All behaviors of an organism are rooted in sensory processing of signals from its environment, and nat ural selection shapes sensory adaptations to ensure successful detection of cues that maximize fitness. Sensory dr...All behaviors of an organism are rooted in sensory processing of signals from its environment, and nat ural selection shapes sensory adaptations to ensure successful detection of cues that maximize fitness. Sensory drive, or divergent selection for efficient signal transmission among heterogeneous environ ments, has been a useful hypothesis for describing sensory adaptations, but its current scope has pri marily focused on visual and acoustic sensory modalities. Chemosensation, the most widespread sensory modality in animals that includes the senses of smell and taste, is characterized by rapid evolu tion and has been linked to sensory adaptations to new environments in numerous lineages. Yet, olfac tion and gustation have been largely underappreciated in light of the sensory drive hypothesis. Here, we examine why chemosensory systems have been overlooked and discuss the potential of chemo sensation to shed new insight on the sensory drive hypothesis and vice versa. We provide suggestions for developing a framework to better incorporate studies of chemosensory adaptation that have the po tential to shape a more complete, coherent, and holistic interpretation of the sensory drive.展开更多
Morphological analyses are critical to quantify phenotypic variation,identify taxa,inform phylogenetic relationships,and shed light on evolutionary patterns.This work is particularly important in groups that display g...Morphological analyses are critical to quantify phenotypic variation,identify taxa,inform phylogenetic relationships,and shed light on evolutionary patterns.This work is particularly important in groups that display great morphological disparity.Such is the case in geomyoid rodents,a group that includes 2 of the most species-rich families of rodents in North America:the Geomyidae(pocket gophers)and the Heteromyidae(kangaroo rats,pocket mice,and their relatives).We assessed variation in skull morphology(including both shape and size)among geomyoids to test the hypothesis that there are statistically significant differences in skull measurements at the family,genus,and species levels.Our sample includes 886 specimens representing all geomyoid genera and 39 species.We used the geometric mean to compare size across taxa.We used 14 measurements of the cranium and lower jaw normalized for size to compare shape among and within taxa.Our results show that skull measurements enable the distinction of geomyoids at the family,genus,and species levels.There is a larger amount of size variation within Geomyidae than within Heteromyidae.Our phylomorphospace analysis shows that the skull shape of the common ancestor of all geomyoids was more similar to the common ancestor of heteromyids than that of geomyids.Geomyid skulls display negative allometry whereas heteromyid skulls display positive allometry.Within heteromyids,dipodomyines,and non-dipodomyines show significantly different allometric patterns.Future analyses including fossils will be necessary to test our evolutionary hypotheses.展开更多
Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of ...Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of behavior in the invasive potential of animals is less studied.The common coqui frog,Eleutherodactylus coqui,is a highly successful invader in Hawai'i.We build on previous research characterizing changes in physiology and morphology to explore behavioral variation across the invasive range of coqui in Hawai'i.Coqui have expanded both outward and upward from their initial introduction site,andby comparing frogs from different densities and elevations-we specifically asked how the physiological challenges of high-elevation living interact with the competitive challenge of high-densities at population centers.To investigate whether differences in the field represent local adaptation or behavioral plasticity,we additionally evaluated behavior following acclimation to a shared laboratory environment.Although we identified only subtle behavioral variation among populations in the field,we found that individuals from all populations became less bold,active,and exploratory in the laboratory,converging on a similar behavioral phenotype.Alongside previous work,our results suggest that coqui adjust their behavior to local environmental conditions across their invasive range and that behavioral flexibility may contribute to invasive success.展开更多
DNA-based approaches to systematics have changed dramatically during the last two decades with the rise of DNA barcoding methods and newer multi-locus methods for species delimitation. During the last half-decade, par...DNA-based approaches to systematics have changed dramatically during the last two decades with the rise of DNA barcoding methods and newer multi-locus methods for species delimitation. During the last half-decade, partly driven by the new sequencing technologies, the focus has shifted to multi-locus sequence data and the identification of species within the frame-work of the multi-species coalescent （MSC）. In this paper, I discuss model-based Bayesian methods for species delimitation that have been developed in recent years using the MSC. Several approximate methods for species delimitation （and their limitations） are also discussed. Explicit species delimitation models have the advantage of clarifying more precisely what is being delimited and what assumptions we are making in doing so. Moreover, the methods can be very powerful when applied to large multi-locus datasets and thus take full advantage of data generated using today＇s technologies [Current Zoology 61 （5）： 846-853,2015].展开更多
