Figure 8
![Figure 8](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1745-6150-2-14/MediaObjects/13062_2007_Article_53_Fig8_HTML.jpg)
Origin of the translation system and the genetic code in the RNA World. Step 4: the original activity of the ribozyme R (X-Y) and the peptide ligase activity are apportioned between two ribozymes as the result of duplication and subfunctionalization; the ancestor of the large ribosomal subunit (R L ) emerges.