title: Female brain size affects the assessment of male attractiveness during mate choice.
abstract: Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.
authors.affiliation: Department of Zoology/Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden.
authors.forename: Alberto
authors.identifier: 0000-0001-7784-0209
authors.initials: A
authors.lastname: Corral-López
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, U.K.
authors.forename: Natasha I
authors.identifier: 0000-0002-4769-1027
authors.initials: NI
authors.lastname: Bloch
authors.affiliation: Department of Zoology/Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden.
authors.forename: Alexander
authors.identifier: 0000-0003-3473-1402
authors.initials: A
authors.lastname: Kotrschal
authors.affiliation: Department of Zoology/Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden.
authors.forename: Wouter
authors.identifier: 0000-0002-7366-1868
authors.initials: W
authors.lastname: van der Bijl
authors.affiliation: Department of Zoology/Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden.
authors.forename: Severine D
authors.initials: SD
authors.lastname: Buechel
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, U.K.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Mank
authors.affiliation: Department of Zoology/Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden.
authors.forename: Niclas
authors.initials: N
authors.lastname: Kolm
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D005260:Female; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D009929:Organ Size; D011036:Poecilia / Q000033:anatomy & histology / Q000502:physiology*; D019655:Quantitative Trait, Heritable
keywords: Poecilia reticulata; Sexual selection; brain size; cognitive ability; female choice; guppies; maintenance of variation; rational choice