Ribosomal RNA
An example can be seen in bacteria: "Escherichia coli" has seven operons encoding various Ribosomal RNA. For each of these genes, rDNA sequences are essentially identical among all of the seven operons (sequence divergence of only 0.195%). In a closely related species, "Haemophilus influenzae" its six ribosomal RNA operons are entirely identical. When the 2 species are compared together however, the sequence divergence of the 16S rRNA gene between them is 5.90%.