  A selective sweep describes the reduction of linked genetic variation due to
strong positive selection. If s is the fitness advantage of a homozygote for
the beneficial allele and h its dominance coefficient, it is usually assumed
that h=1/2, i.e. the beneficial allele is co-dominant. We complement existing
theory for selective sweeps by assuming that h is any value in [0,1]. We show
that genetic diversity patters under selective sweeps with strength s and
dominance 0<h<1 are similar to co-dominant sweeps with selection strength 2hs.
Moreover, we focus on the case h=0 of a completely recessive beneficial allele.
We find that the length of the sweep, i.e. the time from occurrence until
fixation of the beneficial allele, is of the order of sqrt(N/s) generations, if
N is the population size. Simulations as well as our results show that genetic
diversity patterns in the recessive case h=0 greatly differ from all other
cases.
