Figure - link genome size/mutation rate
||Gago S, Elena SF, Flores R, Sanjuán R. Extremely high mutation rate of a hammerhead viroid. Science. 2009 Mar 6 323(5919):1308. doi: 10.1126/science.1169202. p.1308 figure 1PubMed ID19265013
|| P. D. Sniegowski, P. J. Gerrish, T. Johnson, A. Shaver, The evolution of mutation rates: separating causes from consequences. Bioessays. 2000 Dec22(12):1057-66.  Duffy S, Shackelton LA, Holmes EC. Rates of evolutionary change in viruses: patterns and determinants. Nat Rev Genet. 2008 Apr9(4):267-76. doi: 10.1038/nrg2323.PubMed ID11084621, 18319742
||p.1308 left column top paragraph:"[Investigators] estimated the mutation rate of Chrysanthemum chlorotic mottle viroid (CChMVd), a 399-nucleotide chloroplastic viroid with hammerhead ribozymes. Hammerheads are RNA motifs formed by three double-helix regions flanking a core of 15 highly conserved nucleotides critical for catalytic activity (ref 5), which mediate self-cleavage of replicative intermediates and, hence, are essential for viroid replication."
||Caption to figure 1:"Per-site mutation rate versus genome size for CChMVd [Chrysanthemum chlorotic mottle viroid] and other biological entities [reviewed in (primary source 2) and updated with more recent data from (primary source 3)]. RNA viruses (left to right) are tobacco mosaic virus, human rhinovirus, poliovirus, vesicular stomatitis virus, bacteriophage φ6, and measles virus. Single-stranded DNA viruses are bacteriophage φX174 and bacteriophage m13. Double-stranded DNA viruses are bacteriophage λ, herpes simplex virus, bacteriophage T2, and bacteriophage T4. Bacteria is Escherichia coli. Lower eukaryotes are Saccharomyces cerevisiae and Neurospora crassa. Higher eukaryotes are Caenorhabditis elegans, Drosophila melanogaster, Mus musculus, and Homo sapiens. When several estimations were available, the mean value is shown."