Or maybe merely reinforced the ones that were already there ...
Now, unlike in the original, the Ape Planet does not turn out to be Earth. But after Wahlberg returns to the Solar System (while passing through an electromagnetic storm) he discovers that Earth has been taken over by intelligent apes, with the statue of the sadistic chimp general he met on Ape Planet sitting right where the Lincoln Memorial used to be.
Aperaham Lincoln, if you will.
How did Thade (the chimp general) get to Earth? Why are there apes everywhere? Is this even Earth? What the fuck is going on?!
The ending was so notoriously confusing that the movie's DVD came with a graph explaining it.
Just a little supplemental quantum physics homework with your Walhberg flick.
All right, so after Wahlberg got into his pod and set course for Earth, it's implied that Thade and a few of his buddies got into the other pod (there were two of them on the Ape Planet) and followed him. They both then passed through the electromagnetic storm, which also acts as a time portal. However, because of the unstable nature of the temporal storm, they reached Earth at different times. It would seem that Thade and co. landed on Earth many decades/centuries in our relative past, and with nothing better to do, proceeded to take over the place. By the time Wahlberg finally landed back home, humanity had long been enslaved by a race of intelligent apes. Which were created by ... Thade and his time-traveling friends banging our regular apes and slowly creating more and more intelligent primates? That's the sexy answer. We always go with the sexy answer.