Distribution of the trees in the forest of life by topological inconsistency. (a) All trees. (b) Trees partitioned into COG functional categories. The data for the NUTs are also shown. The IS values are classified as very low (VL; values less than 40% of mean IS), low (L; values less than 20% of mean IS), medium (M; values around mean IS ± 20%), high (H; more than 20% of mean IS), and very high (VH; values more than 40% of mean IS).