At first I was gonna give the thread a big
But then I read this and my brain hurts...
But then I read this and my brain hurts...
How about the theory that since all the Pixar movies take place in the same universe, that humans gain the technology (based on the work of Charles Muntz from UP) to grant intelligence to animals and even machines, resulting in Ratatouille, Finding Nemo, A Bug's life, Toy Story, etc. Then, after humans abandon the planet, seen in WALL-E, a sentient race of machines (Cars/Planes) take over and become the dominant "life" form.