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Jennifer H Fewell - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Social Interactions, in the Flow of Information and Disease Spreading in Social Insects Colonies: Effects of Environmental Events and Spatial Heterogeneity
Journal of theoretical biology, 2020Co-Authors: Xiaohui Guo, Jennifer H Fewell, Jun Chen, Asma Azizi, Yun KangAbstract:Abstract The relationship between division of labor and individuals’ spatial behavior in social Insect Colonies provides a useful context to study how social interactions influence the spreading of elements (which could be information, virus or food) across distributed agent systems. In social Insect Colonies, spatial heterogeneity associated with variations of individual task roles, affects social contacts, and thus the way in which agent moves through social contact networks. We used an Agent Based Model (ABM) to mimic three realistic scenarios of elements’ transmission, such as information, food or pathogens, via physical contact in social Insect Colonies. Our model suggests that individuals within a specific task interact more with consequences that elements could potentially spread rapidly within that group, while elements spread slower between task groups. Our simulations show a strong linear relationship between the degree of spatial heterogeneity and social contact rates, and that the spreading dynamics of elements follow a modified nonlinear logistic growth model with varied transmission rates for different scenarios. Our work provides important insights on the dual-functionality of physical contacts. This dual-functionality is often driven via variations of individual spatial behavior, and can have both inhibiting and facilitating effects on elements’ transmission rates depending on environment. The results from our proposed model not only provide important insights on mechanisms that generate spatial heterogeneity, but also deepen our understanding of how social Insect Colonies balance the benefit and cost of physical contacts on the elements’ transmission under varied environmental conditions.
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Scaling of work and energy use in social Insect Colonies
Behavioral Ecology and Sociobiology, 2016Co-Authors: Jennifer H Fewell, Jon F. HarrisonAbstract:Group size has profound effects on the organization of work. In the social Insects, larger colony size is consistently associated with lower mass-specific energy use; similar hypometric relationships between group size and per-gram energy use may extend across other social taxa. The specific mechanisms driving social metabolic scaling vary among species, but evidence suggests that it can be associated with organizational changes in work (task) performance that allow more efficient energy use by larger groups. In social Insect Colonies, larger group size allows stronger individual specialization, greater diversity in task performance, and likely gives improved resilience to stochastic events. Larger Colonies often also allocate a larger proportion of workers to maintenance and reserve rather than to foraging and brood care tasks, potentially reducing costs. For the few species examined, these organizational changes seem to be associated with lower mean but higher variance in movement rates, providing a concrete connection to metabolic use. Interestingly, colony group size is not generally associated with changes in the proportional number of colony workers resting versus doing work, but this may vary across social systems. Colonies with hypometric metabolic scaling tend to show constant or greater efficiency of brood production, consistent with efficiency rather than constraint-based scaling models. These patterns of work and energetics in social groups show distinct parallels with organismal scaling. Investigation into social metabolic scaling could contribute to identifying unifying scaling theories for the disparate fields of animal behavior, physiology, and human sociology.
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Information processing in social Insect networks
PLoS ONE, 2012Co-Authors: James S. Waters, Jennifer H FewellAbstract:Investigating local-scale interactions within a network makes it possible to test hypotheses about the mechanisms of global network connectivity and to ask whether there are general rules underlying network function across systems. Here we use motif analysis to determine whether the interactions within social Insect Colonies resemble the patterns exhibited by other animal associations or if they exhibit characteristics of biological regulatory systems. Colonies exhibit a predominance of feed-forward interaction motifs, in contrast to the densely interconnected clique patterns that characterize human interaction and animal social networks. The regulatory motif signature supports the hypothesis that social Insect Colonies are shaped by selection for network patterns that integrate colony functionality at the group rather than individual level, and demonstrates the utility of this approach for analysis of selection effects on complex systems across biological levels of organization.
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Genetic diversity promotes homeostasis in Insect Colonies
Trends in ecology & evolution, 2007Co-Authors: Benjamin P. Oldroyd, Jennifer H FewellAbstract:Although most Insect Colonies are headed by a singly mated queen, some ant, wasp and bee taxa have evolved high levels of multiple mating or 'polyandry'. We argue here that a contributing factor towards the evolution of polyandry is that the resulting genetic diversity within Colonies provides them with a system of genetically based task specialization, enabling them to respond resiliently to environmental perturbation. An alternate view is that genetic contributions to task specialization are a side effect of multiple mating, which evolved through other causes, and that genetically based task specialization now makes little or no contribution to colony fitness.
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Social Insect networks.
