Inclusive fitness and Hamilton’s rule in a stochastic environment

The Social ◽

Social Encounters ◽

The Individual ◽

Inclusive fitness theory, originally due to W. D. Hamilton, is a popular approach to the study of social evolution, but shrouded in controversy. The theory contains two distinct aspects: Hamilton’s rule (rB > C); and the idea that individuals will behave as if trying to maximize their inclusive fitness in social encounters. These two aspects of the theory are logically separable but often run together. A generalized version of Hamilton’s rule can be formulated that is always true, though whether it is causally meaningful is debatable. However, the individual maximization claim only holds true if the payoffs from the social encounter are additive. The notion that inclusive fitness is the ‘goal’ of individuals’ social behaviour is less robust than some of its advocates acknowledge.

Quantitative genetic versions of Hamilton's rule with empirical applications

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0358 ◽

2014 ◽

Vol 369 (1642) ◽

pp. 20130358 ◽

Cited By ~ 26

Author(s):

Joel W. McGlothlin ◽

Jason B. Wolf ◽

Edmund D. Brodie ◽

Allen J. Moore

Keyword(s):

Quantitative Genetics ◽

Social Evolution ◽

Inclusive Fitness ◽

Good Reason ◽

Empirical Work ◽

Critical Parameters ◽

Simple Extension ◽

Hamilton’S Rule ◽

Quantitative Genetic ◽

Hamilton's theory of inclusive fitness revolutionized our understanding of the evolution of social interactions. Surprisingly, an incorporation of Hamilton's perspective into the quantitative genetic theory of phenotypic evolution has been slow, despite the popularity of quantitative genetics in evolutionary studies. Here, we discuss several versions of Hamilton's rule for social evolution from a quantitative genetic perspective, emphasizing its utility in empirical applications. Although evolutionary quantitative genetics offers methods to measure each of the critical parameters of Hamilton's rule, empirical work has lagged behind theory. In particular, we lack studies of selection on altruistic traits in the wild. Fitness costs and benefits of altruism can be estimated using a simple extension of phenotypic selection analysis that incorporates the traits of social interactants. We also discuss the importance of considering the genetic influence of the social environment, or indirect genetic effects (IGEs), in the context of Hamilton's rule. Research in social evolution has generated an extensive body of empirical work focusing—with good reason—almost solely on relatedness. We argue that quantifying the roles of social and non-social components of selection and IGEs, in addition to relatedness, is now timely and should provide unique additional insights into social evolution.

Helping in cooperatively breeding long-tailed tits: a test of Hamilton's rule

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0565 ◽

2014 ◽

Vol 369 (1642) ◽

pp. 20130565 ◽

Cited By ~ 34

Author(s):

Ben J. Hatchwell ◽

Philippa R. Gullett ◽

Mark J. Adams

Keyword(s):

Social Evolution ◽

Inclusive Fitness ◽

Empirical Studies ◽

Alloparental Care ◽

Hamilton’S Rule ◽

Long Term Study ◽

Cooperatively Breeding ◽

Helping Behaviour ◽

Inclusive fitness theory provides the conceptual framework for our current understanding of social evolution, and empirical studies suggest that kin selection is a critical process in the evolution of animal sociality. A key prediction of inclusive fitness theory is that altruistic behaviour evolves when the costs incurred by an altruist ( c ) are outweighed by the benefit to the recipient ( b ), weighted by the relatedness of altruist to recipient ( r ), i.e. Hamilton's rule rb > c . Despite its central importance in social evolution theory, there have been relatively few empirical tests of Hamilton's rule, and hardly any among cooperatively breeding vertebrates, leading some authors to question its utility. Here, we use data from a long-term study of cooperatively breeding long-tailed tits Aegithalos caudatus to examine whether helping behaviour satisfies Hamilton's condition for the evolution of altruism. We show that helpers are altruistic because they incur survival costs through the provision of alloparental care for offspring. However, they also accrue substantial benefits through increased survival of related breeders and offspring, and despite the low average relatedness of helpers to recipients, these benefits of helping outweigh the costs incurred. We conclude that Hamilton's rule for the evolution of altruistic helping behaviour is satisfied in this species.

