Search

Signal theory predicts organisms should evolve signals that are conspicuous to intended receivers in natural signalling environments. Cleaner shrimps remove ectoparasites from reef fish clients and many signal their intent to clean by whipping long, white antennae. As white is a reliably conspicuous colour in aquatic environments, we hypothesized that selection has acted to increase broad-spectrum antennal reflectance in cleaners. Using scanning electron microscopy, optical models and reflectance measurements, we found that the antennae in three obligate cleaner species from two families (Palaemonidae and Lysmatidae) had thick (∼6 µm) chitinous layers or densely packed high refractive index spheres (300-400 nm diameter), which models show increase reflectance (400-700 nm). Two facultative and non-cleaning species had no visible antennae ultrastructure beyond the chitinous exoskeleton. Antennae reflectance was significantly higher in obligate cleaners than in facultative and non-cleaning species. Our results suggest that some obligate cleaners may have evolved ultrastructures that increase the conspicuousness of their antennae as signals.

Many symbionts are sexually transmitted and impact their host's development, ecology, and evolution. While the significance of symbionts that cause sexually transmitted diseases (STDs) is relatively well understood, the prevalence and potential significance of the sexual transmission of mutualists remain elusive. Here, we study the effects of sexually transmitted mutualist nematodes on their dung beetle hosts. Symbiotic Diplogastrellus monhysteroides nematodes are present on the genitalia of male and female Onthophagus beetles and are horizontally transmitted during mating and vertically passed on to offspring during oviposition. A previous study indicates that the presence of nematodes benefits larval development and life history in a single host species, Onthophagus taurus. However, Diplogastrellus nematodes can be found in association with a variety of beetle species. Here, we replicate these previous experiments, assess whether the beneficial effects extend to other host species, and test whether nematode-mediated effects differ between male and female host beetles. Rearing three relatively distantly related dung beetle species with and without nematodes, we find that the presence of nematodes benefits body size, but not development time or survival across all three species. Likewise, we found no difference in the benefit of nematodes to male compared to female beetles. These findings highlight the role of sexually transmitted mutualists in the evolution and ecology of dung beetles.

Microbes are widely recognized to be vital to host health. This new consensus rests, in part, on experiments showing how hosts malfunction when microbes are removed. More and more microbial dependencies are being discovered, even in fundamental processes such as development, immunity, physiology, and behavior. But why do they exist? The default explanation is that microbes are beneficial; when hosts lose microbes, they also lose benefits. Here I call attention to evolutionary addiction, whereby a host trait evolves a need for microbes without having been improved by them. Evolutionary addiction should be considered when interpreting microbe-removal experiments, as it is a distinct and potentially common process. Further, it may have unique implications for the evolution and stability of host-microbe interactions.

ABSTRACT The intricate web of interactions in nature has led to unexpected partnerships between plants and animals, greatly influencing ecosystem dynamics. In this discussion, we'll explore the Pollination Syndrome Hypothesis and consider a scenario where a partnership with unexpected pollinators emerges. We suggest that ant pollination has been largely overlooked, but ants can surprisingly play a crucial role and have a history of success in pollinating dry system plants. We will present both negative and positive aspects that must be observed in ant‐pollination syndrome. Additionally, we aim to explore the often‐underestimated phenomenon of ant pollination and the overlooked tiny, discreet, unnoticed flowers found in our fields and forests, especially in dry ecosystems, savannas and mountain fields, which may hold numerous undiscovered secrets about these interactions. We encourage young biologists to engage in natural history observations and to perform manipulative experiments directly in the field to understand the true nature of these successful ant‐pollinations. [ABSTRACT FROM AUTHOR]

Symbiotic mutualisms provide critical ecosystem services throughout the world. Anthropogenic stressors, however, may disrupt mutualistic interactions and impact ecosystem health. The plant‐rhizobia symbiosis promotes plant growth and contributes to the nitrogen (N) cycle. While off‐target herbicide exposure is recognized as a significant stressor impacting wild plants, we lack knowledge about how it affects the symbiotic relationship between plants and rhizobia. Moreover, we do not know whether the impact of herbicide exposure on symbiotic traits or plant fitness might be ameliorated by plant or rhizobial genetic variation. To address these gaps, we conducted a greenhouse study where we grew 17 full‐sibling genetic families of red clover (Trifolium pratense) either alone (uninoculated) or in symbiosis with one of two genetic strains of rhizobia (Rhizobium leguminosarum) and exposed them to a concentration of the herbicide dicamba that simulated “drift” (i.e., off‐target atmospheric movement) or a control solution. We recorded responses in immediate vegetative injury, key features of the plant‐rhizobia mutualism (nodule number, nodule size, and N fixation), mutualism outcomes, and plant fitness (biomass). In general, we found that rhizobial variation more than plant variation determined outcomes of mutualism and plant fitness in response to herbicide exposure. Herbicide damage response depended on plant family, but also whether plants were inoculated with rhizobia and if so, with which strain. Rhizobial strain variation determined nodule number and size, but this was herbicide treatment‐dependent. In contrast, strain and herbicide treatment independently impacted symbiotic N fixation. And while herbicide exposure significantly reduced plant fitness, this effect depended on inoculation state. Furthermore, the differential fitness benefits that the two rhizobial strains provided plants seemed to diminish under herbicidal conditions. Altogether, these findings suggest that exposure to low levels of herbicide impact key components of the plant‐rhizobia mutualism as well as plant fitness, but genetic variation in the partners determines the magnitude and/or direction of these effects. In particular, our results highlight a strong role of rhizobial strain identity in driving both symbiotic and plant growth responses to herbicide stress. [ABSTRACT FROM AUTHOR]

Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis. For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level. Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants. Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Based on fieldwork in Danish families living with ADHD, we expand on Nielsen’s insight that ADHD is experienced as a state of desynchronization by showing how family members’ rhythms mutually affect each other. We argue that ADHD is not only a biological and psychiatric condition, but also a temporal and socially responsive phenomenon. The intensity of ADHD is influenced by mutual affect in families and by general life circumstances. Families constitute bodily networks through which sensations, moods, rhythms, and practices spread and are passed down through generations. Yet, families use various time work strategies to manage rhythm affect. [ABSTRACT FROM AUTHOR]

