- and mesogeography more strongly influence thermal overlap than macrogeography. Impressively, an increase of one meter of vertical microhabitat height generates an increase in overlap equivalent to a 5.26&deg; change in latitude. In addition, forested mountains have reduced thermal overlap – 149% lower – relative to non-forested mountains. We provide evidence in support of a climate hypothesis that emphasizes microgeography as a determinant of dispersal, demographics, and behavior, thereby refining classical theory of macroclimate variability as a prominent driver of biogeography. More forthcoming papers &raquo; <p>David H. Klinges and Brett R. Scheffers (Jan 2021) </p> <p><b>Revisiting Janzen 1967’s classic: we show that 🌳, ❄️, microhabitats drive 🌡️ overlap on 29 🏔️s more than latitude </b></p> <p><i><a href="https://dx.doi.org/10.1086/711873">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>ince the publication of Dan Janzen&rsquo;s seminal 1967 paper, &ldquo;Why mountain passes are higher in the tropics&rdquo;, ecologists have pondered the role that mountains play in creating barriers to dispersal. Janzen suggested that tropical organisms, which oftentimes experience similar temperatures year-round, may have a tougher time crossing a cold mountain peak than temperate organisms, which are tolerant of a range of climates due to their cool winters and warm summers. This effectively makes tropical mountains thermally &ldquo;taller&rdquo; than temperate ones of similar height. Yet despite many works exploring the downstream implications of these findings, few have explored other possible drivers of mountain &ldquo;thermal height&rdquo; besides changes in latitude. For examples, forests shade out sunlight in the heat of the day and trap warm air at night, thereby offering more thermally stable conditions&mdash;might forested mountains be therefore taller than non-forested ones?</p><p>Here, researchers at the University of Florida expand upon Janzen’s hypothesis using in-situ measurements globally, and for the first time account for many other geographic variables besides latitude that may influence how much temperature changes across mountains. Their findings suggest that mountains may be thermally “taller” for organisms that live within soils relative to those that live above the ground, as well as for forest-dwellers relative to species in open-air systems. Mountains situated at different latitudes, on the other hand, did not differ substantially in “thermal height”. </p><p>Although this work does not discount Janzen&rsquo;s idea that tropical mountains may act as more difficult barriers to dispersal than temperate mountains, it suggests that more emphasis should be placed on local considerations for determining dispersal. To accompany the classic gradients of latitude and altitude, the authors propose that &ldquo;vertitude&rdquo;&mdash;for lack of a better word to describe the change in climate from below ground, to the surface, to above any vegetation canopy&mdash;ought to be a worthy consideration for biogeography as well.</p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">A</span>n extension of the climate variability hypothesis is that relatively stable climate, such as that of the tropics, induces distinct thermal bands across elevation that render dispersal over tropical mountains difficult compared to temperate mountains. Yet, ecosystems are not thermally static in space-time, especially at small scales, which might render some mountains greater thermal isolators than others. Here, we provide an extensive investigation of temperature drivers from fine to coarse scales, and demonstrate that the degree of similarity in temperatures at high and low elevations on mountains is driven by more than just absolute mountain height and latitude. We compiled a database of 29 mountains spanning 6 continents to characterize &ldquo;thermal overlap&rdquo; by vertically stratified microhabitats, biomes, and owing to seasonal changes in foliage, demonstrating via mixed-effects modeling that micro- and mesogeography more strongly influence thermal overlap than macrogeography. Impressively, an increase of one meter of vertical microhabitat height generates an increase in overlap equivalent to a 5.26&deg; change in latitude. In addition, forested mountains have reduced thermal overlap &ndash; 149% lower &ndash; relative to non-forested mountains. We provide evidence in support of a climate hypothesis that emphasizes microgeography as a determinant of dispersal, demographics, and behavior, thereby refining classical theory of macroclimate variability as a prominent driver of biogeography.</p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 01 Oct 2020 05:00:00 GMT “Ecological character displacement destabilizes food webs” https://amnat.org/an/newpapers/Jan-Barbour.html Matthew A. Barbour (Jan 2021) Mathematical model shows that ecological character displacement generally destabilizes food webs Read the Article (Just Accepted) Species evolve and adapt within an ecosystem where they interact with other species. But how does evolution affect this ecosystem of interactions? Does evolution make an ecosystem more or less sensitive to sudden changes in the environment?A researcher from the University of Zurich sought to answer these questions using a mathematical model. He modeled a particular type of evolution called ecological character displacement. This type of evolution occurs when predators compete for prey and has created much of the biological diversity we see in the natural world. In one model, he created a scenario where a predator could attack two distinct types of prey without a competitor. In a second model, he pitted two predators against each other in competition. After allowing the predators to evolve, he disturbed each model ecosystem to compare how sensitive they were to a sudden change in the environment, i.e., how long it took for the ecosystem to return to normal after being disturbed. He found that the