Mating Preference, AnimalSexual Behavior, AnimalSelection, GeneticBiological EvolutionSex CharacteristicsReproductionCompetitive BehaviorPasseriformesPigmentationBody SizePoeciliaGryllidaeAnimal CommunicationCopulationFeathersGenetic FitnessAntelopesSex RatioSex PreselectionCichlidsCyprinodontiformesPair BondSongbirdsGenetic SpeciationBeetlesFertilityBirdsVocalization, AnimalModels, GeneticSpermatozoaChoice BehaviorCourtshipSpidersEvolution, MolecularHornsTerritorialityGenetic VariationSocial DominanceButterfliesAdaptation, BiologicalHeteropteraConflict (Psychology)PaternityDipteraFertilizationCannibalismSexPhylogenyPhenotypeCoyotesBody Weights and MeasuresGenetics, PopulationHydrocarbonsFirefliesSingingNesting BehaviorSpecies SpecificityBody ConstitutionGenitalia, MaleModels, BiologicalSex AttractantsSmegmamorphaColorElasmobranchiiMicrosatellite RepeatsAnimal MigrationDrosophila melanogasterAgonistic BehaviorGalliformesPaternal BehaviorSex ChromosomesLizardsEnvironmentPopulation DynamicsInheritance PatternsSwallowsPanamaDrosophilaHermaphroditic OrganismsPredatory BehaviorAdaptation, PhysiologicalGeographyHybridization, GeneticPerciformesWingMarriageSnailsSex FactorsFinchesEcosystemCrosses, GeneticArthropodsCeratitis capitataPopulation DensityMontanaSex Determination ProcessesAnuraGene FlowQuantitative Trait, HeritableFishes