Regular repair of normative mother‐toddler conflict is required for relational health; yet, we still need improved delineation of regulation strategies that can promote child cooperation. Contemporary conceptualizations of positive parenting propose that structure and autonomy support each facilitate children's optimal engagement; however, toddler studies rarely address their joint impact and conditional moderation. This observational study examined both dimensions in predicting cooperation among 106 U.S. 30‐month‐olds and their primarily European–American mothers during a demanding request situation. We also assessed mutuality, an indicator of mother‐child relationship quality, from two situations with minimized power differentials to explore whether it moderated associations. Regression analyses confirmed the unique and additive impact of both maternal behavioral dimensions in predicting toddler cooperation and also an interaction effect such that the positive association between maternal autonomy support and toddlers’ level of cooperation was accentuated depending on the dyads’ mutuality. Results suggest that maternal structure and autonomy support may serve as effective approaches for enlisting or maintaining child cooperation during hierarchical negotiations, and that suboptimal relationship mutuality magnifies toddlers’ responses to maternal levels of autonomy support. Findings are likely relevant to parenting programs that advance mother‐child relational health during the transition from infancy to early childhood. [ABSTRACT FROM AUTHOR]

Mutualistic relationships with photosynthetic organisms are common in cnidarians, which form an intracellular symbiosis with dinoflagellates in the family Symbiodiniaceae. The establishment and maintenance of these symbionts are associated with the suppression of key host immune factors. Because of this, there are potential trade-offs between the nutrition that cnidarian hosts gain from their symbionts and their ability to successfully defend themselves from pathogens. To investigate these potential trade-offs, we utilized the facultatively symbiotic polyps of the upside-down jellyfish Cassiopea xamachana and exposed aposymbiotic and symbiotic polyps to the pathogen Serratia marcescens. Symbiotic polyps had a lower probability of survival following S. marcescens exposure. Gene expression analyses 24 hours following pathogen exposure indicate that symbiotic animals mounted a more damaging immune response, with higher levels of inflammation and oxidative stress likely resulting in more severe disruptions to cellular homeostasis. Underlying this more damaging immune response may be differences in constitutive and pathogen-induced expression of immune transcription factors between aposymbiotic and symbiotic polyps rather than broadscale immune suppression during symbiosis. Our findings indicate that in facultatively symbiotic polyps, hosting symbionts limits C. xamachana's ability to survive pathogen exposure, indicating a trade-off between symbiosis and immunity that has potential implications for coral disease research. [ABSTRACT FROM AUTHOR]

ABSTRACT Although huge progress has been made over the past 200 years in identifying the diversity of pollinators of angiosperms and other plants, new discoveries continue to be made each year, especially in tropical areas and in the fossil record. In this perspective article I address the following questions: Just how diverse are the pollinators and what are the phylogenetic limits to that diversity? Which other groups of animals, not currently known to regularly engage with flowers, might be found to be pollinators in the future? Can we predict, from the fossil record and from discoveries in under‐researched parts of the world, which animal groups might turn out in the future to contain pollinators? I also discuss why adding to our knowledge of plant–pollinator interactions is important, but also stress that an incomplete knowledge may not be a bad thing if it means that remote, inaccessible and relatively pristine parts of the world remain that way. [ABSTRACT FROM AUTHOR]

Fire is a major disturbance affecting ecosystems globally, but its impact on mutualisms has received minimal attention. Here, we use a long-term field experiment to investigate the impact of different fire regimes on globally important ant–honeydew and ant–extrafloral nectar (EFN) mutualistic interactions in an Australian tropical savanna. These interactions provide ants with a key energy source, while their plant and hemipteran hosts receive protection services. We examined ant interactions on species of Eucalyptus (lacking EFNs) and Acacia (with EFNs) in three replicate plots each of burning every 2 and 3 years early in the dry season, burning late in the dry season every 2 years, and unburnt for > 25 years. The proportions of plants with ant–honeydew interactions in Acacia (44.6%) and Eucalyptus (36.3%) were double those of Acacia plants with ant–EFN interactions (18.9%). The most common ants, representing 85% of all interactions, were behaviourally dominant species of Oecophylla, Iridomyrmex and Papyrius. Fire promoted the incidence of ant interactions, especially those involving EFNs on Acacia, which occurred on only 3% of plants in unburnt plots compared with 24% in frequently burnt plots. Fire also promoted the relative incidence of behaviourally dominant ants, which are considered the highest quality mutualists. Contrary to expectations, frequent fire did not result in a switching of behaviourally dominant ant partners from forest-adapted Oecophylla to arid-adapted Iridomyrmex. Our findings that frequent fire increases ant interactions mediated by honeydew and extrafloral nectar, and promotes the quality of ant mutualists, have important implications for protective services provided by ants in highly fire-prone ecosystems. [ABSTRACT FROM AUTHOR]

The L‐tryptophan–derived purple pigment violacein (VIO) is produced in recombinant bacteria and studied for its versatile applications. Microbial synthetic co‐cultures are gaining more importance as efficient factories for synthesizing high‐value compounds. In this work, a mutualistic and cross‐feeding Escherichia coli co‐culture is metabolically engineered to produce VIO. The strains are genetically modified by auxotrophies in the tryptophan (TRP) pathway to enable a metabolic division of labor. Therein, one strain produces anthranilate (ANT) and the other transforms it into TRP and further to VIO. Population dynamics and stability depend on the choice of carbon source, impacting the presence and thus exchange of metabolites as well as overall VIO productivity. Four carbon sources (D‐glucose, glycerol, D‐galactose, and D‐xylose) were compared. D‐Xylose led to co‐cultures which showed stable growth and VIO production, ANT‐TRP exchange, and enhanced VIO production. Best titers were ∼126 mg L–1 in shake flasks. The study demonstrates the importance and advantages of a mutualistic approach in VIO synthesis and highlights the carbon source's role in co‐culture stability and productivity. Transferring this knowledge into an up‐scaled bioreactor system has great potential in improving the overall VIO production. [ABSTRACT FROM AUTHOR]

