Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great Book

I can't add very much to the excellent reviews already posted. I'll just say quickly that I enjoyed very much the fresh insight into mating practices among the "lower animals" and among humans. I've read a lot about evolution and biology and so forth, and still found much new material here. I really enjoyed learning about how scientists finally discovered the rampant adultery among birds and how incredible they are at hiding it.Several reviewers warn about having to "make it through" the first part, and I certainly understand that if your primary interest is in the evolutionary origins of human sexuality. However, I really enjoyed the first part as well, because it provides a broad understanding of sex in evolution and give lots of fun examples about different behaviors and adaptations.Although I didn't give the book 5 stars (I reserve that for the best of the best), it showed me that Mr. Ridley is a great writer and I'll check out his other books (I think I'll start with Genome).