I had a bit of an epiphany the other day. Let me ask you a question. Suppose you were to get a letter, from someone on the East coast, saying that they’d been looking into their family tree and had found out that the two of you were 15th cousins, twice removed, and that they’ll be in the Bay Area in June and would you like to meet up? What would you do?
I got an email a bit like this back in 2012 from Barbara, my second cousin once removed, inviting me to the annual Ford family reunion in Bournemouth (I was living in England at the time). I went, and it was great! It was my first time at the reunion, but everyone was really welcoming; I met many of my second cousins for the first time, and we had a lovely afternoon swapping stories together. Even though the main thing we have in common is a shared set of great-grandparents, they treated me like family. Because, well, I am family!
I read once of somebody who had found out that they were Barack Obama’s 8th cousin. This seemed amazing - they were certainly very pleased. It turns out that we each have about 10 to 20 second cousins, around 300 fourth cousins, and something like 70,000 8th cousins. If you grew up in the Bay Area, most people you walk past on the street in San Francisco are your 12th cousin or closer. And everyone on Earth is closer than your 50th cousin, and most are your 15 or 16th cousin.
So: welcome to our weekly family reunion! The person sitting next to you could be a 10th cousin, or maybe a 20th cousin if they grew up in England, or China, or Guatemala, but they are definitely your cousin.
Why stop there? Extending out to more and more cousins means going back in time to greater and greater grandparents. Our 50 times great grandparents were alive in the 11th century, and each one of them is the shared great grandparent of each pair of us 50th cousins today. And if we go back to about 340,000 BCE we get to my 14,000 times great grandparents, a couple who are also yours and everybody else’s 14,000 times great grandparents.
Our shared 600,000 times great grandparents are interesting: these are the grandparents we share with the chimpanzees, all of whom are 600,000th cousins (many times removed, of course, as their generations are shorter than ours). It’s an amazing thought, isn’t it? The Hominid family really is a family. Going to the Zoo will never be the same again.
“Cousin” is a marvellous word. English doesn’t have a special word for second cousin, or any more distant cousins, and what a good thing that is! It means that we can honestly say that every single living thing on this planet is cousin to every other living thing. Cats, dogs, spiders, trees, your own gut bacteria, we are all cousins who share the same trillion times great grandparent, who lived nearly 4 billion years ago and whose frail body was a single microscopic cell. And so the only question for any pair of organisms is, what degree of cousins are we? Are you my second cousin, like Barbara, who emailed me to invite me down to the South coast for the day? Or my 50 millionth cousin, like the whales that call in to the Bay Area twice a year on their annual migration? You may not have spent much time with your distant cousins, but they are family nonetheless.
As you might be able to tell, I wasn’t fully aware of this incredible fact until quite recently. I mean, I knew about evolution, and felt some affinity with some animals, and liked plants, but hadn’t really thought about the simple fact that life on Earth is literally a family. Now I know why people say grace before meals.
It’s interesting to think about how your family and mine is doing, around the world. Your cousins in Syria and Iraq (the Sapiens) are having a hard time, displaced by climate change and desperately seeking security, one way or another. Our family is going to face more and more of these testing times over the next century, as the weather patterns change, land becomes unuseable, and many of us have to move. A lot of us won’t make it, whole branches of our family tree coming to an abrupt halt at the beginning of the anthropocene epoch. I have cousins in Florida, and in Bangladesh (not Fords, but more Sapiens). Which of us will be the first to pick up a pen as the sea levels get higher and higher?
I asked a friend my hypothetical question the other day. What would you do if you got a letter from a long-lost 15th cousin? He said he’d be happy to meet up with them, since they went to the trouble of writing. What about your 50th cousin, I asked. Would you meet up with them? He said, sure.
This reflection was inspired by, and draws heavily on, two wonderful blog posts by Tim Urban at “Wait But Why,” and also Richard Dawkins’ “The Ancestor’s Tale.” According to Tim Urban we each have (n-1)2dnd d-th cousins, where n is about 2.