While many effects of forest fragmentation are reasonably well understood, knowledge of interspecific interactions in fragmented ecosystems is much more limited, particularly for high diversity tropical forests. Using nearly 40 years of data from the Biological Dynamics of Forest Fragments Project in Central Amazonia, we assessed whether forest fragment area and time since isolation impact mutualistic interactions between frugivorous birds and their food resources. We used structural equation modeling to analyze the complex pathways between four main variables determining these interactions: fruiting tree abundance, frugivorous bird abundance, forest fragment area, and time since fragment isolation. Our results confirm that fragment area alters the abundance of some tree resources, with successional plant families increasing in abundance with decreasing fragment size. However, these changes do not drive alterations in the abundance of frugivorous birds. We also tested if bird species with a greater relative diet breadth are less vulnerable to forest fragmentation and found that specialist frugivores are more vulnerable to forest fragmentation immediately after isolation but are not differentially impacted within the long term. Collectively, our results demonstrate the need to further evaluate human‐driven habitat change across multiple timescales to fully understand its impacts on complex species interactions. [ABSTRACT FROM AUTHOR]

This article explores the effects of hurricanes on the relationship between plants and pollinators in the Caribbean. Specifically, it examines the impact of Hurricane Maria on the mutualism between two species of Heliconia plants and the purple-throated carib hummingbird. Before the hurricane, this mutualism was highly specialized, but afterwards, other hummingbird species and a generalized passerine pollinator began visiting the Heliconia flowers at similar rates. This suggests that the population decline of the purple-throated carib allowed for increased visitation by other species, leading to a breakdown in competitive exclusion. The study also raises concerns about the conservation of these relationships in the face of increasing hurricane frequency and intensity due to global warming. [Extracted from the article]

Plant–hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant–hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre‐dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build‐up of both diversities coinciding temporally, and hence suggesting co‐diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species‐level interaction data in macroevolutionary studies. [ABSTRACT FROM AUTHOR]

The quality of transnational higher education partnerships (THEPs) has increasingly come under scrutiny with the growing role of higher education in development. Mutuality has emerged as a key focus of this examination. We seek to understand how mutuality is expressed within North–South THEPs that have a major focus on community engagement. We refer to THEPs with this focus as engaged transnational higher education partnerships (ETHEPs). This study is based on a secondary analysis of extant literature on one ETHEP based in Kenya. A thematic content analysis revealed that celebrated outcomes of mutuality included capacity building, institutionalization, collaborative relationships and solidarity around community engagement. Challenges to mutuality were related to structural and cultural differences, self‐sustainability and equity. A discussion of findings is followed by possible questions to guide inquiry toward strengthening mutuality in North–South ETHEPs. [ABSTRACT FROM AUTHOR]

Pairwise host–parasite relationships are typically embedded in broader networks of ecological interactions, which have the potential to shape parasite evolutionary trajectories. Understanding this 'community context' of pathogen evolution is vital for wildlife, agricultural and human systems alike, as pathogens typically infect more than one host—and these hosts may have independent ecological relationships. Here, we introduce an eco-evolutionary model examining ecological feedback across a range of host–host interactions. Specifically, we analyse a model of the evolution of virulence of a parasite infecting two hosts exhibiting competitive, mutualistic or exploitative relationships. We first find that parasite specialism is necessary for inter-host interactions to impact parasite evolution. Furthermore, we find generally that increasing competition between hosts leads to higher shared parasite virulence while increasing mutualism leads to lower virulence. In exploitative host–host interactions, the particular form of parasite specialization is critical—for instance, specialization in terms of onward transmission, host tolerance or intra-host pathogen growth rate lead to distinct evolutionary outcomes under the same host–host interactions. Our work provides testable hypotheses for multi-host disease systems, predicts how changing interaction networks may impact virulence evolution and broadly demonstrates the importance of looking beyond pairwise relationships to understand evolution in realistic community contexts. [ABSTRACT FROM AUTHOR]

Parasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide‐ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community‐level effects. Here, we investigated the effects of a common trematode parasite (Cercaria opaca) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, Spartina alterniflora, and the ribbed mussel, Geukensia demissa. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient‐rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with C. opaca was most common in mussels in areas experiencing cordgrass die‐off due to drought, and that infection intensity decreased with distance from die‐off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought‐associated die‐off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists. [ABSTRACT FROM AUTHOR]

Soil microbial mutualists like rhizobia bacteria can promote the establishment of rare, late‐successional legumes. Despite restoration efforts, these mutualists are often absent in the microbiome. Therefore, restoring this mutualism by directly inoculating rare legumes with rhizobia mutualists may increase plant establishment. We inoculated seedlings of Amorpha canescens, Dalea purpurea, and Lespedeza capitata with three strains of species‐specific rhizobia each to investigate how this mutualism would promote growth in the field and in the greenhouse. Because many herbaceous plants are vulnerable to herbivory, we used exclosures for half of our field transplantations to prevent mammalian herbivory. We did not find that rhizobia bacteria directly promoted the growth of our legumes in the field but rather that herbivory and environmental conditions overwhelmed the effects of the rhizobia. Of the plants transplanted, only 17.78% of 180 survived to the end of the growing season, all of which were protected from herbivory. Survival at the end of the growing season was also greater in the northern, drier end of the field site. In the second growing season, plants were more likely to survive in the exclosure treatment, while only four recovered in the open treatment. In the greenhouse, we found increased nodulation with inoculations, supporting the hypothesis that species‐specific mutualists are absent from restoration sites. Though several recent studies have shown that restoring mutualistic interactions has the potential to dramatically improve the outcomes of ecological restoration, our results show that protecting rare species from herbivory after transplantation might achieve greater gains in establishment. [ABSTRACT FROM AUTHOR]

