Sex ratio evolution through group selection using diffusion approximation.
We consider a haploid, hermaphrodite population subdivided into an infinite number of demes of finite size N. Assuming recurrent mutation, random union of gametes, partial dispersal, genetic drift, and incorporating group competition, a diffusion approximation is used to describe the evolution of sex ratio, corresponding to sex allocation to male versus female functions. The stationary distribution is deduced. In presence of group selection, a female-biased sex ratio in the whole population is found to be optimal in the sense that an allele coding for this sex ratio is always more frequent at equilibrium when segregating with another allele coding for a different sex ratio than for the same sex ratio. Numerical studies are presented to check the validity and accuracy of this prediction.
Centre de recherche clinique, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4. josiane.courteau@chus.qc.ca
Josiane
J
Courteau
Sabin
S
Lessard
D000465:Algorithms; D000818:Animals; D005075:Biological Evolution; D003163:Competitive Behavior; D012734:Disorders of Sex Development / Q000235:genetics; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D040961:Genetic Drift; D005828:Genetics, Population; D005838:Genotype; D005854:Germ Cells; D006238:Haploidy; D008297:Male; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics; D011157:Population Dynamics; D012641:Selection, Genetic; D012744:Sex Ratio