I just finished City, a series of short stories by Clifford Simak illustrating the end of mankind and the animal civilization which inherited the earth.
There is no dramatic apocalypse for Earth. This is a philosophical story of a quiet dwindling of the human population and the subsequent rise of their robots, dogs, and other animals who make use of the technology humans left behind and their influence on the development of future animal civilization. I do not believe this to be a likely ending of mankind, it seems more of an introvert's dream. But the stories present a thoughtful exploration of fundamental questions about what it means to be human.
So I was trying to explain this book to my son, but had a hard time getting him to take me seriously when I was describing talking dogs who traveled between dimensions, robots who fed a vegetarian world, humans who became gas entities on Jupiter, and ants who used tools to build structures. But in spite of the apparant absurdities, this story pulls off a transcendant picture of a utopian society created in man's wake. It is a story about loneliness and nostalgia for what might have been, and paints a beautiful picture of potential and possibilities for life on Earth.