How threats influence the evolutionary resolution of within-group conflict.

© University of Chicago Press. This is the final published version of the article, deposited in accordance with SHERPA RoMEO guidelines. Also available from: http://www.jstor.org/stable/10.1086/598489Most examples of cooperation in nature share a common feature: individuals can interact to produce a productivity benefit or fitness surplus, but there is conflict over how these gains are shared. A central question is how threats to exercise outside options influence the resolution of conflict within such cooperative associations. Here we show how a simple principle from economic bargaining theory, the outside option principle, can help to solve this problem in biological systems. According to this principle, outside options will affect the resolution of conflict only when the payoff of taking up these options exceeds the payoffs individuals can obtain from bargaining or negotiating within the group; otherwise, threats to exercise outside options are not credible and are therefore irrelevant. We show that previous attempts to incorporate outside options in synthetic models of reproductive conflict fail to distinguish between credible and incredible threats, and then we use the outside option principle to develop credible synthetic models in two contexts: reproductive skew and biparental care. A striking prediction of our analysis is that outside options are least relevant to the resolution of conflict in cooperative groups of kin and are most relevant in transient associations or interactions among nonrelatives. Our analysis shows a way to link the resolution of within-group conflict to the environmental setting in which it occurs, and it illuminates the role of threats in the evolution of social behavior

Singular indecomposable representations of sl(2,ℂ) and relativistic wave equations

A detailed summary is given of the structure of singular indecomposable representations of si (2,ℂ), as developed by Gel'fand and Ponomarev [Usp. Mat. Nauk 23, 3 (1968); translated in Russ. Math. Surveys 23, 1 (1968)]. A variety of four-vector operators Γμ is constructed, acting within direct sums of such representations, including some with nonsingular Γ0. Associated wave equations of Gel'fand-Yaglom type are considered that admit timelike solutions and lead to mass-spin spectra of the Majorana type. A subclass of these equations is characterized in an invariant way by obtaining basis-independent expressions for the commutator and anticommutator of Γμ and Γν. A brief discussion is given of possible applications to physics of these equations and of others in which nilpotent scalar operators appear

Evidence for frequent incest in a cooperatively breeding mammal

Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2014 The Authors.As breeding between relatives often results in inbreeding depression, inbreeding avoidance is widespread in the animal kingdom. However, inbreeding avoidance may entail fitness costs. For example, dispersal away from relatives may reduce survival. How these conflicting selection pressures are resolved is challenging to investigate, but theoretical models predict that inbreeding should occur frequently in some systems. Despite this, few studies have found evidence of regular incest in mammals, even in social species where relatives are spatio-temporally clustered and opportunities for inbreeding frequently arise. We used genetic parentage assignments together with relatedness data to quantify inbreeding rates in a wild population of banded mongooses, a cooperatively breeding carnivore. We show that females regularly conceive to close relatives, including fathers and brothers. We suggest that the costs of inbreeding avoidance may sometimes outweigh the benefits, even in cooperatively breeding species where strong within-group incest avoidance is considered to be the norm.NERCDeutsche Forschungsgemeinschaft standard gran

Policing of reproduction by hidden threats in a cooperative mammal

The evolution of cooperation in animal and human societies is associated with mechanisms to suppress individual selfishness. In insect societies, queens and workers enforce cooperation by “policing” selfish reproduction by workers. Insect policing typically takes the form of damage limitation after individuals have carried out selfish acts (such as laying eggs). In contrast, human policing is based on the use of threats that deter individuals from acting selfishly in the first place, minimizing the need for damage limitation. Policing by threat could in principle be used to enforce reproductive suppression in animal societies, but testing this idea requires an experimental approach to simulate reproductive transgression and provoke out-of-equilibrium behavior. We carried out an experiment of this kind on a wild population of cooperatively breeding banded mongooses (Mungos mungo) in Uganda. In this species, each group contains multiple female breeders that give birth to a communal litter, usually on the same day. In a 7-y experiment we used contraceptive injections to manipulate the distribution of maternity within groups, triggering hidden threats of infanticide. Our data suggest that older, socially dominant females use the threat of infanticide to deter selfish reproduction by younger females, but that females can escape the threat of infanticide by synchronizing birth to the same day as older females. Our study shows that reproduction in animal societies can be profoundly influenced by threats that remain hidden until they are triggered experimentally. Coercion may thus extend well beyond the systems in which acts of infanticide are common

Cancellation of UV Divergences in the N=4 SUSY Nonlinear Sigma Model in Three Dimensions

We study the UV properties of the three-dimensional ${\cal N}=4$ SUSY nonlinear sigma model whose target space is $T^*(CP^{N-1})$ (the cotangent bundle of $CP^{N-1}$) to higher orders in the 1/N expansion. We calculate the $\beta$-function to next-to-leading order and verify that it has no quantum corrections at leading and next-to-leading orders.Comment: 10 pages, 2 figures. references adde

