Study Of Social Evolution Research Articles

Nonlinear social evolution and the emergence of collective action.

Organisms from microbes to humans engage in a variety of social behaviors, which affect fitness in complex, often nonlinear ways. The question of how these behaviors evolve has consequences ranging from antibiotic resistance to human origins. However, evolution with nonlinear social interactions is challenging to model mathematically, especially in combination with spatial, group, and/or kin assortment. We derive a mathematical condition for natural selection with synergistic interactions among any number of individuals. This result applies to populations with arbitrary (but fixed) spatial or network structure, group subdivision, and/or mating patterns. In this condition, nonlinear fitness effects are ascribed to collectives, and weighted by a new measure of collective relatedness. For weak selection, this condition can be systematically evaluated by computing branch lengths of ancestral trees. We apply this condition to pairwise games between diploid relatives, and to dilemmas of collective help or harm among siblings and on spatial networks. Our work provides a rigorous basis for extending the notion of "actor", in the study of social evolution, from individuals to collectives.

Social wasps as models to study the major evolutionary transition to superorganismality.

The major evolutionary transition to superorganismality has taken place several times in the insects. Although there has been much consideration of the ultimate evolutionary explanations for superorganismality, we know relatively little about what proximate mechanisms constrain or promote this major transition. Here, we propose that Vespid wasps represent an understudied, but potentially very useful, model system for studying the mechanisms underpinning superorganismality. We highlight how there is an abundance of behavioural data for many wasp species, confirming their utility in studies of social evolution; however, there is a sparsity of genomic data from which we can test proximate and ultimate hypotheses on this major evolutionary transition.

Spiritual Aspects of Formation of a Threatening Resistant Society

Spirituality protects both the freedom of the individual, and freedom, the independence of the nation. The study of social evolution, the logic of social processes creates the opportunity to identify changes in the system of historical, spiritual, cultural and moral values-accordingly-the dynamics of the development of the society in situations of risks, challenges and threats. To date, mankind has accumulated so many weapons and ammunition that it is enough to destroy the globe several times. However, the greatest danger today is the ongoing ideological struggle for the souls and consciousness of people, especially the younger generation. Today, the decisive role is played not by battles at nuclear test sites, but by fighting on the ideological front. Never forget this bitter truth. The formation of ideological immunity is determined by the degree of its conformity with the nature of the people, the way of life and thinking, and most importantly-how it reflects the national interests and aspirations of society. Only such an ideology will stand the test of time and life, people will believe it and accept it as a belief.

The constant philopater hypothesis: a new life history invariant for dispersal evolution.

Surprising invariance relationships have emerged from the study of social interaction, whereby a cancelling‐out of multiple partial effects of genetic, ecological or demographic parameters means that they have no net impact upon the evolution of a social behaviour. Such invariants play a pivotal role in the study of social adaptation: on the one hand, they provide theoretical hypotheses that can be empirically tested; and, on the other hand, they provide benchmark frameworks against which new theoretical developments can be understood. Here we derive a novel invariant for dispersal evolution: the ‘constant philopater hypothesis’ (CPH). Specifically, we find that, irrespective of variation in maternal fecundity, all mothers are favoured to produce exactly the same number of philopatric offspring, with high‐fecundity mothers investing proportionally more, and low‐fecundity mothers investing proportionally less, into dispersing offspring. This result holds for female and male dispersal, under haploid, diploid and haplodiploid modes of inheritance, irrespective of the sex ratio, local resource availability and whether mother or offspring controls the latter's dispersal propensity. We explore the implications of this result for evolutionary conflict of interests – and the exchange and withholding of contextual information – both within and between families, and we show that the CPH is the fundamental invariant that underpins and explains a wider family of invariance relationships that emerge from the study of social evolution.

