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Biparental care can be favoured when offspring care by both parents provides a stronger fitness incentive to parents than deserting their offspring. In species with precocial offspring, the burden of care is expected to be comparatively low, facilitating desertion by one parent and uniparental care by the abandoned partner. However, care patterns can vary widely between and within precocial species, with some parents deserting their offspring, while other families remain biparental. Understanding the details of the care delivered by males and females in families before desertion is important to provide insight into the mechanisms that influence the stability of biparental care. Here we used detailed behavioural observations from the brood care period to investigate the balance of care between male and female parents in a well-studied precocial shorebird, the Kentish plover, Charadrius alexandrinus , both within families where females subsequently deserted and within families that remained biparental until the offspring were independent. We found that both males and females expressed all care behaviours (brooding, vigilance and brood defence) characteristic of precocial species, and we utilized quantitative mutual entropy analyses to show that the division of parental labour (i.e. care task specialization) was unrelated to the maintenance of biparental care. We also found that while males and females provided broadly similar levels of care, there were subtle differences: females typically delivered slightly more care than males across offspring development, suggesting that sex differences in self-maintenance may underlie sex differences in care. Together our results indicate minor differences in the care patterns of males and females, consistent with theoretical predictions that the division of labour should be limited in populations with frequent desertion and uniparental care. • A division of labour between parents should promote biparental care. • We assessed patterns of brood care in a wild population of Kentish plovers. • Male and female care patterns were similar but females cared slightly more. • The division of labour was not associated with female brood desertion. • Sex differences in care are linked with differences in rates of self-maintenance. [ABSTRACT FROM AUTHOR]

Division of labour is an important factor of social insect ecological success. However, the specific mechanisms associated with division of labour differ widely between species. Often, social groups have to cope with severe perturbations and resume normal functioning as quickly as possible. How well they do so depends on the behavioural mechanisms involved and on species life-history traits. Here, we studied the division of labour in D. lucida, a threatened species of native Brazilian queenless ants with small colony sizes, to assess whether colonies facing a drastic perturbation of the established task allocation are resilient, and through which potential mechanisms. We first separated the colonies into two sub-colonies, one with the foragers and the other with the nurses. As this is an important modification of colony structure, we expected workers to respond quickly by switching tasks. Our experiment showed that, contrary to our hypotheses, workers showed little plasticity in switching tasks, and colonies did show very limited resilience. Foragers, when isolated from nurses, show a certain plasticity in their behavioural repertoire, performing both tasks (foraging and nursing). However, groups of nurses facing the absence of foragers kept almost exclusively to nursing tasks. Only a few performed episodic outside activities. When workers were returned to their original colonies, foragers switched back to foraging. However, the effect of the manipulation could still be observed 20 days after reintroduction, with workers showing lower general activity, ingesting larvae and reproductive workers losing their dominance. Considering our current knowledge about the regulation of both division of labour and reproductive hierarchies in Dinoponera and other ponerine ants, we propose that this lack of resilience is due to the reproductive conflict between nurses, which delays behavioural maturation and reduces motivation to engage in outside tasks. The existence of individual strategies thus imposes severe costs on group functioning. This could be an additional issue when considering the conservation of this endangered species. [ABSTRACT FROM AUTHOR]

Stingless bees are a widespread group of highly social bees found in tropical regions throughout much of the world. Despite an impressive diversity, relatively little is known about worker behaviour and division of labour. In this study, we investigate the progression of colony tasks over the lifespan of worker bees in colonies of the two most commonly kept Australian species: Tetragonula carbonaria and T. hockingsi. We marked cohorts of 25–100 newly emerged female bees with a paint dot and released them back into colonies housed in observation hives before recording twice weekly behaviours of marked bees within the nest. Foragers were observed through a clear plastic entrance tube. We replicated this with 5–6 marked cohorts across three colonies for each species. We found the two species were similar to each other in the frequency and age distribution of behaviours. Young worker bees were mostly found cleaning, filling or constructing brood cells and collecting honey from food pots. Middle aged bees were more likely to build or maintain food pots or supporting structures, with guarding and foraging occupying the oldest bees. There was, however, significant overlap in timing of tasks. Moreover, fast cohorts progressed to foraging in less than half the time of the slowest cohorts. Despite subtle differences between our Tetragonula species and other stingless bees, it adds to the evidence that progression from safe to risky jobs with age is an ancestral feature shared across stingless bees, and has similarities to honeybees despite an independent evolutionary origin. [ABSTRACT FROM AUTHOR]

