He reviews some of his previous work and presents an alternative to the dominant ‘Ancient RNA world’ hypothesis.
The list of common genes in the alignment of Table 1 is enriched in small and large subunit ribosomal proteins that are the most ancient of the ribosomal set, according to the Caetano-Anolles theorem that is mentioned later in the manuscript. Interestingly, the most ancient of them are clustered toward the 5’ end of the genomic sequences that were aligned (S12, S17, S5, S4 and L2, L3 and L24). Could this imply a possible ancient segmental duplication? Also interesting is the placement of the most ancient ribosomal protein S12 between exactly two polymerase (beta and beta prime) and elongation factor (entry and translocation) genes (separated by single and much more derived ribosomal proteins). Could this be an ancient memory of the ribosome mediating translation and replication? A commentary would enhance the value of the section.