Our understanding of eukaryote biology is dominated by the study of land plants, animals and fungi. However, these are only three isolated fragments of the full diversity of extant eukaryotes. The majority of eu-karyo...Our understanding of eukaryote biology is dominated by the study of land plants, animals and fungi. However, these are only three isolated fragments of the full diversity of extant eukaryotes. The majority of eu-karyotes, in terms of major taxa and probably also sheer numbers of cells, consists of exclusively or predomi-nantly unicellular lineages. A surprising number of these lineages are poorly characterized. Nonetheless, they are fundamental to our understanding of eukaryote biology and the underlying forces that shaped it. This article consists of an overview of the current state of our understanding of the eukaryote tree. This includes the identity of the major groups of eukaryotes, some of their important, defining or simply interesting features and the pro-posed relationships of these groups to each other.展开更多
Economists study negotiation as a series of events--partner choice, information gathering, bargaining, etc.--with each step of the process affecting the outcome of the next, and the optimal decision at each stage depe...Economists study negotiation as a series of events--partner choice, information gathering, bargaining, etc.--with each step of the process affecting the outcome of the next, and the optimal decision at each stage depending on the player＇s bargaining power. The context in which these negotiations occur--the market--is critical, since players can adjust their behaviors in response to outside offers. Animals similarly are faced with sequential decisions regarding courtship： who to court, how to approach a potential mate, at what level to display, when to give up, etc. Thus economic models of negotiation in a market provide a framework in which we can view not just the outcome of courtship （assortative mating）, but also the process, where each sex can use tactics to improve their negotiating outcome, using the assets that they have available. Here we propose to use negotiation as a conceptual framework to explore the factors promoting tactical adjustments during sequential stages of courtship in lekking species. Our goal is to discuss the utility of negotiation as a heuristic tool, as well as the promise and peril of co-opting game theoretic models from economics to understand animal interactions. We will provide a brief overview of a few areas where we see promise for using negotiation as a framework to understand animal courtship dynamics： choice of a display territory, tactical partner choice for negotiation, approaching a potential partner and courtship haggling .展开更多
Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each ot...Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms medi- ate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviati- lis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis that won competitions were more aggressive than C, variegatus winners, and more aggression was needed to win against competitor C. variagatus than allopatric C. rubrofluviatilis. Duration of fights also differed based on the relatedness of the competitor. In dichotomous mate choice trials, there were no conspecific or heterospecific preferences expressed by females of either species. Our findings that male-male aggression differs between closely and distantly related groups, but female choice does not suggest that male-male competition may be the more likely mechanism to impede gene flow in this system.展开更多
Conflict is an in here nt part of social life in group-living species. Group members may mediate conflict through submissive and affiliative behaviors, which can reduce aggression, stabilize dominance hierarchies, and...Conflict is an in here nt part of social life in group-living species. Group members may mediate conflict through submissive and affiliative behaviors, which can reduce aggression, stabilize dominance hierarchies, and foster group cohesion. The frequency and resolution of within-group conflict may vary with the presenee of neighboring groups. Neighbors can threaten the territory or resources of the whole group, promoting behaviors that foster within-group cohesion. However, neighbors may also foster conflict of interests among group members: opportunities for subordinate dispersal may alter conflict among dominants and subordinates while opportunities for extrapair reproduction may increase conflict between mates. To understand how neighbors mediate within-group conflict in the cooperatively breeding fish Neolamprologus pulcher, we measured behavioral dynamics and social network structure in isolated groups, groups recently exposed to neighbors, and groups with established neighbors. Aggression and submission between the dominant male and female pair were high in isolated groups, but dominant aggression was directly primarily at subordinates when groups had neighbors. This suggests that neighbors attenuate conflict between mates and foster conflict between dominants and subordinates. Further, aggression and submission between similarly sized group members were most frequent when groups had neighbors, suggesting that neighbors induce rank-related conflict. We found relatively little change in within-group affiliative networks across treatments, suggesting that the presence of neighbors does not alter behaviors associated with promoting group cohesion. Collectively, these results provide some of the first empirical insights into the extent to which intragroup behavioral networks are mediated by intergroup interactions and the broader social context.展开更多
