Invasion and fixation of sex-reversal genes.
We simulated a meta-population with random dispersal among demes but local mating within demes to investigate conditions under which a dominant female-determining gene W, with no individual selection advantage, can invade and become fixed in females, changing the population from male to female heterogamety. Starting with one mutant W in a single deme, the interaction of sex ratio selection and random genetic drift causes W to be fixed among females more often than a comparable neutral mutation with no influence on sex determination, even when YY males have slightly reduced viability. Meta-population structure and interdeme selection can also favour the fixation of W. The reverse transition from female to male heterogamety can also occur with higher probability than for a comparable neutral mutation. These results help to explain the involvement of sex-determining genes in the evolution of sex chromosomes and in sexual selection and speciation.
Vuilleumier
S
S
Eawag Ecology Centre, Kastanienbaum (Lucerne), Switzerland. severine.vuilleumier@epfl.ch
Lande
R
R
VAN Alphen
J J M
JJ
Seehausen
O
O
D000818:Animals; D019143:Evolution, Molecular; D005260:Female; D040961:Genetic Drift; D049810:Genetic Speciation; D005838:Genotype; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D011156:Population Density; D012730:Sex Chromosomes; D019849:Sex Determination Processes; D012744:Sex Ratio