Originally Posted by Oberon sexton
There's this great idea, again from All-Star Superman,
(are people seeing a pattern here?
) that Superman and Lois could never have children together because of their biological differences. But Lex, whilst on Death Row realizes just how wrong he was and basically comes up with a theorem that allows Human/Kryptonian DNA to be combined.
That might have been in the animated movie, but I'm pretty sure it wasn't in the comic.