A NEW PRESENT-DAY ANCESTOR METHOD FOR CONSTRUCTING PHYLOGENETIC TREES TAKING ACCOUNT OF THE COINCIDENCE BETWEEN HOMOLOGOUS MOLECULES OF THE SPECIES BEING STUDIED AND OF THE REFERENCE SPECIES
一种考虑到不同物种同源大分子间的偶合关系的新的今祖法

For constructing phylogenetic trees from molecular sequence data, theoretically the present-day ancestor method makes corrections for unequal rates of evolution among lineages and yields the correct topology. However, in practice it was found that different topologies were often obtained when different species were used as references. The fact is contrary to the anticipation and to the principle about this method. The previous study of the author pointed out that the phenomenon was resulted from the different degrees of the coincidences between the homologous molecules of various species being studied and of the species used as references. In the light of this understanding the author proposes a new method that the matrix d' in the original method (d'ia'b = dia ib -ria -rib ) is converted to matrix DC', DC' ia ib =d/ia ib -COi a i - COib j , where j represents the molecule of the species used as reference, and various COi j display indirectly coincidences between land j. From matrix DC' simple clu-ster analysis can give same and correct topology whichsoever species in other evolutionary branches is used as reference. The establishment, principle and practical applying of the new method are described.