Social evolution and inclusive fitness theory: an introduction

Social behavior has long puzzled evolutionary biologists, since the classical theory of natural selection maintains that individuals should not sacrifice their own fitness to affect that of others. Social Evolution and Inclusive Fitness Theory argues that a theory first presented in 1963 by William D. Hamilton—inclusive fitness theory—provides the most fundamental and general explanation for the evolution and maintenance of social behavior in the natural world. James Marshall guides readers through the vast and confusing literature on the evolution of social behavior, introducing and explaining the competing theories that claim to provide answers to questions such as why animals evolve to behave altruistically. Using simple statistical language and techniques that practicing biologists will be familiar with, he provides a comprehensive yet easily understandable treatment of key concepts and their repeated misinterpretations. Particular attention is paid to how more realistic features of behavior, such as nonadditivity and conditionality, can complicate analysis. Marshall highlights the general problem of identifying the underlying causes of evolutionary change, and proposes fruitful approaches to doing so in the study of social evolution. Social Evolution and Inclusive Fitness Theory describes how inclusive fitness theory addresses both simple and complex social scenarios, the controversies surrounding the theory, and how experimental work supports the theory as the most powerful explanation for social behavior and its evolution.

The social life of eastern water dragons: sex differences, spatial overlap and genetic relatedness

Understanding the ways individuals socialize with each other and how they differ temporally, spatially and phylogenetically is key to unravelling the evolutionary processes that shape social evolution. Our current knowledge of social evolution in vertebrates, however, has primarily come from bird and mammalian studies. Despite being largely understudied, reptiles remain an important piece of the puzzle in our study of social evolution; they represent a major class of vertebrates and, similar to mammals and birds, many are gregarious. Increasing our understanding of sociality in reptiles is important given that it would allow for comparisons across phylogenetically distinct vertebrate classes. In this study, we investigated the social structure of the eastern water dragon, Intellagama lesueurii, and found that males and females showed both preference and avoidance for members of either sex. Furthermore, we found sex differences in the extent of individual sociability: females generally formed stronger associations with one another than any other sex class (e.g. male–male, male–female). Although association patterns correlated to some extent with home range overlap, we found no evidence of a correlation with kinship. Overall, our study presents additional evidence that sociality can evolve outside the realm of kin selection.

The Genotypic View of Social Interactions in Microbial Communities

Dense and diverse microbial communities are found in many environments. Disentangling the social interactions between strains and species is central to understanding microbes and how they respond to perturbations. However, the study of social evolution in microbes tends to focus on single species. Here, we broaden this perspective and review evolutionary and ecological theory relevant to microbial interactions across all phylogenetic scales. Despite increased complexity, we reduce the theory to a simple null model that we call the genotypic view. This states that cooperation will occur when cells are surrounded by identical genotypes at the loci that drive interactions, with genetic identity coming from recent clonal growth or horizontal gene transfer (HGT). In contrast, because cooperation is only expected to evolve between different genotypes under restrictive ecological conditions, different genotypes will typically compete. Competition between two genotypes includes mutual harm but, importantly, also many interactions that are beneficial to one of the two genotypes, such as predation. The literature offers support for the genotypic view with relatively few examples of cooperation between genotypes. However, the study of microbial interactions is still at an early stage. We outline the logic and methods that help to better evaluate our perspective and move us toward rationally engineering microbial communities to our own advantage.

The evolution of multimale groups in Verreaux's sifaka, or how to test an evolutionary demographic model

Theoretical advances in the study of social evolution have highlighted the importance of studying group formation in conjunction with population dynamics. To address this need, a number of demographically explicit models have been developed. We parameterize such a model to study the evolution of multimale associations in Verreaux’s sifaka (Propithecus verreauxi), a diurnal lemur living in small multimale–multifemale groups. We use long-term demographic data from a population in western Madagascar to estimate the fitness prospects of different male behavioral strategies. Our results indicate that dispersing male sifaka, rather than searching for a breeding territory of their own (floating), do better joining an established group as a subordinate with limited reproductive opportunities, mainly because they may later ascend to the dominant position. By contrast, resident males should not accept potential immigrants because we could not find any measurable benefit of living in a multimale group for them. There is thus a conflict over group membership between resident and floater males, and we suggest that floaters at least occasionally win this conflict because they have more to gain from joining than residents stand to lose by sharing their territory. Key words: ecological constraints, group-living, Propithecus verreauxi, social evolution, social queuing. [Behav Ecol]

Intraspecific support for the polygyny-vs.-polyandry hypothesis in the bulldog ant Myrmecia brevinoda

