scholarly journals Pathways to social evolution: reciprocity, relatedness, and synergy

2013 ◽  
Author(s):  
Jeremy Van Cleve ◽  
Erol Akcay
Keyword(s):  
Social Behavior ◽  
Social Evolution ◽  
Genetic Relatedness ◽  
Behavioral Responses ◽  
Biological Mechanisms ◽  
Fitness Effects ◽  
Long Run ◽  
Plastic Responses ◽  
Synthetic Models ◽  
Evolutionarily Stable

Many organisms live in populations structured by space and by class, exhibit plastic responses to their social partners, and are subject to non-additive ecological and fitness effects. Social evolution theory has long recognized that all of these factors can lead to different selection pressures but has only recently attempted to synthesize how these factors interact. Using models for both discrete and continuous phenotypes, we show that analyzing these factors in a consistent framework reveals that they interact with one another in ways previously overlooked. Specifically, behavioral responses (reciprocity), genetic relatedness, and synergy interact in non-trivial ways that cannot be easily captured by simple summary indices of assortment. We demonstrate the importance of these interactions by showing how they have been neglected in previous synthetic models of social behavior both within and between species. These interactions also affect the level of behavioral responses that can evolve in the long run; proximate biological mechanisms are evolutionarily stable when they generate enough responsiveness relative to the level of responsiveness that exactly balances the ecological costs and benefits. Given the richness of social behavior across taxa, these interactions should be a boon for empirical research as they are likely crucial for describing the complex relationship linking ecology, demography, and social behavior.

scholarly journals An evolutionary resolution of manipulation conflict

2014 ◽  
Author(s):  
Mauricio González-Forero
Keyword(s):  
Mathematical Model ◽  
Social Behavior ◽  
Delayed Dispersal ◽  
Fitness Effects ◽  
Long Run ◽  
Social Partners ◽  
Maternal Manipulation ◽  
Selection For ◽  
The Cost

Individuals can manipulate the behavior of social partners. However, manipulation may conflict with the fitness interests of the manipulated individuals. Manipulated individuals can then be favored to resist manipulation, possibly reducing or eliminating the manipulated behavior in the long run. I use a mathematical model to show that conflicts where manipulation and resistance coevolve can disappear as a result of the coevolutionary process. I find that while manipulated individuals are selected to resist, they can simultaneously be favored to express the manipulated behavior at higher efficiency (i.e., providing increasing fitness effects to recipients of the manipulated behavior). Efficiency can increase to a point at which selection for resistance disappears. This process yields an efficient social behavior that is induced by social partners, and over which the inducing and induced individuals are no longer in conflict. A necessary factor is costly inefficiency. I develop the model to address the evolution of advanced eusociality via maternal manipulation (AEMM). The model predicts AEMM to be particularly likely in taxa with ancestrally imperfect resistance to maternal manipulation. Costly inefficiency occurs if the cost of delayed dispersal is larger than the benefit of exploiting the maternal patch. I discuss broader implications of the process. Now published in: Evolution, doi:10.1111/evo.12420

scholarly journals The organization and control of an evolving interdependent population

2015 ◽  
Vol 12 (108) ◽  
pp. 20150044 ◽  
Author(s):  
Dervis C. Vural ◽  
Alexander Isakov ◽  
L. Mahadevan
Keyword(s):  
Evolutionary Game Theory ◽  
Large Scale ◽  
Social Evolution ◽  
Evolutionary Game ◽  
Large Scale Structures ◽  
External Perturbations ◽  
Emergence Of Cooperation ◽  
Scale Structures ◽  
And Control ◽  
Evolutionarily Stable

Starting with Darwin, biologists have asked how populations evolve from a low fitness state that is evolutionarily stable to a high fitness state that is not. Specifically of interest is the emergence of cooperation and multicellularity where the fitness of individuals often appears in conflict with that of the population. Theories of social evolution and evolutionary game theory have produced a number of fruitful results employing two-state two-body frameworks. In this study, we depart from this tradition and instead consider a multi-player, multi-state evolutionary game, in which the fitness of an agent is determined by its relationship to an arbitrary number of other agents. We show that populations organize themselves in one of four distinct phases of interdependence depending on one parameter, selection strength. Some of these phases involve the formation of specialized large-scale structures. We then describe how the evolution of independence can be manipulated through various external perturbations.

