Probably a dumb question...

<p>I'm looking at my book list, and for MMW 1, the same book is listed twice. It's the Smithsonian Intimate Guide to Human Origins, and it is listed both as required AND optional. However, the optional one is more expensive. Is this like hardcover vs. paperback or what?</p>

<p>your professor probably just screwed up and listed it twice. it never matters between hardcover/paperback if it's the same book. just email him/her.</p>