The number of queens per colony and the number of matings per queen are the most important determinants of the genetic structure of ant colonies, and understanding their interrelationship is essential to the study of social evolution. The polygyny-vs.-polyandry hypothesis argues that polygyny and polyandry should be negatively associated because both can result in increased intracolonial genetic variability and have costs. However, evidence for this long-debated hypothesis has been lacking at the intraspecific level. Here, we investigated the colony genetic structure in the Australian bulldog ant Myrmecia brevinoda. The numbers of queens per colony varied from 1 to 6. Nestmate queens within polygynous colonies were on average related (r(qq) = 0.171 ± 0.019), but the overall relatedness between queens and their mates was indistinguishable from zero (r(qm) = 0.037 ± 0.030). Queens were inferred to mate with 1-10 males. A lack of genetic isolation by distance among nests indicated the prevalence of independent colony foundation. In accordance with the polygyny-vs.-polyandry hypothesis, the number of queens per colony was significantly negatively associated with the estimated number of matings (Spearman rank correlation R = -0.490, P = 0.028). This study thus provides the rare intraspecific evidence for the polygyny-vs.-polyandry hypothesis. We suggest that the high costs of multiple matings and the strong effect of multiple mating on intracolonial genetic diversity may be essential to the negative association between polygyny and polyandry and that any attempt to empirically test this hypothesis should place emphasis upon these two key underlying aspects.

Characterization of microsatellite loci isolated from the wasp, Microstigmus nigrophthalmus (Hymenoptera)

Fifty-two microsatellite loci were characterized in 22-31 unrelated females of the wasp (Microstigmus nigrophthalmus) collected from the Mata do Paraiso, Viçosa, M.G., Brazil. Fifty-one of these loci were developed from a microsatellite-enriched genomic library derived from M. nigrophthalmus and one was derived from the wasp, Ormyrus nitidulus. The genus Microstigmus represents an independent origin of social behaviour in the Hymenoptera and is thus of great potential in the study of social evolution.

Solving the freeloaders paradox: Genetic associations and frequency-dependent selection in the evolution of cooperation among nonrelatives.

One of the enduring problems in the study of social evolution has been to understand how cooperation can be maintained in the presence of freeloaders, individuals that take advantage of the more cooperative members of groups they are eager to join. The freeloader problem has been particularly troublesome when groups consist of nonrelatives, and no inclusive fitness benefits accrue to individuals that contribute more heavily to communal activities. These theoretical difficulties, however, are not mirrored by the numerous examples of cooperative or even altruistic behaviors exhibited by groups of nonrelatives in nature (e.g., many human groups, communally nesting bees, multiple queen-founding ants, cellular slime molds, and social bacteria). Using a model in which cooperation and grouping tendencies are modeled as coevolving dynamical variables, I show that the freeloader problem can be addressed when group-size effects on fitness are considered explicitly. I show that freeloaders, whose presence is reflected in the development of linkage disequilibrium between grouping and cooperation, increase in frequency when rare, but are selected against when common due to the reduced productivity of the groups they overburden with their presence. Freeloader frequencies thus periodically rise and fall around an equilibrium shown here to be dynamic. These results highlight the importance of group-level effects in the origin and maintenance of sociality, illustrate the dynamic nature of equilibria when multiple levels of selection are involved, and provide a solution to the freeloaders paradox.

Relatedness in Trait Group Models of Social Evolution

Genetic relatedness is a central concept in the study of social evolution. Though originally defined in terms of genealogy, the modern version of relatedness accommodates genetic similarity of any origin. This paper examines relatedness in group structured modes, in which a trait affects the fitness of all group members. Such traits can be divided into two types, based on whether their group fitness effects encompass all group members including the actor (“whole-group traits”), or only group members other than the actor (“other-only traits”). Both trait types are common in nature as well as in theoretical models, but they have rarely been distinguished clearly. The average relatedness of recipients to actors differs for the two trait types within the same population and even the same individual, leading to different selection pressures and evolutionary outcomes. Total relatedness in group-structured models can be partitioned into two components: structural relatedness due to the size and number of groups in the population, and assortative relatedness due to the distribution of genotypes among groups. Each component differs for whole-group vs. other-only traits, both in terms of their values and the factors that influence them. Some key differences include: positive relatedness requires positive assortment for other-only but not for whole-group traits; negative relatedness is possible for other-only but not whole-group traits; relatedness depends on average group size for whole-group but not other-only traits, and non-random assortment into groups affects relatedness more strongly for other-only than whole-group traits. Recognizing the distinction between these trait types resolves some apparent contradictions in the literature, and clarifies the limits of some previous results.

