Genetic and Cultural Evolution of Mate Choice

Abstract

Darwin suggested that female mate choice explains the evolution of exaggerated male traits, such as an extravagant plumage in birds, which could reduce the survival chances of individuals bearing them. Around 60 years later, Fisher gave a formal verbal expression to the runaway genetic model of female mate choice, where female mating preferences can, by themselves, lead to the evolutionary exaggeration of favored male traits. However, the idea that female preferences are genetically fixed was demolished in the 1990s when it was shown that female mate choice is also affected by cultural transmission, which can even prevail over the fixed genetic preferences. This cultural transmission of behavior is now commonly known as mate-choice copying, or mate copying, and is a widespread mating strategy in animals, from invertebrates to humans. Although this behavior has been claimed to have a significant role in evolution, some initial theoretical models suggested that it could be maladaptive in the long term because it induces a frequency-dependent bias that helps to establish a male trait that decreases male fitness. This conclusion is, however, model dependent and, under some conditions, mate-choice copying can increase a population’s average fitness relative to populations without this behavior. An exciting question is to what extent mate-choice copying is a by-product of a general associative learning process or, rather, it is a domain-specific adaptation.