Morphological studies on castes of Protopolybia chartergoides (Hymenoptera, Vespidae, Epiponini) observed in colonies during male production stage

Social wasps are important for the study of social behavior evolution because their colonies present different degrees of caste differentiation, from morphologically similar to highly conspicuous, associated with the occasional presence of intermediate females, which bears developed ovaries but no insemination. In the Polistinae, depending on the taxon, such differentiation can be discreet or conspicuous. This work intended to study morphological and physiological differences between castes in Protopolybia chartergoides by using morphometric analyses associated with multivariate statistical analyses and physiological evaluations from females' ovarian development. Results evidence low morphological and physiological differences among the castes in P. chartergoides, indicating three groups of females: queens, workers and intermediates. In this way, it was possible to suggest that Protopolybia chartergoides presents post-imaginal caste differentiation (or a very subtle form of pre-imaginal determination).

Handicap mental et psychiatrie [Mental retardation and psychiatry]

In the canton de Vaud (Switzerland) the psychiatric units devoted to mental retardation have been suppressed during the deinstitutionalization process in the 1970/80s. However, the use of psychiatric hospitalizations has increased these last years. This increase is accompanied by an interdiction of seclusion and restraint outside of the specialized psychiatric unit. A unit of liaison psychiatry has been created as an alternative to psychiatric hospitalization and to assist directly the staff of specialized institutions for people with mental retardation or the family of the patient. The article describes the challenges of liaison psychiatry in this field and the potential benefits of research for the psychiatry of mental retardation.

The genome of the fire ant Solenopsis invicta.

Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species.

Nest descriptions of Megalopta aegis (Vachal) and M. guimaraesi Santos & Silveira (Hymenoptera, Halictidae) from the Brazilian Cerrado

We present the first data on the nesting biology of Megalopta aegis and M. guimaraesi from southeastern Brazil. Nests were collected in the Área de Proteção Ambiental Água Limpa, Bauru, São Paulo state. Our data suggest that nest architecture is conserved throughout all species of Megalopta. Two nests of M. guimaraesi consisted of a single female with brood. Of three M. aegis nests, two contained single females with brood and the third nest contained three adult females, with three times more brood than any single female nest. This observation suggests that social behavior in M. aegis is facultative, as known for other Megalopta species.

Are adolescents with chronic conditions particularly at risk for bullying?

OBJECTIVE: To compare the prevalence and intensity of victimization from bullying, and the characteristics of the victims of bullying, comparing adolescents with and without chronic conditions. DESIGN: School survey. SETTING: Post-mandatory schools. PARTICIPANTS: A total of 7005 students (48% females) aged 16-20 years, distributed into adolescents with chronic conditions (728, 50% females) and controls (6277, 48% females). Chronic condition was defined as having a chronic disease and/or a physical disability.OUTCOME MEASURES: Prevalence of bullying; intensity of bullying; and socio-demographic, bio-psychosocial, familial, school, and violence context characteristics of the victims of bullying. RESULTS: The prevalence of bullying in our sample was 13.85%. Adolescents with chronic conditions were more likely to be victims of bullying (Adjusted Odds Ratio [AOR] 1.53), and to be victims of two or three forms of bullying (AOR 1.92). Victims of bullying with chronic conditions were more likely than non-victims to be depressed (Relative Risk Ratio [RRR] 1.57), to have more physical symptoms (RRR 1.61), to have a poorer relationship with their parents (RRR 1.33), to have a poorer school climate (RRR 1.60), and to have been victims of sexual abuse (RRR 1.79) or other forms of violence (RRR 1.80). Although these characteristics apply to victims in general, in most cases they are less pronounced among victims without chronic conditions. CONCLUSIONS: Chronic conditions seem to be a risk factor for victimization from bullying. Therefore, as adolescents with chronic conditions are increasingly mainstreamed, schools should be encouraged to undertake preventive measures to avoid victimization of such adolescents.

Sham nepotism as a result of intrinsic differences in brood viability in ants.

In animal societies, cooperation for the common wealth and latent conflicts due to the selfish interests of individuals are in delicate balance. In many ant species, colonies contain multiple breeders and workers interact with nestmates of varying degrees of relatedness. Therefore, workers could increase their inclusive fitness by preferentially caring for their closest relatives, yet evidence for nepotism in insect societies remains scarce and controversial. We experimentally demonstrate that workers of the ant Formica exsecta do not discriminate between highly related and unrelated brood, but that brood viability differs between queens. We further show that differences in brood viability are sufficient to explain a relatedness pattern that has previously been interpreted as evidence for nepotism. Hence, our findings support the view that nepotism remains elusive in social insects and emphasize the need for further controlled experiments.

