The Huffington Post has an interview with Rise of the Planet of the Apes screenwriters Rick Jaffa and Amanda Silver in which they discuss the evolution of the Caesar character over the course of the film's different drafts. What follows is an excerpt.
HUFFINGTON POST: From where I sit, it stands apart from the movies that are already out there. And obviously, you put a few things in there that allude to what could possibly happen, but what's interesting is that somebody had mentioned, "Oh, now they need to redo the Heston version," and I said, well, I'd almost not want to see that. I'd almost prefer that that's just something that's out there that we as the audience know will happen at some point.
AMANDA SILVER: I agree with you.
RICK JAFFA: Well, I totally agree with that. We never wanted to compete with the original and the Statue of Liberty. What our concept was really, from what we said to Fox, was we want to approach this in a very realistic way. Meaning, what's going on in our world today, that if the right dominoes were to line up, touch each other, it could lead to apes taking over the planet and, perhaps, getting Colonel Taylor on that beach in thirty-nine hundred years. You've gotta tell it realistically, and everyone was on board with that and always through the whole process. So we tried really hard to create a story that would stand on its own and yet also pay homage and honor the movies that came before us. We really took the Planet of the Apes fans very, very seriously and really wanted them to be engaged, and happy that we're trying this. You know, let's take this journey again together, let's do this, but tell it in a fresh and interesting way. So, it does explain how the apes took over, but this is a different Caesar we're looking at, it's not the same Caesar. It's a different story of who Caesar is, and how he came to be. So it's really kind of hard to put a label on it. We are hopefully rebooting it. We hope there's a sequel and we hope we get the chance to continue to tell stories about Caesar and the apes and so forth, and where the Icarus [the fan-given name of Taylor's ship in the original Apes, alluded to in the new film] comes in has yet to be determined. So it's kind of tough to put a specific word to it.
HUFFINGTON POST: The Roddy McDowall Caesar, his arc in Conquest [of the Planet of the Apes] is really motivated by revenge, in that Ricardo Montalban gets killed and that's sort of what pushes him over the brink.. so I was curious how that changed, and how you arrived at the decision to make revenge not so much a motivation [here]. AMANDA SILVER: Well, in early drafts, the character of Caesar has changed. I don't know how many drafts we've done. Like, maybe thirty drafts -- whatever. But in early drafts, like, 2006, 2007 drafts, Caesar is motivated more by revenge. He has more of a... I would almost call it a Michael Corleone trajectory
RICK JAFFA: He becomes a great leader, but he's darker.
AMANDA SILVER: And his heart closes down, and although that worked dramatically, it was kind of less satisfying. We all as a group decided that we loved Caesar too much to let him go so bleak. And that as a figure for revolution we wanted him to be hopeful and positive for the other apes, rather than so dark and negative.
RICK JAFFA: Yeah, he really emerged as a hopeful, populist kind of... it became, it was always structurally a Moses story, but it became more of a Moses story once his character transformed in development to where he ended up. But in one draft, and I can't recall which draft that was, but in one draft we changed Michael Corleone to Che Guevara.