The best animal

I read the following passage from The Curious Incident of the Dog in the Night-time

And people who believe in God think God has put human beings on the earth because they think human beings are the best animal, but human beings are just an animal and they will evolve into another animal, and that animal will be cleverer and it will put human beings into a zoo, like we put chimpanzees and gorillas into a zoo. Or human beings will all catch a disease and die out or they will make too much pollution and kill themselves, and then there will only be insects in the world and they will be the best animal.

and I thought, No, no, binturongs are the best animal.

Then I thought, Dear lord, what has Hal done to my fragile mind?