Science, 2003Co-Authors: Jennifer H FewellAbstract:Social Insect Colonies have many of the properties of adaptive networks. The simple rules governing how local interactions among individuals translate into group behaviors are found across social groups, giving social Insects the potential to have a profound impact on our understanding of the interplay between network dynamics and social evolution.
James S. Waters - One of the best experts on this subject based on the ideXlab platform.
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Collective Behavior and the Respiratory Physiology of Social Insect Colonies
The FASEB Journal, 2015Co-Authors: James S. WatersAbstract:The ecological success of social Insect Colonies depends on the functional integration of metabolism and behavior by a multitude of physically independent individuals. To understand the physiologic...
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Theoretical and empirical perspectives on the scaling of supply and demand in social Insect Colonies
Entomologia Experimentalis Et Applicata, 2014Co-Authors: James S. WatersAbstract:One of the central questions in physiological ecology is how energetic constraints affect organismal performance and the dynamics of ecological systems. Social Insect Colonies integrate the balance of supply and demand across levels of biological organization such that the individual components are simultaneously serving as the supply transport network and also the source of energetic demand. An increasing number of studies have demonstrated that the per-capita metabolic rates of individuals within social Insect Colonies decrease with increasing colony size, a metabolic hypometry much like the pattern exhibited by individual organisms. An important question is thus, whether this scaling pattern is a result of an energetic supply constraint or evidence for an emergent economy of scale. This review synthesizes theoretical models and results from empirical studies on the scaling of resource supply and demand in social Insect Colonies. Scaling in biology is a powerful tool to unify the study of diverse concepts and organisms; increased integration of mechanistic realism into metabolic models will improve our understanding of the evolution of complex biological systems.
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Information processing in social Insect networks
PLoS ONE, 2012Co-Authors: James S. Waters, Jennifer H FewellAbstract:Investigating local-scale interactions within a network makes it possible to test hypotheses about the mechanisms of global network connectivity and to ask whether there are general rules underlying network function across systems. Here we use motif analysis to determine whether the interactions within social Insect Colonies resemble the patterns exhibited by other animal associations or if they exhibit characteristics of biological regulatory systems. Colonies exhibit a predominance of feed-forward interaction motifs, in contrast to the densely interconnected clique patterns that characterize human interaction and animal social networks. The regulatory motif signature supports the hypothesis that social Insect Colonies are shaped by selection for network patterns that integrate colony functionality at the group rather than individual level, and demonstrates the utility of this approach for analysis of selection effects on complex systems across biological levels of organization.
Guy Theraulaz - One of the best experts on this subject based on the ideXlab platform.
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Dynamical Models of Task Organization in Social Insect Colonies
Bulletin of Mathematical Biology, 2016Co-Authors: Yun Kang, Guy TheraulazAbstract:The organizations of Insect societies, such as division of labor, task allocation, collective regulation, mass action responses, have been considered as main reasons for the ecological success. In this article, we propose and study a general modeling framework that includes the following three features: (a) the average internal response threshold for each task (the internal factor); (b) social network communications that could lead to task switching (the environmental factor); and (c) dynamical changes of task demands (the external factor). Since workers in many social Insect species exhibit age polyethism , we also extend our model to incorporate age polyethism in which worker task preferences change with age. We apply our general modeling framework to the cases of two task groups: the inside colony task versus the outside colony task. Our analytical study of the models provides important insights and predictions on the effects of colony size, social communication, and age-related task preferences on task allocation and division of labor in the adaptive dynamical environment. Our study implies that the smaller size colony invests its resource for the colony growth and allocates more workers in the risky tasks such as foraging while the larger colony shifts more workers to perform the safer tasks inside the colony. Social interactions among different task groups play an important role in shaping task allocation depending on the relative cost and demands of the tasks.
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dynamical models of task organization in social Insect Colonies
arXiv: Populations and Evolution, 2015Co-Authors: Yun Kang, Guy TheraulazAbstract:The organizations of Insect societies, such as division of labor, task allocation, collective regulation, mass action responses, have been considered as main reasons for the ecological success. In this article, we propose and study a general modeling framework that includes the following three features: (a) the average internal response threshold for each task (the internal factor); (b) social network communications that could lead to task switching (the environmental factor); and (c) dynamical changes of task demands (the external factor). Since workers in many social Insect species exhibit \emph{age polyethism}, we also extend our model to incorporate \emph{age polyethism} in which worker task preferences change with age. We apply our general modeling framework to the cases of two task groups: the inside colony task versus the outside colony task. Our analytical study of the models provides important insights and predictions on the effects of colony size, social communication, and age related task preferences on task allocation and division of labor in the adaptive dynamical environment. Our study implies that the smaller size colony invests its resource for the colony growth and allocates more workers in the risky tasks such as foraging while the larger colony shifts more workers to perform the safer tasks inside the colony. Social interactions among different task groups play an important role in shaping task allocation depending on the relative cost and demands of the tasks.