Featured Application: Traffic light scheduling optimisation using a task allocation model based on division-of-labour behaviour as observed in insect colonies. Traffic light scheduling is a critical aspect of traffic management with many recently developed solutions that incorporate computational intelligence approaches. This paper presents a traffic light scheduling algorithm based on a task allocation model that simulates the division of labour among insects in a colony, specifically ant colonies. The developed algorithm switches the green light based on a probability calculated every second from the traffic volume around the traffic light. The application of this algorithm to several benchmark simulated traffic scenarios shows optimal performance compared to five other traffic scheduling algorithms. [ABSTRACT FROM AUTHOR]

Heteranthery, the presence of different types of anthers on the same flower, is a floral adaptation that aims to balance the need for pollinators to collect pollen as a food resource while ensuring sufficient pollen for pollination. We investigate the role of heteranthery in the pollination of Senna arnottiana flowers and how it is affected by the behaviour of visiting bee species, with a particular focus on the impact of the invasive bumblebee Bombus terrestris.In three populations of S. arnottiana we measured the size of three sets of anthers and style, stigma–anther separation, pollen quantity and fruit set, and contrasted it with the body size, behaviour, and pollination effectiveness of all floral visitors.Different bee species visited S. arnottiana flowers, and their foraging behaviour varied. Large‐bodied native bees, including Centris cineraria, Caupolicana sp. and Cadeguala occidentalis, preferentially visited short anthers, whereas B. terrestris, an exotic bumblebee, foraged from both short and long anthers without distinction. In addition, B. terrestris contacted the stigma at a lower rate than large‐bodied native bees.Instead of concentrating its pollen‐gathering efforts on the feeding anthers, as predicted by the "division of labor" hypothesis, B. terrestris indiscriminately visited both types of anthers similarly. This behaviour of B. terrestris may disrupt the adaptive significance of heteranthery by mixing the roles of pollination and feeding anthers of S. arnottiana. Therefore, our results highlight the potential disruption of this relationship by exotic pollinators and the need to consider it in conservation efforts. [ABSTRACT FROM AUTHOR]

During the Cold War, large-scale urban development projects were launched in Mongolia with technical assistance from various socialist countries – China, East Germany (the GDR), Poland, Czechoslovakia and, above all, the Soviet Union. Looking at the involvement of these dissimilar countries to Mongolia, this article challenges simplistic narratives about bilateral East-South exchanges, and frames socialist development assistance as multilateral, asymmetric and complementary. It argues that some of the iconic projects of socialist development in Mongolia could hardly be called products of any one donor's aid programme, and instead required the cooperation of various providers, collaborating on multiple, interconnected fronts. Such multilateral assistance was marked by highly hierarchical racialised divisions of labour, and created strong interdependencies between various countries involved in Mongolia. [ABSTRACT FROM AUTHOR]

Historically, the division of labour within the household has been characterized by women allocating more time to domestic labour and men allocating more time to market labour. Although pressure for gender equality in both domestic and market labour is rising, it is unclear how the division of labour within the household relates to life satisfaction. Using panel data from the Household, Income, and Labour Dynamics in Australia Survey (2002–2021) and couple-fixed effects models we estimate, by gender, the relationship between own and partner’s time spent on various household responsibilities and life satisfaction using three different measures of time use for four household responsibilities. Household responsibilities are divided into routine chores, taking care of own children, outdoor tasks, and paid work. Our main findings include that household responsibilities that significantly relate to life satisfaction differ by gender. However, outdoor tasks (maintenance and gardening) positively relate to the life satisfaction of both men and women. We further find that women’s life satisfaction is more sensitive to comparisons to others, both within and outside the home, than men’s life satisfaction. The results also suggest that men experience increased life satisfaction if they spend more time on household responsibilities traditionally performed by women and less time on paid work. Conversely, women's life satisfaction does not increase with greater spousal contribution to these tasks but does increase when they themselves spend less time on paid work. [ABSTRACT FROM AUTHOR]

Guy Delisle's comics have often been categorised among the subgenres of graphic journalism, travelogues, or travel autobiographies. Nonetheless, apart from the obvious detailed depictions of his travel impressions – an amply elaborated topic– there are some important, yet overlooked, recurring themes such as the aporia of creative labour, and the consequences of the changing nature and organisation of work from the beginning of the 1980s to the late 2010s on cultural industries and comics profession. Delisle's memoirs delineate different types of organisational structures, interpersonal relations, and working conditions from the time he was employed as a salaried labourer and animator, along with the setting in which he had to perform his job as a self-employed, freelance artist. His visual narrations constitute a canvas of anecdotes and events, revolving around his working environment and professional context, not only during his sojourn in various countries but also in his hometown, Quebec, Canada. The present article suggests that Delisle's 'travelogues' can be better understood as 'laborlogs'. That is a term coined here from the synthesis of the word labour, toil, and log, a record book, a list, employed in order to lay emphasis on the importance of work and labour in the artist's illustrations. [ABSTRACT FROM AUTHOR]

