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1.
A recent empirical study by Turner and Chao on the evolution of competitive interactions among phage virus strains revealed that a strain grown at high rates of co‐infection evolved towards lowered fitness relative to an ancestral strain. The authors went on to show that the fitness pay‐off matrix between the evolved and ancestral strain conforms to the prisoners’ dilemma. In this paper, I use Turner and Chao’s data to parameterize a simple model of parasite collective action. The prisoners’ dilemma is based on pairwise interactions of a discrete cooperate/defect nature. In contrast, the collective action model explicitly deals with individual–group interactions where the extent of cooperation is a continuous variable. I argue here that the ‘collective action’ modelling approach is more appropriate than the prisoners’ dilemma for the biology of virus evolution, and hence better able to form a predictive framework for further work on related strains of virus, linking mixing ecology, cooperative phenotype and fitness. Furthermore, the collective action model is used to motivate discussion on the evolutionary ecology of viruses, with a focus on the ‘levels of selection’ debate and the evolution of virulence.  相似文献   

2.
3.
Collective signaling for a quorum is found in a wide range of organisms that face collective action problems whose successful solution requires the participation of some quorum of the individuals present. These range from humans, to social insects, to bacteria. The mechanisms involved, the quorum required, and the size of the group may vary. Here we address the general question of the evolution of collective signaling at a high level of abstraction. We investigate the evolutionary dynamics of a population engaging in a signaling N-person game theoretic model. Parameter settings allow for loners and cheaters, and for costly or costless signals. We find a rich dynamics, showing how natural selection, operating on a population of individuals endowed with the simplest strategies, is able to evolve a costly signaling system that allows individuals to respond appropriately to different states of Nature. Signaling robustly promotes cooperative collective action, in particular when coordinated action is most needed and difficult to achieve. Two different signaling systems may emerge depending on Nature’s most prevalent states.  相似文献   

4.
The paper analyses the current limitations of the constraints of decision and action processes in land-use, resource management and conservation policies and approaches, identifying their main factors, proposing alternative strategies to solve the present gaps and limitations. It identifies the need for a new paradigmatic approach based on innovative forms of involvement, commitment and individual and community rewarding systems. This approach is developed based on the characterization of the main drivers of land-use, resource management and conservation policies, namely α-perceptions (immediate and primary satisfaction) and k-perceptions (more mediate and complex consideration of satisfaction, implying long-term perceptions and collective benefits beyond the individual interests). It also analyses the effects of the introduction of new forms of income and incentives (such as trade-offs and payments for environmental services) or management approaches such as Ecological-Based Management or the use of Nature-Based Solutions. The main axioms and instruments necessary to build such a new paradigmatic approach (namely trade-offs, accountability and contractualization) are described. On this basis, it is possible to present a concept for an innovative institutional and social culture and a governance system aimed at an effective land-use, resource management and conservation policies. This governance concept is described and its sustaining individual, social and institutional drivers enunciated.  相似文献   

5.
The origin and the evolutionary stability of cooperation between unrelated individuals is one of the key problems of evolutionary biology. In this paper, a cooperative defence game against a predator is introduced which is based on Hamilton's selfish herd theory and Eshel's survival game models. Cooperation is altruistic in the sense that the individual, which is not the target of the predator, helps the members of the group attacked by the predator and during defensive action the helper individual may also die in any attack. In order to decrease the long term predation risk, this individual has to carry out a high risk action. Here I show that this kind of cooperative behaviour can evolve in small groups. The reason for the emergence of cooperation is that if the predator does not kill a mate of a cooperative individual, then the survival probability of the cooperative individual will increase in two cases. If the mate is non-cooperative, then—according to the dilution effect, the predator confusion effect and the higher predator vigilance—the survival probability of the cooperative individual increases. The second case is when the mate is cooperative, because a cooperative individual has a further gain, the active help in defence during further predator attacks. Thus, if an individual can increase the survival rate of its mates (no matter whether the mate is cooperative or not), then its own predation risk will decrease.  相似文献   

6.
The p53 protein is modified by as many as 50 individual posttranslational modifications. Many of these occur in response to genotoxic or nongenotoxic stresses and show interdependence, such that one or more modifications can nucleate subsequent events. This interdependent nature suggests a pathway that operates through multiple cooperative events as opposed to distinct functions for individual, isolated modifications. This concept, supported by recent investigations, which provide exquisite detail as to how various modifications mediate precise protein–protein interactions in a cooperative manner, may explain why knockin mice expressing p53 proteins substituted at one or just a few sites of modification typically show only subtle effects on p53 function. The present article focuses on recent, exciting progress and develops the idea that the impact of modification on p53 function is achieved through collective and integrated events.  相似文献   

7.
To prevent further biodiversity loss as a result of intensive agricultural practices, Agri-Environmental Schemes (AES) have been implemented on European farmland. Unfortunately these AES have not always been effective in terms of biodiversity and farmer participation. In an effort to improve the AES programme the Dutch government switched from an individual application system to a collective application system for AES payments in 2016. The goal of this paper is to analyse how the resilience of the land use system in terms of farmer participation in the AES and biodiversity is affected by the value farmers attach to biodiversity, and whether the shift from an individual to collective AES will affect the resilience of the land use system. We constructed a multi-objective mathematical programming model in which farmers maximise utility. Farmers are linked through their common effect on biodiversity. In the collective application system payments are only available when the biodiversity in the region is above a certain threshold. Simulation results show no difference in farmer participation and biodiversity between the individual application system and the collective application system when biodiversity weights are high. The land use system loses its resilience in terms farmer participation in the AES and biodiversity if we lower the biodiversity weights, this effect is stronger in the collective AES programme.  相似文献   

8.
Conclusion In this paper I have attempted to examine the relationship between the economic success or failure of two agricultural cooperatives, their social and economic organization and the members' attitude toward collectivization. As we saw there is a relationship between the members' positive attitude toward collectivization, the economic success of the cooperative and its internal organization. It would be tempting at this point to suggest the causal primacy of one of these factors in giving rise to the others. Decentralized cooperative structure and individualized work organization, for example, could be seen as being responsible both for the economic success and the members positive attitudes. In the absence of detailed longitudinal data on all these factors which charted the introduction of modifications in the organization of production against economic success in one cooperative and the lack of these in the other, such causal primacy cannot be assumed. It is possible, however, to examine briefly what the relationship between economic success, economic and social organization and attitudes imply about the emergence of the desired collective work ethic and collective ideology in the peasantry of the socialist state.In the economically successful cooperative there has been a switch from brigades to more independent work, there have been individual incentives introduced, and more liberties with the cultivation and marketing of produce from the household plots allowed — all of which may be seen as a shift to a form of individualized work. It is this individualized or non-collective form of work which seems to be connected to positive attitudes toward collectivization and which is present in the economically successful cooperative. Positive attitudes toward the collective and satisfaction with collectivization then does not necessarily mean that individuals have adjusted to collective work and does not imply a change in work ethics. Within the framework of collective ownership a highly individualized form of work organization came into being beside a parallel, flourishing private enterprise on the household plots. Where this privatization and individualization was allowed to develop, individuals are satisfied with the current status quo and the satisfaction and the work organization both seem to benefit the collective as an economic enterprise. In this generation of farmers, I suggest, it is the collective structure that adjusted to the habits and wishes of its members; the members have not adopted a cooperative work ethic.The data also indicate that what motivates the members in their work and what makes them satisfied with the cooperative are economic rewards, not a commitment to collective ideology. In Etzioni's typology of sanctions the first, moral sanction or ideological commitment, has been seen as a desired goal and an important component of the movement in the early days of collectivization in Hungary. When this commitment was found to be too weak to sustain the movement, the third kind of sanction, force, was resorted to. In recent years, both of these sanctions seem to have been increasingly abandoned in favor of instrumental sanctions or incentives, in which motivations tend to hinge on the pay-off to the producer.From the data presented on the Tiszakecske and Nagykoros cooperatives, it appears that the cooperative that took this step and was able to use instrumental incentives, while still paying lip-service to ideological commitment, gained the needed cooperation of its members. Where this alternative was not available, the use of force was no longer condoned and ideological commitment was low, the cooperation of the members was lacking and dissatisfaction reigned.Much has been said in the anthropological literature about the peasant value system in which a love of the land ranks high. The data from Tiszakecske show that peasants in that community are basically pragmatists who are interested in a pay-off, in the economic support and betterment of their families. As long as this is possible solely through the increasing accumulation of land, private ownership becomes the cornerstone of peasant cultivation. However, when other forms and means of economic improvements are offered, even the more prosperous cultivators are willing to give up their independence in return for security and less responsibility. Peasant resistance to collectivization is not based on an irrational attachment to land ownership but on a rational calculation. Where sufficient economic gain is not forthcoming from collective work, ideological incentives are not sufficient to weigh against previous economic security.As far as the desired new work ethic and socialist morality are concerned, the willingness to support the collective system for individual economic gain and the low level of commitment to its collective ideology present some problems which have been recognized by Hungarian social scientists as well. In a recent article, entitled Effectiveness and Socialist Morality , a Hungarian economist, Janos Kornai examined the contradictions inherent in the two value systems currently operating within the Hungarian economic system. On one side are the requirements for economic effectiveness, such as rationality, individual incentives, flexibility and personal responsibility. On the other side are the ethical tenets of the socialist economy which demand equality, solidarity, security, and the primacy of the collective over individual interests. Kornai feels that there is an unavoidable clash inherent in the tenets of these value systems to which he can offer no solution. Such a solution which would attempt to bring into accord the value system of socialist morality with those of a rational, effective economic system is by definition impossible, and he feels that the future of the Hungarian economy should be seen in terms of compromises.The compromises effected by the Peace and Freedom cooperative in Tiszakecske certainly seem to support the requirements of economic effectiveness. But the values of socialist morality seem to fare far less well.Marida Hollos is a Professor of Anthropology at Brown University, Providence, Rhode Island.
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9.
Basic elements of cognition have been identified in the behaviour displayed by animal collectives, ranging from honeybee swarms to human societies. For example, an insect swarm is often considered a ??super-organism?? that appears to exhibit cognitive behaviour as a result of the interactions among the individual insects and between the insects and the environment. Progress in disciplines such as neurosciences, cognitive psychology, social ethology and swarm intelligence has allowed researchers to recognise and model the distributed basis of cognition and to draw parallels between the behaviour of social insects and brain dynamics. In this paper, we discuss the theoretical premises and the biological basis of Swarm Cognition, a novel approach to the study of cognition as a distributed self-organising phenomenon, and we point to novel fascinating directions for future work.  相似文献   

