Non-nest mate discrimination and clonal colony structure in the parthenogenetic ant Cerapachys biroi

Understanding the interplay between cooperation and conflict in social groups is a major goal of biology. One important factor is genetic relatedness, and animal societies are usually composed of related but genetically different individuals, setting the stage for conflicts over reproductive allocation. Recently, however, it has been found that several ant species reproduce predominantly asexually. Although this can potentially give rise to clonal societies, in the few well-studied cases, colonies are often chimeric assemblies of different genotypes, due to worker drifting or colony fusion. In the ant Cerapachys biroi, queens are absent and all individuals reproduce via thelytokous parthenogenesis, making this species an ideal study system of asexual reproduction and its consequences for social dynamics. Here, we show that colonies in our study population on Okinawa, Japan, recognize and effectively discriminate against foreign workers, especially those from unrelated asexual lineages. In accord with this finding, colonies never contained more than a single asexual lineage and average pairwise genetic relatedness within colonies was extremely high (r = 0.99). This implies that the scope for social conflict in C. biroi is limited, with unusually high potential for cooperation and altruism.

Food availability dictates the timing of parturition in insectivorous mouse-eared bats

Which of these two confounding factors, weather or food availability - that largely correlate and interact - controls the timing of parturition in insectivorous bats? To answer this question. we took advantage of a predator-prey system that offers a unique opportunity to perform natural experiments. The phenology of reproduction of two sibling bat species that inhabit the same colonial roosts, but exploit different feeding niches. was investigated. Myotis myotis feeds mainly on carabid beetles, a food source available from the end of hibernation onwards, whereas bush crickets, the main prey of M. blythii, are not available early in the season due to their successive instars; cockchafers are actually the sole possible alternative prey for M. blythii at that time of the year, but they occur every third year only, independently of local weather conditions. By comparing the species responses to the presence/absence of cockchafers, we could test the hypothesis that food availability, rather than climate. influences the timing of bat parturition. Our data show that Nt. blythii gave birth, on average. 10 d later than M. myotis in years without cockchafers, whilst parturition (1) was synchronous during cockchafer years, and (2) did not show much among-year time variation in M. myotis. This suggests that food availability is the chief factor regulating the timing of parturition in mouse-eared bats.

Cultures jeunes et religions en Europe

Après la révolution religieuse des années 60, une nouvelle religiosité est-elle née ? Cette question est au coeur du livre. Il met, en effet, en scène les jeunes des années 80, les filles et les fils de la génération d'après-guerre, celle de Mai 68. Les parents ont pris leurs distances avec les différentes formes institutionnelles de l'autorité, y compris celle des Églises. Ils avaient été laissés libres de s'initier à une voie « spirituelle » : liberté de conscience et autonomie individuelle, deux valeurs clés attachées à la génération d'après-guerre, avaient orienté leur démarche religieuse. Les années 80 constituent de plus un contexte spécifique. Derrière le rideau de l'abondance, les contours de la précarité se dessinent. L'effondrement du mur de Berlin a entraîné celui des certitudes et des points de repère. L'apparition du sida a mis en cause le mythe dominant d'une jeunesse presque éternelle ouvrant sur une société sans âge et sans conflits de génération. Ces événements ont infléchi les quêtes de sens contemporaines. Fruit de la collaboration de vingt-deux sociologues venant de différents pays de l'Union européenne et de la Suisse, l'ouvrage, plutôt que de mettre côte à côte des observations empruntées aux pays concernés, propose des analyses transversales. Il permet ainsi de se faire une idée du changement religieux qui touche l'Europe dans son ensemble et de dégager quelques enjeux communs suscités par l'incertitude ambiante. Partant de l'analyse de la condition des jeunes dans les années 80, l'ouvrage aborde tour à tour la question de leur identité religieuse, celle de leurs systèmes de croyance, puis s'attarde sur les institutions qui ont contribué à leur socialisation religieuse. L'expérience constitue une caractéristique de la vie religieuse contemporaine, alors que la pluralité de l'offre reflète le changement socioculturel. Un chapitre est ainsi consacré à la présentation de quelques trajectoires typiques illustrant la gestion de l'incertitude dans laquelle est plongée la génération en cause. Enfin est abordée la question posée par une jeunesse qui apparaît aujourd'hui dépourvue d'encadrement institutionnel dans le champ religieux comme dans d'autres domaines : cette situation ne traduit-elle pas la crise de reproduction des institutions elles-mêmes ?

