Figure 7
From: Structure and dynamics of the pan-genome of Streptococcus pneumoniae and closely related species
Histogram of the parsimony score Spof the presence/absence of the variable regions of size greater than 500 bp, computed for the tree shown in Figure 1. For a given dispensable region, Sprepresents the number of acquisition and loss events (Sp= Na+ Nl, where Naand Nlare the number of acquisitions and losses, respectively) required for its pattern of presence/absence on the tree in Figure 1. The colors indicate the number of acquisitions Na, while the number of losses can be calculated as Nl= Sp-Na. For simplicity, all segments with Na> 1 have been collapsed in a single bar. Since an acquisition followed by a recombination event can always be explained by multiple acquisitions, events with Na> 1 are possible intra-species recombination events.