For a given set of

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

like X, and a set of

splits A split (commonly referred to as splits or the splits) is a physical position in which the legs are in line with each other and extended in opposite directions. Splits are commonly performed in various athletic activities, including dance, figu ...

S on X, usually together with a non-negative weighting, which may represent character changes distance, or may also have a more abstract interpretation, if the set of splits S is

compatible Compatibility may refer to: Computing * Backward compatibility, in which newer devices can understand data generated by older devices * Compatibility card, an expansion card for hardware emulation of another device * Compatibility layer, compo ...

, then it can be represented by an unrooted

phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

and each edge in the tree corresponds to exactly one of the splits. More generally, S can always be represented by a split network, which is an unrooted

phylogenetic network A phylogenetic network is any graph used to visualize evolutionary relationships (either abstractly or explicitly) between nucleotide sequences, genes, chromosomes, genomes, or species. They are employed when reticulation events such as hybridi ...

with the property that every split s in S is represented by an array of parallel edges in the network. A split network N can be obtained from a number of different types of data: *Split networks from distances *Split networks from trees *Split networks from sequences *Split networks from quartets

References

Further reading