A Family Tree of the Entire Human Race

A.J. Jacobs
A.J. Jacobs / A.J. Jacobs

Some of my relatives are pretty impressive. There’s my cousin Albert, who was an expert on gravity and untamed hairstyles. There’s Gwyneth, another cousin and a fine actress, even if she did popularize the unfortunate phrase “conscious uncoupling.” And of course there are also some black sheep, like my cousin Jeffrey Dahmer, the serial killer. But let’s not dwell on him.

If it sounds as if I’m boasting, well, I’m not. As it turns out, you have these very same relatives. (Yes, you.) In fact, you may be on my family tree already. And if you’re not, I am going to do my darnedest to include you.

I’m one of thousands of researchers tackling the biggest challenge in the history of ancestry: We are building a family tree of the entire human race. All seven billion members.

It’s an incredibly ambitious project, requiring countless hours online, billions of obscure records, and unprecedented numbers of DNA tests. And frankly, we’ve got a long way to go. But at least we’ve made a dent: Currently, the world family tree includes some 77 million people in all seven continents (including Antarctica). That’s 77 million people on a single tree, all connected by blood or marriage or (sometimes) both. Which makes for the longest branches in human history. Paltrow is 17 steps from me. Einstein is 21. President Obama is my aunt’s fifth great-aunt’s husband’s father’s wife’s seventh great-nephew. Practically my older brother!

Twenty years ago, we wouldn’t have been able to conceive of this megatree. Back then, in order to build your tree, you had to schlep to, say, a Cleveland courthouse or write oft-ignored letters to distant relatives. Then along came the Internet and the Wikipedia model. Several sites—including WikiTree and Geni (which is owned by MyHeritage)—have revolutionized the field with a collaborative, crowdsourced approach to family-tree planting.

So how does it work, exactly? You start small with a family sampling, entering the details you know. If the “A.J. Jacobs” on your tree matches the “A.J. Jacobs” on somebody else’s tree, then you are given the option to combine them. With a click, your tree can double. Repeat this a few times and you will eventually be linked to a worldwide family tree. (Geni’s Big Tree is 77 million, and WikiTree’s is 7 million).

“It’s much easier to collaborate instead of working on your own,” says Gilad Japhet, the CEO of MyHeritage and Geni. “Imagine a million people solving a single multibillion-piece jigsaw puzzle instead of everyone solving their own separate puzzles. In a decade or less, I believe we’ll have a single tree that will include most of the people living on earth.”

Before we get there, we’ve got obstacles to overcome. One big challenge is accuracy. If you’ve got thousands of collaborators, what’s to stop one from changing the tree so that Jimi Hendrix is the son of Chester A. Arthur? Luckily, a core of volunteer experts (they call themselves forest rangers) is trying to verify the connections and make sure they’re well-documented. But this remains an area of dispute, especially the further you go back. (Some branches claim to go back to Biblical times, which requires more leaps of faith than I’m willing to make.)

There’s also the privacy issue. Some traditional genealogists don’t like that family names are out in the open. Instances of sabotage have even occurred, where profiles are deleted and branches cut. Geni and WikiTree do obscure the names of living persons, but privacy continues to be a flash point for modern genealogists.

Some skeptics have asked why we should care about identifying all these branches of our family trees. “This sounds like a nightmare,” one friend told me. “I have enough trouble with the relatives I have already. I don’t want millions more.”

I understand his point, but here’s why I think the mega-tree will be world-changing, assuming we can pull it off. First: the scientific value. A team of MIT scientists is studying the Geni world family tree to see how populations migrate and how diseases are passed down, which will help pinpoint genes and cures. In fact, it’s already yielding insights into the heritability of longevity. Second, and I know this sounds idealistic, but my collaborators and I believe it might make the world a kinder place. Yes, families don’t always get along (I have three sons, and I’ve seen how they wrestle). But overall, humans are biased to treat family members with more consideration.

