Wonkette has an interesting item (as Wonkette is wont to do) on Lynne Cheney's statement that her dear husband shares a somewhat recent common ancestor with one Barack Hussein Obama. Well, I mean! Next thing you know, we're gonna find out that there is a treasure map on the back of the Declaration of Independence.Oh.The whole thing brought to mind a fascinating profile in the Atlantic Monthly five years ago which offered mathematical data proving who is related to which historical figures. For instance, anyone whose family lived in western europe in the 12th century is directly descended from Charlemagne, and if you go back even further and have Spanish blood, you are a direct descendent of the prophet Muhammad (via the Emir of Sevilla). The math is actually fairly straightforward--your total number of ancestors goes up exponentially the further you trace your roots. For example, you have 2 parents, 4 grandparents, 8 great-grandparents, 16 great-great-grandparents, and so on. So if you go back 30 or so generations, you would theoretically have more relatives than the actual population of a given region at the time. Once you factor in the percentage of family lines that die out of a long period of time, that narrows the pool even more.It's a subscription-only article, so I might have gotten the dates wrong off the top of my head, but that's the main idea.