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The biological principles of swarm intelligence
Swarm Intelligence, 2007Co-Authors: Simon Garnier, Jacques Gautrais, Guy TheraulazAbstract:The roots of swarm intelligence are deeply embedded in the biological study of self-organized behaviors in social Insects. From the routing of traffic in telecommunication networks to the design of control algorithms for groups of autonomous robots, the collective behaviors of these animals have inspired many of the foundational works in this emerging research field. For the first issue of this journal dedicated to swarm intelligence, we review the main biological principles that underlie the organization of Insects’ Colonies. We begin with some reminders about the decentralized nature of such systems and we describe the underlying mechanisms of complex collective behaviors of social Insects, from the concept of stigmergy to the theory of self-organization in biological systems. We emphasize in particular the role of interactions and the importance of bifurcations that appear in the collective output of the colony when some of the system’s parameters change. We then propose to categorize the collective behaviors displayed by Insect Colonies according to four functions that emerge at the level of the colony and that organize its global behavior. Finally, we address the role of modulations of individual behaviors by disturbances (either environmental or internal to the colony) in the overall flexibility of Insect Colonies. We conclude that future studies about self-organized biological behaviors should investigate such modulations to better understand how Insect Colonies adapt to uncertain worlds.
Deborah M Gordon - One of the best experts on this subject based on the ideXlab platform.
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social Insects cuticular hydrocarbons inform task decisions
Nature, 2003Co-Authors: Michael J Greene, Deborah M GordonAbstract:Social Insect Colonies are organized without central control, and must not only accomplish many tasks, such as foraging and nest construction, but must also respond to changing conditions by adjusting the number of workers performing each task1,2. Here we use chemically treated, artificial ants to show that cuticular hydrocarbons, which differ according to task, are used by workers of the red harvester ant (Pogonomyrmex barbatus) to recognize the tasks of the ants that they encounter. Encounters with other ants thus inform a worker's decision on whether to perform a particular task.
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the organization of work in social Insect Colonies
Complexity, 2002Co-Authors: Deborah M GordonAbstract:A social Insect colony operates without any central control; no one is in charge, and no colony member directs the behavior of another. A worker cannot assess the needs of the colony. How do individual workers, using fairly simple, local information, in the aggregate produce the behavior of Colonies? The dynamics of colony behavior results in task allocation [1]. Colonies perform various tasks, such as foraging, care of the young, and nest construction. As environmental conditions and colony needs change, so do the numbers of workers engaged in each task. For example, when more food is available or there are more larvae to feed, more foragers may work to collect food. Task allocation is the process that adjusts the numbers of workers engaged in each task in a way appropriate to the current situation. I study task allocation in harvester ants (Pogonomyrmex barbatus) [2]. Inside the nest, ants care for the brood (the preadult forms: eggs, larvae, and pupae); process and store seeds; construct and maintain chambers; and simply stand around doing nothing. The ants that work outside the nest are a distinct group, apparently older than the interior workers. I divide the behavior I see outside the nest into four tasks: foraging, searching for and retrieving food; patrolling, assessing food supply and the presence of foragers from neighboring Colonies; midden work, sorting the colony refuse pile or midden; and nest maintenance work, the construction and clearing of chambers inside the underground nest. Tasks are interdependent; numbers engaged in one task depend on numbers engaged in another [3,4]. Ants switch tasks, though not all transitions are possible. In harvester ants, task switching funnels ants into foraging and away from tasks inside the nest [4]. An ant’s decision whether to perform a task depends, first, on cues about the physical state of the environment: for example, if part of the nest is damaged, more ants do nest maintenance work to repair it. Task decisions also depend on social cues arising from interactions with other ants. Workers from different task groups meet as they come in and out of the nest. The rate at which one ant encounters others influences its task decisions. The pattern of interactions among ants as they move around can be seen as a kind of ad hoc, dynamical network [5,6]. Task allocation is the process that adjusts the numbers of workers engaged in each task in a way appropriate to the current situation. DEBORAH M. GORDON
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the organization of work in social Insect Colonies
