One of the single-most transformative events in human history was the agricultural revolution. Why did we stop hunting and gathering, and start planting and harvesting? It's a mystery, but scholars have speculated that perhaps it was because of a changing climate, or a drop in animal numbers in certain regions. A third option, which author and religious scholar Reza Aslan supports, is the hypothesis that institutionalized religion spurred early human agriculture in southeastern Turkey about 12,000 to 14,000 years ago—and he believes it has been a disaster for our species. "Human beings actually ended up consuming fewer calories—and certainly fewer proteins—during the agricultural revolution than they did when we were hunter-gatherers," he says. "... We’ve discovered that the process of farming actually created a whole range of new and, at that time, absolutely novel diseases and problems with human beings." In this view, organized religion is also responsible for the inequality that dominates the world today. Surplus food stocks and the advent of ownership in newly settled communities led to wealth accumulation and, ultimately, the stratification of society. The agricultural revolution may have been a net negative for humanity, says Aslan. What's more difficult to say, however, is where we'd be right now without it. Reza Aslan's latest book is God: A Human History.