Figure 4

Binary refinements and unrooted reconciliation. All 27 unrooted binary refinements of the gene tree G from Figure 3 shown in star-like topology. Observe, that the edge adjacent to a leaf labelled by a is optimal in every refinement of G, and it has the same type as in G (i.e., it is an empty edge). The optimal duplication cost equals 1. The optimal edges with this cost are marked in gene trees G₁₉, G₂₃ and G₂₅. The bottom-right part of this figure depicts the embedding of the optimal rooting of G₂₅ into the species tree S from Figure 3.