Haplotypes in a Genome Region after Spread of an Advantageous Mutation That Establishes a Balanced Polymorphism

An advantageous mutation (denoted by the star) arises and quickly spreads to a high frequency. Variants (black dots) in the region of genome around the selected site will be carried to high frequency in the haplotypes with the mutation, and recombination subsequently introduces variants from the rest of the population, especially at sites distant from the selected site. Mutations may also occur. Note that the hitchhiking does not contribute to differentiation between haplotypes, since the variants were present before the selective event.