Fig. 3

Illustration of the RF distance and the Bourque distance. A Two unrooted 1-labeled trees. The RF distance between them is 4, as in the left tree, the edges (2, 4) and (7, 8) induces two partitions that are not found in the right tree and vice versa. B The labels 0–5 are the labels appearing in the two trees. The Bourque distance between them is 9 (see the main text for details). C The two labeled trees are rooted at different nodes. The RF distance between the left tree and the right tree is 2, as the partitions induced by (6, 4) of Tree A and (4, 6) of Tree B are different