The ecological success of social insects makes their colony organization fascinating to scientists studying collective systems. In recent years, the combination of automated behavioural tracking and social network analysis has deepened our understanding of many aspects of colony organization. However, because studies have typically worked with single species, we know little about interspecific variation in network structure. Here, we conduct a comparative network analysis across five ant species from five subfamilies, separated by more than 100 Myr of evolution. We find that social network structure is highly conserved across subfamilies. All species studied form modular networks, with two social communities, a similar distribution of individuals between the two communities, and equivalent mapping of task performance onto the communities. Against this backdrop of organizational similarity, queens of the different species occupied qualitatively distinct network positions. The deep conservation of the two community structure implies that the most fundamental behavioural division of labour in social insects is between workers that stay in the nest to rear brood, and those that leave the nest to forage. This division has parallels across the animal kingdom in systems of biparental care and probably represents the most readily evolvable form of behavioural division of labour. [ABSTRACT FROM AUTHOR]

Eusocial insects belong to distinct queen and worker castes, which, in turn, can be divided into several morphologically specialized castes of workers. Caste determination typically occurs by differential nutrition of developing larvae. We present a model for the coevolution of larval signalling and worker task allocation—both modelled by flexible smooth reaction norms—to investigate the evolution of caste determination mechanisms and worker polymorphism. In our model, larvae evolve to signal their nutritional state to workers. The workers evolve to allocate time to foraging for resources versus feeding the brood, conditional on the larval signals and their body size. Worker polymorphism evolves under accelerating foraging returns of increasing body size, which causes selection to favour large foraging and small nursing workers. Worker castes emerge because larvae evolve to amplify their signals after obtaining some food, which causes them to receive more food, while the other larvae remain unfed. This leads to symmetry-breaking among the larvae, which are either well-nourished or malnourished, thus emerging as small or large workers. Our model demonstrates the evolution of nutrition-dependent caste determination and worker polymorphism by a self-reinforcement mechanism that evolves from the interplay of larval signalling and worker response to the signals. [ABSTRACT FROM AUTHOR]

Using the Canadians Censuses of 2001, 2006, 2016, and the National Household Survey of 2011, this article compares intra-household specialization patterns of married and cohabiting couples by gender composition of households. Household specialization is operationalized in several ways. The first set of measures captures the earnings differentials between spouses, while the second set of measures relies on labour supply. In line with previous studies, we often find a lower level of intra-household specialization for both male-male and female-female couples, compared with their heterosexual counterparts. However, the difference with heterosexuals is much larger for female-female couples. When the most recent dataset is split by income level, it appears that the specialization gaps are largely driven by the more affluent households. We also find considerable heterogeneity in the patterns when the sample is split by generational status. [ABSTRACT FROM AUTHOR]

The joint actions of animals in partnerships or social groups evolve under both natural selection from the wider environment and social selection imposed by other members of the pair or group. We used experimental evolution to investigate how jointly expressed actions evolve upon exposure to a new environmental challenge. Our work focused on the evolution of carrion nest preparation by pairs of burying beetles Nicrophorus vespilloides, a joint activity undertaken by the pair but typically led by the male. In previous work, we found that carrion nest preparation evolved to be faster in experimental populations without post-hatching care (No Care: NC lines) than with post-hatching care (Full Care: FC lines). Here, we investigate how this joint activity evolved. After 15 generations of experimental evolution, we created heterotypic pairs (NC females with FC males and NC males with FC females) and compared their carrion nest making with homotypic NC and FC pairs. We found that pairs with NC males prepared the nest more rapidly than pairs with FC males, regardless of the female's line of origin. We discuss how social coadaptations within pairs or groups could act as a post-mating barrier to gene flow. [ABSTRACT FROM AUTHOR]

