- Billera et al. (2001) developed a distance from the geometry of a tree
- space. The distance between two trees can be seen as the sum of the
- branch lengths that need be erased to have two similar trees.
+ The branch length score may be seen as similar to the previous
+ distance but taking branch lengths into account. Kuhner and
+ Felsenstein (1994) proposed to calculate the square root of the sum of
+ the squared differences of the (internal) branch lengths defining
+ similar bipartitions (or splits) in both trees.
+}
+\note{
+ The geodesic distance of Billera et al. (2001) has been disabled: see
+ the package \pkg{distory} on CRAN.