plot explanation - Final scene in Planet of the Apes (2001)

I'm confused by the final scene in the Planet of the Apes film (2001, not the recent Rise film).

Leo lands on Earth in his own time to find it run by the Apes. How does this happen?

• I'm assuming that the Ape planet they're on for the majority of the film is not Earth, as we're certainly not given any reason to believe it is Earth that I can tell. The ship makes a point of telling him he's landing on Earth which it hasn't elsewhere. If it is however we're led to believe it's many years in the future.


• Leo travels back in time from the future alien world to Earth (you can see the clock counting down when he's flying)


• There's a statue to Thade instead of Lincoln

This implies either that the clock is wrong and this was Earth all along, his navigation is broken, he's going forward in time at the end, not back, and Ape society has mirrored human history.

This is a parallel Earth of some kind.

Or that somehow Thade managed to escape from a locked room on a crashed ship with no fuel (or use Leo's originally crashed pod?). Take off, fly through the storm and arrive on Earth at some time in Earth's history then take over the entire planet?

What was the logic behind this scene? There must be a reason for it being in the film?

Answer

It's been a few years since I've seen that movie but the actual DVD cover had an insert that showed a time map to help make sense of the movie. It is two different planets as it was in the original novel Monkey Planet and Mark Walhberg does end up back on Earth (not a duplicate Earth) in the current time. Apparently the time vortex works in reverse so that the first one in is the last one out. The space ship Oberon goes in last but has crashed thousands of years in the past. It was originally planned to have at least a sequel which would have explained the current Earth better.

http://voices.yahoo.com/the-return-planet-apes-8931359.html
The ending of Burton's film confused just about everyone, so much so that when the DVD was released it included a chart explaining how the apes on the planet were able to build their own space ship, enter the vortex, end up in Earth's past, and end up dominating that planet as well. The problem here, without the chart the ending makes no sense.