Mixed-species bird flocks constitute a striking example of heterospecific sociality, offering participants potential benefits such as enhanced foraging efficiency and reduced predation risk. Yet, not all species join these flocks with the same frequency. Moreover, beyond simply participating, species may play distinct roles within flock networks. While some bird species may exhibit high nuclearity and occupy a central position in flock formation, cohesion, and dynamics (i.e., social hubs), others are merely peripheral followers. Understanding how phenotypic and ecological traits relate to both flocking propensity and network position can provide key insights into the drivers of interspecific social behavior in birds. Using a comprehensive dataset of over 3,000 flocks, we applied network theory to explore the relationship between species-level network metrics (connectivity, strength, and closeness), flocking propensity, and key phenotypic traits (residual eye size, beak shape, maximum song frequency, and plumage coloration) in Neotropical birds. Bayesian phylogenetic models revealed that flocking propensity was positively associated with maximum song frequency and carotenoid-based coloration, and negatively associated with residual eye size. In addition, the extent of white in plumage significantly predicted species centrality. This is the first study to evaluate whether acoustic and visual traits predict both flocking propensity and a species' structural role within flock networks. These findings, along with the moderate phylogenetic signal detected in network metrics, suggest that the evolution of heterospecific sociality may involve distinct morphological and sensory adaptations.

ABSTRACT This article argues that Elio Vittorini’s novels Conversazione in Sicilia (1941), Uomini e no (1945), and Il Sempione strizza l’occhio al Frejus (1947) trace a progression in his thought through their symbolic use of family structures. The organisation of the family—matriarchal, patriarchal, or post-patriarchal—functions as a metaphor for Italy’s historical, social, and moral evolution. Focusing on the elephant-grandfather in Il Sempione, I argue that he embodies a generational legacy both prosperous and complicit in the rise of Fascism. As a figure marked by ambivalence, he must be symbolically ‘eliminated’ to enable renewal. Reading the three novels in dialogue, and in light of key literary and biblical allusions, the article shows how Vittorini moves beyond a Manichaean worldview toward a more complex vision of post-war social reconstruction.

Cooperative breeders are defined by a division of reproductive labour among group members that can respond flexibly to changing conditions via phenotypic plasticity. But such plasticity can be costly and is likely to be influenced by previous experience. Polistes paper wasps live in small societies where non-reproductive (worker) and reproductive (queen) individuals can switch roles throughout adulthood. Such plasticity in reproductive roles positions them as important models for social evolution. However, the limits of their individual-level plasticity have not been fully tested. We experimentally forced queens and workers of Polistes canadensis to nest alone, requiring them to express reproductive and non-reproductive characteristics simultaneously. At the behavioural level, although all isolated wasps laid eggs and foraged, ex-queens were less good than ex-workers at brood rearing. We attribute this to subtle differences in neuroplasticity. While brain transcription of both ex-queens and ex-workers changed in response to the manipulation, converging on a state intermediate to that of control queens and workers, ex-queens did not upregulate some key molecular processes required for expression of an effective worker phenotype. Our findings demonstrate that both Polistes queens and workers can exhibit behavioural, physiological and molecular plasticity, but reveal how previous life history can impose limits to that plasticity.

ABSTRACT This article provides a philosophical response to the need for truth-telling about colonial history, focussing on the Australian context. The response consists in inviting philosophers and the public to engage in social-justice practices specified by a model called Distributed Truth-Telling (DTT), which integrates the historiography of injustices affecting Indigenous peoples with insights from social philosophy and cultural evolution theory. By contrast to official and large-scale truth commissions, distributed truth-telling is a set of non-elitist practices that weave three components: first, multisite, multiformat, and multiscale inquiries into injustices; second, remedial imaginings and reasoning about moral repair and reconciliated futures; and finally, emotions suitable for motivating agents to cooperatively plan and implement moral revolutions. Distributed truth-telling can entrench virtuous feedback loops that contribute to moral revolutions. However, vicious feedback loops associated with collective denial and biases can impair distributed truth-telling and thwart moral revolutions.

Every generation of intellectual, cultural, and political elites, from antiquity to the present, has characterized its society as being suboptimal in some respect, or heading down the wrong track, or spiraling into decay and toward oblivion, or else becoming incomprehensibly and disconcertingly complex due to social and political evolution, technological developments, population growth, demographic shifts, and so on. A key to analyzing these characterizations lies in understanding the ways in which a society vacillates between being “open”—that is, to the extent that its political and administrative structures accommodate change without bloodshed—and, conversely, becoming “closed” to the possibility of peaceful change. Open societies, desirable as they are, nevertheless contain seeds of their own destruction due to conflicting political ideologies and social visions, to competing private interests that are contrary to open societies’ overarching purposes, and to natural social, economic, and political cycles. Defensive bulwarks against these intrinsic “enemies” are essential for sustaining an open society. This article visualizes and evaluates the open society’s nature, and advances two constitutionally feasible defenses against its enemies.