ecosystem with competition was more sensitive to a disturbance than the ecosystem without competition. This increased sensitivity was because competing predators evolved to have a bigger impact on their prey. This suggests that species in competitive ecosystems are more vulnerable to extinction if the environment were to change suddenly. This curious finding suggests that the same evolutionary process that creates biological diversity also makes diversity more vulnerable to extinction. If this is true, many ecosystems may be more fragile than we realize. Abstract Ecological character displacement is an adaptive process that generally increases phenotypic diversity. Despite the fact that this diversification is due to an eco-evolutionary feedback between consumers competing for shared resources, its consequences for food-web dynamics have received little attention. Here, I study a model of two consumers competing for two shared resources to examine how character displacement in consumer attack rates affects resource abundances and the resilience of food webs to perturbations. I found that character displacement always strengthened consumer-resource interactions whenever consumers competed for resources that occurred in different habitats. This increase in interaction strength resulted in lower resource abundances and less resilient food webs. This occurred under different evolutionary tradeoffs and in both simple and more realistic foraging scenarios. Taken together, my results show that the adaptive process of character displacement may come with the ecological cost of decreasing food-web resilience. More forthcoming papers &raquo; <p>Matthew A. Barbour (Jan 2021) </p> <p><b>Mathematical model shows that ecological character displacement generally destabilizes food webs </b></p> <p><i><a href="https://dx.doi.org/10.1086/711875">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>pecies evolve and adapt within an ecosystem where they interact with other species. But how does evolution affect this ecosystem of interactions? Does evolution make an ecosystem more or less sensitive to sudden changes in the environment?</p><p>A researcher from the University of Zurich sought to answer these questions using a mathematical model. He modeled a particular type of evolution called ecological character displacement. This type of evolution occurs when predators compete for prey and has created much of the biological diversity we see in the natural world. </p> <p>In one model, he created a scenario where a predator could attack two distinct types of prey without a competitor. In a second model, he pitted two predators against each other in competition. After allowing the predators to evolve, he disturbed each model ecosystem to compare how sensitive they were to a sudden change in the environment, i.e., how long it took for the ecosystem to return to normal after being disturbed. </p><p>He found that the ecosystem with competition was more sensitive to a disturbance than the ecosystem without competition. This increased sensitivity was because competing predators evolved to have a bigger impact on their prey. This suggests that species in competitive ecosystems are more vulnerable to extinction if the environment were to change suddenly. </p> <p>This curious finding suggests that the same evolutionary process that creates biological diversity also makes diversity more vulnerable to extinction. If this is true, many ecosystems may be more fragile than we realize. </p> <hr /><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>cological character displacement is an adaptive process that generally increases phenotypic diversity. Despite the fact that this diversification is due to an eco-evolutionary feedback between consumers competing for shared resources, its consequences for food-web dynamics have received little attention. Here, I study a model of two consumers competing for two shared resources to examine how character displacement in consumer attack rates affects resource abundances and the resilience of food webs to perturbations. I found that character displacement always strengthened consumer-resource interactions whenever consumers competed for resources that occurred in different habitats. This increase in interaction strength resulted in lower resource abundances and less resilient food webs. This occurred under different evolutionary tradeoffs and in both simple and more realistic foraging scenarios. Taken together, my results show that the adaptive process of character displacement may come with the ecological cost of decreasing food-web resilience. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 01 Oct 2020 05:00:00 GMT “Emigrating together but not establishing together: A cockroach rides ants and leaves” https://amnat.org/an/newpapers/Jan-Phillips.html Zachary I. Phillips (Jan 2021) A miniature cockroach hitchhikes twice on its journey between host ant colonies, bypassing vulnerable young colonies Read the Article (Just Accepted)Each spring after the rains arrive in Texas, cockroaches mount winged ants at daybreak and ride them across the sky. Where are the cockroaches going? The author, bless his heart, once thought this would be a straightforward question to address in his dissertation. Attaphila fungicola, a miniature cockroach that lives with leaf-cutter ant colonies and their mutualist fungal gardens, hitchhikes on female alates (winged queens) during colony nuptial flights. The roach’s only available host in the region is the Texas leaf-cutter ant (Atta texana), and hitchhiking on female alates suggests that the roach is vertically transmitted from leaf-cutter parent colony to daughter colony, remaining with female alates as they transition into queens founding new nests; however, leaf-cutter queens initiating colonies have few resources and extremely high mortality rates. As a consequence, vertical transmission could tether roaches to vulnerable hosts likely to die.Drawing from principles of disease