today the commercial ancestry market is worth billions and relies on a weak supposition that the composition of your DNA will reveal the identities of your forebears in time and space. At best it’s a fudge, a spell to bewitch your romantic and sentimental urges—to belong to a tribe of Vikings, Anglo-Saxons or other noble warriors. But really it’s just gassy bullshit. What modern genetics has shown unequivocally is that while there are differences among people around the world, which manifest broadly as

