I give this book 2 stars because frankly I didn't understand most of it. I read it when I was 12 or 13, so that's to be expected. I am not a biologist and have never been a fan of biology (it involves almost no calculation; clearly bad news for lazy persons like me), so I couldn't say if I agree or disagree since I have no scientific basis for my opinion. My rating is solely based on my understanding of the content of the book (as with other books I read).
Perhaps I should re-read it. My knowledge in biology now is deeper than it was then (though I've stopped studying biology since starting college), so maybe I could understand it better. Unfortunately, I lent this book to my cousin and she lost it. I haven't found another copy to borrow. Clearly I'm not planning to buy the same book twice.