ecology, the author proposes that roaches have evolved an alternative mode of horizontal transmission: Instead of remaining with new queens, roaches use female alates as dispersal agents to reach already established colonies. In its general form, this mode of transmission might be used by a variety of symbionts (parasites, mutualists and commensals) to co-disperse with host propagules and, following dispersal, to avoid infecting low quality early stages of host development. To test this hypothesis, the author conducted behavioral assays in the field. The results indicate that roaches abandon female alates after nuptial flights, bypass early stages of colony development, and can use a sequence of two hitchhiking steps to disperse between established colonies. First, the roaches can ride female alates to emigrate from upstream host colonies, and second, the roaches can ride leaves carried by foragers to infect downstream host colonies. Abstract Symbionts of ant colonies can hitchhike on winged ant reproductives (alates) during colony nuptial flights. Attaphila fungicola Wheeler, a miniature cockroach that lives in the nests of Texas leaf-cutter ants (Atta texana Buckley), hitchhikes on female alates (winged queens). Hitchhiking roaches are presumably vertically transmitted from leaf-cutter parent colony to daughter colony, remaining with female alates as they transition into foundresses (workerless queens); however, foundresses have limited resources and high mortality rates. Rather than remaining with foundresses likely to die (vertical transmission), roaches might abandon them during dispersal to infect higher quality later stages of colony development (female alate-vectored transmission). In field experiments, I find evidence for female alate-vectored transmission, and discover roaches use a second hitchhiking step, riding foraged plant material, to infect established colonies. This work reveals a novel relationship between host dispersal and symbiont transmission, and shows colony development can be an important selection pressure on transmission. More forthcoming papers &raquo; <p>Zachary I. Phillips (Jan 2021)</p> <p><b>A miniature cockroach hitchhikes twice on its journey between host ant colonies, bypassing vulnerable young colonies </b></p> <p><i><a href="https://dx.doi.org/10.1086/711876">Read the Article</a></i> (Just Accepted)</p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>ach spring after the rains arrive in Texas, cockroaches mount winged ants at daybreak and ride them across the sky. Where are the cockroaches going? The author, bless his heart, once thought this would be a straightforward question to address in his dissertation.</p> <p><i>Attaphila fungicola</i>, a miniature cockroach that lives with leaf-cutter ant colonies and their mutualist fungal gardens, hitchhikes on female alates (winged queens) during colony nuptial flights. The roach&rsquo;s only available host in the region is the Texas leaf-cutter ant (<i>Atta texana</i>), and hitchhiking on female alates suggests that the roach is vertically transmitted from leaf-cutter parent colony to daughter colony, remaining with female alates as they transition into queens founding new nests; however, leaf-cutter queens initiating colonies have few resources and extremely high mortality rates. As a consequence, vertical transmission could tether roaches to vulnerable hosts likely to die.</p><p>Drawing from principles of disease ecology, the author proposes that roaches have evolved an alternative mode of horizontal transmission: Instead of remaining with new queens, roaches use female alates as dispersal agents to reach already established colonies. In its general form, this mode of transmission might be used by a variety of symbionts (parasites, mutualists and commensals) to co-disperse with host propagules and, following dispersal, to avoid infecting low quality early stages of host development. </p><p>To test this hypothesis, the author conducted behavioral assays in the field. The results indicate that roaches abandon female alates after nuptial flights, bypass early stages of colony development, and can use a sequence of two hitchhiking steps to disperse between established colonies. First, the roaches can ride female alates to emigrate from upstream host colonies, and second, the roaches can ride leaves carried by foragers to infect downstream host colonies. </p> <hr /><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>ymbionts of ant colonies can hitchhike on winged ant reproductives (alates) during colony nuptial flights. <i>Attaphila fungicola</i> Wheeler, a miniature cockroach that lives in the nests of Texas leaf-cutter ants (<i>Atta texana</i> Buckley), hitchhikes on female alates (winged queens). Hitchhiking roaches are presumably vertically transmitted from leaf-cutter parent colony to daughter colony, remaining with female alates as they transition into foundresses (workerless queens); however, foundresses have limited resources and high mortality rates. Rather than remaining with foundresses likely to die (vertical transmission), roaches might abandon them during dispersal to infect higher quality later stages of colony development (female alate-vectored transmission). In field experiments, I find evidence for female alate-vectored transmission, and discover roaches use a second hitchhiking step, riding foraged plant material, to infect established colonies. This work reveals a novel relationship between host dispersal and symbiont transmission, and shows colony development can be an important selection pressure on transmission. