Data from: It is better to be choosy in small populations: Drift promotes the evolution of weak female preference for rare phenotypes

Evidence from lab and field studies suggests that females sometimes prefer
males bearing rare phenotypes. Such a finding poses a theoretical
challenge because preference for a rare phenotype makes that phenotype
less rare, thereby lowering the fitness of sons bearing it. Further, a
preference for rarity creates negative frequency-dependent selection,
which leads to equal representation of male types. This then eliminates
any benefit to a preference for rarity. It seems paradoxical, then, that
preference for rarity has been observed across so many taxa. Genetic
drift, by promoting stochastic fixation or loss of alleles, is a source of
constant rarity. Here, we ask whether finite population sizes might
provide the necessary conditions that favour a preference for rarity.
Indeed, we find that drift, by constantly perturbing male display allele
frequencies, provides the fuel required to favour a choosy female
preference allele. Once this preference allele spreads, resultant negative
frequency-dependent selection at the male display locus can act to
maintain diversity in male display ornaments. Thus, drift plays an
atypical role by helping maintain diversity. Further, we show that this
finding is stronger in multi-patch landscapes. This work provides a novel
potential explanation for the repeated evolution of female preference for
rarity.