How choosy should I be? The relative searching time predicts evolution of choosiness under direct sexual selection.
Most theoretical research in sexual selection has focused on indirect selection. However, empirical studies have not strongly supported indirect selection. A well-established finding is that direct benefits and costs exert a strong influence on the evolution of mate choice. We present an analytical model in which unilateral mate choice evolves solely by direct sexual selection on choosiness. We show this is sufficient to generate the evolution of all possible levels of choosiness, because of the fundamental trade-off between mating rate and mating benefits. We further identify the relative searching time (RST, i.e. the proportion of lifetime devoted to searching for mates) as a predictor of the effect of any variable affecting the mating rate on the evolution of choosiness. We show that the RST: (i) allows one to make predictions about the evolution of choosiness across a wide variety of mating systems; (ii) encompasses all alternative variables proposed thus far to explain the evolution of choosiness by direct sexual selection; and (iii) can be empirically used to infer qualitative differences in choosiness.
Institut des Sciences de l'Évolution, Université Montpellier II, CNRS, , Montpellier 34095, France, Leibniz Institute for Zoo and Wildlife Research, , Berlin 10315, Germany.
Loïc
L
Etienne
François
F
Rousset
Bernard
B
Godelle
Alexandre
A
Courtiol
D000818:Animals; D005075:Biological Evolution; D002755:Choice Behavior; D052586:Mating Preference, Animal; D008957:Models, Genetic
choosiness; direct benefits; mate choice; operational sex ratio; relative searching time; sexual selection