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 01 Oct 2020 05:00:00 GMT “Density-dependent adaptive topography in a small passerine bird, the collared flycatcher” https://amnat.org/an/newpapers/Jan-Saether-A.html Bernt-Erik S&aelig;ther, Steinar Engen, Lars Gustafsson, Vidar Gr&oslash;tan, and Stefan J. G. Vriend (Jan 2021) This study shows that density-dependent selection affects evolution of reproductive strategies in collared flycatchers Read the Article (Just Accepted)Abstract The adaptive topography is a central concept in evolutionary biology, describing how the mean fitness of the population changes with gene frequencies or mean phenotypes. We use expected population size as quantity to be maximized by natural selection to show that selection on pairwise combinations of reproductive traits of collared flycatchers caused by fluctuations in population size generated an adaptive topography with distinct peaks often located at intermediate phenotypes. This occurred because r- and K-selection made phenotypes favored at small densities different from those with higher fitness at population sizes close to the carrying capacity K. The fitness decreased rapidly with a delay in the timing of egg-laying with a density-dependent effect especially occurring among early-laying females. The number of fledglings maximizing fitness was larger at small population sizes than close to K. Finally, there was directional selection for large fledglings independent of population size. We suggest that these patterns can be explained by increased competition for some limiting resources or access to favorable nest sites at high population densities. Thus, r- and K-selection based on expected population size as evolutionary maximization criterion may influence life history evolution and constrain the selective responses to changes in the environment. More forthcoming papers &raquo; <p>Bernt-Erik S&aelig;ther, Steinar Engen, Lars Gustafsson, Vidar Gr&oslash;tan, and Stefan J. G. Vriend (Jan 2021)</p> <p><b>This study shows that density-dependent selection affects evolution of reproductive strategies in collared flycatchers </b></p> <p><i><a href="https://dx.doi.org/10.1086/711752">Read the Article</a></i> (Just Accepted)</p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">T</span>he adaptive topography is a central concept in evolutionary biology, describing how the mean fitness of the population changes with gene frequencies or mean phenotypes. We use expected population size as quantity to be maximized by natural selection to show that selection on pairwise combinations of reproductive traits of collared flycatchers caused by fluctuations in population size generated an adaptive topography with distinct peaks often located at intermediate phenotypes. This occurred because <i>r</i>- and <i>K</i>-selection made phenotypes favored at small densities different from those with higher fitness at population sizes close to the carrying capacity <i>K</i>. The fitness decreased rapidly with a delay in the timing of egg-laying with a density-dependent effect especially occurring among early-laying females. The number of fledglings maximizing fitness was larger at small population sizes than close to <i>K</i>. Finally, there was directional selection for large fledglings independent of population size. We suggest that these patterns can be explained by increased competition for some limiting resources or access to favorable nest sites at high population densities. Thus, <i>r</i>- and <i>K</i>-selection based on expected population size as evolutionary maximization criterion may influence life history evolution and constrain the selective responses to changes in the environment. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 01 Oct 2020 05:00:00 GMT “Observed ecological communities are formed by species combinations that are among the most likely to persist under changing environments” https://amnat.org/an/newpapers/Jan-Medeiros-A.html Lucas P. Medeiros, Karina Boege, Ek del-Val, Alejandro Zaldivar-Riverón, and Serguei Saavedra (Jan 2021) Observed ecological communities are not all equally likely to be seen, rather they are among the most likely to persist Read the Article (Just Accepted) Abstract Despite the rich biodiversity found in nature, it is unclear the extent to which some combinations of interacting species while conceivable in a given place and time may never be realized. Yet, solving this problem is important in order to understand the role of randomness and predictability in the assembly of ecological communities. Here, we show that the specific combinations of interacting species that emerge from the ecological dynamics within regional species pools are not all equally likely to be seen, rather they are among the most likely to persist under changing environments. First, we use niche-based competition matrices and Lotka-Volterra models to demonstrate that realized combinations of interacting species are more likely to persist under random parameter perturbations than the majority of potential combinations with the same number of species that could have been formed from the regional pool. We then corroborate our theoretical results using a 10-year observational study recording 88 plant-herbivore communities across three different forest successional stages. By inferring and validating plant-mediated communities of competing herbivore species, we find that observed combinations of herbivores have an expected probability of species persistence higher than half of all potential combinations. Our findings open up the opportunity to establish a formal probabilistic and predictive understanding of the composition of ecological communities. More forthcoming papers &raquo; <p>Lucas P. Medeiros, Karina Boege, Ek del-Val, Alejandro Zaldivar-Riverón, and Serguei Saavedra (Jan 2021) </p> <p><b>Observed ecological communities are not all equally likely to be seen, rather they are among the most likely to persist </b></p> <p><i><a href="https://dx.doi.org/10.1086/711663">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">D</span>espite the rich biodiversity found in nature, it is unclear the extent to which some combinations of interacting species while conceivable in a given place and time may never be realized. Yet, solving this problem is important in order to understand the role of randomness and predictability in the assembly of