Interpersonal coordination is fundamental to social evolution. We investigate its phenomenology and neural underpinnings in humans and macaques, examining the behavioral adaptations required for mutual coordination during motor interactions and the extent to which the underlying brain mechanisms are shared across species. Using a common interpersonal coordination paradigm, we conducted functional magnetic resonance imaging (fMRI) in humans and intracranial local field potential (LFP) recordings in macaques. Despite between-species behavioral discrepancies, both monkeys and humans coordinate through adjustments that proved to be based on proactive adaptation of motor planning and execution. Evidence from fMRI and time-resolved decoding analysis of LFPs converged to show modulation of premotor brain activity associated with interpersonal coordination and its effectiveness. Moreover, a dynamic sequential coding emerged, whereby the action context is represented early during planning, and coordination features near movement onset. Our findings reveal an evolutionarily conserved cortical architecture across primates that supports cooperative motor behavior.

Humans are uniquely capable of reaching consensus within large, hierarchically structured societies. Yet the pathways by which consensus emerges, especially under constraints imposed by social organization, remain poorly understood. We use an agent-based model to explore how marriage structure, social group nesting and decision-making norms can shape a group's ability to reach consensus. In our model, simulated agents are embedded in multi-level social networks and possess noisy information. Decisions are spread via three different cascades, each with different interaction norms. We find that grouping of individuals into families via marriages impedes consensus by slowing the rate of information diffusion and elevating informational entropy, especially when nested further into kin groups. By contrast, increasing the size of nested subgroups in a multi-level network reduces redundant social ties and promotes consensus. Finally, decision-making norms that rely on formation of coalitions or representative bodies lead to faster group decisions by bypassing early-stage clustering of information within families. These results offer insights into how consensus dynamics are shaped by social structure and provide a theoretical bridge between research on network topology, collective intelligence and human social evolution. This article is part of the theme issue 'The evolution of collective intelligence'.

Rethinking the epigenetic foundations of social behavior evolution in insects.

The wasps of Rhynchium exemplify solitary vespid predators controlling Lepidopteran pests through venom-mediated paralysis, with their venom possessing significant medicinal potential. As dominant models within the species-rich subfamily Eumeninae representing 70% of Vespidae diversity, they provide critical insights into sociality evolution and biocontrol mechanisms. To boost research on Vespidae, we used PacBio long-read, short-read RNA-seq (Illumina) and Hi-C scaffolding technologies to create a high-quality chromosome-level genome assembly for Rhynchium brunneum, an important solitary insect. We obtained a 328.90 Mb assembly with a Scaffold N50 size of 15.98 Mb. We detected 96.2% Benchmarking Universal Single-Copy Orthologues (BUSCO) in the genome assembly, which contains 51.77% repetitive sequences and has 12,999 protein-coding genes annotated. In R. brunneum, we identified 173 gene expansions and 274 genes that underwent contraction or loss. The high-quality genome of R. brunneum provides a valuable genetic resource for future research in evolution, molecular biology, and applied studies.

Humanity is entering a new phase of social evolution with rapid digitalisation and increasing use of artificial intelligence in our lives. Psychiatric conditions also evolve with social changes. Like other branches of medicine, the management of psychiatric conditions is benefiting from recent growth in neuroscience, neuropsychology, genetics, imaging, and technological advances. Greater public awareness of mental health conditions is reducing stigma and barriers to care. On the other hand, as social structures change, idioms of human distress and help-seeking behaviours are evolving in ways that risk overwhelming healthcare systems. It will be a challenge for healthcare strategists to strike the right balance between funding care for common conditions (often symptoms of psychosocial distress) and care for those with severe mental disorders. The answer may lie in tapping into privately funded care for common disorders, rather than through publicly funded systems—which should prioritise care of the very unwell. However, there is a significant risk that this balance will be hard to achieve in the face of vocal expectations and consumer pressures. These gaps will likely continue to widen within and between societies, especially if recent trends of egocentric political philosophies take primacy.

