On the Structure of Reconciliations

摘要

In this paper we present an extended model related to reconciliation concepts. It is based on gene duplications, gene losses and speciation events. We define an evolutionary scenario (called a DLS-tree) which informally can represent an evolution of genes in species. We are interested in all scenarios - not only parsimonious ones. We propose a system of rules for transforming the scenarios. We prove that the system is confluent, sound and strongly normalizing. We show that a scenario in normal form (i.e. non-reducible) is unique and minimal in the sense of the cost computed as the total number of gene duplications and losses. Moreover, we present a classification of the scenarios and analyze their hierarchy. Finally, we prove that the tree in normal form could be easily transformed into the reconciled tree in duplication-loss model. This solves some open problems stated in [13].