There has long been a fundamental divide in the study of cooperation: researchers focus either on cooperation within species, including but not limited to sociality, or else on cooperation between species, commonly termed mutualism. Here, we explore the ecologically and evolutionarily significant ways in which within- and between-species cooperation interact. We highlight two primary cross-linkages. First, cooperation of one type can change the context in which cooperation of the other type functions, and thus potentially its outcome. We delineate three possibilities: (i) within-species cooperation modulates benefits for a heterospecific partner; (ii) between-species cooperation affects the dynamics of within-species cooperation; and (iii) both processes take place interactively. The second type of cross-linkage emerges when resources or services that cooperation makes available are obtainable either from members of the same species or from different species. This brings cooperation at the two levels into direct interaction, to some extent obscuring the distinction between them. We expand on these intersections between within- and between-species cooperation in a diversity of taxa and interaction types. These interactions have the potential to weave together social networks and trophic dynamics, contributing to the structure and functioning of ecological communities in ways that are just beginning to be explored. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'. [ABSTRACT FROM AUTHOR]

While most flowering plants engage in mutualistic interactions with their pollinators, Arisaema species employ a unique, seemingly antagonistic strategy by imprisoning and causing the pollinators to perish within their spathes. Recent studies have revealed that Arisaema thunbergii primarily relies on a fungus gnat, Leia ishitanii, with some individuals possibly escaping female spathes after oviposition. We investigated interactions between A. urashima and its pollinating fungus gnats, given that A. urashima is closely related to A. thunbergii. Specifically, we tested whether decaying A. urashima serve as brood‐sites for some pollinators and whether these pollinators can escape seemingly lethal floral traps. We retrieved A. urashima spathes together with adult insect corpses trapped within the spathes and incubated the spathes to see if conspecific insects emerged. In addition, under laboratory conditions, we observed the escape behaviour of Sciophila yokoyamai, whose next‐generation adults most frequently emerge from the decaying spathes. Our findings indicate that S. yokoyamai almost always escapes from the female spathe after oviposition while using the inflorescence as a nursery. In contrast, other pollinators of A. urashima, including Mycetophila spp., remain trapped and perished within the spathes. This study demonstrates that A. urashima spathes can function both as lethal traps and mutualistic nurseries, with outcomes differing among pollinator species. Our results also suggest that the contribution of certain pollinators to Arisaema reproduction is underestimated or even neglected, given that information on their pollinator assemblages has been based on floral visitors trapped within the inflorescences. [ABSTRACT FROM AUTHOR]

In this essay, I reflect on the origins of relational psychoanalysis during my training years at the NYU Postdoctoral Program between 1983 and 1989, and the subsequent evolution of my own psychoanalytic credo in which I place the essential mutuality of the psychoanalytic process at the heart of the therapeutic action that it generates. I explore the idea that all analysis is at heart a form of mutual analysis in which personal transformation and healing is inevitably bi-directional. [ABSTRACT FROM AUTHOR]

Polyphagy is an adaptative strategy allowing species to develop and survive on multiple diets. Phytophagous insects can be exposed to sub-optimal resources, as host plants vary in nutritional quality. Some insects may rely on symbiotic bacteria to better utilize less favorable substrates. The invasive fruit fly Drosophila suzukii is a highly successful pest worldwide. The use of ripening and ripe fruits, a niche neglected by other drosophilids, and its polyphagy may have contributed to its global spread. The role of D. suzukii's Wolbachia strain (wSuz) remains unconfirmed, although a mutualistic role has been hypothesized via virus protection or dealing with abiotic stress. In some insect species, Wolbachia acts as a nutritional mutualist. This study explored the role of wSuz in D. suzukii adaptation to fluctuating diet regimes. To simulate a diet shift, we used Wolbachia-infected and uninfected flies, maintained on a corn-based (low-starch) or a grape-based (high-starch) diet for at least 10 generations. Then, we placed individuals from each line on one or the other diet for 30 days. The effects of Wolbachia and the diet treatments were assessed by quantifying female fecundity, egg-to-adult development time and survival, and offspring mass. The presence of Wolbachia positively affected female fecundity and offspring mass after a diet shift. Wolbachia also increased survival during larval development regardless of the diet, supporting its mutualistic role. Our results underline the role of wSuz on D. suzukii diet tolerance and performance. A better understanding of the role of symbionts in invasive species could help to improve management strategies. [ABSTRACT FROM AUTHOR]

A critical and common, but much ignored, plant-animal interaction is primary seed dispersal by ants (myrmecochory). Ants are ubiquitous across many landscapes, so it may not be surprising that many plants have evolved to utilize them to move their seeds. In fact, myrmecochory has independently evolved over 100 times. Myrmecochory carries all the usual benefits of biotic seed dispersal, such as reduction of competition with siblings, as well as a few more (notably, escape from fire). Seeds dispersed by ants generally possess an attached food body (elaiosome), which attracts and rewards ants. Elaiosomes are commonly described as fat bodies comprising lipids. However, their nutritional and chemical composition can vary widely, with some plant species producing elaiosomes with higher concentrations of protein or carbohydrates than of lipids. Elaiosomes of even quite closely related plant species can vary in chemical composition. Once ants encounter a seed with an elaiosome, they generally return to the nest with that seed, remove the elaiosome, and consume it, although which individuals within the nest consume the elaiosome is in many cases unclear. Once the elaiosomes have been removed, seeds are then disposed of either within the nest or outside of the nest, where they can be potentially secondarily dispersed by wind, water, or animals, including other ant species. This primer will focus on primary dispersal, the initial movement of seeds away from a parent plant. This primer defines myrmecochory, provides an overview of elaiosome traits, summarizes how ants choose and interact with elaiosome-bearing seeds, describes the current understanding of how elaiosomes evolved, and touches on how ant seed dispersal may respond to anthropogenic changes, such as the introduction of invasive species and climate change. This primer is guided by five major questions: (i) What is seed dispersal and myrmecochory? (ii) What are the benefits of myrmecochory? (iii) What is an elaiosome? (iv) How do ants choose and interact with seeds? (v) How did elaiosomes and myrmecochory evolve? [ABSTRACT FROM AUTHOR]

