The evolution of age‐specific choosiness when mating

• Published in: Journal of evolutionary biology Vol. 34; no. 3; pp. 477 - 485
• Main Authors: Cotto, Olivier, Day, Troy
• Format: Journal Article
• Language: English
• Published: Switzerland Blackwell Publishing Ltd 01.03.2021; Wiley
• Subjects: Age; assortative mating; Evolution; Fitness; Genetics; life history; Life Sciences; Mate selection; Mating; Mutation; Offspring; Populations and Evolution; Reproductive fitness; Reproductive isolation; senescence; sexual selection; theory; senescence; assortative mating; theory; life history; sexual selection
• ISSN: 1010-061X; 1420-9101
• DOI: 10.1111/jeb.13750

Mate choice is a crucial element of many processes in evolutionary biology. Empirical research has shown that mating preference and choosiness often change with age. Understanding the evolutionary causes of patterns of age‐specific choosiness is challenging because different mechanisms can give rise to the same pattern. Instead of focusing on the optimal age‐specific choosiness strategy given fitness trade‐offs, we approach this question from a more general standpoint and ask how the strength of selection on choosiness changes with the age at which it is expressed. We show that the strength of selection on a modifier of choosiness at a given age depends on the relative contribution of this age class to the pool of offspring but does not depend directly on the strength of selection on fitness components at the age affected by the modifier. We illustrate our results by contrasting two life histories from the literature. We further show how mutation–selection balance at the choosiness locus can shape age‐specific choosiness. Our results provide new insights for understanding the evolution of choosiness throughout life, with implications for understanding the evolution of mate choice and reproductive isolation. We developed a theoretical model to ask how the strength of selection on choosiness changes with the age at which it is expressed. We show that the strength of selection on a modifier of choosiness at a given age depends on the relative contribution of this age class to the pool of offspring, which in turn depends on the life history. Overall we highlight how the efficiency of evolution to shape choosiness patterns depends on age.