I’ve witnessed this while making my own tree. To take an admittedly trivial example, I’d always considered tennis player John McEnroe an obnoxious, overgrown brat. But when I figured out how I was related to him, my perception shifted. Maybe he’s not so bad! It’s probably just a shtick.

By revealing how the cliché of “We’re all one big family” is true, we hope to provide bad news to bigots, who will have to face the important fact that they are closely related to whatever ethnic group they despise. The Aryan Nations might not be ready to group hug the NAACP, but perhaps this project will bring them a tad more empathy.

I also think it will be democratizing. Some ancestral research can have an elitist tinge, as in “I’m descended from Mary, Queen of Scots, and you’re not, so you can’t join my golf club.” Now, we can see how everyone is linked to royalty, even those, like me, whose great-grandfathers grew up in a Ukrainian shtetl.

For my kids, this is an astoundingly fun way to learn about history. When they realized they were related to John Adams (just 27 links!), he was not just a dead white guy. He was (dead) Uncle John, and they wanted to know what he did as president.

We have another powerful tool besides the Internet to help us build the world family tree: DNA testing. There are now several consumer genetic services, such as 23andMe and FamilyTree DNA. You buy a kit, spit in a tube, send it off, and a few weeks later you receive a list of hundreds of fellow spitters who share enough DNA to qualify as cousins: information that can be integrated into the Big Tree.

I found some interesting new cousins through 23andMe, including ... my wife, who was listed as a “distant cousin.” She didn’t like the “cousin” part but was relieved by the adjective “distant.”

It shouldn’t be surprising, though. Geneticists say that we are all descended from the same male and female. Their nicknames are Mitochondrial Eve and Y Chromosome Adam, and they lived 100,000 to 300,000 years ago. We all have a bit of their DNA. They are our great-great-great- (just keep repeating that about 5000 times) grandparents.

Some geneticists say our most recent common ancestor is far more contemporary than that. MIT computer scientist David Rohde argued in the journal Nature that a shared ancestor for all humans lived about 5000 years ago, thanks in part to increasing intermarriage. Which means that the vast majority of humans are probably, at most, 100th cousins by blood.

When I discovered I had 77 million relatives, I asked myself: What can I do with this information?

Attend the Global Family Reunion!

And that’s when I decided to undertake another challenge: throwing a colossal party. I’m organizing the Global Family Reunion, which will be, I hope, the biggest and most remarkable family reunion in history. I’ve already chosen the date and venue: June 6, 2015, on the grounds of the 1964 World’s Fair in New York. You are invited. In fact, every member of the human family is invited. Those with a proven connection to me will get a special bracelet and be part of the recordbreaking family photo.

The current Guinness record for a family reunion is 4515, held by the Porteau-Boileve family from France. They took the title away from the Lilly family of West Virginia, whose 2005 reunion had 2514 people.

Frankly, I’m overwhelmed. This is a massive task with plenty of pitfalls. Arranging to have Sister Sledge sing “We Are Family” is just one of the organizational hurdles I must leap. And what if the reunion sets off an epic family feud? (I can trace a link to both Mia Farrow and Woody Allen, so if, by some small chance, I can get them both there ...). How can I get enough people to come? When I email distant cousins, I sometimes get replies like “Is this some sort of Nigerian scam?” Also, where should I draw the line? One cousin wrote me that bananas share 50 percent of their DNA with humans, so you could argue bananas are cousins. To which I say, yes, bring bananas to the reunion!

Luckily, I’ve also gotten huge support. I’m working with WikiTree and Geni, who have both introduced tools that allow you to figure out your connection.

And I’ve been traveling the country recruiting cousins and drumming up support as well. I recently flew to Houston to tell President George H.W. Bush that he was my cousin by 18 steps—and that he’s also linked to Bill Clinton by 12 steps. The latter made him happy. “We’ve always thought of President Clinton as a son from another mother,” Mrs. Bush told me. Those are just the sort of connections I’m looking to make, so if you’re free in June 2015, I hope you’ll join me in overcoming this challenge. You kind of have to. You’re family.

If you want to figure out how you're related to everyone on earth, go to GlobalFamilyReunion.com.