The Abbé Sieyès is usually portrayed as a thoroughly modern thinker and a critic of the nostalgic Classical Republicanism of some of his contemporaries, in favour of a "modern republicanism", founded upon the division of labour and commercial sociability in a nation composed of equal labourers and producers. But Sieyès's unpublished manuscripts suggest he, in fact, regarded modern labourers as unskilled "Machines du Travail", dulled by work and incapable of exercising the duties of citizenship, a critique grounded in a critical account of commercial society as compared to the ideal republican polity. Where most scholars regard this as either a simple contradiction or a passing juvenile nostalgia, this paper argues that, influenced by Jean-Jacques Rousseau, Sieyès consistently sought to counteract the degrading effects of the inequalities generated by commercial society and the division of labour. It was on this basis that Sieyès sought to construct a new political system which would reconcile participatory politics with representative government, enabling all citizens to enjoy a life of Active Citizenship. Based on these insights, this paper reinterprets Sieyès's political project as an attempt to reconcile the classical conception of citizenship with the demands of a commercial society. [ABSTRACT FROM AUTHOR]

Moralists and radical realists both seem to employ a division of intellectual labour to enable their theories to be action-guiding. Moralists typically distinguish between formulating normative principles and devising suitable means for implementing or approximating them. Radical realists, meanwhile, seem to distinguish between the findings of ideology critique and further political theorising informed by these findings. However, radical realist criticisms of the moralist division of labour may suggest a tu quoque objection to radical realism: if the moralist division of labour is defective, why does the same not also hold for the radical realist division of labour? My aim in this article is to answer this question. I identify two distinct radical realist objections to the moralist division of labour, which I refer to as the seminar room objection and the motivation objection respectively. I then argue that radical realists can deal effectively with these objections if they were to be turned against their version of the division of labour. Hence, radical realists can consistently criticise moralist versions of the division of labour while simultaneously employing their own version. [ABSTRACT FROM AUTHOR]

The functioning of biological systems relies on the cooperation of specialized components and understanding the processes that produce such specialization is a major challenge in biology. Here, we study the ontogeny of biological systems at a new phenotypic level: the superorganisms (i.e. insect societies with specialized individuals).We investigate how founding queens, the earliest developmental stage of ant colonies, transition from expressing behavioural pluripotency to becoming strictly specialized in egg production.We demonstrate that the presence of workers both initiates and maintains this queen specialization, and propose that such a social control of queen behaviour is common in ants and regulated by ancestral mechanisms.These findings contradict the traditional view of social insect queens as being intrinsically specialized in egg production and may reshape our understanding of the division of labour in insect societies. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This paper contemplates repression as a factor of production in Anti-Oedipus. Repression is part of the division of labour which defines the composition of the labour–capital relation, what Deleuze and Guattari conceive of as a differential relation. In interpreting Deleuze and Guattari's concepts of repression, commentaries have elaborated on the influences of Marx's theories of reification and of the state. However, the influence of Marx's theory of division of labour in capitalism has not been fully examined. This theory, which involves dispossession of intellectual potentialities and suppression of productive drives, is essential to Deleuze and Guattari's Spinozist hypothesis that the masses came to desire fascism under a particular set of historical conditions. Through a reading of Capital, guided by Balibar's reading in particular, and an analysis of schizophrenia in alignment with Foucault's, Deleuze and Guattari develop a theory of repression as immanent to production. Based in this theory, they conceive of fascism as a line of flight from the limits of capital, emerging among several counteracting factors against the tendency for the rate of profit to fall. In assessing how repression operates in Deleuze and Guattari's form of psychoanalysis, this paper references Marx's Capital and Spinoza's Ethics as well as Balibar's contribution to the 1965 book Reading Capital and Foucault's 1962 Mental Illness and Psychology. The paper concludes with remarks on the further development of this theory in Deleuze and Guattari's 1980 A Thousand Plateaus and Deleuze's 1990 'Postscript on Control Societies'. [ABSTRACT FROM AUTHOR]

Collective behaviours, such as flocking in birds or decision making by bee colonies, are some of the most intriguing behavioural phenomena in the animal kingdom. The study of collective behaviour focuses on the interactions between individuals within groups, which typically occur over close ranges and short timescales, and how these interactions drive larger scale properties such as group size, information transfer within groups and group-level decision making. To date, however, most studies have focused on snapshots, typically studying collective behaviour over short timescales up to minutes or hours. However, being a biological trait, much longer timescales are important in animal collective behaviour, particularly how individuals change over their lifetime (the domain of developmental biology) and how individuals change from one generation to the next (the domain of evolutionary biology). Here, we give an overview of collective behaviour across timescales from the short to the long, illustrating how a full understanding of this behaviour in animals requires much more research attention on its developmental and evolutionary biology. Our review forms the prologue of this special issue, which addresses and pushes forward understanding the development and evolution of collective behaviour, encouraging a new direction for collective behaviour research. This article is part of a discussion meeting issue 'Collective behaviour through time'.

