SPOILER*****
Fontaine and Ryan are two different people. Fontaine is an "outside world" smuggler, hence the mass amounts of booze, bibles, and crucifixes you find throughout the game. Ryan is the guy that started the city. Fontaine is the guy that thought Ryan was abusing his power and thus became a much larger beast than Ryan himself. Ryan slept with a hooker and your character (Jack) is the love child. Fontaine and the Australian female doctor sent you to the real world to escape the terrible world. Your character is actually only 12 years old, but because of the plasmids you've developed much faster. It's hard to understand if you don't stay on top of finding the radio diaries. They explain EVERYTHING that the game pertains to, which goes back to my post about no dialog-filled cutscenes.