Data from: Estimating the number of sexual events per generation in a facultatively sexual haploid population

In populations of facultatively sexual organisms the proportion of
sexually produced offspring contributed each generation is a critical
determinant of their evolutionary potential. However, estimating this
parameter in natural populations has proved difficult. Here we develop a
population genetic model for estimating the number of sexual events
occurring per generation for facultatively sexual haploids possessing a
biallelic mating type locus (e.g. Chlamydomonas, ascomycete fungi). Our
model treats the population as two subpopulations possessing opposite
mating type alleles which exchange genes only when a sexual event takes
place. Where mating types are equally abundant we show that, for a neutral
genetic marker, genetic differentiation between mating type subpopulations
is a simple function of the effective population size, the frequency of
sexual reproduction and the recombination fraction between the genetic
marker and the mating type locus. We employ simulations to examine the
effects of linkage of markers to the mating type locus, inequality of
mating type frequencies, mutation rate and selection on this relationship.
Finally we apply our model to estimate the number of sexual reproduction
events per generation in populations of four species of facultatively
sexual ascomycete fungi which have been jointly scored for mating type and
a range of polymorphic molecular markers. Relative estimates of are in
line with expectations based on the known reproductive biology of these
species.