Robinson-Foulds Metric

The Robinson-Foulds metric, also called the symmetric difference metric, is a way of measuring the distance between two phylogenetic trees, published by D. F. Robinson and Leslie Foulds in February 1981 in the journal Mathematical Biosciences. The distance between two trees is calculated as the number of bipartitions, splits of the leaves into two groups, found in one tree but not the other, summed over both trees, and the original paper proved that this quantity is a genuine mathematical metric. It is widely used to compare evolutionary trees in phylogenetics, has been adopted in quantitative comparative linguistics to compare trees of language relationships, and is implemented in software such as PHYLIP's treedist program, RAxML, DendroPy and several R packages. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/