The Evolution of Two-Component Systems in Bacteria Reveals Different Strategies for Niche Adaptation
Figure 11
The number of HPKs entering a lineage is shown as a function of the time each HPK entered that lineage (i.e., the distance of that species to the last ancestor predicted to contain that HPK). Red lines/diamonds indicate LSE events, and blue lines/triangles indicate HGT events. Plots are cumulative showing all events dating more recently than the distance shown on the x-axis. HGT lines do not extend as far to the right as LSE lines, since they require genes to be lost from two consecutive outgroups. The vertical dashed line shows the phylogenetic cutoff distance, and the horizontal dashed line shows the total number of HPKs in each genome. Symbols indicate the evolutionary distance (arbitrary units; see Methods) of outgroups used in the analysis. Some clades with greater taxon sampling have better resolved timings. The last panel shows total numbers for all genomes.