kevinpet says>"...nothing I've read has proposed any mechanism whereby it could evolve..."[italics mine] If a biochemical mechanism exists then it is possible

kevinpet says>"...nothing I've read has proposed any mechanism whereby it could evolve..."[italics mine] If a biochemical mechanism exists then it is possible for it to be conscripted in evolution. Its not as if something called "evolution" sits around waiting for permission (and from whom and when?). Instead, a gene is modified randomly and blam a new mechanism occurs (or doesn't, mostly) which either enhances replication and persists in the genome or doesn't. In the long run you'd expect all chemical pathways possible to be eventually probed many, many times by evolution.