A branching usually 'rooted' diagram that reflects the relationships of a group of taxa. The taxonomic hierarchy can be represented in a dendrogram, with kingdom at the base and subform as the terminal branches. Specific types of dendrogram can be recognized. Phenograms represent the degree of phenetic similarity and are based solely on phenetic data. Phenon lines drawn at right angles to the phenogram (see diagram), show values of similarity as percentages (the greater the value the higher the level of similarity). Clusters of similar groups are termed phenons and phenons may be assigned rank according to the level on the phenogram at which they branch off. Thus in the diagram the four clusters above the 80% phenon line could be assigned the rank of genus while the two clusters at the 55% similarity level might be assigned the rank of subfamily. Phylogenetic trees are also dendrograms, but unlike phenograms, the vertical axes represent time (though not necessarily to scale) or relative advancement. See also cladogram.  A dendrogram showing phenetic similarity. The phenon lines delimit groups of the same rank. |