Conditional Behaviors and Inclusive Fitness

Social Evolution and Inclusive Fitness Theory ◽

10.23943/princeton/9780691161563.003.0006 ◽

2015 ◽

Author(s):

James A.R. Marshall

Keyword(s):

Genetic Relatedness ◽

Inclusive Fitness ◽

Social Behaviors ◽

Phenotypic Assortment ◽

Hamilton’S Rule ◽

Implicit And Explicit ◽

This chapter examines social behaviors that are expressed conditional on the phenotype of others. David Queller argued that inclusive fitness analyses need to be done on a per-behavior basis, citing as an example the decision over whether to reproduce directly, and whether to aid a reproductive. Queller showed that inclusive fitness predictions are only sensible when one analyzes what an individual should do, given it finds itself in a particular behavioral role. The chapter first provides an overview of implicit and explicit conditionality and presents two classic examples: William D. Hamilton's greenbeard traits and Robert Trivers's theory of reciprocal cooperation. It also introduces an extension of Hamilton's rule to deal with explicitly conditional behaviors; this extension features a measure of phenotypic assortment that appears not to be the classic genetic relatedness of Hamilton's rule.

Inclusive Fitness and Hamilton’s Rule

Social Evolution and Inclusive Fitness Theory ◽

10.23943/princeton/9780691161563.003.0004 ◽

2015 ◽

Author(s):

James A.R. Marshall

Keyword(s):

Sex Allocation ◽

Charles Darwin ◽

Inclusive Fitness ◽

Price Equation ◽

Additive Effects ◽

Eusocial Insect ◽

Hamilton’S Rule ◽

Biological Phenomena ◽

This chapter examines how the logic of inclusive fitness theory can be mathematically formalized using the Price equation, and how that formalization can be used to derive Hamilton's rule in its simplest form, as applied to unconditional behaviors having additive effects on fitness. Various biological phenomena, such as sex allocation and working policing within eusocial insect colonies, have been analyzed by considering what strategies maximize individuals' inclusive fitness, and how observed social behaviors should correlate with quantities such as relatedness. The chapter derives Hamilton's rule by introducing some notation for the effects of behaviors on fitnesses of individuals that interact socially, to make explicit precisely how genes (and later phenotypes) affect fitness, and to give a general form of Hamilton's rule that will apply to any (unconditional, additive) behavior regardless of its details. It shows that inclusive fitness is a genuinely novel extension of the classical fitness studied by Charles Darwin, R. A. Fisher, and others.

Using the Price equation to detect inclusive fitness in class-structured populations

10.1101/2020.03.09.982892 ◽

2020 ◽

Author(s):

António M. M. Rodrigues

Keyword(s):

Inclusive Fitness ◽

Causal Structure ◽

Regression Method ◽

Structured Populations ◽

Price Equation ◽

Hamilton’S Rule ◽

Key Variables ◽

Hamilton's Rule ◽

Simple Regression

AbstractInclusive fitness theory has transformed the study of adaptive evolution since 1964, contributing to significant empirical findings. However, its status as a theory has been challenged by the proposals of several alternative frameworks. Those challenges have been countered by analyses that use the Price equation and the regression method. The Price equation is a universal description of evolutionary change, and the partitioning of the Price equation using the regression method immediately yields Hamilton’s rule, which embodies the main tenets of inclusive fitness. Hamilton’s rule captures the intensity and direction of selection acting on social behaviour and its underlying causal structure. Recent work, however, has suggested that there is an anomaly in this approach: in some cases, the regression method fails to estimate the correct values of the variables in Hamilton’s rule and the causal structure of the behaviour. Here, I address this apparent anomaly. I argue that the failure of the simple regression method occurs because social players vary in baseline fecundity. I reformulate the Price equation and regression method to recover Hamilton’s rule and I show that the method correctly estimates its key variables. I show that games where baseline fecundity varies among individuals represent a more general set of games that unfold in class-structured populations. This framework supports the robustness and validity of inclusive fitness.

The benefits of grouping as a main driver of social evolution in a halictine bee

Science Advances ◽

10.1126/sciadv.1700741 ◽

2018 ◽

Vol 4 (10) ◽

pp. e1700741 ◽

Cited By ~ 3

Author(s):

Yusaku Ohkubo ◽

Tatsuhiro Yamamoto ◽

Natsuki Ogusu ◽

Saori Watanabe ◽

Yuuka Murakami ◽

...