The olfactory system plays a fundamental role in mediating insect behaviour. Worker bees exhibit an age‐dependent division of labour, performing discrete sets of behaviours throughout their lifespan. The behavioural states of bees rely on their sense of the environment and chemical communication via their olfactory system, the antennae. However, the olfactory adaptation mechanism of worker bees during their behavioural development remains unclear. In this study, we conducted a comprehensive and quantitative analysis of antennal gene expression in the Apis mellifera of newly emerged workers, nurses, foragers and defenders using RNA‐seq. We found that the antenna tissues of honey bees continued developing after transformation from newly emerged workers to adults. Additionally, we identified differentially expressed genes associated with bee development and division of labour. We validated that major royal jelly protein genes are highly and specifically expressed in nurse honey bee workers. Furthermore, we identified and validated significant alternative splicing events correlated with the development and division of labour. These findings provide a comprehensive transcriptome profile and a new perspective on the molecular mechanisms that may underlie the worker honey bee division of labour. [ABSTRACT FROM AUTHOR]

In highly organized animal societies, behavioural heterogeneity of the members can be crucial for group success. In contrast to eusocial insects, in which task specialization is common, a clear division of labour is often absent in cooperatively breeding species. In these species, contributions to different tasks are sometimes positively correlated across individuals; this phenomenon is called helping syndrome. Previously, eusocial naked mole-rats, Heterocephalus glaber , were thought to display a helping syndrome consisting of burrowing, food carrying and nest building. However, previous studies combined different burrowing tasks in which the locomotive patterns varied widely, possibly missing substantial variation in the behavioural types of individuals. Therefore, it is necessary to reexamine the relations between task contributions among naked mole-rats in more detail. This study analysed six types of activities including four tasks in captive naked mole-rats, and partially confirmed the presence of a helping syndrome in nonbreeding individuals. Frequencies of different activities were significantly positively correlated across individuals in some combinations, but were not significantly correlated in other combinations. Also, individual behavioural types did not simply depend on activity time. Although age- or size-based polyethisms were found in different trends across task types, the results of the correlations between tasks remained mostly unchanged after controlling for the effects of age or body mass. This suggests large interindividual variation that could not be sufficiently explained by age- or size-based polyethisms. The partial support of a helping syndrome suggested that the task allocation system among these eusocial mammals may be more complex than previously assumed. • Contributions to different tasks are often positively correlated in helpers. • The correlations were partially positive in the naked mole-rat. • Age- or size-based polyethisms were found in different trends across task types. • Relationships between tasks did not change even accounting for age or body mass. [ABSTRACT FROM AUTHOR]

The dynamics of basic and applied research at university and industry have steadily changed since the Eighties, with the private sector reducing its investments in science and universities experiencing significant remodelling in the governance of their funding. While studies have focussed on documenting these changes in industry, less attention has been paid to observe the trajectories of basic and applied research in universities. This work contributes to fill this gap by looking at the evolution of publicly funded research that has been patented by universities between 1978 and 2015. First, we adopt a critical perspective of the basic versus applied dichotomy and identify patents according to three typologies of research: basic, mission-oriented, and applied research. Second, we describe the evolution of these three typologies in universities compared to industry. Our results show that over the years, patents from academic research that was publicly funded have become more oriented towards pure basic research, with mission-oriented basic research and pure applied research decreasing from the late 1990s. These results complement and extend the literature on basic and applied research dynamics in the private sector. By introducing mission-oriented research as a type of basic research with consideration of use, the work problematises the basic and applied research dichotomy and provides insights into the evolution of academic research focus, offering a more complex picture of how university research contributes to industry and broader social value creation. [ABSTRACT FROM AUTHOR]

As gender equality is the basis for realizing social–environmental–economic sustainability, inequality in gender can significantly hamper economic productivity and negatively affect individuals’ lives. This study examines the desired attitudes towards gender norms that can be used to improve gender inequality in a developing country for sustainable development. A survey was conducted with 230 adults from middle-income households in Lahore, Pakistan. A paired sample t-test was used to determine the difference between the desired role allocation for men and women and gender stereotypes. The results revealed that participants believed in the traditional private/public division of gender roles. However, the inclination towards gender equality in daily activities in the public domain, such as shopping and meeting friends and certain professions (e.g., white-collar jobs), encourages empowerment-based intervention. To enhance gender equality in Pakistan and similar societies, people must know they are not alone in thinking and prioritizing gender equality in everyday roles and professions. Acknowledging that ‘others’ in society are also willing to forego traditional patriarchal trends may promote action toward the desired perception.

