摘要：The current taxonomic system, based on the hierarchy of Linnaean ranks, is said to be unsatisfactory. Many people insist that the very concept of rank should be eliminated, and the current taxonomic system should be replaced with a rankless system based on phylogenetic taxonomy. However, it is not the elimination of the concept of rank but rather the correct ranking of characters that will promote stability in taxonomy. The first problem of both traditional and phylogenetic taxonomies is the chaotic employment of differences that leads to the segregation of groups which are not comparable in rank. A proper rank coordination could be carried out by the special weighting of differences among tentative groups. Groups become equal in rank when they are distinguished by state combinations of the same character set. The second problem of both traditional and phylogenetic taxonomies is the employment of internal polymorphism of genera and families for the re-unification of species into new taxa. This could be overcome if taxonomists take into consideration the law of homologous variation within closely related genera and families
关键词：Character weighting – ranks – taxonomic system