10.
植物数量性状遗传体系的分离分析方法研究   总被引:65,自引:2,他引:65  
盖钧镒 《遗传》2005,27(1):130-136
在传统的数量性状多基因遗传模型基础上提出主基因-多基因遗传模型具普遍性,纯主基因或纯多基因遗传模型只是其特例。由此初步建立了植物数量性状遗传体系分离分析方法。目前该方法可以检验2~3个主基因的个别遗传效应、多基因整体的遗传效应和两者的遗传率。本文介绍这种分离分析方法的研究经过、主要进展及应用效果,并以实例说明其分析步骤、方法和效果。  相似文献   

11.
While many hormones play vital roles in facilitating or reinforcing cooperative behaviour, the neurohormones underlying competitive and cooperative behaviours are largely conserved across all mammals. This raises the question of how endocrine mechanisms have been shaped by selection to produce different levels of cooperation in different species. Multiple components of endocrine physiology—from baseline hormone concentrations, to binding proteins, to the receptor sensitivity and specificity—can evolve independently and be impacted by current socio-ecological conditions or individual status, thus potentially generating a wide range of variation within and between species. Here, we highlight several neurohormones and variation in hormone receptor genes associated with cooperation, focusing on the role of oxytocin and testosterone in contexts ranging from parenting and pair-bonding to reciprocity and territorial defence. While the studies reviewed herein describe the current state of the literature with regard to hormonal modulators of cooperation and collective action, there is still a paucity of research on hormonal mechanisms that help facilitate large-scale collective action. We end by discussing several potential areas for future research.  相似文献   

12.
In the Tournaisian deposits of southern Ireland, Cyrtospora cristifer (Luber) nov. comb. et emend. Van der Zwan, Ceratosporites sp.A (present paper) and Mooreisporites sp.A. (present paper) are regular components. These species show continuous variation. In order to emphasize such a variation, the morphon concept is here established. This concept is intermediate between the typological classification and the interpretative palynodeme concept.In the present paper the taxonomy of the individual species united into the C. cristifer morphon, and the application of the C. cristifer morphon in biostratigraphy and phytogeography are discussed.  相似文献   

