Quite a few biochemists will argue that RNA and DNA are
storage devices which evolved only after living cells were well
established. In particular, the intermediate (ancestral)
metabolism was required before RNA and DNA could be used,
since nitrogen-containing compounds are not cheap and easy
to find.
So sayeth Harold Morowitz (book due out soon), and there is
another new book out on the topic of the origins of life
which also refutes the RNA-first theory (sorry, no citation).
Una
--
Una Smith una at phy.duke.edu School of the Environment
Duke University
Durham, NC 27706