The soil animal Mongoloniscus sinensis （Dollfus, 1901） is distributed in Northern China together with three other congeneric species only found in Asia. Compared to European and North American Oniscidea, little phyl...The soil animal Mongoloniscus sinensis （Dollfus, 1901） is distributed in Northern China together with three other congeneric species only found in Asia. Compared to European and North American Oniscidea, little phylogeographic information about this Asian genus has been reported. Herein, we infer the genetic structure and demographic history of M. sinensis based on mitochondrial cytochrome c oxidase subunit I （mtCoI）. The total dataset included 193 individuals from 26 locations in four provinces （Shanxi, Henan, Hebei and Shandong） of China. Most of the 87 haplotypes were unique to a sampling location, but seven haplotypes were shared among the populations. The results showed that high genetic differentiation exists both within populations and among the groups and populations ofM. sinensis. According to the distribution of phylogenic clades and geographic analyses, it is suggested that mountain ranges play an important role in population separation and that the possible evolutionary trajectory of this species is from north to south. The most likely place of origin is the Northeast Plain of China with an estimated time of isolation separating populations around 8 Mya.展开更多
Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive wor...Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent clade.However,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual dimorphism.We use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s rule.Our results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact universal.There is evidence for variation in sexual dimorphism across populations.Additionally,in many taxa,geographic variation appears to overwhelm existing sexual dimorphism.We find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape dimorphism.There is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family level.Together,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary events.Future studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.展开更多
The extraction of DNA for molecular analyses is often a limiting factor in terms of cost, time, and availability of skilled labor Here the authors describe a simple extraction protocol for obtaining DNA from field and...The extraction of DNA for molecular analyses is often a limiting factor in terms of cost, time, and availability of skilled labor Here the authors describe a simple extraction protocol for obtaining DNA from field and greenhouse grown plants. This method was optimized for sampling mature wild sorghum populations in remote areas of Ethiopia and young greenhouse grown seedlings for genetic studies using microsatellite loci. Initially, the leaf squashes are made on Whatman FTA plant saver cards or small cards of Whatman chromatography paper. After several washes, sufficient DNA to run up to 70 PCR amplifications is eluted from a 6 mm disk. Both types of cards were equally effective for collecting genomic DNA from young and mature sorghum plants for PCR-based analyses. The use of this technology for extracting genomic DNA from seedlings and/or mature plants in situ is particularly attractive for sampling at sites that are far from the laboratory where samples are ultimately analyzed. Moreover, highly skilled personnel are not required to collect DNA samples using this protocol. The Whatman FTA card is more expensive than the Wbatman chromatography paper. Therefore, without compromising efficiency, the lower cost chromatography paper can be used for DNA extraction, especially for institutions in developing countries.展开更多
Many animals use color to signal their quality and/or behavioral motivations.Colorful signals have been well studied in the contexts of competi-tion and mate choice;however,the role of these signals in nonsexual,affil...Many animals use color to signal their quality and/or behavioral motivations.Colorful signals have been well studied in the contexts of competi-tion and mate choice;however,the role of these signals in nonsexual,affiliative relationships is not as well understood.Here,we used wild social groups of the cichlid fish Neolamprologus pulcher to investigate whether the size of a brightly colored facial patch was related to 1)individual quality,2)social dominance,and/or 3)affiliative relationships.Individuals with larger patches spent more time foraging and tended to perform more aggressive acts against conspecific territory intruders.We did not find any evidence that the size of these yellow patches was related to social rank or body size,but dominant males tended to have larger patches than dominant females.Additionally,patch size had a rank-specific relationship with the number of affiliative interactions that individuals engaged in.Dominant males with large patches received fewer affiliative acts from their groupmates compared to dominant males with small patches.However,subordinates with large patches tended to receive more affiliative acts from their groupmates while performing fewer affiliative acts themselves.Taken together,our results suggest that patch size reflects interindividual variation in foraging effort in this cichlid fish and offer some of the first evidence that colorful signals may shape affiliative relationships withinwildsocialgroups.展开更多
Climate change will impact coastal ecosystems,threatening subsistence fisheries including those in mangrove forests.Despite their global contributions and roles in nutrition and cultural identity,mangrove subsistence ...Climate change will impact coastal ecosystems,threatening subsistence fisheries including those in mangrove forests.Despite their global contributions and roles in nutrition and cultural identity,mangrove subsistence fisheries are poorly studied.Here,we offer a foundation for improving the management of mangrove subsistence fisheries to deal with the impending effects of climate change.This multidisciplinary review—drawing on organismal biology,ecology,fisheries,and social science—focuses on the climate impacts relevant to mangrove ecosystems:heat waves,low-category,and high-category typhoons.First,we provide an overview of the mangroves,their harvestable stocks(fish,crustaceans,molluscs),and the fishers,offering an understanding of how they may be affected by relevant environmental variables;i.e.,shifts in temperature,salinity,oxygen,flooding,and sediments.Then,we examine the potential effects of climate change on mangrove stocks and fishers,indicating the scope of impending changes.By combining the above information,we develop a simple model that forecasts the number of“fishing-days”lost by fishers due to climate change over the next decade(between 11 and 21 days will be lost per year per fisher).This indicates which aspects of climate change will have the greatest impacts on stocks and fishers.We found that high-category typhoons had more impacts than heat waves,which in turn had a greater impact than low-category typhoons).Finally,recognising gaps in our knowledge and understanding,we offer recommendations for approaches for future work to improve our predictions.展开更多
