Distribution of AMFEs. Boxplot of AMFEs for non-conserved (S
, red) and conserved pre-miRNAs (S
2, and S
3, black) from human (A), mouse (B), and chicken genomes (C). The number of pre-miRNAs within each set is indicated in brackets. S
1 for chicken was excluded as it contained fewer than five pre-miRNAs.