Genetic caste determination in Pogonomyrmex harvester ants imposes costs during colony founding.

Some populations of Pogonomyrmex harvester ants comprise genetically differentiated pairs of interbreeding lineages. Queens mate with males of their own and of the alternate lineage and produce pure-lineage offspring which develop into queens and inter-lineage offspring which develop into workers. Here we tested whether such genetic caste determination is associated with costs in terms of the ability to optimally allocate resources to the production of queens and workers. During the stage of colony founding, when only workers are produced, queens laid a high proportion of pure-lineage eggs but the large majority of these eggs failed to develop. As a consequence, the number of offspring produced by incipient colonies decreased linearly with the proportion of pure-lineage eggs laid by queens. Moreover, queens of the lineage most commonly represented in a given mating flight produced more pure-lineage eggs, in line with the view that they mate randomly with the two types of males and indiscriminately use their sperm. Altogether these results predict frequency-dependent selection on pairs of lineages because queens of the more common lineage will produce more pure-lineage eggs and their colonies be less successful during the stage of colony founding, which may be an important force maintaining the coexistence of pairs of lineages within populations.

Comparative genomic analysis of the odorant-binding protein family in 12 Drosophila genomes: purifying selection and birth-and-death evolution

Background: Chemoreception is a widespread mechanism that is involved in critical biologic processes, including individual and social behavior. The insect peripheral olfactory system comprises three major multigene families: the olfactory receptor (Or), the gustatory receptor (Gr), and the odorant-binding protein (OBP) families. Members of the latter family establish the first contact with the odorants, and thus constitute the first step in the chemosensory transduction pathway.Results: Comparative analysis of the OBP family in 12 Drosophila genomes allowed the identification of 595 genes that encode putative functional and nonfunctional members in extant species, with 43 gene gains and 28 gene losses (15 deletions and 13 pseudogenization events). The evolution of this family shows tandem gene duplication events, progressive divergence in DNA and amino acid sequence, and prevalence of pseudogenization events in external branches of the phylogenetic tree. We observed that the OBP arrangement in clusters is maintained across the Drosophila species and that purifying selection governs the evolution of the family; nevertheless, OBP genes differ in their functional constraints levels. Finally, we detect that the OBP repertoire evolves more rapidly in the specialist lineages of the Drosophila melanogaster group (D. sechellia and D. erecta) than in their closest generalists.Conclusion: Overall, the evolution of the OBP multigene family is consistent with the birth-and-death model. We also found that members of this family exhibit different functional constraints, which is indicative of some functional divergence, and that they might be involved in some of the specialization processes that occurred through the diversification of the Drosophila genus.

Evolution: plastic sociality in a sweat bee.

How and why do bees become social? A transplant experiment shows that sweat bees can adopt a solitary or social lifestyle in response to their environment.

The determinants of queen size in a socially polymorphic ant.

In social animals, body size can be shaped by multiple factors, such as direct genetic effects, maternal effects, or the social environment. In ants, the body size of queens correlates with the social structure of the colony: colonies headed by a single queen (monogyne) generally produce larger queens that are able to found colonies independently, whereas colonies headed by multiple queens (polygyne) tend to produce smaller queens that stay in their natal colony or disperse with workers. We performed a cross-fostering experiment to investigate the proximate causes of queen size variation in the socially polymorphic ant Formica selysi. As expected if genetic or maternal effects influence queen size, eggs originating from monogyne colonies developed into larger queens than eggs collected from polygyne colonies, be they raised by monogyne or polygyne workers. In contrast, eggs sampled in monogyne colonies were smaller than eggs sampled in polygyne colonies. Hence, eggs from monogyne colonies are smaller but develop into larger queens than eggs from polygyne colonies, independently of the social structure of the workers caring for the brood. These results demonstrate that a genetic polymorphism or maternal effect transmitted to the eggs influences queen size, which probably affects the social structure of new colonies.

Resistance to extreme strategies, rather than prosocial preferences, can explain human cooperation in public goods games.