Using Notches to Uncover Optimization Frictions and Structural Elasticities: Theory and Evidence from Pakistan *

2013 ◽  
Vol 128 (2) ◽  
pp. 669-723 ◽  
Author(s):  
Henrik J. Kleven ◽  
Mazhar Waseem
Keyword(s):  
Administrative Data ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Tax Incentives ◽  
Missing Mass ◽  
Zero Mass ◽  
Long Run ◽  
Choice Sets ◽  
Price Distortions

Abstract We develop a framework for nonparametrically identifying optimization frictions and structural elasticities using notches—discontinuities in the choice sets of agents—introduced by tax and transfer policies. Notches create excess bunching on the low-tax side and missing mass on the high-tax side of a cutoff, and they are often associated with a region of strictly dominated choice that would have zero mass in a frictionless world. By combining excess bunching (observed response attenuated by frictions) with missing mass in the dominated region (frictions), it is possible to uncover the structural elasticity that would govern behavior in the absence of frictions and arguably capture long-run behavior. We apply our framework to tax notches in Pakistan using rich administrative data. While observed bunching is large and sharp, optimization frictions are also very large as the majority of taxpayers in dominated ranges are unresponsive to tax incentives. The combination of large observed bunching and large frictions implies that the frictionless behavioral response to notches is extremely large, but the underlying structural elasticity driving this response is nevertheless modest. This highlights the inefficiency of notches: by creating extremely strong price distortions, they induce large behavioral responses even when structural elasticities are small.

scholarly journals Kin and group selection are both flawed but useful data analysis tools

2019 ◽  
Author(s):  
jeff smith ◽  
R. Fredrik Inglis
Keyword(s):  
Empirical Research ◽  
Social Evolution ◽  
Multilevel Selection ◽  
Selection Theory ◽  
Fitness Effects ◽  
Data Driven Approach ◽  
Biological Interpretation ◽  
Multilevel Selection Theory ◽  
Microbial Systems ◽  
Analytical Tools

AbstractFor understanding the evolution of social behavior in microbes, mathematical theory can aid empirical research but is often only used as a qualitative heuristic. How to properly formulate social evolution theory has also been contentious. Here we evaluate kin and multilevel selection theory as tools for analyzing microbial data. We reanalyze published datasets that share a common experimental design and evaluate these theories in terms of data visualization, statistical performance, biological interpretation, and quantitative comparison across systems. We find that the canonical formulations of both kin and multilevel selection are almost always poor analytical tools because they use statistical regressions that are poorly specified for the strong selection and nonadditive fitness effects common in microbial systems. Analyzing both individual and group fitness outcomes helps clarify the biology of selection. We also identify analytical practices in empirical research that suggest how theory might better handle the challenges of microbial data. A quantitative, data-driven approach thus shows how kin and multilevel selection theory both have substantial room for improvement as tools for understanding social evolution in all branches of life.

scholarly journals Social Bacteriophages

2020 ◽  
Vol 8 (4) ◽  
pp. 533
Author(s):  
Pilar Domingo-Calap ◽  
Lucas Mora-Quilis ◽  
Rafael Sanjuán
Keyword(s):  
Spatial Structure ◽  
Social Evolution ◽  
Genetic Relatedness ◽  
Population Level ◽  
Mechanisms Of Action ◽  
Evolution Theory ◽  
Superinfection Exclusion ◽  
Key Population ◽  
Viral Product ◽  
Host Exploitation

Despite their simplicity, viruses can display social-like interactions such as cooperation, communication, and cheating. Focusing on bacteriophages, here we review features including viral product sharing, cooperative evasion of antiviral defenses, prudent host exploitation, superinfection exclusion, and inter-phage peptide-mediated signaling. We argue that, in order to achieve a better understanding of these processes, their mechanisms of action need to be considered in the context of social evolution theory, paying special attention to key population-level factors such as genetic relatedness and spatial structure.

scholarly journals Male relatedness and familiarity are required to modulate male-induced harm to females in Drosophila

2017 ◽  
Vol 284 (1860) ◽  
pp. 20170441 ◽  
Author(s):  
Sally Le Page ◽  
Irem Sepil ◽  
Ewan Flintham ◽  
Tommaso Pizzari ◽  
Pau Carazo ◽  
...  
Keyword(s):  
Potential Role ◽  
Genetic Relatedness ◽  
Inclusive Fitness ◽  
Kin Recognition ◽  
Female Reproduction ◽  
Fitness Effects ◽  
Inclusive Fitness Theory ◽  
Indirect Fitness ◽  
Female Lifespan

Males compete over mating and fertilization, and often harm females in the process. Inclusive fitness theory predicts that increasing relatedness within groups of males may relax competition and discourage male harm of females as males gain indirect benefits. Recent studies in Drosophila melanogaster are consistent with these predictions, and have found that within-group male relatedness increases female fitness, though others have found no effects. Importantly, these studies did not fully disentangle male genetic relatedness from larval familiarity, so the extent to which modulation of harm to females is explained by male familiarity remains unclear. Here we performed a fully factorial design, isolating the effects of male relatedness and larval familiarity on female harm. While we found no differences in male courtship or aggression, there was a significant interaction between male genetic relatedness and familiarity on female reproduction and survival. Relatedness among males increased female lifespan, reproductive lifespan and overall reproductive success, but only when males were familiar. By showing that both male relatedness and larval familiarity are required to modulate female harm, these findings reconcile previous studies, shedding light on the potential role of indirect fitness effects on sexual conflict and the mechanisms underpinning kin recognition in fly populations.

