Figure 4. Pan genomes of the lambdoid phages encoding recombination functions (Rec⁺) are larger than those lacking them (Rec⁻).

The pan genome size (y-axis) of each type of phage genome was computed for increasing numbers of genomes (x-axis). For each value of x we draw x genomes randomly and compute the pan genome. This is repeated 1000 times for each value of x to draw the 95% interval of confidence of the pan genome size (grey zone).