The most provocative human studies have cataloged the geographic distribution of the D4DR variant. Nomadic and migratory populations have higher frequencies of the variant gene. And the farther one moves from the original site of human dispersal from Africa, the more frequently the variant seems to appear as well. Perhaps the subtle drive caused by the D4DR variant drove the “out-of-Africa” migration, by throwing our ancestors out to sea. Many attributes of our restless, anxious modernity, perhaps, are products of a restless, anxious gene.