A new epoch in joint studies of social evolution: molecular and behavioural ecology of aphid soldiers

A new epoch in joint studies of social evolution: molecular and behavioural ecology of aphid soldiers

Evolutionary Materialism: A Theoretical Strategy for the Study of Social Evolution

Existing approaches to the study of social evolution are insufficient for the task of explaining the full range of social evolution from the Neolithic Revolution down to the present day. Some anthropological approaches shed considerable light on the evolution of preindustrial and precapitalist societies but are less capable of explaining the evolution of the modern world. Sociological approaches usually have the opposite result: they shed light on the evolution of the modern world but falter with respect to premodern times. This article presents a comprehensive formal-propositional theoretical approach to social evolution that combines the strengths of anthropological and sociological approaches while minimizing their weaknesses. The theoretical approach offered, referred to as evolutionary materialism, comprises propositions concerned with the directional nature of world history, the substance or content of social evolution, the principal causal factors in social evolution, the adaptational character of social evolution, the interplay of agency and structure in social evolution, the units of social evolution, the pace of social evolution, and methods of studying social evolution. The second half of the article attempts a brief logical and empirical justification of evolutionary materialism.

Ritual, time and history

Abstract It is often claimed that studies of social evolution are impeded by the limits of resolution imposed by the prehistoric time scale. This paper distinguishes between the mundane time and ritual time, contending that public ritual often develops at a different pace from everyday existence. That makes it more amenable to study by archaeological methods. Whilst ritual systems may be rooted in the past, however, their operation often sheds light on changing social and political circumstances. The argument is illustrated by the development of Stonehenge.

On Adams' Monistic Concept of Social Evolution

Adams' monistic concept of social evolution is understood as the most coherent theoretical proposition on this matter available today. And yet, the theory of Monistic Materialism fails to retain its materialist stance at the methodological level; it falls back on the mind-matter-dichotomy. Consequently, "power" based on the mindful control of matter turns into the most fundamental term of reference in social studies. This limits the analytical potency of Materialism in the study of social evolution and in offering alternatives for society's future. This paper suggests that a dialectical appropriation of Monism promises to overcome these difficulties.

The Social Wisdom of the Primitives with Special Reference to Their Proverbs

T HE indispensable prerequisites to any social thought are association and language. It is due to association that men, even the most primitive, become aware of the various aspects of human nature, and it is out of association that their attitudes and ideas grow, however vague and fantastic they may be, regarding social relationships generally, the requirements of group conduct, social and psycho-social processes, social institutions, and human life in general. Without language there can be no communication of any kind; nor are men capable of developing concepts of any kind. To pick up social thought at the precise moment when man developed the combination of simple association and rude speech is impossible at this stage of the study of social evolution. We may in time know quite a bit about man at this point in his development. On the basis of his skeletal remains we now know something about him as an anatomical specimen, and with the aid of his rude artifacts we can piece together some aspects of his culture, but we have almost no inkling of his thought. The most rudimentary social thought now available is that of recent and contemporary primitive peoples -peoples who, while relatively rude, and simple, have a fairly substantial culture, including established ideas, standardized relationships, a flexible language, and a full equipment of institutions. The thought of primitive peoples is largely pre-scientific and pre-literate. Their ideas are not reached by deliberate reasoning nor by careful and conscious investigation. They are direct and intuitive, the products of minds that are alogical, uncritical and credulous on the whole, and that depend on common experience, observation, and imagination for explanations.' Being pre-literate, their thought,

Book Review: An Introduction to the Study of Social Evolution: The Prehistoric Period

Book Review: An Introduction to the Study of Social Evolution: The Prehistoric Period