WCN26-432 Relationship between social vulnerability and evolution of glomerular filtration rate in patients with polycystic kidney disease

Male same-sex sexual behavior (SSB) is widespread among animal species, but its proximate (mechanistic) and ultimate (evolutionary) explanations remain unclear. A prevailing view is that SSB reflects impaired sex recognition, especially in insects. By unbiased behavioral screening, we identified a Drosophila species, D. santomea, in which males seldom attack and spontaneously court males vigorously, in addition to females. Behavioral, chemical, and optogenetic neuronal manipulations indicate that D. santomea males can distinguish conspecific sex and retain functional aggression circuitry. Instead, male SSB reflects three evolved pheromonal changes affecting two separate signaling systems, resulting in both reduced pheromone production and behavioral valence reversal. One of these occurs unexpectedly in females and may have evolved to prevent hybridization with an interfertile, geographically overlapping sibling species. Remarkably, male SSB and similar pheromonal changes also selectively co-occur in D. persimilis, a geographically and phylogenetically distant species and member of another sympatric sibling pair, implying evolutionary convergence in the two young taxa. The results identify a pheromonal mechanism for rapid social evolution in Drosophila and suggest a plausible evolutionary origin for male SSB as arising in concert with female adaptations that ensure reproductive isolation during speciation.

This article takes one of the technical cores - regulatory mechanisms - as the starting point to discuss the direct risks such as off target and chimerism caused by the failure or imperfection of regulatory mechanisms; And analyze the potential medical risks, gene pool changes, ethical risks, and social evolution risks that this technology may bring from the perspectives of personal level, reproductive genetics, ethical and social aspects, and ecological evolution. This article also attempts to propose specific and feasible risk prevention and regulatory measures from the perspectives of technology, evaluation standards, laws and regulations, and social supervision, in order to benefit the cautious and rational use of embryo gene editing technology.

Understanding the social structure and evolutionary dynamics of microbial communities requires the identification and characterization of relevant mutant subpopulations. While Pseudomonas aeruginosa employs quorum sensing (QS) to coordinate population-wide behaviors, the social traits of many QS mutants remain poorly defined. In this study, we developed an iterative "targeted gene duplication followed by mutant screening" (TGD-MS) approach to systematically identify noncanonical QS cheater mutants. We discovered that a single-nucleotide mutation in rpoA, which encodes the α subunit of RNA polymerase (RNAP), produces a QS-deficient phenotype resembling QS-null mutants. This RpoA variant mutant exhibits characteristic features of social cheating, including a competitive growth advantage in mixed populations, impaired QS-dependent virulence factor production, and attenuated pathogenicity. Structural and biochemical analyses revealed that the RpoA variant impairs RNAP binding to the promoters of core QS genes (lasI and lasR), leading to diminished QS activity. Further examination of natural RpoA variants uncovered a spectrum of QS-related phenotypes, suggesting that RpoA has a dual regulatory role in QS control. Within the C-terminal domain (α-CTD) of RpoA, we identified two distinct functional determinants that, through adaptive mutations, can acquire opposing regulatory effects on QS. This enables an environmentally dependent phenotypic switch between cooperation and cheating. Our discovery of noncanonical RpoA-mediated QS cheaters expands the framework of bacterial social evolution, demonstrating that mutations outside the canonical QS circuitry can disrupt cooperative behaviors. These findings underscore how core transcriptional machinery can be evolutionarily co-opted to modulate complex social interactions in dynamic environments.IMPORTANCETo understand how bacterial populations function and evolve, it is essential to identify socially significant subpopulations, including previously unrecognized types of cheaters. In this study, we uncover an unexpected role of RNA polymerase (RNAP) in regulating quorum sensing (QS) and QS-associated social behaviors in P. aeruginosa. Specifically, we demonstrate that the α subunit of RNAP (RpoA) is a key regulatory component in this process. A single-nucleotide mutation within the C-terminal domain of RpoA was found to alter QS activity, driving an environment-dependent transition between cooperative and cheating phenotypes. This discovery of this novel, noncanonical QS cheater mutant offers new insights into intra-population interactions, population stability, and evolutionary dynamics. These findings carry significant implications for microbial ecology and deepen our understanding of social evolution in bacterial communities.

In the family of Vespidae there are examples of social evolution that are particular, compared to those found among other social insects. The characteristics of eusociality are, however, found only in three subfamilies, those of Stenogastrinae, Vespinae and Polistinae, but the problem of whether eusociality appeared one or two times has long been debated. Biomolecular analysis studies have definitively demonstrated that the Stenogastrinae are the representatives of a social lineage completely independent from that of the Polistinae and the Vespinae. In the present paper, I want to emphasize the various phenotypic characteristics, especially studied by the group for the study of social insects of the University of Florence, which make these social wasps different from the others.

