[Evolution of RNA-dependent RNA-polymerases from positive RNA viruses: comparison of phylogenetic trees constructed by different methods]. / Evoliutsiia RNK-zavisimykh RNK-polimeraz pozitivnykh ribovirusov: sravnenie filogeneticheskikh derev'ev, postroennykh raznymi metodami.

Presumptive phylogenetic trees of evolutionary conserved fragments of RNA-dependent RNA polymerases of 26 positive strand RNA viruses were generated using a simple clustering procedure or a novel approach based on the so-called maximal topologic similarity principle. The latter methodology involves a quantitative measure of the degree of correspondence between the topology of generated trees and structure of the initial distance matrix. The algorithm for tree construction based on the maximal topologic similarity principle does not include the assumption of evolutionary rate constancy, as opposed to the clustering procedure. Nevertheless, it is demonstrated that the trees generated by the two methods are topologically similar, indicating that no drastic change of evolutionary rate had occurred in evolution of the positive strand RNA virus RNA polymerases. This in turn suggests that RNA-dependent RNA polymerases (or at least their evolutionary conserved core domains used for construction of the phylogenetic trees) are principally functionally equivalent in all positive strand RNA viruses.

[A principle of maximum topological similarity in molecular systematics]. / Printsip maksimal'nogo topologicheskogo podobiia v molekuliarnoi sistematike.

The paper deals with the problem of phylogenetic reconstruction on the basis of comparative analysis of features. Main attention is paid to comparison and classification of the biopolymer sequences. Different approaches to this task are critically reviewed. The novel principle of construction of tree-like classification schemes permitting subsequent evolutionary analysis is proposed. It concentrates on reconstruction of the tree with a topologic structure that is most close to topologic features, imprinted in the source distance matrix. Realization of this approach was made possible by development of the special formalism, enabling evaluation and comparison of topologic features of distance matrices and trees.

[Algorithms for constructing phylogenetic trees of maximum topological similarity]. / Algoritmy postroeniia filogeneticheskikh derev'ev maksimal'nogo topologicheskogo podobiia.

The paper concerns the practical realization of the maximum topologic similarity principle for phylogenetic reconstruction. This novel principle is described in the accompanying paper. Two algorithms that were embodied in the computer program allow one to find out the unique tree in case when source data admit the existence of such tree. In case if numerous parallel mutations make such precise realization impossible, algorithms allow one to obtain approximations to the maximum topologic similarity trees with a high computation efficiency. Examples illustrating use of these algorithms, as well as discussion of biological consistency of the novel concept are presented.