By Abdul Ahmed
Arizona State University, Ira Fulton School of Engineering
This paper presents a case of historical dynamics of social solidarity, self segregation and emergence of alternative social organizations in modern day Somalia. The paper introduces the drivers of parochial interests such as Clan Affinity “a peculiar concept that combines clan or kinfolk interest and homophily”. The author then discusses and surveys anthropological studies to describe the unique systematic segmentary structure of patrilineal Clans System that maps the Somali society. This survey is then used to construct an agent based to represent Somali society and simulate the social interaction in modern day Somalia.
The model is presents the role of path-dependent patterns and processes in regionalism, self-segregation and emergence of new social organizations or compositions. Furthermore, the paper presents an analysis of clan based political identification as a product of and a driving force behind social conflict in Somali territories (clan as a feedback medium). The analysis of the model shows:
(1) How central governance fails under pressure from parochial clan interests that drive local cooperative interaction and outside competition.
(2) Formation of clan clusters and hence the emergence of traditional and alternative institutions of social organization.
(3) The role of initial conditions and emergence of path-dependent patterns and processes
The outcomes of the simulation provide plausible explanations and in-depth insights to the collapse of central authority; the ongoing social and political conflict in Somalia, the emergence of new forms of social organization as well as the restoration traditional clan based local governance.
Variable Environments, Contingent Responses and the Evolution of Sociality
By Athena Aktipis
University of Arizona
Models such as Maynard Smith’s Haystack model have shown that high rates of movement (i.e., migration, mixing, dispersal) undermine the evolution of cooperation. However, these models generally assume that movement is unconditional. The present model replaces the assumption of unconditional movement with conditional movement; individuals stay in groups that provide higher returns (by virtue of having more cooperators), and ‘Walk Away’ from groups providing low returns. Implementing this conditional movement rule generates a number of findings including: 1) when individuals have high thresholds, corresponding to low tolerance for defectors, this lead to selection for cooperation, 2) high thresholds lead to high rates of movement initially and lower rates of movement after selection for cooperators, and 3) population structure becomes more stable after selection increases the proportion of cooperators in the population. These findings challenge the standard view derived from Maynard Smith’s Haystack model and others that high rates of movement undermine selection for cooperation. In contrast, the current model demonstrates that high rates of conditional movement can be associated with stronger selection for cooperation. These results show that high rates of migration observed in nature are not prohibitive for the evolution of cooperation, as standard group selection models have assumed.
Further, conditional movement is very cognitively simple, evolutionarily ancient and widespread in nature, making its inclusion in models of cooperation essential if we are to understand the evolution of cooperation in organisms capable of responding to their local environments. In the language of the haystack models, if individuals are able to ‘walk away’ from haystacks with fewer cooperators, this allows cooperation to evolve much more readily than the haystack model concluded.
This model demonstrates that, when cooperators enrich their local environments, they enhance group stability. Future directions of this work include demonstrating how very simple adaptations designed for detecting and responding to the quality of the local environment (i.e., foraging adaptations) may play important roles in the formation and stability of various kinds of groups including kin groups, non-kin groups and even aggregations of different species.
Social Scaling and Correspondences to Group Identities
By Linnda R.Caporael
Rensselaer Polytechnic Institute, Department of Science & Technology Studies
This paper focuses on human coordination, specifically the ways in which individuals organize themselves into groups that subsequently come to act as higher-level entities. Two topics are of particular concern: scaling in face-to-face groups and correlated shifts in individual and group identity.
A pervasive and dominating assumption of universal self-interest, whether justified by economics or genetics, has obscured the constraints imposed on it by human sociality and obligatory interdependence, not only for understanding cooperation, but also conflict, competition and selection. In a purely metaphoric sense, genes may be “selfish” (and humans certainly can be selfish), but phenotypic self-interest is constrained. After 40 million years of evolution resulting in a variety of social primates, humans are not only selfish, but also obligately interdependent: they are unable to survive and reproduce without a group. Coalition formation cannot explain the evolution of human sociality (although it may help to explain the extreme lability of human group identification) because forming a coalition requires an already highly developed capacity for coordinating behavior. Hence, the “central problem” for theories of sociality is more than the evolution of altruism. Coordination evolves directly, contingently or as a by- product as a result of selection pressures for developing and maintaining group membership. Coordination refers to the skillful blend of diverse elements into a harmonious operation. In the case of humans, more theoretical leverage can be gained by attending to developmental systems and multiple levels of analysis, an evolutionary approach more characteristic of evo-devo than traditional neo-Darwinism.
