Dick Cheney

Many of us snickered to hear that Barack Obama and Dick Cheney are cousins. Imagine that family reunion!

The most entertaining tidbit in all of this, though, might have come from Lynne Cheney, the vice president's wife, who brought the relationship to the media's attention while she was promoting one of her books.

She told MSNBC that it was "an amazing American story that one ancestor ... could be responsible down the family line for lives that have taken such different and varied paths."

Barack Obama

How far does the apple fall?

Obama's and Cheney's lives have taken varied paths? Gee, let's think this through: Obama is a United States senator and Cheney is president of the Senate. Not only do they have the same health insurance plan, they probably live within a few miles of each other. They also meet in the same building, almost certainly walking the same hallway stretches.

If this is Mrs. Cheney's idea of "different and varied paths," then I'm guessing her idea of variety is eating M&M's. Look! They're different colors! What variety! Wheee!

These two might have different political philosophies and demeanors, but it's not as though one of them ended up in jail for skinning kittens while the other went on to cure cancer. They're both leaders of this nation -- as is another of Barack Obama's distant cousins, George W. Bush.

That's right. Not only do Obama and Cheney share a common ancestor, Obama and President Bush do, as well. Given this saucy-sounding revelation, it's tempting to think, "Gee whiz. If you did a bad job picking your ancestors, you have no shot of rising to power, even in a place like the United States."

Allow me to explain why. You probably know what a first cousin is. That's the child of your aunt or uncle. You share grandparents. How much genetic material do you have in common? Well, unless your parents are identical twins who married identical twins (it has happened), you share 1/8th of your genetic material with your first cousins. (Math lovers -- you can calculate this by dividing 1 by 2 to the number of generations represented. In this case, it's 1/(2^3).)

So what does it mean to be an 11th cousin, as Obama is with President Bush? Let's walk it through. Second cousins are the children of first cousins. Do you have a first cousin? Do you and your cousin both have kids? Your kids are each other's second cousins. The kids share the same great-grandparents (and 1/16th of their genetic material).

Extending that relationship, 11th cousins share the same great-great-great-great-great-great-great-great-great-great-grandparents. Mathematically speaking, they share 1/8192nd of each other's genetic material. In other words, not much (a little over 1/100th of a percent).

That is, if they weren't already married to women, and if they were willing to travel to Massachusetts, the only U.S. state to recognize same-sex marriage.

The odds of that seem somewhat less than the amount of genetic material these powerful men share. So hold off on checking the registry, OK?

This math does assume, of course, that the Bush-Obama-Cheney ancestors hadn't married their cousins at any point along the way. This practice is far from unheard of, especially way back when. (And despite what you might think, it's legal in 26 states for first cousins to marry.)

The piece of genealogical data I'd be interested in digging up next is if any of these men is descended from Genghis Khan. A 2003 study estimated 16 million people worldwide, including almost one in 12 Asian men, can trace their ancestry to the megalomaniacal Mongol, who made it a practice to spread his seed as wide as his empire. That's astounding.

There is at least one American man who's found he has that particular genetic marker, the Times of London reported a couple of years ago. How far has his path varied from that taken by Grandpa Genghis?

Well, Tom Robinson is a moderate Republican ... he does not ride horses ... he's an accountant in Florida ... and he is the last of his line, as he and his wife have no kids of their own. The apple, perhaps, sometimes does fall far from the tree.