ecological communities. Here, we show that the specific combinations of interacting species that emerge from the ecological dynamics within regional species pools are not all equally likely to be seen, rather they are among the most likely to persist under changing environments. First, we use niche-based competition matrices and Lotka-Volterra models to demonstrate that realized combinations of interacting species are more likely to persist under random parameter perturbations than the majority of potential combinations with the same number of species that could have been formed from the regional pool. We then corroborate our theoretical results using a 10-year observational study recording 88 plant-herbivore communities across three different forest successional stages. By inferring and validating plant-mediated communities of competing herbivore species, we find that observed combinations of herbivores have an expected probability of species persistence higher than half of all potential combinations. Our findings open up the opportunity to establish a formal probabilistic and predictive understanding of the composition of ecological communities. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Wed, 30 Sep 2020 05:00:00 GMT “Environmental change, if unaccounted, prevents detection of cryptic evolution in a wild population” https://amnat.org/an/newpapers/Jan-Potter-A.html Tomos Potter, Ronald D. Bassar, Paul Bentzen, Emily W. Ruell, Julián Torres-Dowdall, Corey A. Handelsman, Cameron K. Ghalambor, Joseph Travis, David N. Reznick, and Tim Coulson (Jan 2021) Increased population density drives evolution in wild guppies, but also confounds estimation of genetic change Read the Article (Just Accepted) Abstract Detecting contemporary evolution requires demonstrating that genetic change has occurred. Mixed-effects models allow estimation of quantitative genetic parameters and are widely used to study evolution in wild populations. However, predictions of evolution based on these parameters frequently fail to match observations. Here, we applied three commonly used quantitative genetic approaches to predict the evolution of size at maturity in a wild population of Trinidadian guppies. Crucially, we tested our predictions against evolutionary change observed in common garden experiments performed on samples from the same population. We show that standard quantitative genetic models underestimated or failed to detect the cryptic evolution of this trait as demonstrated by the common garden experiments. The models failed because: 1) size at maturity and fitness both decreased with increases in population density, 2) offspring experienced higher population densities than their parents, and 3) selection on size was strongest at high densities. When we accounted for environmental change, predictions better matched observations in the common garden experiments, although substantial uncertainty remained. Our results demonstrate that predictions of evolution are unreliable if environmental change is not appropriately captured in models. More forthcoming papers &raquo; <p>Tomos Potter, Ronald D. Bassar, Paul Bentzen, Emily W. Ruell, Julián Torres-Dowdall, Corey A. Handelsman, Cameron K. Ghalambor, Joseph Travis, David N. Reznick, and Tim Coulson (Jan 2021) </p> <p><b>Increased population density drives evolution in wild guppies, but also confounds estimation of genetic change </b></p> <p><i><a href="https://dx.doi.org/10.1086/711874">Read the Article</a></i> (Just Accepted) </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">D</span>etecting contemporary evolution requires demonstrating that genetic change has occurred. Mixed-effects models allow estimation of quantitative genetic parameters and are widely used to study evolution in wild populations. However, predictions of evolution based on these parameters frequently fail to match observations. Here, we applied three commonly used quantitative genetic approaches to predict the evolution of size at maturity in a wild population of Trinidadian guppies. Crucially, we tested our predictions against evolutionary change observed in common garden experiments performed on samples from the same population. We show that standard quantitative genetic models underestimated or failed to detect the cryptic evolution of this trait as demonstrated by the common garden experiments. The models failed because: 1) size at maturity and fitness both decreased with increases in population density, 2) offspring experienced higher population densities than their parents, and 3) selection on size was strongest at high densities. When we accounted for environmental change, predictions better matched observations in the common garden experiments, although substantial uncertainty remained. Our results demonstrate that predictions of evolution are unreliable if environmental change is not appropriately captured in models. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Wed, 30 Sep 2020 05:00:00 GMT “Trends and transitions in 150 years of <i>The American Naturalist</i>” https://amnat.org/an/newpapers/Dec-Smocovitis-A.html Vassiliki B. Smocovitis, Daniel I. Bolnick, Christopher M. Moore, and Patricia L. Morse (Dec 2020) Read the Article&nbsp;Abstract The American Naturalist recently passed its sesquicentennial. Throughout this long history, it regularly encountered moments of introspection and debate over its goals, mission, identity and audience. Here, we chronicle the history of those debates and transitions at critical moments. The Naturalist began as a popular magazine for amateur naturalists in the late 1860s. In the late 1870s it transitioned to an increasingly academic journal for professional scientists, from all branches of the natural sciences. By the turn of the century, academic specialization led to increasing fragmentation of the sciences into a multitude of societies and journals, creating an identity crisis for the once broad-reaching American Naturalist. This identity crisis was resolved when