You can buy a kit that comes with a vial and a cotton swab—gloss it over the inside of your cheek, send it off to a company which promises to unlock medical and genetic mysteries in your family tree and find your ancestors' migration patterns. Perhaps fill in, once and for all, the many gaps in family stories. At best, however, these are estimates, though people have found their way to unexpected results—who got knocked up in the war, who they were not a chlid of, after all. Who gave you that leaky heart, that questioning nature, that inability to believe.