Craig T. Palmer & Lyle B. Steadman 
Supernatural and Natural Selection [PDF ebook] 
Religion and Evolutionary Success

Spanning many different epochs and varieties of religious experience, this book develops a new approach to religion and its role in human history. The authors look across a range of religious phenomena-from ancestor worship to totemism, shamanism, and worldwide modern religions-to offer a new explanation of the evolutionary success of religious behaviors. Their book is more empirical and verifiable than most previous books on evolution and religion because they develop an approach that removes guesswork about beliefs in the supernatural, focusing instead on the behaviors of individuals. The result is a pioneering look at how and why natural selection has favored religious behaviors throughout history.