the journal pivoted around 1910 to focus on fundamental advances in the newly emerging field of genetics. In the 1960s the journal underwent a remarkably rapid transition to its present focus on evolution and ecology. The profound shifts in the journal’s contents over this time are a reflection of the historical changes in science as a whole: from amateur naturalists, to polymath professionals, to increasingly specialized academics. This chronicle reveals the ways in which The American Naturalist has left its mark on many disciplines, many of which are today only loosely affiliated with the journal, if at all. More forthcoming papers &raquo; <p>Vassiliki B. Smocovitis, Daniel I. Bolnick, Christopher M. Moore, and Patricia L. Morse (Dec 2020)</p> <p><i><a href="https://dx.doi.org/10.1086/711418">Read the Article</a></i>&nbsp;</p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">T</span><i>he American Naturalist</i> recently passed its sesquicentennial. Throughout this long history, it regularly encountered moments of introspection and debate over its goals, mission, identity and audience. Here, we chronicle the history of those debates and transitions at critical moments. The <i>Naturalist</i> began as a popular magazine for amateur naturalists in the late 1860s. In the late 1870s it transitioned to an increasingly academic journal for professional scientists, from all branches of the natural sciences. By the turn of the century, academic specialization led to increasing fragmentation of the sciences into a multitude of societies and journals, creating an identity crisis for the once broad-reaching <i>American Naturalist</i>. This identity crisis was resolved when the journal pivoted around 1910 to focus on fundamental advances in the newly emerging field of genetics. In the 1960s the journal underwent a remarkably rapid transition to its present focus on evolution and ecology. The profound shifts in the journal’s contents over this time are a reflection of the historical changes in science as a whole: from amateur naturalists, to polymath professionals, to increasingly specialized academics. This chronicle reveals the ways in which <i>The American Naturalist</i> has left its mark on many disciplines, many of which are today only loosely affiliated with the journal, if at all. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Wed, 30 Sep 2020 05:00:00 GMT “Evolved phenological cueing strategies show variable responses to climate change” https://amnat.org/an/newpapers/Jan-Edwards.html Collin B. Edwards and Louie H. Yang (Jan 2021) A model simulating the evolution of phenological cueing strategies with climate data shows variable phenological shifts Read the Article (Just Accepted) As the climate changes, plants and animals are shifting the timing of their activities (“phenology”): many butterflies are now active earlier in the spring, for example, and many plants now flower weeks earlier than they used to. However, these changes are not always consistent: different species may shift their phenology very differently. In a study appearing in The&nbsp;American Naturalist, Dr. Collin Edwards (graduate student at Cornell University, now a postdoctoral researcher at Tufts University) and Dr. Louie Yang (associate professor at University of California, Davis) demonstrate how the evolution of cue use could produce these variable responses to climate change. They present a simulation study in which organisms can evolve to start their life activity (e.g. a plant can germinate or an insect can emerge) based on a combination of three environmental cues – the local temperature, the local precipitation, and the day of the year (photoperiod). By simulating populations of these organisms using real climate data from 78 locations across North America and Hawaii, the authors demonstrate two mechanisms that could lead to the variability seen in real species. First, they found that simulated species evolved to respond to different environmental cues in the different climates across North America, and the best strategy depended on how reliably different combinations of cues predicted favorable weather in the future. For example, simulated populations in Farmington, Maine generally relied on precipitation as a cue, while simulation populations in Davis, California did not. Surprisingly, they also find that for any given climate, there are often multiple strategies that are equally viable but rely on very different cues. For example, some populations simulated in the Davis climate relied almost entirely on temperature as a cue, while others relied almost entirely on day of year. When populations differed in strategy – either because they evolved in different climates or because they evolved different strategies in the same climate – they responded differently to simulated climate change, just as real species are responding differently. This study reveals a novel mechanism driving the evolution of phenological strategies, and suggests that as the climate continues to change, we should expect to see increasing variation between species in the timing of activities like germination, hatching, flowering, and mating. Abstract Several studies have documented a global pattern of phenological advancement that is consistent with ongoing climate change. However, the magnitude of these phenological shifts is highly variable across taxa and locations. This variability of phenological responses has been difficult to explain mechanistically. To examine how the evolution of multi-trait cueing strategies could produce variable responses to climate change, we constructed a model in which organisms evolve strategies that integrate multiple environmental cues to inform anticipatory phenological decisions. We simulated the evolution of phenological cueing strategies in multiple environments, using historic climate data from 78 locations in North America and Hawaii to capture features of climatic correlation structures in the real world. Organisms in our model