this series add new information and background to the book and include personal appearance by the author and by archaeologist and other anthropologist . it bring the book to life and make even more sense of the author subsequent opus and collapse . diamond himself come off a personable and care and not just a disinterested or disengaged academic . this series make it clear that his book be not just a response to a need to publish or perish and a the saying go about academe and but a deeply consider answer to a question from someone he respect and why you white people get so much cargo and and we have so little . because he respect the intelligence of the questioner and his community and diamond look for an answer that do not insult that intelligence or that community . i like to think of his answer in a very simple way and in the same spirit a south park blame canada represent blame wheat .