Mutualisms constitute a diverse class of ecologically important interactions, yet their ecological and evolutionary stability remain topics of debate in coevolutionary theory. Recent theoretical and empirical work has suggested that coevolutionary arms races may be involved in the maintenance of mutualistic interactions, sustaining mutually beneficial outcomes for interacting species while producing exaggerated traits. Here we present an individual-based model that evaluates how asynchronous life histories—that is, partners with different average lifespans—change the dynamics of trait coevolution, the expected fitness outcomes for species involved, and the dynamics of selection differentials across time for each species. Results indicate that a longer-lived mutualist will consistently "lose" an otherwise balanced coevolutionary arms race, being outpaced in both the mean trait value and fitness outcome compared with a shorter-lived partner. Furthermore, linear selection differentials on mutualistic traits become increasingly divergent as life histories become increasingly asynchronous, with the longer-lived species experiencing persistent directional selection and the shorter-lived species experiencing weaker, more inconsistent selection. These results suggest that asynchronous life histories can complicate the maintenance of mutualistic interactions via coevolutionary arms races and that detecting coevolution via selection differentials may be difficult when life histories are sufficiently divergent. [ABSTRACT FROM AUTHOR]

Host-associated organisms (i.e., symbionts) commonly interact within their shared hosts to form complex ecological communities. Here we suggest that within-host facilitation, where the presence of one symbiont group promotes establishment, growth, or reproduction of another, is prevalent, can arise from six fundamental mechanisms, and has broad implications for ecosystem dynamics. [ABSTRACT FROM AUTHOR]

Division of roles was observed during group hunting by the false cleanerfish, Aspidontus taeniatus (Blenniidae), when they raid the nests of the damselfish (Pomacentridae) and eat their guarded eggs. In this paper, we provide the first description of the collaborative group egg-eating behavior by the false cleanerfish. When raiding the nests of the three-spot dascyllus, Dascyllus trimaculatus, whose eggs are guarded by parents, the false cleanerfish divided roles as follows: "decoy" or "watcher" to draw attention and attract attacks from the parents, and "hider" or "intruder" to avoid detection by the parents and invade the nest. The potential differential costs associated with each role are unique among examples of group hunting strategies in fishes. However, once any individual in the group successfully invaded the nest, all individuals quickly achieved successful predation of the eggs and gained immediate shared benefit. We propose that the group egg-eating behavior of the false cleanerfish not only reinforces the evidence that fish can collaborate with other individuals but also suggests the hypothesis that collaborative hunting can evolve through mutualism even in fishes. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo240411at01a, and http://www.momo-p.com/showdetail-e.php?movieid=momo240411at02a. [ABSTRACT FROM AUTHOR]

Primary nectar-robbers feed through holes they make in flowers, often bypassing the plant's reproductive organs in the process. In many robbed plants, multiple holes are made in a single flower. Why a flower should be robbed repeatedly is difficult to understand: a hole signals that a nectar forager has already fed, which would seem likely to predict low rewards. We tested three explanations for this pattern in Corydalis caseana (Fumariaceae), a bumble bee pollinated and robbed plant: (1) multiple holes appear only after all flowers have been robbed once; (2) individual foragers make multiple holes during single visits; and (3) it is more profitable for bees to rob older flowers, even if they have already been robbed. We tested these hypotheses from 2014 to 2016 in a Colorado, USA population using data on robbing rates over time, floral longevity, nectar accumulation in visited and unvisited flowers, and the accumulation of robbing holes across the life of flowers. Multiple holes were already appearing when two-thirds of flowers still lacked a single hole, allowing us to reject the first hypothesis. The second hypothesis cannot offer a full explanation for multiple robbing holes because 35% of additional holes appeared in flowers one or more days after the first hole was made. Repeated sampling of bagged and exposed inflorescences revealed that flowers filled at a constant rate and refilled completely after being drained. Consequently, young flowers are of consistently low value to foragers compared to older flowers even if they had previously been robbed, consistent with the third hypothesis. While further studies are needed, these results offer a simple explanation for the paradoxical clustering of nectar-robbing damage in this and possibly other plant species. [ABSTRACT FROM AUTHOR]

This study systematically rejects the long‐standing notion of cospeciation as the dominant driver of codiversification between flowering plants and their specialist pollinators. Through cophylogenetic analysis of six classical specialized pollination systems, the research finds that cospeciation events are consistently outnumbered by non‐cospeciation events, such as host‐switch, duplication, and association losses. The findings support a more dynamic and diffuse codiversification paradigm, highlighting the importance of considering a broader range of evolutionary events in understanding plant–pollinator codiversification. This new understanding is robust across diverse pollination systems and has significant implications for conservation strategies in the face of environmental change. [ABSTRACT FROM AUTHOR]

Introduction: Pollinating flower-consuming mutualisms are considered exemplary models for studying coevolution due to their rarity. Visual cues are considered to have a major role in facilitating the evolution of floral patterns in these systems. We present a new specialized pollinating flower-consuming mutualism from the plant Wurfbainia villosa, which is a traditional Chinese herbal medicine, by a pollinating weevil, Xenysmoderes sp. Methods: In this study, We utilized monochrome plates for binary-choice tests to determine weevil color preferences, conducted behavioral choice experiments, using trackballs, photographed flowers and weevils, and employed blue sticky boards to attract weevils in the field. Results: Tests were conducted using colorpreferring weevils in both indoor and outdoor field systems, and validation experiments were performed. Behavioral tests were conducted to investigate the role of the visual cues in the pollinator attraction of W. villosa, which is a selfcompatible insect-pollinated plant that relies primarily on the Xenysmoderes sp. weevil for pollination due to its specialized gynandrium-like structure. Behavioral tests demonstrated that a blue color wavelength of 480 nm and the blue color system, as along with the UV-style pattern of the flowers, particularly the parts with specialized gynandrium-like structures in the labellum, were significantly attractive to both male and female weevils. These results were further confirmed through the field blue sticky board trap method. Discussion: These findings indicated that the interaction between W. villosa and Xenysmoderes sp. weevil was a novel symbiotic relationship involving pollinator flower consumption. Additionally, Wurfbainia villosa flowers developed specific visual cues of UV patterns and specialized structures that played a crucial role in attracting pollinators. [ABSTRACT FROM AUTHOR]

