Local male competition and the sex ratio.
D000818:Animals; D003163:Competitive Behavior; D004171:Diploidy; D004330:Drosophila; D005260:Female; D005838:Genotype; D006238:Haploidy; D008297:Male; D008540:Meiosis; D008957:Models, Genetic; D009154:Mutation; D012744:Sex Ratio; D012726:Sexual Behavior, Animal