This study explores a new governance mechanism aimed at regional integration and explains how this mechanism can achieve optimal governance of water resources through the division of labour in politics and the economy. This study adopts political economic geography as the research approach. The data used in the analysis were obtained from official documents, interviews and field investigations, and its authenticity was interactively checked via triangulation. The results show that ‘spatial shifts’ were the driving force behind water redistribution. The division of labour between politics and the economy eliminates obstacles to water distribution through the mutual adjustment and division of underground rhizomes; ‘creative destruction’ and ‘destructive creation’ are alternately used to achieve dialectical progress. This study concludes that in this case, the process of regional integration simultaneously generates circular mechanisms in which political power and economic productivity are consolidated.

Traffic light scheduling is a critical aspect of traffic management with many recently developed solutions that incorporate computational intelligence approaches. This paper presents a traffic light scheduling algorithm based on a task allocation model that simulates the division of labour among insects in a colony, specifically ant colonies. The developed algorithm switches the green light based on a probability calculated every second from the traffic volume around the traffic light. The application of this algorithm to several benchmark simulated traffic scenarios shows optimal performance compared to five other traffic scheduling algorithms.

This research was conducted to determine the relationship between the organizational climate variable and the job satisfaction variable among administrative employees in a UGEL in Nuevo Chimbote, 2023. The study was non-experimental and had a correlational design. A sample of 82 employees from the educational unit in question was surveyed using two validated questionnaires for each variable. The questionnaire on organizational climate consisted of 5 dimensions with 50 items, while the job satisfaction questionnaire comprised 7 dimensions with 36 items. In the end, a low but significant correlation between the variables was confirmed, which was established through the Spearman's Rho statistic = 0.273 with a p-value of 0.000. [ABSTRACT FROM AUTHOR]

The size–complexity rule posits that the evolution of larger cooperative groups should favour more division of labour. Examples include more cell types in larger multicellular organisms, and more polymorphic castes in larger eusocial colonies. However, a correlation between division of labour and group size may reflect a shared response of both traits to resource availability and/or profitability. Here, this possibility was addressed by investigating the evolution of sterile caste number (worker and soldier morphotypes) in termites, a major clade of eusocial insects in which the drivers of caste polymorphism are poorly understood. A novel dataset on 90 termite species was compiled from the published literature. The analysis showed that sterile caste number did increase markedly with colony size. However, after controlling for resource adaptations and phylogeny, there was no evidence for this relationship. Rather, sterile caste number increased with increasing nest–food separation and decreased with soil-feeding, through changes in worker (but not soldier) morphotype number. Further, colony size increased with nest–food separation, thus driving the false correlation between sterile caste number and colony size. These findings support adaptation to higher energy acquisition as key to the rise of complex insect societies, with larger size being a by-product. [ABSTRACT FROM AUTHOR]

Groups of animals often cooperate on shared tasks, but individual contributions are not necessarily equal: individuals can specialize on different tasks (division of labour) or vary in total work performed. Either of these patterns can have fitness consequences. However, few studies have examined division of labour and workload inequality in vertebrates. We analysed individual contributions to parental care in the greater ani, Crotophaga major , a bird that nests communally in groups of two or three pairs and up to two nonbreeding helpers. We examined nearly 600 h of video footage of 10 groups to quantify individual contributions to nest building, incubation, brooding and nestling feeding. There was no clear evidence of division of labour; rather, contributions across some behaviours were positively correlated, suggesting individual differences in overall work performed. Indeed, helpers and one of the breeding pairs in three-pair groups contributed significantly less than the other two pairs. Inequality in overall workload, as measured by the Gini coefficient, was significantly higher in three-pair groups than in two-pair groups, as predicted by collective action theory. However, there were no significant differences in inequality of specific behaviours between two- and three-pair groups, possibly due to low sample size. Finally, anecdotal observations of aggression directed at the pair that contributed the least to parental care in three-pair groups suggested that the lowest-contributing pair's access to the nest might be limited by such aggression, which could be driven by conflicts of interest over group size and membership. • Parental care workload was unevenly distributed in a communally nesting bird. • In two-pair groups, breeding pairs shared workload relatively evenly. • In three-pair groups, one breeding pair contributed less care than expected. • Neither two-pair nor three-pair groups showed clear evidence of division of labour. • Workload inequality may reflect attempts to limit access to the nest. [ABSTRACT FROM AUTHOR]

Adam Smith saw in Pufendorf the idea of a sociability prior to government, arising from a perception of the advantages of cooperation in overcoming the alleged natural inability of human beings to provide for their needs. The idea of a principle of sociability independent of government was crucial to Smith, who also addressed since the beginning of the Wealth of Nations the advantages of cooperation. However, as this article intends to show, for him sociability did not arise from the need for the assistance of others, as it is often said, but from the desire for deserved esteem. [ABSTRACT FROM AUTHOR]