While different stages of mutualism can be observed in natural communities, the dynamics and mechanisms underlying the gradual erosion of independence of the initially autonomous organisms are not yet fully understood. In this study, by conducting the laboratory evolution on an engineered microbial community, we reproduce and molecularly track the stepwise progression towards enhanced partner entanglement. We observe that the evolution of the community both strengthens the existing metabolic interactions and leads to the emergence of de novo interdependence between partners for nitrogen metabolism, which is a common feature of natural symbiotic interactions. Selection for enhanced metabolic entanglement during the community evolution repeatedly occurred indirectly, via pleiotropies and trade-offs within cellular regulatory networks, and with no evidence of group selection. The indirect positive selection of metabolic dependencies between microbial community members, which results from the direct selection of other coupled traits in the same regulatory network, may therefore be a common but underappreciated driving force guiding the evolution of natural mutualistic communities. Here, the authors investigate the mechanisms behind mutualism with an engineered microbial community, finding that repeated indirect selection for enhanced metabolic dependencies may be a common factor in the evolution of mutualistic communities. [ABSTRACT FROM AUTHOR]

Background: The symbiosis among plants, rhizobia, and arbuscular mycorrhizal fungi (AMF) is one of the most well-known symbiotic relationships in nature. However, it is still unclear how bilateral/tripartite symbiosis works under resource-limited conditions and the diverse genetic backgrounds of the host. Results: Using a full factorial design, we manipulated mungbean accessions/subspecies, rhizobia, and AMF to test their effects on each other. Rhizobia functions as a typical facilitator by increasing plant nitrogen content, plant weight, chlorophyll content, and AMF colonization. In contrast, AMF resulted in a tradeoff in plants (reducing biomass for phosphorus acquisition) and behaved as a competitor in reducing rhizobia fitness (nodule weight). Plant genotype did not have a significant effect on AMF fitness, but different mungbean accessions had distinct rhizobia affinities. In contrast to previous studies, the positive relationship between plant and rhizobia fitness was attenuated in the presence of AMF, with wild mungbean being more responsive to the beneficial effect of rhizobia and attenuation by AMF. Conclusions: We showed that this complex tripartite relationship does not unconditionally benefit all parties. Moreover, rhizobia species and host genetic background affect the symbiotic relationship significantly. This study provides a new opportunity to re-evaluate the relationships between legume plants and their symbiotic partners. [ABSTRACT FROM AUTHOR]

Dispersal is a key process in ecology and evolution. While the effects of dispersal on diversity are broadly acknowledged, our understanding of the influence of diversity on dispersal remains limited. This arises from the dynamic, context-dependent, nonlinear and ubiquitous nature of dispersal. Diversity outcomes, such as competition, mutualism, parasitism and trophic interactions can feed back on dispersal, thereby influencing biodiversity patterns at several spatio-temporal scales. Here, we shed light on the dispersal–diversity causal links by discussing how dispersal–diversity ecological and evolutionary feedbacks can impact macroecological patterns. We highlight the importance of dispersal–diversity feedbacks for advancing our understanding of macro-eco-evolutionary patterns and their challenges, such as establishing a unified framework for dispersal terminology and methodologies across various disciplines and scales. This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'. [ABSTRACT FROM AUTHOR]

Cyanobacteria are globally occurring photosynthetic bacteria notable for their contribution to primary production and production of toxins which have detrimental ecosystem impacts. Furthermore, cyanobacteria can form mutualistic symbiotic relationships with a diverse set of eukaryotes, including land plants, aquatic plankton and fungi. Nevertheless, not all cyanobacteria are found in symbiotic associations suggesting symbiotic cyanobacteria have evolved specializations that facilitate host-interactions. Photosynthetic capabilities, nitrogen fixation, and the production of complex biochemicals are key functions provided by host-associated cyanobacterial symbionts. To explore if additional specializations are associated with such lifestyles in cyanobacteria, we have conducted comparative phylogenomics of molecular functions and of biosynthetic gene clusters (BGCs) in 984 cyanobacterial genomes. Cyanobacteria with host-associated and symbiotic lifestyles were concentrated in the family Nostocaceae, where eight monophyletic clades correspond to specific host taxa. In agreement with previous studies, symbionts are likely to provide fixed nitrogen to their eukaryotic partners, through multiple different nitrogen fixation pathways. Additionally, our analyses identified chitin metabolising pathways in cyanobacteria associated with specific host groups, while obligate symbionts had fewer BGCs. The conservation of molecular functions and BGCs between closely related symbiotic and free-living cyanobacteria suggests the potential for additional cyanobacteria to form symbiotic relationships than is currently known. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Chemoreception is crucial for insect fitness, underlying for instance food-, host-, and mate finding. Chemicals in the environment are detected by receptors from three divergent gene families: odorant receptors (ORs), gustatory receptors (GRs), and ionotropic receptors (IRs). However, how the chemoreceptor gene families evolve in parallel with ecological specializations remains poorly understood, especially in the order Coleoptera. Hence, we sequenced the genome and annotated the chemoreceptor genes of the specialised ambrosia beetle Trypodendron lineatum (Coleoptera, Curculionidae, Scolytinae) and compared its chemoreceptor gene repertoires with those of other scolytines with different ecological adaptations, as well as a polyphagous cerambycid species. Results: We identified 67 ORs, 38 GRs, and 44 IRs in T. lineatum ('Tlin'). Across gene families, T. lineatum has fewer chemoreceptors compared to related scolytines, the coffee berry borer Hypothenemus hampei and the mountain pine beetle Dendroctonus ponderosae, and clearly fewer receptors than the polyphagous cerambycid Anoplophora glabripennis. The comparatively low number of chemoreceptors is largely explained by the scarcity of large receptor lineage radiations, especially among the bitter taste GRs and the 'divergent' IRs, and the absence of alternatively spliced GR genes. Only one non-fructose sugar receptor was found, suggesting several sugar receptors have been lost. Also, we found no orthologue in the 'GR215 clade', which is widely conserved across Coleoptera. Two TlinORs are orthologous to ORs that are functionally conserved across curculionids, responding to 2-phenylethanol (2-PE) and green leaf volatiles (GLVs), respectively. Conclusions: Trypodendron lineatum reproduces inside the xylem of decaying conifers where it feeds on its obligate fungal mutualist Phialophoropsis ferruginea. Like previous studies, our results suggest that stenophagy correlates with small chemoreceptor numbers in wood-boring beetles; indeed, the few GRs may be due to its restricted fungal diet. The presence of TlinORs orthologous to those detecting 2-PE and GLVs in other species suggests these compounds are important for T. lineatum. Future functional studies should test this prediction, and chemoreceptor annotations should be conducted on additional ambrosia beetle species to investigate whether few chemoreceptors is a general trait in this specialized group of beetles. [ABSTRACT FROM AUTHOR]

