Sex-specific genetic differentiation and coalescence times: estimating sex-biased dispersal rates.
I derive the equilibrium values of sex-specific FST parameters, in an island model for a dioecious species with sex-biased dispersal and binomial distribution of family size before dispersal (as assumed in a Wright-Fisher population). I show that FST may take different values among males and among females whenever dispersal is a trait conditioned on gender. This has not always been recognized, because some models assumed that genes are sampled before dispersal. In particular, the ratios of sex-specific FST parameters evaluated after dispersal over FST evaluated before dispersal are simple functions of sex-specific dispersal rates. Therefore, a simple moment-based estimator of sex-specific dispersal rate is proposed. This method is based on the comparison of FST estimated before and after dispersal and assumes equilibrium between migration and drift. I evaluate this method through stochastic simulations for a range of sex-specific dispersal rates and sampling effort (sample size, number of loci scored).
Vitalis
Renaud
R
Laboratoire Génétique et Environnement, C.C. 065, Institut des Sciences de l'Evolution de Montpellier (UMR 5554), Université Montpellier II, F-34095 Montpellier Cedex 05, France. vitalis@isem,univ-montp2.fr
D000818:Animals; D003198:Computer Simulation; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D008297:Male; D008957:Models, Genetic; D012737:Sex Factors