I read this book quite awhile ago. I was intrigued by the title, and I wasn't disappointed.
The best thing about this book for me was simply the plot. The continual unraveling of the author's speculation on the origins of man were so fascinating that it kept my interest until the very end. There was a lot of actual history in it. The connection to reality was the anchor that kept me guessing.
It's a great mystery, a grand adventure, and has characters with depth. I'm not sure you can ask more from a book. I'll be re-reading this one.