I believe brains evolved from an unmyelinated state to a myelinated state.
Since this did involve an additional investment of biological energy, myelin
is almost certainly an evolutionary advantage.
-- sentience@pobox.com Eliezer S. Yudkowsky http://tezcat.com/~eliezer/singularity.html http://tezcat.com/~eliezer/algernon.html Disclaimer: Unless otherwise specified, I'm not telling you everything I think I know.