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Phylogenetic tree

A phylogenetic tree is a tree showing the evolutionary interrelationships between various species or other entities that are believed to have a common ancestor. A phylogenetic tree is a form of cladogram.

In a phylogenetic tree, each node with descendants represents the most recent common ancestor of the descendants, and edge lengths correspond to time estimates.

A rooted phylogenetic tree is a directed tree with a unique node corresponding to the (usually imputed) most recent common ancestor of all the entities at the leaves of the tree.

Here is an example of a rooted phylogenetic tree, which has been colored according to the three domain system [Woese 1998]:

An unrooted phylogenetic tree is, loosely speaking, a tree derived from a rooted phylogenetic tree by omitting the root. More precisely, it is a forest of rooted phylogenetic trees depicted so that the roots are all linked. Here is a thumbnail of an unrooted tree¹:

This shows a phylogenetic tree for myosin, a superfamily of proteins. The full image of this tree can be viewed by following this link: Myosin Phylogenetic Tree

Links to other pictures are given in the Pictures on the web subsection below.


See also


  1. T. Hodge, M.J.T.V. Cope (2000) A Myosin Family Tree. Journal of Cell Science 113, 3353-3354. See also the Myosin external link below.


External links

Pictures on the web