13.
Common-pool resource (CPR) dilemmas distinguish themselves from general public good problems by encompassing both social and physical features. This paper examines how a physical mechanism, namely asymmetric payoff; and a social mechanism, reciprocity; simultaneously affect collective cooperation in theoretical water sharing interactions. We present an iterative N-person game theoretic model to investigate the joint effects of these two mechanisms in a linear fully connected river system under three information assumptions. From a simple evolutionary perspective, this paper quantitatively addresses the conditions for Nash Equilibrium in which collective cooperation might be established. The results suggest that direct reciprocity increases every actor’s motivation to contribute to the collective good of the river system. Meanwhile, various upstream and downstream actors manifest individual disparities as a result of the direct reciprocity and asymmetric payoff mechanisms. More specifically, the downstream actors are less willing to cooperate unless there is a high probability that long-term interactions are ensured; however, a greater level of asymmetries is likely to increase upstream actors’ incentives to cooperate even though the interactions could quickly end. The upstream actors also display weak sensitivity to an increase in the total number of actors, which generally results in a reduction in the other actors’ motivation for cooperation. It is also shown that the indirect reciprocity mechanism relaxes the overall conditions for cooperative Nash Equilibrium.  相似文献   

14.
Based on the traditional polygene inheritance model of quantitative traits, the author suggests the major gene and polygene mixed inheritance model. The model was considered as a general one, while the pure major gene and pure polygene inheritance model was a specific case of the general model. Based on the proposed theory, the author established the segregation analysis procedure to study the genetic system of quantitative traits of plants. At present, this procedure can be used to evaluate the genetic effect of individual major genes (up to two to three major genes), the collective genetic effect of polygene, and their heritability value. This paper introduces how to establish the procedure, its main achievements, and its applications. An example is given to illustrate the steps, methods, and effectiveness of the procedure. Translated from Hereditas, 2005, 27(1) (in Chinese)  相似文献   

15.
Persuasion is at the core of norm creation, emergence of collective action, and solutions to ‘tragedy of the commons’ problems. In this paper, we show that the directionality of friendship ties affect the extent to which individuals can influence the behavior of each other. Moreover, we find that people are typically poor at perceiving the directionality of their friendship ties and that this can significantly limit their ability to engage in cooperative arrangements. This could lead to failures in establishing compatible norms, acting together, finding compromise solutions, and persuading others to act. We then suggest strategies to overcome this limitation by using two topological characteristics of the perceived friendship network. The findings of this paper have significant consequences for designing interventions that seek to harness social influence for collective action.  相似文献   

16.
Recent research in group cognition points towards the existence of collective cognitive competencies that transcend individual group members’ cognitive competencies. Since rationality is a key cognitive competence for group decision making, and group cognition emerges from the coordination of individual cognition during social interactions, this study tests the extent to which collaborative and consultative decision rules impact the emergence of group rationality. Using a set of decision tasks adapted from the heuristics and biases literature, we evaluate rationality as the extent to which individual choices are aligned with a normative ideal. We further operationalize group rationality as cognitive synergy (the extent to which collective rationality exceeds average or best individual rationality in the group), and we test the effect of collaborative and consultative decision rules in a sample of 176 groups. Our results show that the collaborative decision rule has superior synergic effects as compared to the consultative decision rule. The ninety one groups working in a collaborative fashion made more rational choices (above and beyond the average rationality of their members) than the eighty five groups working in a consultative fashion. Moreover, the groups using a collaborative decision rule were closer to the rationality of their best member than groups using consultative decision rules. Nevertheless, on average groups did not outperformed their best member. Therefore, our results reveal how decision rules prescribing interpersonal interactions impact on the emergence of collective cognitive competencies. They also open potential venues for further research on the emergence of collective rationality in human decision-making groups.  相似文献   