Complexity, 2002Co-Authors: Deborah M GordonAbstract:A social Insect colony operates without any central control; no one is in charge, and no colony member directs the behavior of another. A worker cannot assess the needs of the colony. How do individual workers, using fairly simple, local information, in the aggregate produce the behavior of Colonies? The dynamics of colony behavior results in task allocation [1]. Colonies perform various tasks, such as foraging, care of the young, and nest construction. As environmental conditions and colony needs change, so do the numbers of workers engaged in each task. For example, when more food is available or there are more larvae to feed, more foragers may work to collect food. Task allocation is the process that adjusts the numbers of workers engaged in each task in a way appropriate to the current situation. I study task allocation in harvester ants (Pogonomyrmex barbatus) [2]. Inside the nest, ants care for the brood (the preadult forms: eggs, larvae, and pupae); process and store seeds; construct and maintain chambers; and simply stand around doing nothing. The ants that work outside the nest are a distinct group, apparently older than the interior workers. I divide the behavior I see outside the nest into four tasks: foraging, searching for and retrieving food; patrolling, assessing food supply and the presence of foragers from neighboring Colonies; midden work, sorting the colony refuse pile or midden; and nest maintenance work, the construction and clearing of chambers inside the underground nest. Tasks are interdependent; numbers engaged in one task depend on numbers engaged in another [3,4]. Ants switch tasks, though not all transitions are possible. In harvester ants, task switching funnels ants into foraging and away from tasks inside the nest [4]. An ant’s decision whether to perform a task depends, first, on cues about the physical state of the environment: for example, if part of the nest is damaged, more ants do nest maintenance work to repair it. Task decisions also depend on social cues arising from interactions with other ants. Workers from different task groups meet as they come in and out of the nest. The rate at which one ant encounters others influences its task decisions. The pattern of interactions among ants as they move around can be seen as a kind of ad hoc, dynamical network [5,6]. Task allocation is the process that adjusts the numbers of workers engaged in each task in a way appropriate to the current situation. DEBORAH M. GORDON
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Resources and the flexible allocation of work in the desert ant, Aphaenogaster cockerelli
Insectes Sociaux, 2002Co-Authors: Nathan J. Sanders, Deborah M GordonAbstract:Social Insect Colonies can respond to changes in resource availability by altering their foraging behavior. Colonies of the desert ant, Aphaenogaster cockerelli, responded to experimental changes in the distribution and type of available resources by adjusting the numbers of ants engaged in foraging and other tasks outside the nest, and by adjusting the temporal patterns of these activities. Colonies foraged more intensely for protein resources than for seed resources, and for high-density resources more than for low-density resources. This flexible allocation and resource use may promote coexistence with interspecific competitors such as ants in the genus Myrmecocystus.
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the organization of work in social Insect Colonies
Nature, 1996Co-Authors: Deborah M GordonAbstract:In social Insect Colonies, workers perform a variety of tasks, such as foraging, brood care and nest construction. As the needs of the colony change, and as resources become available, Colonies adjust the numbers of workers engaged in each task. Task allocation is the process that results in specific workers being engaged in specific tasks, in numbers appropriate to the current situation.
Benjamin P. Oldroyd - One of the best experts on this subject based on the ideXlab platform.
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Social Insects: rearing temperature affects ant thermoregulatory behaviour.
Current biology : CB, 2009Co-Authors: Benjamin P. OldroydAbstract:Differing task thresholds among workers are crucial to the efficient allocation of work in self-organized Insect Colonies. New evidence suggests that the rearing temperature of ant pupae causes lifelong changes in an ant's response threshold to temperature.
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When Workers Disunite: Intraspecific Parasitism by Eusocial Bees
Annual review of entomology, 2008Co-Authors: Madeleine Beekman, Benjamin P. OldroydAbstract:One of the most obvious characteristics of an Insect society is reproductive cooperation. Yet Insect Colonies are vulnerable to reproductive parasitism, both by workers from their own colony and by workers from others. Little is known about the mechanisms Insect societies have evolved to protect themselves from being exploited from within and outside the colony and the mechanisms that social parasites have evolved to circumvent these mechanisms. Here we showcase recently discovered cases of intraspecific parasitism by workers in eusocial bees. These discoveries overturn the widespread view that Insect Colonies are like fortresses populated by female eunuchs, and yield important insights into the mechanisms that normally enforce functional worker sterility.
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Genetic diversity promotes homeostasis in Insect Colonies
Trends in ecology & evolution, 2007Co-Authors: Benjamin P. Oldroyd, Jennifer H FewellAbstract:Although most Insect Colonies are headed by a singly mated queen, some ant, wasp and bee taxa have evolved high levels of multiple mating or 'polyandry'. We argue here that a contributing factor towards the evolution of polyandry is that the resulting genetic diversity within Colonies provides them with a system of genetically based task specialization, enabling them to respond resiliently to environmental perturbation. An alternate view is that genetic contributions to task specialization are a side effect of multiple mating, which evolved through other causes, and that genetically based task specialization now makes little or no contribution to colony fitness.