Final answer:
Linked genes are occasionally separated and recombined through crossing over during prophase I of meiosis I, which contributes to genetic diversity and can be used to create linkage maps.
Step-by-step explanation:
Linked genes occasionally switch from one homologous chromosome to the other through the process of crossing over. This occurs during prophase I of meiosis I, when homologous chromosomes line up and exchange segments of their genetic material. The closer together two genes are on a chromosome, the less likely they will be separated by crossing over. The exchange results in recombinant chromosomes that enhance genetic variation within the offspring. Additionally, the frequency of crossing over between genes can be used to create a linkage map, which shows the locations of genes on a chromosome.