Similarity Analysis of DNA Sequences Using “Molecular Connectivity Indices” Method

A New Alignment Free Method for Phylogenetic Tree Construction

“…Similarly k=3, 4 3 =64 possible combinations can be formed and so on. As we increase the value of k there will be an exponential increase in the number of the possible k-tuples and most of them may not be present in a sequence [5][6]. So the extraction of features from k-tuple based method becomes a tedious task.…”

“…Another method based on distance reduces the information of long sequences into evolutionary distance and is considered to be computationally efficient [5]. The sequence pairs having the smallest number of sequence changes between them are termed as neighbors.…”

Modified k-Tuple Method for the Construction of Phylogenetic Trees

“…The goal of the distance methods is to identify a tree that positions the neighbours correctly and reproduces the original data as closely as possible with its branch lengths. Distance between two sequences is expressed as the number of changes per site i.e., the ratio of the number of mutations to the number of sites (You et al, 2009) and it assumes that all sites can vary and in case the unvaried sites are present it will underestimate the changes occurred at the variable sites.…”