The results of numerous economic games suggest that humans behave more cooperatively than would be expected if they were maximizing selfish interests. It has been argued that this is because individuals gain satisfaction from the success of others, and that such prosocial preferences require a novel evolutionary explanation. However, in previous games, imperfect behavior would automatically lead to an increase in cooperation, making it impossible to decouple any form of mistake or error from prosocial cooperative decisions. Here we empirically test between these alternatives by decoupling imperfect behavior from prosocial preferences in modified versions of the public goods game, in which individuals would maximize their selfish gain by completely (100%) cooperating. We found that, although this led to higher levels of cooperation, it did not lead to full cooperation, and individuals still perceived their group mates as competitors. This is inconsistent with either selfish or prosocial preferences, suggesting that the most parsimonious explanation is imperfect behavior triggered by psychological drives that can prevent both complete defection and complete cooperation. More generally, our results illustrate the caution that must be exercised when interpreting the evolutionary implications of economic experiments, especially the absolute level of cooperation in a particular treatment.

The relationship between cognitive errors and interpersonal patterns in depressed women.

Individuals with depression process information in an overly negative or biased way (e.g., Henriques & Leitenberg, 2002) and demonstrate significant interpersonal dysfunction (e.g., Zlotnick, Kohn, Keitner, & Della Grotta, 2000). This study examined the relationship between cognitive errors (CEs) and interpersonal interactions in early psychotherapy sessions of 25 female patients with major depression. Transcripts were rated for CEs using the Cognitive Error Rating Scale (Drapeau, Perry, & Dunkley, 2008). Interpersonal patterns were assessed using the Structural Analysis of Social Behavior (Benjamin, 1974). Significant associations were found between CEs and markers of interpersonal functioning in selected contexts. The implications of these findings in bridging the gap between research and practice, enhancing treatment outcome, and improving therapist training are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

An evolutionary analysis of the relationship between spite and altruism.

We investigate the selective pressures on a social trait when evolution occurs in a population of constant size. We show that any social trait that is spiteful simultaneously qualifies as altruistic. In other words, any trait that reduces the fitness of less related individuals necessarily increases that of related ones. Our analysis demonstrates that the distinction between "Hamiltonian spite" and "Wilsonian spite" is not justified on the basis of fitness effects. We illustrate this general result with an explicit model for the evolution of a social act that reduces the recipient's survival ("harming trait"). This model shows that the evolution of harming is favoured if local demes are of small size and migration is low (philopatry). Further, deme size and migration rate determine whether harming evolves as a selfish strategy by increasing the fitness of the actor, or as a spiteful/altruistic strategy through its positive effect on the fitness of close kin.

War and the evolution of belligerence and bravery.

Tribal war occurs when a coalition of individuals use force to seize reproduction-enhancing resources, and it may have affected human evolution. Here, we develop a population-genetic model for the coevolution of costly male belligerence and bravery when war occurs between groups of individuals in a spatially subdivided population. Belligerence is assumed to increase an actor's group probability of trying to conquer another group. An actor's bravery is assumed to increase his group's ability to conquer an attacked group. We show that the selective pressure on these two traits can be substantial even in groups of large size, and that they may be driven by two independent reproduction-enhancing resources: additional mates for males and additional territory (or material resources) for females. This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women.

Similarity in food cleaning techniques within matrilines in wild vervet monkeys.

Social learning and the formation of traditions rely on the ability and willingness to copy one another. A central question is under which conditions individuals adapt behaviour to social influences. Here, we demonstrate that similarities in food processing techniques emerge on the level of matrilines (mother-offspring) but not on the group level in an experiment on six groups of wild vervet monkeys that involved grapes covered with sand. Monkeys regularly ate unclean grapes but also used four cleaning techniques more similarly within matrilines: rubbing in hands, rubbing on substrate, open with mouth, and open with hands. Individual cleaning techniques evolved over time as they converged within matrilines, stabilised at the end and remained stable in a follow-up session more than one year later. The similarity within matrilines persisted when we analyzed only foraging events of individuals in the absence of other matriline members and matriline members used more similar methods than adult full sisters. Thus, momentary conversion or purely genetic causation are unlikely explanations, favouring social learning as mechanism for within matriline similarities. The restriction of traditions to matriline membership rather than to the group level may restrict the development of culture in monkeys relative to apes or humans.