Import Pokemon from GBA slot

If you upload your pokemon from the GBA game to the DS game, do you lose them in the GBA game? Or does it just make a duplicate?
 
No. Once Pokemon are in P/D, they're locked there and forever gone from R/S/E. Kind of a scary thought, but then you figure that you're probably going to be doing 99.9% of your battling on P/D.

I can't imagine all the glitches that could be spawned if you were allowed to send them back to R/S/E. o_O I've already seen some pretty crazy ones played out on YouTube.