Translation is the process of protein synthesis.
Translation systems evolved around transfer RNA (tRNA).
tRNA is the major innovation in evolution of life on earth.
Once tRNA evolved, translation systems and the genetic code could evolve.
Without tRNA, complex life would never have evolved on earth. 
Dr. Burton published a clean model for tRNA evolution.
With the help of Bruce Kowiatek, Yunsoo Kim and Kris Opron, I also figured out how type II tRNAs evolved.
The central issue in evolution of life on earth, which is tRNA evolution, can be solved as a moderately challenging puzzle, much easier than a New York Times Crossword Puzzle.