A supertree is a single phylogenetic tree

Phylogenetic tree

A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...

 assembled from a combination of smaller phylogenetic trees, which may have been assembled using different datasets (e.g. morphological and molecular) or a different selection of taxa. Supertree algorithms can highlight areas where additional data would most usefully resolve any ambiguities. The input trees of a supertree should behave as samples from the larger tree.

Construction methods

The construction of a supertree scales exponentially with the number of taxa included; therefore for a tree of any reasonable size it is not possible to examine every possible supertree and weigh its success at combining the input information. Heuristic

Heuristic

Heuristic refers to experience-based techniques for problem solving, learning, and discovery. Heuristic methods are used to speed up the process of finding a satisfactory solution, where an exhaustive search is impractical...

 methods are thus essential, although these methods are vulnerable to biases; the result extracted is often biased or affected by irrelevant characteristics of the input data.

The Robinson-Foulds

Robinson-Foulds metric

The Robinson–Foulds metric is a way to measure the distance between unrooted phylogenetic trees. It is defined as where A is the number of partitions of data implied by the first tree but not the second tree and B is the number of partitions of data implied by the second tree but not the first...

 distance is the most popular of many ways of measuring how similar a supertree is to the input trees. It is a metric for the number of clades from the input trees that are retained in the supertree. Robinson-Foulds optimization methods search for a supertree that minimizes the total (summed) Robinson-Foulds differences between the (binary) supertree and each input tree.

Adittional methods include the Min Cut Supertree approach, ...

Application

Supertrees have been applied to produce phylogenies of many groups, notably the angiosperms, eukaryotes and mammals. They have also been applied to larger-scale problems such as the origins of diversity, vulnerability to extinction, and evolutionary models of ecological structure.