Selection of sex-ratio and the evolution of sex-determination.
Deterministic selection forces operating at a modifier level within a population lead to the establishment of systems of sex-determination which, under a variety of natural conditions, induce sex-ratios close to 1 : 1.
D000818:Animals; D005075:Biological Evolution; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008954:Models, Biological; D009154:Mutation; D011336:Probability; D012641:Selection, Genetic; D012732:Sex Determination Analysis; D012744:Sex Ratio