Mutualistic and similar ecological associations between tarantulas (Mygalomorphae: Theraphosidae) and other animals are reviewed. Such associations are found to occur in at least nine theraphosid subfamilies. We present 63 new cases of theraphosid–anuran associations from 10 countries, documenting these interactions for the first time in Brazil, Chile, the Dominican Republic, and the Philippines. These findings are the first documentation of such associations for 13 theraphosid and 20 anuran taxa. Additionally, we report, for the first time, associations potentially of mutualistic nature between tarantulas and snakes, whip spiders, and harvestmen. Furthermore, we provide new reports of associations with ants and termites. While some of these interactions appear to be merely tolerated cohabitations, those involving anurans and ants seem to be more prevalent and complex, clearly offering benefits for both organisms. Additionally, based on multiple observations and field experiments, we propose a new hypothesis regarding the evolution of hirsuteness in theraphosids as a defensive strategy against predatory ants. This hypothesis supports previous findings that suggest a similar function for urticating setae incorporated into egg sacs and moulting mats. We further document a unique escape strategy against ants in New World arboreal theraphosids. Finally, the possibility of a chemical defence mechanism through specialised epidermal glands in theraphosids is briefly discussed. [ABSTRACT FROM AUTHOR]

The article discusses the role of microbes in facilitating communication among plants in agroecosystems. It proposes categorizing plant genes involved in plant-microbe interactions into microbiome-shaping genes (Ms genes) and microbiome-responsive genes (Mr genes). Ms genes shape microbial communities through various mechanisms, such as the modulation of metabolites and the transfer of miRNAs. On the other hand, Mr genes are sensitive to microbial activity and regulate plant adaptation to environmental stressors. The article suggests that understanding the interaction between Ms and Mr genes can inform the design of precision agriculture and breeding strategies. [Extracted from the article]

This paper considers the resources of Trinitarian theology for conceiving of the relationship between divine action and the natural world. We begin with the core commitments of Trinitarian theology alongside common desiderata for divine action, namely a conception of reality that grants sufficient independence to creation to allow meaningful interaction with and from the Creator. I then examine this claim in the light of contrasting non-Trinitarian theistic approaches and argue that Trinitarian theology uniquely grounds a particular kind of motivated divine action that undergirds the value of volitional and nomic independence within a framework of mutuality in relationship. [ABSTRACT FROM AUTHOR]

Ectomycorrhizal fungi employ different strategies for mycelial growth and host colonization under varying nutrient conditions. However, key genes associated with mycorrhizal interaction should be influenced solely by the inoculation treatment and not by nutrient variations. To utilize subtle nutrient differences and rapidly screen for key genes related to the interaction between Suillus luteus and Pinus massoniana, we performed an inoculation experiment using culture bottles containing high- and low-nutrient media. Interestingly, S. luteus LS88 promoted the growth of P. massoniana seedlings without mature ectomycorrhiza, and the impact of LS88 inoculation on P. massoniana roots was greater than that of nutrient changes. In this study, the resequenced genome of the LS88 strain was utilized for transcriptome analysis of the strain. The analysis indicated that a unique gene encoding glutathione S-transferase (GST) in LS88 is likely involved in colonizing P. massoniana roots. In this study, the GST gene expression was independent of nutrient levels. It was probably induced by P. massoniana and could be used as a marker for S. luteus colonization degree. [ABSTRACT FROM AUTHOR]

Simple Summary: In symbiotic interactions, microorganisms associated with the intestinal tract, constituting the gut microbiome, are especially important, because they influence the life history and fitness of their host organisms. The gut microbiome of ground beetles, one of the most species-rich animal families, is poorly known, and research on sex-specific differences is almost completely missing. Investigating the gut bacterial microbiome of a widespread European carnivorous species, Carabus convexus, using next-generation high-throughput sequencing, we found 1138 different operational taxonomic units belonging to 21 bacterial phyla, 90 families, and 197 genera. One of the most abundant bacterial families and genera was previously not known from the digestive tracts of other ground beetle species. We also detected carbohydrate-degrading gut bacterial symbionts, which indicated possible plant feeding in this predatory species. Although the composition of the gut bacterial microbiome was not significantly different between the sexes, the gut symbionts showed more between-individual variability in females. This difference may result from the different mobility of sexes and the difference in reproductive investment. Biological interactions, including symbiotic ones, have vital roles in ecological and evolutionary processes. Microbial symbionts in the intestinal tracts, known as the gut microbiome, are especially important because they can fundamentally influence the life history, fitness, and competitiveness of their hosts. Studies on the gut-resident microorganisms of wild animals focus mainly on vertebrates, and studies on species-rich invertebrate taxa, such as ground beetles, are sparse. In fact, even among the species-rich genus Carabus, only the gut microbiome of two Asian species was studied, while results on European species are completely missing. Here, we investigated the gut bacterial microbiome of a widespread European Carabus species, targeting the V3 and V4 regions of the 16S ribosomal RNA genes by next-generation high-throughput sequencing. We identified 1138 different operational taxonomic units assigned to 21 bacterial phyla, 90 families, and 197 genera. Members of the carbohydrate-degrading Prevotellaceae family, previously not detected in ground beetles, were the most abundant in the gut microbiome of the carnivorous C. convexus. Presumably, individuals from the studied wild populations also consume plant materials, especially fruits, and these carbohydrate-degrading bacterial symbionts can facilitate both the consumption and the digestion of these supplementary foods. [ABSTRACT FROM AUTHOR]