Keyword(s):

Social Evolution ◽

Inclusive Fitness ◽

Nest Defense ◽

The Past ◽

Hamilton’S Rule ◽

Main Driver ◽

Relatedness Asymmetry ◽

Over the past decade, the cause of sociality has been much debated. Inclusive fitness [brin Hamilton’s rule (br−c> 0)] has been criticized but is still useful in the organization of a framework by elucidating mechanisms through whichbr(benefit × relatedness) becomes larger thanc(cost). The beeLasioglossum baleicumis suitable for investigation of this issue because of the sympatric occurrence of both social and solitary nesting in its populations. We show that a large part (approximately 92%) of the inclusive fitness of a eusocial worker can be attributed to the benefits of grouping. A 1.5-fold relatedness asymmetry benefit in singly mated haplo-diploids explains a small part (approximately 8.5%) of the observed inclusive fitness. Sociality enables this species to conduct foraging and nest defense simultaneously, which is not the case in solitary nests. Our results indicate that this benefit of grouping is the main source of the increased inclusive fitness of eusocial workers.

The Philosophy of Social Evolution

10.1093/oso/9780198733058.001.0001 ◽

2017 ◽

Cited By ~ 25

Author(s):

Jonathan Birch

Keyword(s):

Social Behaviour ◽

Social Evolution ◽

Inclusive Fitness ◽

Natural World ◽

Special Role ◽

Philosophical Foundations ◽

Hamilton’S Rule ◽

Social Traits ◽

Hamilton's Rule ◽

The Way

From microbes to humans, the natural world is full of spectacular examples of social behaviour. In the 1960s, W. D. Hamilton introduced three key innovations—now known as Hamilton’s rule, kin selection, and inclusive fitness—that changed the way we think about how social behaviour evolves, beginning a research program now known as social evolution theory. This is a book about the philosophical foundations and future prospects of that program. Part I, ‘Foundations’, provides a philosophical analysis of Hamilton’s core ideas, with some modifications along the way. We will see that Hamilton’s rule provides a compelling way of organizing our thinking about the ultimate causes of social behaviour; and we will see how, in inclusive fitness, Hamilton found a fitness concept with a special role to play in explaining cumulative adaptation. Part II, ‘Extensions’, shows how these ideas, when extended in certain ways, can help us understand cooperation in micro-organisms, cooperation among the cells of a multicellular organism, and culturally evolved cooperation in the earliest human societies. In all these cases and more, living things cooperate because they are related, where the concept of relatedness picks out relevant statistical patterns of similarity in the transmissible basis (genetic or otherwise) of social traits.

Darwin's ‘one special difficulty’: celebrating Darwin 200

Biology Letters ◽

10.1098/rsbl.2009.0014 ◽

2009 ◽

Vol 5 (2) ◽

pp. 214-217 ◽

Cited By ~ 10

Author(s):

Joan M Herbers

Keyword(s):

Natural Selection ◽

Kin Selection ◽

Inclusive Fitness ◽

The Past ◽

Hamilton’S Rule ◽

Insect Societies ◽

Darwin identified eusocial evolution, especially of complex insect societies, as a particular challenge to his theory of natural selection. A century later, Hamilton provided a framework for selection on inclusive fitness. Hamilton's rule is robust and fertile, having generated multiple subdisciplines over the past 45 years. His suggestion that eusociality can be explained via kin selection, however, remains contentious. I review the continuing debate on the role of kin selection in eusocial evolution and suggest some lines of research that should resolve that debate.

The inclusive fitness controversy: finding a way forward

Royal Society Open Science ◽

10.1098/rsos.170335 ◽

2017 ◽

Vol 4 (7) ◽

pp. 170335 ◽

Cited By ~ 18

Author(s):

Jonathan Birch

Keyword(s):

Social Evolution ◽

Design Thinking ◽

Inclusive Fitness ◽

Weak Selection ◽

Individual Organism ◽

Causal Property ◽

Hamilton’S Rule ◽

This paper attempts to reconcile critics and defenders of inclusive fitness by constructing a synthesis that does justice to the insights of both. I argue that criticisms of the regression-based version of Hamilton's rule, although they undermine its use for predictive purposes, do not undermine its use as an organizing framework for social evolution research. I argue that the assumptions underlying the concept of inclusive fitness, conceived as a causal property of an individual organism, are unlikely to be exactly true in real populations, but they are approximately true given a specific type of weak selection that Hamilton took, on independent grounds, to be responsible for the cumulative assembly of complex adaptation. Finally, I reflect on the uses and limitations of ‘design thinking’ in social evolution research.