The social behaviors of microbes provide unique opportunities for testing social evolution theories. How can altruistic behaviors arise by natural selection is a central challenge in biology. Green-beard effect has been proposed as a basic mechanism for the evolution of altruistic behaviors. Yet, green-beard genes are generally thought to be rare. Here, we find that the Schizosaccharomyces pombe gsf2 gene mediates flocculation-like aggregation, and flocculation is triggered by acid stresses. gsf2-expressing cells preferentially adhere to each other. The expression of gsf2 is costly, but gsf2-expressing cells preferentially adhere to each other and protect each other from external stress. Gsf2 is highly variable in natural populations, likely contributing to different flocculation intensity. These findings suggest that gsf2 is a gradient green-beard gene that drives the altruism among gsf2 carriers. Moreover, we find that gsf2 is a new gene that originated very recently. Our results provide insights into the origin and evolution of green-beard genes.

The long-standing view that bonobos (Pan paniscus) are peaceful while chimpanzees (Pan troglodytes) are aggressive has shaped our understanding of primate and human social evolution. However, recent observations from the wild challenge this dichotomy, warranting standardized comparative analyses of aggression in the Pan species. Here, we examined aggressive interactions across 22 zoo-housed groups of chimpanzees (N = 9 groups, 101 individuals) and bonobos (N = 13 groups, 88 individuals) using Bayesian social network analysis. We find no species differences in overall or contact aggression rates, accounting for group size and sex ratio. However, aggression patterns diverge by sex: Bonobos exhibit higher female-to-male aggression, while chimpanzees show the reverse. Notably, absolute aggression rates varied substantially between groups within each species, reinforcing recent evidence on group-specific social structures in Pan. These findings challenge the traditional aggression dichotomy between bonobos and chimpanzees and provide insights into the evolutionary dynamics of social conflict strategies in great apes, including humans.

In this article, the evolution of social power is studied within a unified framework comprising two classes of individuals: oblivious individuals and stubborn individuals, whose opinion dynamics are described by the DeGroot averaging model and the Friedkin-Johnsen model, respectively. A proper subset of the simplex is identified to ensure the well-posedness of social power, and it is demonstrated that the corresponding opinion dynamics is convergent for each issue by restricting the initial social power to this proper subset. Through the reflected appraisal mechanism, a nonlinear mapping governing the social power evolution together with its invariant set is derived, and some sufficient conditions with linear time complexity for the convergence of social power are established by proving that this nonlinear mapping is contractive on the invariant set. Furthermore, for the final social power, it is found that both autocratic and democratic social power cannot be achieved during the evolution, and the average social power of oblivious individuals is larger than that of stubborn individuals, indicating that the network topology has a greater impact on social power than individual stubbornness. In addition, it is observed that the final social power ranking of oblivious individuals is consistent with their centrality ranking, and a rigorous lower bound on the final social power is derived for each stubborn individual. Finally, a numerical example is provided to demonstrate the correctness of the theoretical analysis.

• From 2003 to 2018, subcontracted mining jobs in Mexico grew by 550 %. • In gold mining, 3 out of 4 workers were hired through subcontracting. • Big companies held 88 % of all subcontracted mining workers in 2018. • Most women entered mining jobs through subcontracting. • The anti-outsourcing law cut mining subcontracting from 42 % to 24 %. This study analyzes, at the national scale, the territorial, sectoral, and social evolution, and the magnitude of labor outsourcing in the mining-metallurgical industry in Mexico between 2003 and 2018, as well as its main implications for workers. Using census data, company reports, interviews, and document reviews, the analysis shows a 550.7 % growth in outsourced work in extractive mining, concentrated in precious metals and in states such as Colima, with little presence in the metallurgical industry. The consolidation of this model was driven by large companies that, taking advantage of regulatory flexibility and union fragmentation, managed to reduce costs at the expense of lower wages, instability, and loss of labor rights of thousands of workers. Likewise, this study documents the extreme use of outsourcing as a strategy to incorporate women into mining, which accentuated specific barriers related to motherhood, workplace violence and unequal access to training and promotion, thereby reproducing structural gender inequalities. In also reveals a marked asymmetry in the use of this scheme between companies operating in Mexico, Peru, Canada, and the United States: in more institutionally flexible contexts, outsourcing is widely used, whereas in settings with stricter regulation and oversight its use is considerably lower. It is concluded that outsourcing contributed to the increase in precariousness among mine workers and that the 2021 labor reform was an effective response to its abuses, although mechanisms of labour precarisation persist and require complementary policies to strengthen labor justice.

Erratum to “Towards the integration of collective behaviour and social evolution” [Animal Behaviour 224 (June 2025) 123161