Genetic data has been used to construct the phylogenetic tree of all the living organisms. Ribosomal RNA sequences and genome data have been used for the tree construction. Both trees have shown the separation of the organisms into three domains of life: Archaea, Bacteria and Eukarya. The trees suggest that all contemporary organisms have been derived from the last common ancestor. The last common ancestor has been called LUCA, LCA, Cenancestor or Commonote. We have defined the last common ancestor Commonote as the species, which is a group of living organisms with sufficient gene interaction to constitute a single gene-pool.