A hierarchical model for evolution of 23S ribosomal RNA. 2009. K.Bokov and S. V. Steinberg. Nature 457: 977-980.
The key breakthrough came when they realized that the ribosome is organized by a set of simple structural rules and that it had to be assembled from basic building blocks in a very specific order; otherwise it would have fallen apart. They then mathematically showed that the construction of the ribosome likely followed an ordered series of steps to form the structure found in the first living cell. To this day, that structure exists almost unchanged in our own cells.
"Thanks to the research of Sergey Steinberg and Konstantin Bokov, scientists now have a glimpse of one key event that emerged spontaneously out of the primordial chemical soup of the early Earth," explains Stephen Michnick. link