evolved diverse strategies that were spatially autocorrelated across locations on a continental scale, showing that similar strategies tend to evolve in similar climates. Within locations, organisms often evolved a wide range of strategies that showed similar response phenotypes and fitness outcomes under historical conditions. However, these strategies responded differently to novel climatic conditions, with variable fitness consequences. Our model shows how the evolution of phenological cueing strategies can explain observed variation in phenological shifts and unexpected responses to climate change. More forthcoming papers &raquo; <p>Collin B. Edwards and Louie H. Yang (Jan 2021) </p> <p><b>A model simulating the evolution of phenological cueing strategies with climate data shows variable phenological shifts </b></p> <p><i><a href="https://dx.doi.org/10.1086/711650">Read the Article</a></i> (Just Accepted) </p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">A</span>s the climate changes, plants and animals are shifting the timing of their activities (“phenology”): many butterflies are now active earlier in the spring, for example, and many plants now flower weeks earlier than they used to. However, these changes are not always consistent: different species may shift their phenology very differently. In a study appearing in <i>The&nbsp;American Naturalist</i>, Dr. Collin Edwards (graduate student at Cornell University, now a postdoctoral researcher at Tufts University) and Dr. Louie Yang (associate professor at University of California, Davis) demonstrate how the evolution of cue use could produce these variable responses to climate change. They present a simulation study in which organisms can evolve to start their life activity (e.g. a plant can germinate or an insect can emerge) based on a combination of three environmental cues – the local temperature, the local precipitation, and the day of the year (photoperiod). By simulating populations of these organisms using real climate data from 78 locations across North America and Hawaii, the authors demonstrate two mechanisms that could lead to the variability seen in real species. First, they found that simulated species evolved to respond to different environmental cues in the different climates across North America, and the best strategy depended on how reliably different combinations of cues predicted favorable weather in the future. For example, simulated populations in Farmington, Maine generally relied on precipitation as a cue, while simulation populations in Davis, California did not. Surprisingly, they also find that for any given climate, there are often multiple strategies that are equally viable but rely on very different cues. For example, some populations simulated in the Davis climate relied almost entirely on temperature as a cue, while others relied almost entirely on day of year. When populations differed in strategy – either because they evolved in different climates or because they evolved different strategies in the same climate – they responded differently to simulated climate change, just as real species are responding differently. This study reveals a novel mechanism driving the evolution of phenological strategies, and suggests that as the climate continues to change, we should expect to see increasing variation between species in the timing of activities like germination, hatching, flowering, and mating. </p> <hr /> <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>everal studies have documented a global pattern of phenological advancement that is consistent with ongoing climate change. However, the magnitude of these phenological shifts is highly variable across taxa and locations. This variability of phenological responses has been difficult to explain mechanistically. To examine how the evolution of multi-trait cueing strategies could produce variable responses to climate change, we constructed a model in which organisms evolve strategies that integrate multiple environmental cues to inform anticipatory phenological decisions. We simulated the evolution of phenological cueing strategies in multiple environments, using historic climate data from 78 locations in North America and Hawaii to capture features of climatic correlation structures in the real world. Organisms in our model evolved diverse strategies that were spatially autocorrelated across locations on a continental scale, showing that similar strategies tend to evolve in similar climates. Within locations, organisms often evolved a wide range of strategies that showed similar response phenotypes and fitness outcomes under historical conditions. However, these strategies responded differently to novel climatic conditions, with variable fitness consequences. Our model shows how the evolution of phenological cueing strategies can explain observed variation in phenological shifts and unexpected responses to climate change. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 18 Sep 2020 05:00:00 GMT “Daily nest predation rates decrease with body size in passerine birds” https://amnat.org/an/newpapers/Dec-Unzeta-A.html Mar Unzeta, Thomas E. Martin, and Daniel Sol (Dec 2020) Lower daily nest predation in larger passerine birds reduces total predation compensating their extended development Read the Article Abstract Body size evolution is generally framed by the benefits of being large, while costs are largely overlooked. An important putative cost of being large is the need to extend development periods, which should increase exposure to predation and potentially select against larger size. In birds, this selection pressure can be important because predation is the main source of offspring mortality and predators should more readily detect the larger nests associated with larger body sizes. Here, we show for diverse passerine birds across the world that, counter to expectations, larger species suffer lower daily nest predation rates than smaller species. This pattern is