In this paper, we present a variability map of the eukaryotic large subunit ribosomal RNA, showing the distribution of variable and conserved sites in this molecule. The variability of each site in this map is indicated by means of a colored dot. Construction of the variability map was based on the substitution rate calibration (SRC) method, in which the substitution rate of each nucleotide site is computed by looking at the frequency with which sequence pairs differ at that site as a function of their evolutionary distance. Variability maps constructed by this method provide a much more accurate and objective description of site-to-site variability than visual inspection of sequence alignments.