Evolutionary considerations of human morphology and ecology suggest a model of four significant “core configurations” in face-to-face groups. These result from shifting dynamics of subgroup size and task within and between heterarchical group structures. Core configurations are tentatively labeled dyad, workgroup (3-7 individuals), band (25-50 individuals) and macroband, (about 25 bands). These configurations are a joint function of group size and modal tasks that engage adaptive functions evolved at that level. For example, the dyad affords micro-coordination (e.g., facial imitation in a mother-infant dyad, the automatic adjustment of gait that occurs when two people walk together). If core configurations function in the coordination of human behavior, and are repeatedly assembled, generation to generation, in human ontogeny, and in daily life, then we should expect some aspects of human mental systems and interactions to correlate with core configurations.
The model organizes a range of previously unrelated scientific findings; this presentation explores shifts in individual and group identities as psychological correlates of social scaling. Broader implications of the model are also noted: Capabilities specialized for specific configurations can be extended and recombined for novel behavior and situations, including cross-cutting group memberships in modern societies. Conceptual, empirical, and agent-based modeling simulations are needed to compare the resulting differences from assuming societies to be “smooth-textured” aggregates of individualistic decision makers or “lumpy-textured” overlaps of meta-individuals.
Evolution and Ecology of Collective and Individual Problem-Solving in Social Insects
By Anna Dornhaus
University of Arizona, Department of Ecology and Evolutionary Biology
Adam Smith proposed, for human societies, that the benefits of division of labor are threefold: individuals who specialize improve in efficiency, switching costs are reduced, and machines can be invented. In social insects, division of labor is widespread, but there is little quantitative information on whether colonies reap these kinds of benefits from division of labor. Although ants with morphologically specialized workers almost certainly benefit from individuals with high efficiency in particular tasks, most ant species lack such morphological differentiation. In a recent study, I showed that at least one ant species has specialized workers who are in fact not more effective at their work than non-specialists from the same colony. New data on bumble bees also show that some workers seem to be performing tasks in which they do not perform better than other workers. What, then, are the benefits of division of labor, which seems to come at the cost of flexibility loss? I discuss some hypotheses and how they may be tested.
Us without Them: On the Intragroup Origin of Group Formation and Positive Ingroup Regard
By Lowell Gaertner
University of Tennessee, Department of Psychology
The social-psychological literature on social-groups is guided by an ingroup-requires-outgroup assumption suggesting that (a) psychological group formation arises from perceptions of relative similarity between aggregates of individuals and (b) ensuing positive ingroup regard (i.e., favorable attitudes and actions toward ingroup members) is an emergent property of intergroup comparison. The current talk, in contrast, overviews experiments that manipulate the feasibility for inter-aggregate comparison orthogonal to other dynamic factors plausibly contributing to group formation, such as interaction and interdependence. Results indicate that (at least among humans) those dynamic factors give rise to a sense of ingroupness (i.e., entitativity – “we are an entity”) which in turn promotes favorable attitudes and actions toward ingroup members. Importantly, that process occurred regardless of whether inter-aggregate comparison was feasible. These data imply that an understanding of group phenomena requires research and theory to move beyond intergroup issues of us-vs.-them to encompass intragroup issues of “us.” To that end, the talk concludes with a bio-social model that situates groups in an evolutionary framework that considers positive-ingroup-regard as attitudinal and behavioral expressions of hormones (such as oxytocin) that evolved to release to a sense-of-groupness and function to promote the stability of the group and the individuals membership therein.
Does Biology Need an Organism Concept?
By Matthew Herron & John Pepper
University of Arizona, Department of Ecology and Evolutionary Biology
Among biologists, there is no general agreement on exactly what entities qualify as ‘organisms’. Instead, there are multiple competing organism concepts and definitions. While some authors think this is a problem that should be corrected, others have suggested that biology does not actually need an organism concept. We argue that the organism concept is central to biology and should not be abandoned. Both organism concepts and operational definitions are useful. We review criteria used for recognizing organisms and conclude that they are not categorical but rather continuously variable. Different organism concepts are useful for addressing different questions, and it is important to be explicit about which is being used. Finally, we examine the origins of the derived state of organismality, and suggest that it may result from positive feedback between natural selection and functional integration in biological entities.
Fostering Emergence: Activities, Frameworks, and Tools to Actualize Small Groups
By Dario Nardi & Susanne Lohmann
University of California Los Angeles, Human Complex Systems
When is a small group a cohesive, dynamic and adaptive system? What learning activities, conceptual frameworks, and evaluative tools assist individuals to act as both keen observers and active participants in the life of small groups? And how does focusing on the group as a unique entity facilitate group performance?
For over ten years, the author has regularly facilitated a month-long group dynamics workshop for undergraduate students. Each group of six to nine students is tasked to do a presentation on their group's process of preparing to give that presentation. This highly self-reflexive activity often illuminates essential qualities of group dynamics and spotlights the group as a single entity rather than a collection of dispirit members.
