Figure 1.

Effect of the diameter of an HGT edge on the change in the likelihood score. The diameter of an HGT edge from node x to node y in the phylogenetic network is measured as the length of the path between x and y in the underlying tree (the network without the red arrows in (a)). Each of the 12 HGT edges was assessed individually, and never in combinations in this experiment. (b) Effect of the diameter for HGTs with different diameters but with a fixed donor node (taxon 1); these results correspond to each of the 6 HGT edges involving taxa 3--8. The diameters of the HGT edges vary from 0.15, for the HGT edge from taxon 1 to taxon 3, to 0.65, for the HGT edges from taxon 1 to taxon 8, with increments of 0.1. (c) Effect of the diameter for HGTs with different diameters but with a fixed recipient node (taxon 16); these results correspond to each of the 6 HGT edges involving taxa 9--14. The diameters of the HGT edges vary from 0.15, for the HGT edge from taxon 14 to taxon 16, to 0.65, for the HGT edges from taxon 9 to taxon 16, with increments of 0.1. Diameter = 0 corresponds to the underlying tree.