Leaf cutting ants of the genus Atta cultivate fungal gardens,carefully modifying environmental conditions to maintain optimal temperature for fungal growth.Antennal nerves from Atta are highly temperature sensitive,bu...Leaf cutting ants of the genus Atta cultivate fungal gardens,carefully modifying environmental conditions to maintain optimal temperature for fungal growth.Antennal nerves from Atta are highly temperature sensitive,but the underlying molecular sensor is unknown.Here,we utilize Atta texana(Texas leaf cutter ant)to investigate the molecular basis of ant temperature sensation and how it might have evolved as the range expanded northeast across Texas from ancestral populations in Mexico.We focus on transient receptor potential(TRP)channel genes,the best characterized temperature sensor proteins in animals.Atta texana antennae express 6 of 13 Hymenopteran TRP channel genes and sequences are under a mix of relaxed and intensified selection.In a behavioral assay,we find A.texana workers prefer 24℃(range 21−26℃)for fungal growth.There was no evidence of regulatory evolution across a temperature transect in Texas,but instead Hymenoptera-specific TRPA(HsTRPA)expression highly correlated with ambient temperature.When expressed in vitro,HsTRPA from A.texana is temperature activated with Q10 values exceeding 100 on initial exposure to temperatures above 33℃.Surprisingly,HsTRPA also appears to be activated by cooling,and therefore to our knowledge,the first non-TRPA1 ortholog to be described with dual heat/cold activation and the first in any invertebrate.展开更多
Aims Wildfire and ungulate herbivore pressure are increasing globally due to human activities,including arid ecosystems that are sensitive to disturbance,and are highly dependent on pollinator mutualisms.We evaluated ...Aims Wildfire and ungulate herbivore pressure are increasing globally due to human activities,including arid ecosystems that are sensitive to disturbance,and are highly dependent on pollinator mutualisms.We evaluated how wildfire and ungulate herbivore pressure influ-ence plant reproductive success and pollinator mutualisms.Methods We evaluated flower production,floral herbivory,pollinator visita-tion and fruit set of two Yucca species with highly specialized polli-nator mutualisms(Yucca baccata and Yucca brevifolia)in unburned and burned landscapes created by fires that occurred in the Mojave Desert in 2005.Important Findings Yucca baccata plants in burned landscapes had a greater propor-tion of flowering individuals than plants in unburned areas(23 versus 12%).All Y.brevifolia individuals in burned and unburned landscapes produced flowers.Sixty-four percent of Y.baccata inflorescences were removed due to herbivory by cattle in burned areas,compared to 51%in unburned locations.Forty-two percent of Y.brevifolia inflorescences on branches≤2 m in height were removed in burned areas due to cattle herbivory compared to 39%in unburned locations.However,we did not observe any inflores-cence removal on Y.brevifolia branches>2 m where the major-ity of Y.brevifolia inflorescences are produced.Yucca moths,the only known pollinators of these two species,visited Y.brevifolia uniformly in burned and unburned areas but failed to visit Y.bac-cata altogether.Yucca brevifolia had strong fruit production,but not a single fruit was produced among the thousands of flowering Y.baccata plants surveyed.Floral herbivory and the loss of obligate pollinator mutualisms appear to be critical threats to the long-term viability of Y.baccata populations in this landscape.the reproduc-tive resilience of Y.brevifolia and the maintenance of its pollinator populations appear to be due to its taller stature,which allows verti-cal escape of flowers from ungulate herbivores.Removal of live-stock during the flowering period appears to be a critical first step to restoring Y.baccata’s pollinator mutualisms and capacity for sexual reproduction.展开更多
文摘All behaviors of an organism are rooted in sensory processing of signals from its environment, and nat ural selection shapes sensory adaptations to ensure successful detection of cues that maximize fitness. Sensory drive, or divergent selection for efficient signal transmission among heterogeneous environ ments, has been a useful hypothesis for describing sensory adaptations, but its current scope has pri marily focused on visual and acoustic sensory modalities. Chemosensation, the most widespread sensory modality in animals that includes the senses of smell and taste, is characterized by rapid evolu tion and has been linked to sensory adaptations to new environments in numerous lineages. Yet, olfac tion and gustation have been largely underappreciated in light of the sensory drive hypothesis. Here, we examine why chemosensory systems have been overlooked and discuss the potential of chemo sensation to shed new insight on the sensory drive hypothesis and vice versa. We provide suggestions for developing a framework to better incorporate studies of chemosensory adaptation that have the po tential to shape a more complete, coherent, and holistic interpretation of the sensory drive.
