Figure 4From: Reconciliation and local gene tree rearrangement can be of mutual profitA gene tree G with a weak edge (w,v) selected for an NNI. v is connected to two subtrees G c and G d , while w is connected to v and to the subtree G b . Performing an NNI operation around (w,v) means interchanging subtree G b with either G c or G d , leading to trees G ′ and respectively.Back to article page