We are doomed to repeat history if we fail to learn from it, but how are we affected by the forces that are invisible to us? We know that heredity helps determine who we are, but here Christine Kenneally shows how trust is an inherited trait in Africa, silence is passed down in Tasmania, and the history of nations shows up in our DNA. From fateful ancient encounters to modern mass migrations and medical diagnoses, this 2014 New York Times Notable Book of the Year (deemed "the richest, freshest, most fun book on genetics in some time") explains how the forces that shaped world history ultimately shape each human who inhabits it.