Figure 1From: Comparative classification of species and the study of pathway evolution based on the alignment of metabolic pathwaysThe "pages" matrix and its uses. (A) A "page" summarizes the alignment results for one pathway which actually describes the evolution of a pathway; Many such pages, stacked on top of each other, create an organisms*organisms*pathways 3D matrix. The 3D matrix can be used for building phylogenetic trees (B) while comparison of pages can be used to study co-evolution of pathways (C).Back to article page