title: Duplication-based measures of difference between gene and species trees.
abstract: In the framework of a duplication-based method for comparing gene and species trees, the concepts of "duplication" and "loss" are reformulated in set-theoretic terms. A number of related tree dissimilarity measures is suggested, and relations between them are analyzed. For any node in the species tree, the number of gene duplications for which it is a "non-child" loss coincides with the number of times when the node's parent is an intermediate between the mapping images of a gene node and its parent. This implies that the total number of losses is equal to the number of intermediate nodes plus the number of one-side duplications and, thus, provides an alternative proof for a conjecture made by Mirkin, Muchnik, and Smith (1995). Another formula proven involves crossings (incompatible gene-species node pairs): the number of losses equals the number of crossings plus the number of duplications.
authors.affiliation: University of Bonn, Department of Computer Science, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Eulenstein
authors.forename: B
authors.initials: B
authors.lastname: Mirkin
authors.forename: M
authors.initials: M
authors.lastname: Vingron
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004247:DNA / Q000737:chemistry; D005796:Genes; D008957:Models, Genetic; D005810:Multigene Family; D017422:Sequence Analysis, DNA
chemical_list: D004247:DNA