基金This research was funded by a Paleontological Society Norman Newel Award,a College of Arts and Sciences Regional Campus Research and Creative Activity Grant from the Ohio State University,a research grant from the Ohio State University at Marion,startup funds from the Ohio State University to JC,and Summer Research Assistantship funds from the Ohio State University at Marion to LN.Some of the ideas for this project were developed while JC was supported by a Meaningful Inquiry grant from The Ohio State University library system.
文摘Morphological analyses are critical to quantify phenotypic variation,identify taxa,inform phylogenetic relationships,and shed light on evolutionary patterns.This work is particularly important in groups that display great morphological disparity.Such is the case in geomyoid rodents,a group that includes 2 of the most species-rich families of rodents in North America:the Geomyidae(pocket gophers)and the Heteromyidae(kangaroo rats,pocket mice,and their relatives).We assessed variation in skull morphology(including both shape and size)among geomyoids to test the hypothesis that there are statistically significant differences in skull measurements at the family,genus,and species levels.Our sample includes 886 specimens representing all geomyoid genera and 39 species.We used the geometric mean to compare size across taxa.We used 14 measurements of the cranium and lower jaw normalized for size to compare shape among and within taxa.Our results show that skull measurements enable the distinction of geomyoids at the family,genus,and species levels.There is a larger amount of size variation within Geomyidae than within Heteromyidae.Our phylomorphospace analysis shows that the skull shape of the common ancestor of all geomyoids was more similar to the common ancestor of heteromyids than that of geomyids.Geomyid skulls display negative allometry whereas heteromyid skulls display positive allometry.Within heteromyids,dipodomyines,and non-dipodomyines show significantly different allometric patterns.Future analyses including fossils will be necessary to test our evolutionary hypotheses.
基金supported by the United States Department of Agriculture National Institute of Food and Agriculture Hatch project 1026333(ILLU-875-984 to K.M.S)a University of Ilinois Graduate College Master's Fellowship(to K.M.S)+2 种基金a University of Illinois Graduate College Travel Award(to K.M.S)Ilinois State Toll Highway Authority funding(to D.E and A.L.C)University of Illinois Laboratory Start-up funds(to E.K.F).
文摘Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of behavior in the invasive potential of animals is less studied.The common coqui frog,Eleutherodactylus coqui,is a highly successful invader in Hawai'i.We build on previous research characterizing changes in physiology and morphology to explore behavioral variation across the invasive range of coqui in Hawai'i.Coqui have expanded both outward and upward from their initial introduction site,andby comparing frogs from different densities and elevations-we specifically asked how the physiological challenges of high-elevation living interact with the competitive challenge of high-densities at population centers.To investigate whether differences in the field represent local adaptation or behavioral plasticity,we additionally evaluated behavior following acclimation to a shared laboratory environment.Although we identified only subtle behavioral variation among populations in the field,we found that individuals from all populations became less bold,active,and exploratory in the laboratory,converging on a similar behavioral phenotype.Alongside previous work,our results suggest that coqui adjust their behavior to local environmental conditions across their invasive range and that behavioral flexibility may contribute to invasive success.
文摘DNA-based approaches to systematics have changed dramatically during the last two decades with the rise of DNA barcoding methods and newer multi-locus methods for species delimitation. During the last half-decade, partly driven by the new sequencing technologies, the focus has shifted to multi-locus sequence data and the identification of species within the frame-work of the multi-species coalescent （MSC）. In this paper, I discuss model-based Bayesian methods for species delimitation that have been developed in recent years using the MSC. Several approximate methods for species delimitation （and their limitations） are also discussed. Explicit species delimitation models have the advantage of clarifying more precisely what is being delimited and what assumptions we are making in doing so. Moreover, the methods can be very powerful when applied to large multi-locus datasets and thus take full advantage of data generated using today＇s technologies [Current Zoology 61 （5）： 846-853,2015].
