The Coadaptation of Parental Supply and Offspring Demand

Abstract

The evolution of parent-offspring interactions for the provisioning of care is usually explained as the phenotypic outcome of resolved conflicting selection pressures. However, parental care and offspring solicitation are expected to have complex patterns of inheritance. Here we present a quantitative genetic model of parentoffspring interactions that allows us to investigate the evolutionary maintenance of a state of resolved conflict. We show that offspring solicitation and parental provisioning are expected to become genetically correlated through coadaptation and that their genetic architecture is dictated by an interaction between patterns of selection and the proximate mechanisms regulating supply and demand. When selection is predominately on offspring solicitation, our model suggests that the genetic correlations between provisioning and solicitation are usually positive if provisioning reduces solicitation. Conversely, when selection is predominately on parental provisioning, the correlations are mostly negative as long as parents show a positive response to offspring demand. Empirical estimates of the genetic architecture of traits involved in family interactions fit these predictions. Our model demonstrates how the evolutionary maintenance of parent-offspring interactions can result in variable patterns of coadaptation, and it provides an explanation for the diversity of family interactions within and among species.

Heritable Variation in Maternal Yolk Hormone Transfer in a Wild Bird Population

“…Importantly, a high consistency of yolk T deposition within females and between mothers and daughters does not preclude a plastic and adaptive female response to environmental variation, but in addition, it opens up the opportunity for hormone-mediated maternal effects to respond to selection and thus to evolve. Such indirect genetic effects can modify or accelerate phenotypic change in natural populations and might thereby play an important role in evolutionary processes such as parentoffspring coevolution (Kölliker et al 2000(Kölliker et al , 2005Müller et al 2007;Tschirren and Richner 2008), the evolution of behavioral syndromes (Dingemanse et al 2003;van Oers et al 2004;Groothuis and Carere 2005;Gil and Faure 2007;Tobler and Sandell 2007;Groothuis et al 2008), or dispersal behavior and the colonization of new environments (Hahn et al 2005;Duckworth and Badyaev 2007;Tschirren et al 2007) in a range of taxa. We hope that by elucidating the heritable basis of yolk hormone deposition, this study will bring us closer to an understanding of the evolution of hormone-mediated maternal effects, the patterns that shape their current expression both within and among species, and their consequences for the direction and speed of phenotypic change in natural populations.…”

The quantitative genetics of sex differences in parenting

“…The demonstration of sex differences in the genetic variation underlying parental care also has consequences for theories of parent-offspring coadaptation (31)(32)(33)(34). There is a growing interest in the potential evolution of genetic correlations between parental provisioning and offspring solicitation as a sign of parent-offspring coadaptation (32,34).…”

“…There is a growing interest in the potential evolution of genetic correlations between parental provisioning and offspring solicitation as a sign of parent-offspring coadaptation (32,34). Studies have now demonstrated both positive (19,21,24) and negative (22,26) genetic correlations between female parents and their offspring.…”

Parent–offspring conflict and co-adaptation: behavioural ecology meets quantitative genetics

“…Parent-offspring conflict and co-adaptation P. T. Smiseth et al 1827 demand response functions. Traditional quantitative genetics and behavioural ecology approaches implicitly assume that parental and offspring response functions are fixed over evolutionary time (Godfray 1991(Godfray , 1995aWolf & Brodie 1998;Parker et al 2002a,b;Kö lliker et al 2005). Yet, parents and offspring are also assumed to change their behaviour adaptively in response to variation in each other's behaviour, thus implying that response functions have an adaptive function.…”

“…In these same systems, the offspring also adjust their begging behaviour in response to the amount of resources received from the parents (Kilner & Johnstone 1997;Budden & Wright 2001;Wright & Leonard 2002). The evolution of such complex and dynamic behavioural interactions between parents and offspring has been, and continues to be, a major area of research interest in behavioural ecology and quantitative genetics (Royle et al 2002;Wright & Leonard 2002;Kö lliker et al 2005).…”