Well define intelligence. Animals show signs of feelings, even trees have been studied to warn other trees about dangers, and tomatoes yell when you cut them.
There's a lot more intelligence than just being able to be human. And we still don't know if there are even hundreds of species that are more intelligent than us.
And also the same principles of living work for every species even if we think they are dumb, and they keep getting born so why would it be limited to only something we see as even almost equal?
This is just my own theory for the fact that somehow we started controlling this body in the first place, so likely it will happen again. I'm not believing in some major religion theories about good and bad and how you get better afterlife you be good