文摘Our understanding of eukaryote biology is dominated by the study of land plants, animals and fungi. However, these are only three isolated fragments of the full diversity of extant eukaryotes. The majority of eu-karyotes, in terms of major taxa and probably also sheer numbers of cells, consists of exclusively or predomi-nantly unicellular lineages. A surprising number of these lineages are poorly characterized. Nonetheless, they are fundamental to our understanding of eukaryote biology and the underlying forces that shaped it. This article consists of an overview of the current state of our understanding of the eukaryote tree. This includes the identity of the major groups of eukaryotes, some of their important, defining or simply interesting features and the pro-posed relationships of these groups to each other.
基金Acknowledgements We wish to thank Jack Bradbury for the suggestion to explore the negotiation literature to understand lekking sage-grouse, and Heather McKibben and Kyle Joyce for the help in interpreting the literature. Additional thanks to two anonymous reviewers and editor, Eileen Hebets. This work was funded in part by a National Science Foundation grant to GLP and AHK （IOS-0925038）.
文摘Economists study negotiation as a series of events--partner choice, information gathering, bargaining, etc.--with each step of the process affecting the outcome of the next, and the optimal decision at each stage depending on the player＇s bargaining power. The context in which these negotiations occur--the market--is critical, since players can adjust their behaviors in response to outside offers. Animals similarly are faced with sequential decisions regarding courtship： who to court, how to approach a potential mate, at what level to display, when to give up, etc. Thus economic models of negotiation in a market provide a framework in which we can view not just the outcome of courtship （assortative mating）, but also the process, where each sex can use tactics to improve their negotiating outcome, using the assets that they have available. Here we propose to use negotiation as a conceptual framework to explore the factors promoting tactical adjustments during sequential stages of courtship in lekking species. Our goal is to discuss the utility of negotiation as a heuristic tool, as well as the promise and peril of co-opting game theoretic models from economics to understand animal interactions. We will provide a brief overview of a few areas where we see promise for using negotiation as a framework to understand animal courtship dynamics： choice of a display territory, tactical partner choice for negotiation, approaching a potential partner and courtship haggling .
文摘Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms medi- ate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviati- lis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis that won competitions were more aggressive than C, variegatus winners, and more aggression was needed to win against competitor C. variagatus than allopatric C. rubrofluviatilis. Duration of fights also differed based on the relatedness of the competitor. In dichotomous mate choice trials, there were no conspecific or heterospecific preferences expressed by females of either species. Our findings that male-male aggression differs between closely and distantly related groups, but female choice does not suggest that male-male competition may be the more likely mechanism to impede gene flow in this system.
文摘Conflict is an in here nt part of social life in group-living species. Group members may mediate conflict through submissive and affiliative behaviors, which can reduce aggression, stabilize dominance hierarchies, and foster group cohesion. The frequency and resolution of within-group conflict may vary with the presenee of neighboring groups. Neighbors can threaten the territory or resources of the whole group, promoting behaviors that foster within-group cohesion. However, neighbors may also foster conflict of interests among group members: opportunities for subordinate dispersal may alter conflict among dominants and subordinates while opportunities for extrapair reproduction may increase conflict between mates. To understand how neighbors mediate within-group conflict in the cooperatively breeding fish Neolamprologus pulcher, we measured behavioral dynamics and social network structure in isolated groups, groups recently exposed to neighbors, and groups with established neighbors. Aggression and submission between the dominant male and female pair were high in isolated groups, but dominant aggression was directly primarily at subordinates when groups had neighbors. This suggests that neighbors attenuate conflict between mates and foster conflict between dominants and subordinates. Further, aggression and submission between similarly sized group members were most frequent when groups had neighbors, suggesting that neighbors induce rank-related conflict. We found relatively little change in within-group affiliative networks across treatments, suggesting that the presence of neighbors does not alter behaviors associated with promoting group cohesion. Collectively, these results provide some of the first empirical insights into the extent to which intragroup behavioral networks are mediated by intergroup interactions and the broader social context.