scholarly journals Pro-social behavior in rats is modulated by social experience

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Inbal Ben-Ami Bartal ◽  
David A Rodgers ◽  
Maria Sol Bernardez Sarria ◽  
Jean Decety ◽  
Peggy Mason
Keyword(s):  
Social Behavior ◽  
Genetic Relatedness ◽  
Social Motivation ◽  
Social Experience ◽  
Pro Social Behavior

In mammals, helping is preferentially provided to members of one’s own group. Yet, it remains unclear how social experience shapes pro-social motivation. We found that rats helped trapped strangers by releasing them from a restrainer, just as they did cagemates. However, rats did not help strangers of a different strain, unless previously housed with the trapped rat. Moreover, pair-housing with one rat of a different strain prompted rats to help strangers of that strain, evidence that rats expand pro-social motivation from one individual to phenotypically similar others. To test if genetic relatedness alone can motivate helping, rats were fostered from birth with another strain and were not exposed to their own strain. As adults, fostered rats helped strangers of the fostering strain but not rats of their own strain. Thus, strain familiarity, even to one’s own strain, is required for the expression of pro-social behavior.

scholarly journals Recognition of familiar objects in tortoise hatchlings (Testudo spp.)

2021 ◽  
Author(s):  
Silvia Damini ◽  
Gionata Stancher ◽  
Elisabetta Versace
Keyword(s):  
Social Behavior ◽  
Parental Care ◽  
Social Interactions ◽  
Behavioral Responses ◽  
Familiar Object ◽  
Novelty Effect ◽  
Object A ◽  
Solitary Species ◽  
Familiar Objects

ABSTRACTTortoises do not show parental care and live solitary except for the context of reproduction. Despite their limited need to interact with conspecifics, we previously observed that young tortoises, at their first experiences with conspecifics, can discriminate between familiar and unfamiliar conspecifics after just one encounter with another tortoise. Tortoise hatchlings ignored familiar conspecifics, while they first explored and then actively avoided unfamiliar conspecifics. It remains to be established whether the different reactions to unfamiliar and familiar individuals in tortoise hatchlings are reactions to novelty, or whether they are specific to the interactions with living animals. To test this, we familiarized one-month-old tortoise hatchlings with an object (a brown cone vs. a blue sphere) and then tested them in a novel arena once with the familiar object and once with an unfamiliar one. To measure the reactions toward familiar and unfamiliar objects, we measured the distance between the tortoise and the object throughout the test. Differently from what happened with unfamiliar and familiar conspecifics, we found no difference in behavior toward familiar and unfamiliar objects. This shows that the different reactions toward familiar and unfamiliar conspecifics previously observed are specific for social interactions and are not a mere reaction to the novelty effect. The behavioral responses displayed by young tortoises for unfamiliar conspecifics, but not for unfamiliar objects, show the relevance of social behavior from the beginning of life, even for solitary species.

scholarly journals The evolutionarily stable distribution of fitness effects

2014 ◽  
Author(s):  
Daniel P. Rice ◽  
Benjamin H. Good ◽  
Michael M. Desai
Keyword(s):  
Steady State ◽  
Population Genetic ◽  
Evolutionary Process ◽  
Simple Relationship ◽  
Fitness Effects ◽  
Constant Environment ◽  
Long Time ◽  
Evolutionarily Stable ◽  
Null Expectation ◽  
Key Parameter

The distribution of fitness effects of new mutations (the DFE) is a key parameter in determining the course of evolution. This fact has motivated extensive efforts to measure the DFE or to predict it from first principles. However, just as the DFE determines the course of evolution, the evolutionary process itself constrains the DFE. Here, we analyze a simple model of genome evolution in a constant environment in which natural selection drives the population toward a dynamic steady state where beneficial and deleterious substitutions balance. The distribution of fitness effects at this steady state is stable under further evolution, and provides a natural null expectation for the DFE in a population that has evolved in a constant environment for a long time. We calculate how the shape of the evolutionarily stable DFE depends on the underlying population genetic parameters. We show that, in the absence of epistasis, the ratio of beneficial to deleterious mutations of a given fitness effect obeys a simple relationship independent of population genetic details. Finally, we analyze how the stable DFE changes in the presence of a simple form of diminishing returns epistasis.

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