We certainly have the data, too much so actually. I should correct the statement to say, we have insufficiently developed _applied_ information theory.
We know how to quantify homology, it just has not been applied to sufficient depth to the field of RNA/viroid evolution to resolve how much of an RNA element with extensive secondary structure, or ribozyme is evidence of a homology vs. convergence. And how could we resolve the two? It's easy with protein sequences, tricky with protein structures, but deep RNA evolution? That's a mystery.
We know how to quantify homology, it just has not been applied to sufficient depth to the field of RNA/viroid evolution to resolve how much of an RNA element with extensive secondary structure, or ribozyme is evidence of a homology vs. convergence. And how could we resolve the two? It's easy with protein sequences, tricky with protein structures, but deep RNA evolution? That's a mystery.