Based on 1,364 children across Grades 1, 3, and 5, the present study explored the mutualism of (externalizing and internalizing) behavioral problems and language, and whether social skills explained such mutualism. The random intercept cross-lagged panel models were conducted to control for between-person level variance and to explore mutualism of variables on the within-person level. Results indicated the mutualistic coupling of language and externalizing behavioral problems from Grades 3 to 5. When including social skills in the model, only social skills and externalizing behavioral problems formed the mutualism from Grades 3 to 5; language only predicted behavioral problems and social skills in the early elementary stage (Grades 1–3). These results suggest that language and behavioral management early on are important investing skills for the development of language, behavior skills, and social skills. With development, social skills may become more important than general language skills to manage problem behaviors. These findings indicated that interventions targeting behavioral problems may need to adapt their focus as children develop: fostering general language abilities early on but shifting to building social skills in later grades. Educational Impact and Implications Statement: This work shows that language is important for social skills and behavioral management early on. With development, social skills become more important than language skills for managing behavioral problems. To target behavioral problems, it may be important to foster language abilities early on but shift to building social skills in later grades. [ABSTRACT FROM AUTHOR]

The article investigates the effect of seasonal rainfall pattern on the phenology of the fig plant, Ficus racemosa, from north Kerala, South India. The study examines changes associated with uncommon rainfall patterns, humidity and temperature, including leaf and syconium phenology at various developmental stages, synchrony and asynchrony on individual plants, development of fig pollinators, leaf falling, leaf flushing and leaf maturation.

Copyright of Biodiversity & Conservation is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Cyanobacteria are globally occurring photosynthetic bacteria notable for their contribution to primary production and production of toxins which have detrimental ecosystem impacts. Furthermore, cyanobacteria can form mutualistic symbiotic relationships with a diverse set of eukaryotes, including land plants, aquatic plankton and fungi. Nevertheless, not all cyanobacteria are found in symbiotic associations suggesting symbiotic cyanobacteria have evolved specializations that facilitate host-interactions. Photosynthetic capabilities, nitrogen fixation, and the production of complex biochemicals are key functions provided by host-associated cyanobacterial symbionts. To explore if additional specializations are associated with such lifestyles in cyanobacteria, we have conducted comparative phylogenomics of molecular functions and of biosynthetic gene clusters (BGCs) in 984 cyanobacterial genomes. Cyanobacteria with host-associated and symbiotic lifestyles were concentrated in the family Nostocaceae, where eight monophyletic clades correspond to specific host taxa. In agreement with previous studies, symbionts are likely to provide fixed nitrogen to their eukaryotic partners, through multiple different nitrogen fixation pathways. Additionally, our analyses identified chitin metabolising pathways in cyanobacteria associated with specific host groups, while obligate symbionts had fewer BGCs. The conservation of molecular functions and BGCs between closely related symbiotic and free-living cyanobacteria suggests the potential for additional cyanobacteria to form symbiotic relationships than is currently known.

This article develops a novel theory of sport that I call 'Confucian mutualism'. Confucian mutualism is underpinned by the Confucian Golden Rule and the Confucian conception of human dignity. It resembles the mutualist theory of sport developed by Robert L. Simon in maintaining that sport participants ethically ought to prioritize promoting sporting excellence both in themselves and in their co-participants. However, while Simon's mutualism maintains that sporting excellence consists in proficiency at sport constitutive skills, Confucian mutualism maintains that sporting excellence consists in success at achieving the Confucian virtues through sport participation. I provide a preliminary case for why Confucian mutualism's virtue-centric conception of sporting excellence makes it better able than Simon's mutualism to explain why sporting excellence is stance-independently ethically significant for all sport participants. I do so by trying to show that we have prima facie justification for believing that Confucian mutualism is not vulnerable to certain kinds of criticisms that have been leveled at Simon's mutualism. [ABSTRACT FROM AUTHOR]

The practices of social movements during the pandemic show how severe limitations on political and social organization have been turned into opportunities by increasing the focus on social justice and care-based initiatives, building trust and solidarity. This case study explores how the urban militants of the anti-military occupation movement A Foras (Out) maintained visibility during the pandemic. Besides calling attention to the unethical growth of military spending concurrent with the lack of investment in public health during the COVID-19 crisis, the movement engaged in mutualistic action against pandemic-related issues, such as isolation, and social exclusion. We examine ethnographically this hybridized mobilization, which is grounded on the significance of solidarity, community, and the nature of public life. By making social inequality, exclusion and isolation more visible, mutualistic practices act in the social justice arena as a 'purposive orientation'. This case study offers an example of a grassroots social movement renewing its space of knowledge production by widening its agency and reconfiguring care as an action for political change, adding to the notion of caring democracy by giving rise to a mutualist initiative based on horizontality and potential reciprocity. The article provides an up-to-date understanding of how imaginaries and care practices activated around solidarity, security, and safety are recasting society in southern Europe in the wake of COVID-19. It contributes to the debate around caring democracy in social movements studies by rethinking the significance of caring infrastructures and, ultimately, the meaning of solidarity and trust. [ABSTRACT FROM AUTHOR]

Our ethnographic fieldwork with Congolese and Zimbabwean economic migrants, asylum seekers, refugees and educational migrants reveals a complex narrative of exclusion and inclusion in South Africa. Frontier Africans – South African citizens and African transmigrants alike – initiate and maintain connections that create a vexing and entangled narrative of hard and soft borders. A deeper consideration of how South African citizens and African transmigrants subvert and transcend state-centric categorisation of citizen and migrant other, through amity, conviviality and mutuality – a process of humaning – harasses the alignment of political categorisation with analytical elucidation. [ABSTRACT FROM AUTHOR]