基金supported by National Natural Science Foundation of China(31471970)
文摘The soil animal Mongoloniscus sinensis （Dollfus, 1901） is distributed in Northern China together with three other congeneric species only found in Asia. Compared to European and North American Oniscidea, little phylogeographic information about this Asian genus has been reported. Herein, we infer the genetic structure and demographic history of M. sinensis based on mitochondrial cytochrome c oxidase subunit I （mtCoI）. The total dataset included 193 individuals from 26 locations in four provinces （Shanxi, Henan, Hebei and Shandong） of China. Most of the 87 haplotypes were unique to a sampling location, but seven haplotypes were shared among the populations. The results showed that high genetic differentiation exists both within populations and among the groups and populations ofM. sinensis. According to the distribution of phylogenic clades and geographic analyses, it is suggested that mountain ranges play an important role in population separation and that the possible evolutionary trajectory of this species is from north to south. The most likely place of origin is the Northeast Plain of China with an estimated time of isolation separating populations around 8 Mya.
基金funded by a Paleontological Society Norman Newel Award,a College of Arts and Sciences Regional Campus Research and Creative Activity Grant from the Ohio State University,a research grant from the Ohio State University at Marion,and startup funds from the Ohio State University to J.C.Some of the ideas for this project were developed while J.Cwas supported by a Meaningful Inquiry grant from the Ohio State University library system.
文摘Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent clade.However,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual dimorphism.We use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s rule.Our results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact universal.There is evidence for variation in sexual dimorphism across populations.Additionally,in many taxa,geographic variation appears to overwhelm existing sexual dimorphism.We find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape dimorphism.There is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family level.Together,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary events.Future studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.
文摘The extraction of DNA for molecular analyses is often a limiting factor in terms of cost, time, and availability of skilled labor Here the authors describe a simple extraction protocol for obtaining DNA from field and greenhouse grown plants. This method was optimized for sampling mature wild sorghum populations in remote areas of Ethiopia and young greenhouse grown seedlings for genetic studies using microsatellite loci. Initially, the leaf squashes are made on Whatman FTA plant saver cards or small cards of Whatman chromatography paper. After several washes, sufficient DNA to run up to 70 PCR amplifications is eluted from a 6 mm disk. Both types of cards were equally effective for collecting genomic DNA from young and mature sorghum plants for PCR-based analyses. The use of this technology for extracting genomic DNA from seedlings and/or mature plants in situ is particularly attractive for sampling at sites that are far from the laboratory where samples are ultimately analyzed. Moreover, highly skilled personnel are not required to collect DNA samples using this protocol. The Whatman FTA card is more expensive than the Wbatman chromatography paper. Therefore, without compromising efficiency, the lower cost chromatography paper can be used for DNA extraction, especially for institutions in developing countries.
基金supported by a Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery grant provided to SB(RGPIN-2016-05772)the National Science Foundation under grant No.1557836 provided to IMH.
文摘Many animals use color to signal their quality and/or behavioral motivations.Colorful signals have been well studied in the contexts of competi-tion and mate choice;however,the role of these signals in nonsexual,affiliative relationships is not as well understood.Here,we used wild social groups of the cichlid fish Neolamprologus pulcher to investigate whether the size of a brightly colored facial patch was related to 1)individual quality,2)social dominance,and/or 3)affiliative relationships.Individuals with larger patches spent more time foraging and tended to perform more aggressive acts against conspecific territory intruders.We did not find any evidence that the size of these yellow patches was related to social rank or body size,but dominant males tended to have larger patches than dominant females.Additionally,patch size had a rank-specific relationship with the number of affiliative interactions that individuals engaged in.Dominant males with large patches received fewer affiliative acts from their groupmates compared to dominant males with small patches.However,subordinates with large patches tended to receive more affiliative acts from their groupmates while performing fewer affiliative acts themselves.Taken together,our results suggest that patch size reflects interindividual variation in foraging effort in this cichlid fish and offer some of the first evidence that colorful signals may shape affiliative relationships withinwildsocialgroups.
基金funded and supported by the Commission on Higher Education(CHED),Transnational Education Scholarship Grant under the K to 12 transition programs,stipulated in CHED Memorandum Order(CMO)No.17,Series of 2018.
