a Conservation levels were calculated based on a large sample of Archaeal, bacterial, and eukaryotic nuclear, mitochondrial and chloroplast rRNA sequences. The three conservation ranges (>98%, 90-98% and 80-90%) were determined for positions that are present in more than 95% of all sequences.
  Conservation 16 S 23 S
nt % total nt % total
all rRNA residues > 98% 178 11.5 150 5.2
90 — 98% 175 11.3 203 7.0
80 — 90% 116 7.5 168 5.8
Total 1542 100.0 2904 100.0
nt prior to: all introns > 98% 18 21.4 17 24.7
90 — 98% 14 16.7 12 17.4
80 — 90% 12 14.3 5 7.2
Total 84 100.0 69 100.0
group I > 98% 11 28.2 10 24.4
90 — 98% 4 10.3 4 9.8
80 — 90% 4 10.3 4 9.8
Total 39 100.0 41 100.0
group II > 98% 1 33.3 3 37.5
90 — 98% 1 33.3 2 25.0
80 — 90% 0 0 0 0
Total 3 100.0 8 100.0
Archaeal > 98% 4 28.6 3 50.0
90 — 98% 7 50.0 2 33.3
80 — 90% 1 7.1 0 0
Total 14 100.0 6 100.0
Spliceosomal > 98% 0 0 1 7.1
90 — 98% 2 9.1 4 28.6
80 — 90% 7 31.8 1 7.1
Total 22 100.0 14 100.0