We recently finished the book Moral Minds: The Nature of Right and Wrong by Marc D. Hauser. He explores the roles of psychology, ethics, and evolutionary biology in developing the moral code that humans hold today.
The anecdotal evidence in the book is quite fascinating and illustrate how certain portions of our moral sense are hard coded into our DNA and he speculates on where, when, and how these arose from history. However, he fails to deliver on some of his key tenets approached in the beginning of the book.
Quick vote: All bark, and no bite. We enjoyed it, but it left us disappointed.