A method of annotating biomolecular sequences. The method comprises (a) computationally clustering the biomolecular sequences according to a progressive homology range, to thereby generate a plurality of clusters each being of a predetermined homology of the homology range; and (b) assigning at least one ontology to each cluster of the plurality of clusters, the at least one ontology being: (i) derived from an annotation preassociated with at least one biomolecular sequence of each cluster; and/or (ii) generated from analysis of the at least one biomolecular sequence of each cluster thereby annotating biomolecular sequences.