The genealogical relationship between species.

Evolutionary changes in attributes of a species that do not involve branching or speciation.

during speciation, either through cladogenesis or reticulate speciation. In the phylogenetic system, only species can be ancestral taxa. Groups of species are specifically excluded from being ancestra [..]

A taxon that does not correspond to a unit involved in the evolutionary process or to a unit of evolutionary history (see also grade). There two kinds of artificial groups, paraphyletic and polyphylet [..]

A special type of classification for a series of taxa whose phylogenetic history is unknown because no one has ever reconstructed the evolutionary history of the group. Many current classifications ar [..]

A relative position in a hierarchical biological classification. The category of a taxon indicates its relative place in the hierarchy of the classification. The Linnaean hierarchy is the most common [..]

Branching or divergent evolution caused by speciation. Results in two or more branches on the phylogenetic tree where earlier only a single branch existed. A species resulting from cladogenesis has on [..]

Phylogenetic trees that have clearly implied patterns of ancestry and descent, and a relative time axis. A cladogram is one kind of phylogenetic tree, a common ancestry tree. For some phylogenetic sys [..]

contain only monophyletic groups and/or species. This type of classification is logically consistent with the phylogenetic relationships of the taxa being classified (as they are currently understood) [..]