INDIRECT GENETIC EFFECTS INFLUENCE ANTIPREDATOR BEHAVIOR IN GUPPIES: ESTIMATES OF THE COEFFICIENT OF INTERACTIONPSIAND THE INHERITANCE OF RECIPROCITY

Abstract

How and why cooperation evolves, particularly among nonrelatives, remains a major paradox for evolutionary biologists and behavioral ecologists. Although much attention has focused on fitness consequences associated with cooperating, relatively little is known about the second component of evolutionary change, the inheritance of cooperation or reciprocity. The genetics of behaviors that can only be expressed in the context of interactions are particularly difficult to describe because the relevant genes reside in multiple social partners. Indirect genetic effects (IGEs) describe the influence of genes carried in social partners on the phenotype of a focal individual and thus provide a novel approach to quantifying the genetics underlying interactions such as reciprocal cooperation. We used inbred lines of guppies and a novel application of IGE theory to describe the dual genetic control of predator inspection and social behavior, both classic models of reciprocity. We identified effects of focal strain, social group strain, and interactions between focal and group strains on variation in focal behavior. We measured ψ, the coefficient of the interaction, which describes the degree to which an individual's phenotype is influenced by the phenotype of its social partners.The genetic identity of social partners substantially influences inspection behavior, measures of threat assessment, and schooling and does so in positively reinforcing manner. We therefore demonstrate strong IGEs for antipredator behavior that represent the genetic variation necessary for the evolution of reciprocity. The inheritance and evolution of social behavior are enigmatic because such behaviors are expressed by individuals, but fundamentally depend upon interactions with others. Genes expressed by social partners may alter the magnitude and form of social

Indirect genetic effects and the genetic bases of social dominance: evidence from cattle

“…Such an approach has shown to be useful also in genetic investigations for social behaviours such as courtship (Miller and Moore, 2007), cooperation (Charmantier et al, 2007) and predator avoidance (Bleakley and Brodie, 2009). Moreover, in recent years animal breeding practices have also shown appreciable benefits when social components have been accounted for, especially in managing social species reared in the groups of conspecifics, such as hens or pigs (Bijma et al, 2007b;Van Vleck et al, 2007;Chen et al, 2008).…”

Estimating Indirect Genetic Effects: Precision of Estimates and Optimum Designs

“…IGEs attract increasing attention, as illustrated by the increasing number of publications (e.g., Bleakley and Brodie 2009;Wilson et al 2009;Chenoweth et al 2010;Hsu et al 2010;Mcglothlin et al 2010;Muir et al 2010). This development is warranted, given the large impact of IGEs on both the direction and magnitude of response to genetic selection and the increasing empirical evidence of their existence (see Introduction).…”

“…A well-known example in mammals is the maternal-genetic effect of a mother on preweaning growth rate of her offspring (Willham 1963;Mousseau and Fox 1998). The IGE modeling approach has its roots in quantitative genetic models for maternally affected traits, which are widely used in agriculture (Dickerson 1947;Willham 1963;Cheverud 1984;Kirkpatrick and Lande 1989;Lynch and Walsh 1998), but is increasingly applied to other traits, both in animals and plants (e.g., Muir 2005;Petfield et al 2005;Mutic and Wolf 2007;Bergsma et al 2008;Cappa and Cantet 2008;Bleakley and Brodie 2009;Chenoweth et al 2010).…”

Socially flexible female choice differs among populations of the Pacific field cricket: geographical variation in the interaction coefficient psi (Ψ)

“…We adapted the analytical approaches of Bleakley & Brodie [15] and Chenoweth et al [16] to detect differences in C by evaluating whether the interaction between social treatment and population is significant. A significant interaction would indicate that crickets in different populations respond differently, on average, to variation in the social environment, and therefore that C is different.…”