Figure 2From: SPRIT: Identifying horizontal gene transfer in rooted phylogenetic treesThe two X-trees T' 1 and T' 2 to the right in the figure are both distanced to T by two R SPRs. The shadowed areas mark the sub problems to be solved by the algorithm. T'1 can be subdivided into two small problems, while T'2 cannot be subdivided.Back to article page