Eusociality and cooperation

The evolution of eusociality, here defined as the emergence of societies with reproductive division of labour and cooperative brood care, was first seen as a challenge to Darwin's theory of evolution by natural selection. Why should individuals permanently forgo direct reproduction to help other individuals to reproduce? Kin selection, the indirect transmission of genes through relatives, is the key process explaining the evolution of permanently nonreproductive helpers. However, in some taxa helpers delay reproduction until a breeding opportunity becomes available. Overall, eusociality evolved when ecological conditions promote stable associations of related individuals that benefit from jointly exploiting and defending common resources. High levels of cooperation and robust mechanisms of division of labour are found in many animal societies. However, conflicts among individuals are still frequent when group members that are not genetically identical compete over reproduction or resource allocation.

Involvement of nuclear factor-kappaB in macrophage migration inhibitory factor gene transcription up-regulation induced by interleukin- 1 beta in ectopic endometrial cells.

OBJECTIVE: To investigate the involvement of the nuclear factor (NF)-kappaB in the interleukin (IL)-1 beta-mediated macrophage migration inhibitory factor (MIF) gene activation. DESIGN: Prospective study. SETTING: Human reproduction research laboratory. PATIENT(S): Nine women with endometriotic lesions. INTERVENTION(S): Endometriotic lesions were obtained during laparoscopic surgery. MAIN OUTCOME MEASURE(S): The MIF protein secretion was analyzed by ELISA, MIF mRNA expression by quantitative real-time polymerase chain reaction (PCR), NF-kappaB translocation into the nucleus by electrophoresis mobility shift assay, I kappaB phosphorylation and degradation by Western blot, and human MIF promoter activity by transient cell transfection. RESULT(S): This study showed a significant dose-dependent increase of MIF protein secretion and mRNA expression, the NF-kappaB translocation into the nucleus, I kappaB phosphorylation, I kappaB degradation, and human MIF promoter activity in endometriotic stromal cells in response to IL-1 beta. Curcumin (NF-kappaB inhibitor) significantly inhibited all these IL-1 beta-mediated effects. Analysis of the activity of deletion constructs of the human MIF promoter and a computer search localized two putative regulatory elements corresponding to NF-kappaB binding sites at positions -2538/-2528 bp and -1389/-1380 bp. CONCLUSION(S): This study suggests the involvement of the nuclear transcription factor NF-kappaB in MIF gene activation in ectopic endometrial cells in response to IL-1 beta and identifies a possible pathway of endometriosis-associated inflammation and ectopic cell growth.

Foreign ant queens are accepted but produce fewer offspring.

Understanding social evolution requires us to understand the processes regulating the number of breeders within social groups and how they partition reproduction. Queens in polygynous (multiple queens per colony) ants often seek adoption in established colonies instead of founding a new colony independently. This mode of dispersal leads to potential conflicts, as kin selection theory predicts that resident workers should favour nestmate queens over foreign queens. Here we compared the survival of foreign and resident queens as well as their relative reproductive share. We used the ant Formica exsecta to construct colonies consisting of one queen with workers related to this resident queen and introduced a foreign queen. We found that the survival of foreign queens did not differ from that of resident queens over a period of 136 days. However, the genetic analyses revealed that resident queens produced a 1.5-fold higher number of offspring than introduced queens, and had an equal or higher share in 80% of the colonies. These data indicate that some discrimination can occur against dispersing individuals and that dispersal can thus have costs in terms of direct reproduction for dispersing queens.

Altruism across disciplines: one word, multiple meanings

Altruism is a deep and complex phenomenon that is analysed by scholars of various disciplines, including psychology, philosophy, biology, evolutionary anthropology and experimental economics. Much confusion arises in current literature because the term altruism covers variable concepts and processes across disciplines. Here we investigate the sense given to altruism when used in different fields and argumentative contexts. We argue that four distinct but related concepts need to be distinguished: (a) psychological altruism, the genuine motivation to improve others' interests and welfare; (b) reproductive altruism, which involves increasing others' chances of survival and reproduction at the actor's expense; (c) behavioural altruism, which involves bearing some cost in the interest of others; and (d) preference altruism, which is a preference for others' interests. We show how this conceptual clarification permits the identification of overstated claims that stem from an imprecise use of terminology. Distinguishing these four types of altruism will help to solve rhetorical conflicts that currently undermine the interdisciplinary debate about human altruism.