  Recurrent mutations are a common phenomenon in population genetics. They may
be at the origin of the fixation of a new genotype, if they give a phenotypic
advantage to the carriers of the new mutation. In this paper, we are interested
in the genetic signature left by a selective sweep induced by recurrent
mutations at a given locus from an allele A to an allele a, depending on the
mutation frequency. We distinguish three possible scales for the mutation
probability per reproductive event, which entail distinct genetic signatures.
Besides, we study the hydrodynamic limit of the A- and a-population size
dynamics when mutations are frequent, and find non trivial equilibria leading
to several possible patterns of polymorphism.
