Fig. 5

Absence of an abrupt transition for denoting the species rank. The average degree of exclusivity based on the core-genome average patristic distances (y-axis) is shown for clades with increasing breadth (x-axis) on the pan-genome tree. The lack of a relationship between exclusivity and clade diversity (maximum in-group distance) in Streptomycetaceae (left) or Bacillus (right) shows that there is no phase transition in exclusivity that could serve as an objective species-level ranking criterion. The gray region shows ± one standard deviation from the average exclusivity at each maximum in-group distance