17.
This is the second article in a series of review articles addressing biosemiotic terminology. The biosemiotic glossary project is designed to integrate views of members within the biosemiotic community based on a standard survey and related publications. The methodology section describes the format of the survey conducted July–August 2014 in preparation of the current review and targeted on Jakob von Uexküll’s term ‘Umwelt’. Next, we summarize denotation, synonyms and antonyms, with special emphasis on the denotation of this term in current biosemiotic usage. The survey findings include ratings of eight citations defining or making use of the term Umwelt. We provide a summary of respondents’ own definitions and suggested term usage. Further sections address etymology, relevant contexts of use, and related terms in English and other languages. A section on the notion’s Uexküllian meaning and later biosemiotic meaning is followed by attempt at synthesis and conclusion. We conclude that the Umwelt is a centerpiece phenomenon, a phenomenon that other phenomena in the living realm are organized around. To sum up Uexküll’s view, we can characterize an Umwelt as the subjective world of an organism, enveloping a perceptual world and an effector world, which is always part of the organism itself and a key component of nature, which is held together by functional cycles connecting different Umwelten. In order to pay respect to Uexküll’s work, we must move from notion to model, from mention of Uexküll’s Umwelt term to actual application of it.  相似文献   

18.
Ecology is a fundamental driving force for the evolutionary transition from solitary living to breeding cooperatively in groups. However, the fact that both benign and harsh, as well as stable and fluctuating, environments can favour the evolution of cooperative breeding behaviour constitutes a paradox of environmental quality and sociality. Here, we propose a new model – the dual benefits framework – for resolving this paradox. Our framework distinguishes between two categories of grouping benefits – resource defence benefits that derive from group‐defended critical resources and collective action benefits that result from social cooperation among group members – and uses insider–outsider conflict theory to simultaneously consider the interests of current group members (insiders) and potential joiners (outsiders) in determining optimal group size. We argue that the different grouping benefits realised from resource defence and collective action profoundly affect insider–outsider conflict resolution, resulting in predictable differences in the per capita productivity, stable group size, kin structure and stability of the social group. We also suggest that different types of environmental variation (spatial vs. temporal) select for societies that form because of the different grouping benefits, thus helping to resolve the paradox of why cooperative breeding evolves in such different types of environments.  相似文献   

19.
Oligomerization is a functional requirement for many proteins. The interfacial interactions and the overall packing geometry of the individual monomers are viewed as important determinants of the thermodynamic stability and allosteric regulation of oligomers. The present study focuses on the role of the interfacial interactions and overall contact topology in the dynamic features acquired in the oligomeric state. To this aim, the collective dynamics of enzymes belonging to the amino acid kinase family both in dimeric and hexameric forms are examined by means of an elastic network model, and the softest collective motions (i.e., lowest frequency or global modes of motions) favored by the overall architecture are analyzed. Notably, the lowest-frequency modes accessible to the individual subunits in the absence of multimerization are conserved to a large extent in the oligomer, suggesting that the oligomer takes advantage of the intrinsic dynamics of the individual monomers. At the same time, oligomerization stiffens the interfacial regions of the monomers and confers new cooperative modes that exploit the rigid-body translational and rotational degrees of freedom of the intact monomers. The present study sheds light on the mechanism of cooperative inhibition of hexameric N-acetyl-L-glutamate kinase by arginine and on the allosteric regulation of UMP kinases. It also highlights the significance of the particular quaternary design in selectively determining the oligomer dynamics congruent with required ligand-binding and allosteric activities.  相似文献   

20.
Filip Jaroš 《Biosemiotics》2017,10(2):279-293
The social cognition of domestic cats (Felis catus) is a scarcely studied topic due to the reputation of the animal as individualistic. Nevertheless, cats are capable of cognitively demanding cooperative activities such as a communal nest-moving. The cognitive abilities of free-ranging cats are evaluated against the background of the shared intentionality hypothesis, proposed by a research group of Michael Tomasello. Although their comparative studies are carried out on chimpanzees, they are valuable as a source of conceptual work linking empirical cognitive studies with the philosophical accounts of joint agency. We critically analyze theoretical cognitive concepts interpreting the triadic interactions of great apes and the collective hunting among chimpanzees. Contrary to the shared intentionality hypothesis, it is argued that cats have cognitive abilities to share attention, truly cooperate and constitute shared meanings. Finally, we introduce the concept of the natural interaction ritual by Randall Collins and outline its significance for our case study about cats as well as for a general biosemiotic theory of the development of symbols.  相似文献   

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