Question

Difference between rooted and unrooted phylogenetic tree

Answer 1

The difference between rooted and un-rooted phylogenetic tree


Rooted phylogenetic tree 
Phylogenetic trees are central to the field of phylogenetic.  In a rooted phylogenetic tree, each node with descendants represents the inferred most recent common ancestors of the descendants, and the edge lengths in some trees may be interpreted as time estimates.

In rooted tress the ancestral state of organisms or genes is shown at the bottom of the tree, and the tree branches, or bifurcates until it reaches the terminal branches, tips or leaves at the top of the tree.

Rooted trees shows the most basal ancestor of the tree.

Unrooted phylogenetic tree

Unrooted phylogenetic tree does not show an ancestral root.
Unrooted binary tree is unrooted tree in which each vertex has either one or three neighbors.
Unrooted trees represents the branching order but do not indicate the root or location of the last common ancestor.

Unrooted trees shows the relatedness  of organisms without indicating ancestry.

Answer 2

Answer: Phylogenetic tree is also called as an evolutionary tree. It is a branching tree, which depicts evolutionary relationships between different living organisms. It is constructed on the basis of genetic or physical characteristics.

It is divided into rooted and unrooted tress on the basis of the presence or absence of the common ancestor.

A rooted tree is the one which contains the direction to the common ancestor of the living organisms. This tree converges to a point called as the root of the tree. This root depicts the common ancestor of the life forms.

On the contrary, an unrooted tree does not contain common ancestor. This means that we can not depict the common ancestor of the life forms.