The blurb is wrong
What's left of humanity in this book does not exist to serve anyone, it just exists to survive. As the book opens, aliens have already taken over the planet, over 1,000 years prior. Some of the aliens even think that Man is already extinct. The aliens took over for one reason: to mine our minerals.
Then, one of the aliens gets an idea to make money and captures a Man, which he thinks of as an animal. The few remaining humans in this book have been living in the hills and mountains and have reverted back to almost the dark ages. The man who is captured is different in that he has questioned the ways of his people.
When he is captured, he finds out the truth about how man was defeated and nearly became extinct and decides to fight back.
A great story. I heard the movie was awful, so if you saw it, don't let it keep you from reading the book. Everyone knows the book is always better anyway, right?