文摘Climate change will impact coastal ecosystems,threatening subsistence fisheries including those in mangrove forests.Despite their global contributions and roles in nutrition and cultural identity,mangrove subsistence fisheries are poorly studied.Here,we offer a foundation for improving the management of mangrove subsistence fisheries to deal with the impending effects of climate change.This multidisciplinary review—drawing on organismal biology,ecology,fisheries,and social science—focuses on the climate impacts relevant to mangrove ecosystems:heat waves,low-category,and high-category typhoons.First,we provide an overview of the mangroves,their harvestable stocks(fish,crustaceans,molluscs),and the fishers,offering an understanding of how they may be affected by relevant environmental variables;i.e.,shifts in temperature,salinity,oxygen,flooding,and sediments.Then,we examine the potential effects of climate change on mangrove stocks and fishers,indicating the scope of impending changes.By combining the above information,we develop a simple model that forecasts the number of“fishing-days”lost by fishers due to climate change over the next decade(between 11 and 21 days will be lost per year per fisher).This indicates which aspects of climate change will have the greatest impacts on stocks and fishers.We found that high-category typhoons had more impacts than heat waves,which in turn had a greater impact than low-category typhoons).Finally,recognising gaps in our knowledge and understanding,we offer recommendations for approaches for future work to improve our predictions.
文摘Leaf cutting ants of the genus Atta cultivate fungal gardens,carefully modifying environmental conditions to maintain optimal temperature for fungal growth.Antennal nerves from Atta are highly temperature sensitive,but the underlying molecular sensor is unknown.Here,we utilize Atta texana(Texas leaf cutter ant)to investigate the molecular basis of ant temperature sensation and how it might have evolved as the range expanded northeast across Texas from ancestral populations in Mexico.We focus on transient receptor potential(TRP)channel genes,the best characterized temperature sensor proteins in animals.Atta texana antennae express 6 of 13 Hymenopteran TRP channel genes and sequences are under a mix of relaxed and intensified selection.In a behavioral assay,we find A.texana workers prefer 24℃(range 21−26℃)for fungal growth.There was no evidence of regulatory evolution across a temperature transect in Texas,but instead Hymenoptera-specific TRPA(HsTRPA)expression highly correlated with ambient temperature.When expressed in vitro,HsTRPA from A.texana is temperature activated with Q10 values exceeding 100 on initial exposure to temperatures above 33℃.Surprisingly,HsTRPA also appears to be activated by cooling,and therefore to our knowledge,the first non-TRPA1 ortholog to be described with dual heat/cold activation and the first in any invertebrate.
基金We thank Alyssa DeFranco,Rachel Nettles,Justin Taylor,Anson Call,Amy Clark and Tara Bishop for field assistance and Loreen Allphin for providing guidance.We express gratitude to the Lytle Preserve and the Bureau of Land Management for logistical support.This project was supported by the Redd Center for Western Studies fellowship.This project was funded by USDA NIFA grant:2010-38415-21908.Conflict of interest statement.None declared.
文摘Aims Wildfire and ungulate herbivore pressure are increasing globally due to human activities,including arid ecosystems that are sensitive to disturbance,and are highly dependent on pollinator mutualisms.We evaluated how wildfire and ungulate herbivore pressure influ-ence plant reproductive success and pollinator mutualisms.Methods We evaluated flower production,floral herbivory,pollinator visita-tion and fruit set of two Yucca species with highly specialized polli-nator mutualisms(Yucca baccata and Yucca brevifolia)in unburned and burned landscapes created by fires that occurred in the Mojave Desert in 2005.Important Findings Yucca baccata plants in burned landscapes had a greater propor-tion of flowering individuals than plants in unburned areas(23 versus 12%).All Y.brevifolia individuals in burned and unburned landscapes produced flowers.Sixty-four percent of Y.baccata inflorescences were removed due to herbivory by cattle in burned areas,compared to 51%in unburned locations.Forty-two percent of Y.brevifolia inflorescences on branches≤2 m in height were removed in burned areas due to cattle herbivory compared to 39%in unburned locations.However,we did not observe any inflores-cence removal on Y.brevifolia branches>2 m where the major-ity of Y.brevifolia inflorescences are produced.Yucca moths,the only known pollinators of these two species,visited Y.brevifolia uniformly in burned and unburned areas but failed to visit Y.bac-cata altogether.Yucca brevifolia had strong fruit production,but not a single fruit was produced among the thousands of flowering Y.baccata plants surveyed.Floral herbivory and the loss of obligate pollinator mutualisms appear to be critical threats to the long-term viability of Y.baccata populations in this landscape.the reproduc-tive resilience of Y.brevifolia and the maintenance of its pollinator populations appear to be due to its taller stature,which allows verti-cal escape of flowers from ungulate herbivores.Removal of live-stock during the flowering period appears to be a critical first step to restoring Y.baccata’s pollinator mutualisms and capacity for sexual reproduction.