Human ecological success relies on our characteristic ability to flexibly self-organize into cooperative social groups, the most successful of which employ substantial specialization and division of labour. Unlike most other animals, humans learn by trial and error during their lives what role to take on. However, when some critical roles are more attractive than others, and individuals are self-interested, then there is a social dilemma: each individual would prefer others take on the critical but unremunerative roles so they may remain free to take one that pays better. But disaster occurs if all act thus and a critical role goes unfilled. In such situations learning an optimum role distribution may not be possible. Consequently, a fundamental question is: how can division of labour emerge in groups of self-interested lifetime-learning individuals? Here, we show that by introducing a model of social norms, which we regard as emergent patterns of decentralized social sanctioning, it becomes possible for groups of self-interested individuals to learn a productive division of labour involving all critical roles. Such social norms work by redistributing rewards within the population to disincentivize antisocial roles while incentivizing prosocial roles that do not intrinsically pay as well as others. [ABSTRACT FROM AUTHOR]

This article argues that two orthodox views of meaningful work--the subjective view and the autonomy view--are deficient. In their place is proposed the contributive view of meaningful work, which is constituted by work that is both complex and involves persons in its contributive aspect. These conditions are necessary due to the way work is inherently tied up with the idea of social contribution and the interdependencies between persons. This gives such features of the contributive view a distinct basis from those found in existent accounts of meaningful work. [ABSTRACT FROM AUTHOR]

Social organisms benefit from division of labour and collective behaviours. However, if individuals overlap widely in their efforts, these benefits may not be proportional to the number of individuals that take part in an activity. We examined foraging behaviour and route fidelity in colonies of the ant Dinoponera grandis (formerly Dinoponera australis), a large species with relatively few active foragers that lack nestmate recruitment and chemical trailing behaviour. For 12 colonies, we marked individual foragers and mapped their foraging routes to test the hypothesis that each ant specializes in a particular area around the nest and that this route fidelity increases the overall area covered by the colony. For each individual, we recorded the mean direction and duration of each foraging trip, foraging success and maximal distance from the nest. For each colony, we measured the number of workers and the total foraging area. Additionally, we measured Shannon's entropy to describe foraging behaviour structure of the colonies. Overall, we mapped 272 foraging routes from 95 different foragers. The total area used by each colony averaged 66.2 m2. Within colonies, over 68% of foragers exhibited a high degree of route fidelity, with most foragers following different foraging directions. Most colonies had a high Shannon's entropy, suggesting an even exploration of the foraging territory. Our results suggest that D. grandis exhibit route fidelity and high entropy. This strategy likely increases foraging efficiency and search area and may be particularly important for species with relatively few foragers. • The giant ant Dinoponera grandis exhibits route fidelity when foraging. • Different areas within each territory were explored with similar probability. • By departing in different directions, foragers may increase their search area. • Shannon's entropy is a useful measure to quantify foraging behaviour patterns. • The number of foragers determines the size of the foraging territory. [ABSTRACT FROM AUTHOR]

The architect William Lethaby was a prolific writer of architectural history and an influential educator, yet the overriding focus he gave to practical, hands-on learning raises questions as to how he considered history might be taught to architects. This essay outlines how history teaching was considered within the establishments that Lethaby either taught in, or those where he had a significant influence over the curricula. It then reflects on his motivations, and finally, suggests how, through this seeming paradox, Lethaby was able to relate his ideas on architectural practice, teaching, and history. [ABSTRACT FROM AUTHOR]

Adam Smith saw the division of labour and specialisation as the driver of 'universal opulence', a process limited by the scope of the market. He also believed that competition was essential to ensure growth benefited the public. Yet eventually there could be a trade-off between these two mechanisms. In today's era of global production networks, the markets at certain links in supply chains may support just one specialised supplier; and in winner-take-all digital markets there is a single supplier even at global scale. When the scope of the market is global, there may be a trade-off between specialisation and competition. [ABSTRACT FROM AUTHOR]