This presentation describes the activity used and lessons learned. One lesson is the crucial actions a facilitator or a group participant can take (or not take) to help a collection of individuals transition into a cohesive group. Another lesson touches on which conceptual models of group dynamics are most useful to analyze groups as wholes as well as which models and methods can be misleading unless handled with care. Finally, the author will showcase several computational multiagent simulations that demonstrate emergence of group-level behaviors.
The mechanistic Basis for the Evolution of Reproductive Altruism
By Aurora Nedelcu
University of New Brunswick, Department of Biology
University of Arizona, Department of Ecology and Evolutionary Biology
Altruism is central to the evolution of various biological phenomena, from social behavior to evolutionary transitions in individuality. Although the selective conditions favoring altruism are being increasingly understood, the mechanistic basis for the evolution of this behavior is yet to be deciphered. Reproductive altruism is an extreme form of altruism best typified by the existence of sterile castes in eusocial insects and somatic cells in multicellular organisms. We have argued that the evolution of soma in multicellular lineages involved the co-option of life-history genes whose expression in their unicellular ancestors was conditioned on environmental cues (as an adaptive strategy to enhance survival at an immediate cost to reproduction) through shifting their expression from a temporal (environmentally-induced) into a spatial (developmental) context. To address this proposal, we are using a group of closely related green algae (Volvocales) comprising both unicellular species (e.g., Chlamydomonas reinhardtii) and multicellular forms with a complete division of labor between reproductive and somatic cells (e.g., Volvox carteri). The terminal differentiation of somatic cells in V. carteri is dependent on the expression of regA – a gene that encodes a transcription factor thought to repress several nuclear genes coding for chloroplast proteins. As a result, the growth (dependent on photosynthesis) and reproduction (dependent on growth) of somatic cells are suppressed. Previously, we identified regA’s closest homolog in C. reinhardtii and showed that this gene (rls1) is induced in the dark, when the expression of chloroplast proteins is down-regulated. Based on these findings, we hypothesized that rls1 is generally induced under conditions when the temporary down-regulation of photosynthesis is beneficial; these include acclimation to various environmental changes, when available energy is re-distributed towards survival and away from growth and reproduction. Recently, we found that rls1 is expressed as part of the acclimation response to various environmental stresses, and its expression coincides with cessation of reproduction. These findings complement and provide support to proposals that cast differentiation in eusocial insects involved the remodeling of regulatory circuits present in solitary ancestors and, thus, argue that the two biological phenomena, although involving very different systems, are based on a common selective framework. Here, we propose a model in which by simulating the general acclimation signal in a spatial rather than temporal context, responses beneficial to solitary individuals could be co-opted into an altruistic behavior at the group level.
Individuals as Groups: How do Multicellular Animals Suppress Internal Evolution?
By John Pepper
University of Arizona, Department of Ecology and Evolutionary Biology
A multicellular organism can be viewed as a population of cooperating cells. This population is subject to the same evolutionary processes as any other population undergoing reproduction, death, mutation, and competition for limiting resources. Selection within a metazoan will inevitably favor those cells that are better at reproductive competition and survival. Yet, the characteristics that help cells compete effectively within an organism are generally detrimental to organismal integrity and fitness. Thus there is a fundamental conflict between selection among cells within organisms (somatic selection) and selection among organisms within populations (organismal selection). Multicellular organisms could not emerge as functional entities before organismal selection had led to the evolution of mechanisms to suppress somatic selection. Here I propose a fundamental mechanism for the suppression of somatic cellular evolution in animals. The hypothesis is tested using a computational model. Results support the hypothesis that observed patterns of ongoing cell differentiation serve the function of suppressing somatic cellular evolution.
Weak individual preference versus strong collective sensitivity: a density-dependent process
By Grégory Sempo, Stéphane Canonge, Claire Detrain & Jean-Louis Deneubourg
Université libre de Bruxelles, Unit of Social Ecology
Aggregation occurs in many biological systems: from bacteria to vertebrates. Its functional value was shown to result notably in facilitated cooperation, enhanced control of environmental fluctuations and sharing of information. In the absence of sophisticated communication and global knowledge of the environment, cockroaches are able to assess the availability of resources and to reach a consensual decision: the group aggregates in the better resting site. The amplification process leading to this selection relies on the modulation of their resting time, according to the perception of two local cues: the shelters’ luminosity and the number of congeners already aggregated. We show that aggregation dynamics and collective shelter selection of cockroaches are positively density-dependent. Unlike single individuals, groups of cockroaches are more likely to discriminate between environmental resources. Indeed, individuals tested alone show only a weak preference for the better site with the lower luminosity. Nevertheless, this weak individual preference is strongly amplified through interactions between group members, leading to the collective selection of the better site in the majority of trials. Moreover, the fraction of total sheltered population increases with the population density. Data from the literature suggest that such collective decision-making characteristics are shared by many other group living species.