Element of Molecular Phylogeny

The evolutionary history inferred from phylogenetic analysis is usually depicted as branching (treelike) diagrams. The correct evolutionary tree is a rooted tree that graphically depicts the cladistic relationships that exist among the operational taxonomic units 

The number of possible tree topologies rapidly increases with an increase in the number (N) of OUTs. The general equation (Miyamoto and Cracroft, 1991) for the possible number of topologies for bifurcating nmooted trees (Tn) with n ( 3) OUTs (taxa) is given by 

It is clear that a search for the tme phylogenetic tree by phylogenetic analysis of a large number of sequences is computationally demanding and difficult. 

Phylogenetics is the science of estimating the evolutionary past, in the case of molecular phylogeny, based on the comparison of DNA, RNA or protein seqnences. It aims to reconstruct a phylogenetic tree as a statistical inference of a true phylogenetic tree, which is unknown. Various assumptions/approximations are made, a number of potential problems need to be considered  

Scarcity/mixtures of the data can produce misleading results. 

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