> Since both gumbo file' and rootbeer are derived from sassafras, can they
> be substituted for each other?
Root beer has more than just sassafras flavor. (Note that the FDA banned
sassafras in root beer quite a few years ago.) You can REALLY taste the
wintergreen in some brands of root beer. Birch beer and sarsparilla are
similar to root beer but not much like gumbo filé. Of course you don't have
ANY natural flavors in the cheap root beers. (Hmmm... Given that wintergreen
flavor flavor I mentioned, I wonder how root beer would be as the braising
liquid for lamb.)
So the bottom line is no, they really can't be substituted for each other;
they're not very much alike.