consistent despite latitudinal variation in predation and does not seem to reflect a tendency of larger species to use more protected nests or less exposed nest locations. Evidence instead suggests that larger species attack a wider array of predator sizes, which could reduce predation rates at nests of large-bodied species. Regardless of the mechanism, the lower daily nest predation rates of larger species yield slightly lower predation rates over the entire development period compared to smaller species. These results highlight the importance of behavior as a mechanism to alter selection pressures, and have implications for body size evolution. More forthcoming papers &raquo; <p>Mar Unzeta, Thomas E. Martin, and Daniel Sol (Dec 2020)</p> <p><b>Lower daily nest predation in larger passerine birds reduces total predation compensating their extended development </b></p> <p><i><a href="https://dx.doi.org/10.1086/711413">Read the Article</a></i> </p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">B</span>ody size evolution is generally framed by the benefits of being large, while costs are largely overlooked. An important putative cost of being large is the need to extend development periods, which should increase exposure to predation and potentially select against larger size. In birds, this selection pressure can be important because predation is the main source of offspring mortality and predators should more readily detect the larger nests associated with larger body sizes. Here, we show for diverse passerine birds across the world that, counter to expectations, larger species suffer lower daily nest predation rates than smaller species. This pattern is consistent despite latitudinal variation in predation and does not seem to reflect a tendency of larger species to use more protected nests or less exposed nest locations. Evidence instead suggests that larger species attack a wider array of predator sizes, which could reduce predation rates at nests of large-bodied species. Regardless of the mechanism, the lower daily nest predation rates of larger species yield slightly lower predation rates over the entire development period compared to smaller species. These results highlight the importance of behavior as a mechanism to alter selection pressures, and have implications for body size evolution. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 18 Sep 2020 05:00:00 GMT “Did mammals bring the first mistletoes into the tree-tops?” https://amnat.org/an/newpapers/Dec-Watson-A.html David M. Watson (Dec 2020) Mistletoes are the quintessential bird-dispersed plants, but ancient mammals may have first brought them to the treetops Read the Article&nbsp;Abstract As the only woody parasitic plants that infect host canopies, the growth habit of mistletoes represents a key innovation. How this aerially-parasitic habit originated is unknown—mistletoe macrofossils are relatively recent, from long after they adapted to canopy life and evolved showy bird-pollinated flowers, sticky bird-dispersed seeds and woody haustoria diverting water and nutrients from host branches. Since the transition to aerial parasitism predates the origin of their contemporary avian seed dispersers by 20–30 million years, this begs the question—who were the original mistletoe dispersers? By integrating fully resolved phylogenies of mistletoes and aligning the timing of historic events, I identify two ancient mammals as likely candidates for ‘planting’ the Viscaceae and Loranthaceae in the canopy. Just as modern mouse lemurs and galagos disperse Viscaceous mistletoe externally (grooming the sticky seeds from their fur), Cretaceous primates (such as Purgatorius) may have transported seeds of root-parasitic understory shrubs up into the canopy of Laurasian forests. In the Eocene, ancestors of the today’s mistletoe-dispersing marsupials Dromiciops likely fed on the nutritious fruit of root-parasitic Loranthaceous shrubs, depositing them atop western Gondwanan forest crowns. Having colonized the canopy, subsequent mistletoe evolution and diversification coincided with the rise of nectar and fruit-dependent birds. More forthcoming papers &raquo; <p>David M. Watson (Dec 2020)</p> <p><b>Mistletoes are the quintessential bird-dispersed plants, but ancient mammals may have first brought them to the treetops </b></p> <p><i><a href="https://dx.doi.org/10.1086/711396">Read the Article</a></i>&nbsp;</p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">A</span>s the only woody parasitic plants that infect host canopies, the growth habit of mistletoes represents a key innovation. How this aerially-parasitic habit originated is unknown—mistletoe macrofossils are relatively recent, from long after they adapted to canopy life and evolved showy bird-pollinated flowers, sticky bird-dispersed seeds and woody haustoria diverting water and nutrients from host branches. Since the transition to aerial parasitism predates the origin of their contemporary avian seed dispersers by 20–30 million years, this begs the question—who were the original mistletoe dispersers? By integrating fully resolved phylogenies of mistletoes and aligning the timing of historic events, I identify two ancient mammals as likely candidates for ‘planting’ the Viscaceae and Loranthaceae in the canopy. Just as modern mouse lemurs and galagos disperse Viscaceous mistletoe externally (grooming the sticky seeds from their fur), Cretaceous primates (such as <i>Purgatorius</i>) may have transported seeds of root-parasitic understory shrubs up into the canopy of Laurasian forests. In the Eocene, ancestors of the today’s mistletoe-dispersing marsupials <i>Dromiciops</i> likely fed on the nutritious fruit of root-parasitic Loranthaceous shrubs, depositing them atop western Gondwanan forest crowns. Having colonized the canopy, subsequent mistletoe evolution and diversification coincided with the rise of nectar and fruit-dependent birds. </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 18 Sep 2020 05:00:00 GMT