@cwhenderson, how did you manage to fight the temptation to go with a full-bore four-for-four—if not an outright shameless five-by-five—alliteration? (At three-for four you were so close to a grand slam!)
I have no self-respect whatsoever, so I would have been puerily prone to post “Plausible Prebiotic Production of Pryimidine/Purines” if I had had the chance.
(And to those pesky pedants who may protest: the plosive word, puerily, though perhaps peculiarly opaque and unpopular, is nevertheless—per se—a properly picked adverb, perfectly and particularly appropriate to this pubescent post. Profuse pardons. Please.)