Molecular phylogeny is used to analyze hereditary differences in DNA sequences between organisms in order to determine their evolutionary relationship.
Every living organism carries DNA; closely related organisms share similarities in their DNA, while DNA from more distantly related organisms is more dissimilar. DNA found in conserved sequences is expected to accumulate
Assuming this occurs at a constant rate in these sequences, scientists can date
between different organisms. Molecular phylogeny uses the data obtained in order to build a phylogenetic tree showing the probable evolution of various organisms (see phylogenetic tree of West Nile virus strains).