This book is definitely geared toward those who are already familiar with the basic tenets of evolution, but who don't really have it driven home.
The author uses anthropological evidence behind how things came to be, as well as biological factors as to why animals are distributed the way they are. It's an interesting hodge podge of anthropology, biology, chemistry, and history. I strongly recommend it for high school students to read it as a method to hammer home the fact that evolution is real. It would also be good reading for a homeschooled child to demonstrate how evolution works. However, it's written in such a way that adults would like it too without feeling like it's a textbook.