Background Pseudanthia or 'false flowers' are multiflowered units that resemble solitary flowers in form and function. Over the last century the term 'pseudanthium' has been applied to a wide array of morphologically divergent blossoms, ranging from those with easily noticeable florets to derived, reduced units in which individual flowers become almost indistinguishable. Although initially admired mostly by botanists, the diversity and widespread distribution of pseudanthia across angiosperms has already made them a fascinating topic for evolutionary and developmental comparative studies. Scope This review synthesizes historical and current concepts on the biology of pseudanthia. Our first aim is to establish a clear, operational definition of pseudanthium and disentangle common terminological misconceptions surrounding that term. Our second aim is to summarize knowledge of the morphological and developmental diversity of pseudanthia and embed it within a modern phylogenetic framework. Lastly, we want to provide a comprehensive overview on the evolution and ecological importance of pseudanthia and outline perspectives for future studies. Conclusions The understanding of pseudanthia has changed multiple times and reflects three different interpretations of their 'flower-like' qualities: developmental (similarity in structure), figural (similarity in form and function) and phylogenetic (homology between angiosperm flowers and monoecious reproductive shoots in gymnosperms). Here, we propose to narrow the term pseudanthium to multiflowered blossoms resembling zoophilous flowers in form, i.e. in being structurally subdivided in a showy periphery and a reproductive centre. According to this definition, pseudanthia sensu stricto evolved independently in at least 41 angiosperm families. The recurrent acquisition of pseudanthia sensu stricto in all major lineages of flowering plants indicates repeated interactions between developmental constraints (smallness of flowers, meristematic conditions) and selective pressures, such as demands of pollinators and/or environmental conditions. [ABSTRACT FROM AUTHOR]

Many social insects display age polyethism: young workers stay inside the nest, and only older workers forage. This behavioural transition is accompanied by genetic and physiological changes, but the mechanistic origin of it remains unclear. To investigate if the mechanical demands on the musculoskeletal system effectively prevent young workers from foraging, we studied the biomechanical development of the bite apparatus in Atta vollenweideri leaf-cutter ants. Fully matured foragers generated peak in vivo bite forces of around 100 mN, more than one order of magnitude in excess of those measured for freshly eclosed callows of the same size. This change in bite force was accompanied by a sixfold increase in the volume of the mandible closer muscle, and by a substantial increase of the flexural rigidity of the head capsule, driven by a significant increase in both average thickness and indentation modulus of the head capsule cuticle. Consequently, callows lack the muscle force capacity required for leaf-cutting, and their head capsule is so compliant that large muscle forces would be likely to cause damaging deformations. On the basis of these results, we speculate that continued biomechanical development post eclosion may be a key factor underlying age polyethism, wherever foraging is associated with substantial mechanical demands. [ABSTRACT FROM AUTHOR]

Old Dongola, with a history reaching back to the 5th century AD, was originally the capital of Makuria, one of the three medieval Nubian kingdoms. After the collapse of Makuria, its capital city saw migratory movements and political changes that resulted in the emergence of new power relations. In the 16th and 17th centuries, the city was the seat of a local ruler subordinate to the Funj Sultanate. New communities that emerged in this setting inhabited the city until the colonial era. This paper examines the ways in which Funj-period households, as fundamental social units in Old Dongola, were mutually constitutive with houses, engaging with their spatiality and materiality through social practices. The authors investigate domestic labour, which was an essential factor in the negotiation of social differences and identities within the household. Differences in building techniques are analysed to compare various ways in which dwellers engaged with houses and to assess their implications for social differentiation within the city. [ABSTRACT FROM AUTHOR]

Juvenile hormone (JH) in insects plays a key role in regulating reproduction, but in some social insects it has also acquired secondary functions in regulating the age-related division of labour among the workers. Previous work has shown that JH regulates division of labour in honey bees, in several primitively eusocial paper wasps and in leafcutter ants, which comprise three independent origins of sociality. It remains unclear, however, to what degree JH could have a conserved role in regulating division of labour within these clades. To this end, we investigated whether JH also regulates division of labour in the highly eusocial Vespine wasp Vespula vulgaris , in which JH had previously been shown only to regulate reproduction and affect queen pheromone signalling. In line with JH having a conserved role in regulating division of labour in social wasps, we show that JH in this species indeed affected behavioural maturation and division of labour in the worker caste. In particular, topical application of the JH analogue methoprene onto workers accelerated behavioural maturation and hastened the onset of foraging, thereby significantly decreasing the time they spent conducting activities inside the nest. We discuss how this conserved role of JH in regulating division of labour could indicate the same conserved genetic toolkits being used to regulate division of labour across several independent origins of sociality. In addition, we examine the implications of JH having several pleiotropic effects in this species and discuss whether this could constrain the expression of reproductive conflicts in their societies. • JH regulates the temporal polyethism in the common wasp, V. vulgaris. • JH analogue methoprene sped up the transition from intranidal to foraging tasks. • JH has a conserved role in regulating polyethism in several social Hymenoptera. [ABSTRACT FROM AUTHOR]