My apologies if other people have mentioned this, but check out this shot from the scene where Elizabeth first comes to talk to Rodney about Ascension:
I think Rodney is using his altered DNA to enjoy citrus!
I totally have an unfinished fic where he does that. (Hmm. Perhaps I should just turn it into a porny missing scene?)
Rodney, I love that between making scientific advancements in the field of science and being like Jesus, in a way, you found time to sample Asian lemon...whatever. *heart*
ETA: Oooh! And again! Good, he got to try the orange, too: