There's a difference between seeing a three letter word in your alphabet soup and a paragraph describing in detail how to make more alphabet soup.
even if those three letters allow you access to a new environment/niche? would be more efficient to only use three letters if three letters will do. why waste a paragraph?
oh ok, getting confused btw the ecoli & RNA. The self replicating RNA a paragraph which could make more soup. One of the simplest examples of something that could be considered alive.