What is the primary consequence of selective sweeps on genomic variation?

The primary consequence of selective sweeps on genomic variation is the elimination of nearby genomic variation. A selective sweep occurs when a beneficial mutation increases in frequency within a population due to positive selection. As this advantageous allele becomes more common, it effectively "sweeps" through the population, dragging along adjacent alleles and markers on the chromosome due to linkage disequilibrium.

This process reduces genetic variation in the vicinity of the beneficial allele because as the favored allele rises to fixation, the alleles that were originally present in that region tend to be lost. This creates a genomic region with lower diversity, particularly for polymorphisms close to the selected site, leading to a reduction in variation compared to other regions of the genome that are not influenced by the sweep.

In contrast, enhancement of genetic diversity, creation of new alleles, and stabilization of genetic variation would imply an increase or maintenance of variation, which does not align with the immediate effect of selective sweeps, which fundamentally reduces variation in the affected genomic region.