Pregnancy is detected via odour in a wild cooperative breeder

Among mammals, scent has long been known to encode oestrus, however in many species detecting pregnancy may also be important in terms of both competition and mate-choice. Here we show, through odour presentation experiments, that pregnancy is discernible via scent by both sexes in the cooperatively breeding banded mongoose. Males spent more time investigating and were more likely to scent mark the odours of non-pregnant females, compared to pregnant females. Females showed increased levels of scent marking when odours were of the same reproductive state as themselves. These results present the first direct demonstration that pregnancy is detectable via scent in wild cooperative breeders. Detecting pregnancy may be particularly important in cooperative breeders as, in addition to the competition between males for receptive mates, there is also intense competition between females for access to alloparental care. Consequently, dominant females benefit from targeting reproductive suppression towards subordinates that represent direct threats, such as pregnant females

Using social parasitism to test reproductive skew models in a primitively eusocial wasp

Remarkable variation exists in the distribution of reproduction (skew) among members of cooperatively breeding groups, both within and between species. Reproductive skew theory has provided an important framework for understanding this variation. In the primitively eusocial Hymenoptera, two models have been routinely tested: concessions models, which assume complete control of reproduction by a dominant individual, and tug-of-war models, which assume on-going competition among group members over reproduction. Current data provide little support for either model, but uncertainty about the ability of individuals to detect genetic relatedness and difficulties in identifying traits conferring competitive ability mean that the relative importance of concessions versus tug-of-war remains unresolved. Here, we suggest that the use of social parasitism to generate meaningful variation in key social variables represents a valuable opportunity to explore the mechanisms underpinning reproductive skew within the social Hymenoptera. We present a direct test of concessions and tug-of-war models in the paper wasp Polistes dominulus by exploiting pronounced changes in relatedness and power structures that occur following replacement of the dominant by a congeneric social parasite. Comparisons of skew in parasitized and unparasitized colonies are consistent with a tug-of-war over reproduction within P. dominulus groups, but provide no evidence for reproductive concessions

Adjustment of costly extra-group paternity according to inbreeding risk in a cooperative mammal

Females of many animal species seek mating opportunities with multiple males, despite being able to obtain sufficient sperm to father their offspring from a single male. In animals that live in stable social groups, females often choose to mate outside their group resulting in extra-group paternity. One reason proposed to explain female choice for extra-group males is to obtain compatible genes, for example in order to avoid inbreeding depression in offspring. The benefits of such extra-group paternities could be substantial if they result in fitter, outbred offspring. However, avoiding inbreeding in this way could be costly for females, for example through retaliation by cuckolded males or through receiving aggression whilst prospecting for extra-group mating opportunities. We investigate the costs and benefits of extra-group paternity in the banded mongoose Mungos mungo, a cooperatively breeding mammal in which within-group mates are sometimes close relatives. We find that pups born to females that mate with extra-group males are more genetically heterozygous, are heavier and are more likely to survive to independence than pups born to females that mate within their group. However, extra-group matings also involve substantial costs as they occur during violent encounters that sometimes result in injury and death. This appears to lead female banded mongooses to adaptively adjust extra-group paternity levels according to the current risk of inbreeding associated with mating within the group. For group-living animals, the costs of inter-group interactions may help to explain variation in both inbreeding rates and extra-group paternity within and between species

New challenges for the internationalization of firms. Italian companies in China: business models and market policies

The emergence of markets such as China opens new opportunities in the internationalization process. For companies, especially for small and medium sized enterprises, the international context is a challenge to be faced by mobilizing and sharing the resources and knowledge of other players. This is subject to establishing strategic relations, in both the internal and foreign markets, which affect the entire corporate supply chain. This theme was investigated by means of a study of a sample of companies operating in or for the Chinese market. The work provides managerial implications based on an evolutionary model to understand firm behavior in international markets

Switching the stereochemical outcome of 6-endo-trig cyclizations; Synthesis of 2,6-Cis-6-substituted 4-oxopipecolic acids

A base-mediated 6-endo-trig cyclization of readily accessible enone-derived α-amino acids has been developed for the direct synthesis of novel 2,6-cis-6- substituted-4-oxo-L-pipecolic acids. A range of aliphatic and aryl side chains were tolerated by this mild procedure to give the target compounds in good overall yields. Molecular modeling of the 6-endo-trig cyclization allowed some insight as to how these compounds were formed, with the enolate intermediate generated via an equilibrium process, followed by irreversible tautomerization/neutralization providing the driving force for product formation. Stereoselective reduction and deprotection of the resulting 2,6-cis-6-substituted 4-oxo-L-pipecolic acids to the corresponding 4-hydroxy-L-pipecolic acids was also performed