Research On Algorithms Of Constructing Phylogenetic Network Based On The Species Characteristics

Phylogenetic analysis is by tracing the process of speciation,and analyzing the evolutionary relationships between the species.The initial evolutionary relationships are represented by the phylogenetic trees.However,deep research has found that reticular events(such as hybridization,recombination,and horizontal gene transfer)often occur during evolution,which results some species have more than one parents.Phylogenetic trees cannot describe such complex evolutionary history.Phylogenetic networks can describe reticulate evolutionary relationships and can represent conflicting evolutionary information of phylogenetic trees.Moreover,phylogenetic trees are regarded as a special form of phylogenetic networks.In this paper,we study the construction of phylogenetic networks based on species characteristics.The main contents include:? We deeply study the construction of phylogenetic trees.We propose a new method for constructing phylogenetic trees based on the distance matrix,called ENJ,which is an effective improvement of Neighbor-joining algorithm.Neighbor-joining is a frequently used algorithm for constructing phylogenetic trees,which is fast,accurate and suitable for large data sets.In the experiment,compared with INJ algorithm,the difference between the phylogenetic trees constructed by ENJ and the initial trees is smaller,which can better represent the information of the initial trees.? We deeply study the construction of phylogenetic networks.We propose a new method for constructing phylogenetic networks based on the rooted phylogenetic trees,called Frin,which is an effective improvement of Cass algorithm.Cass algorithm accepts arbitrary multiple phylogenetic trees as input,which is an effective algorithm for constructing phylogenetic networks.Frin selects removed taxa based on taxa frequency and incompatibility degree,which weakens the influence of input data order and accelerates the construction of phylogenetic networks.Experimental results show that compared with Cass?Lnetwork and BIMLR,Frin significantly weakens the influence of input data order;Frin constructs a simpler network with fewer redundant clusters;Frin effectively constructs a phylogenetic network for Poaceae.