In which case they aren't reproducible because they aren't reproducing, not beacuse you can't do it more than once, perhaps heritable would have been a better way to phrase it. You can't have post-transational modifications with nothing to translate, and the post seem to imply no role for gnetic material, all you are doing is moving the mutation from the coding region of one enzyme to the coding region of the protein doing the post-translational modification not removing the genetic component. The evolution is still clearly in the genetic sequence and not in the enzyme.
Perhaps you could have an environmental factor causing a post-translational modification without the involvement of another protein but I don't se how this could be heritable.
TTFN,
WK
This message has been edited by Wounded King, 08-07-2004 06:23 AM