Who’s Your Daddy?

“It’s All Relative:

Adventures Up and Down the World’s Family Tree”

A.J. Jacobs

Simon and Schuster, $27

A decade ago there was no point even considering researching your roots if you weren’t prepared to spend days, months, or potentially years trawling through dusty registers and reels of microfilm. But now, people just sit at their kitchen table on an otherwise unexceptional weekday morning and drool saliva into a test tube.

During the Winter Olympics last week, a commercial for 23 and Me, a consumer genetic testing company, came on promoting its home-based saliva collection kit to help you discover if, as the commercial said, you possess “the DNA of a champion.”

According to ABC News, genealogy is the second most popular hobby in the United States after gardening, and the second most visited category of websites, after pornography. It’s a billion-dollar industry that has spawned profitable websites, television shows, scores of books, and a cottage industry in DNA ancestry testing, including apps for people who not only want to learn more about their DNA, but to keep interacting with it. 

Now, a new book: “It’s All Relative: Adventures Up and Down the World’s Family Tree,” by A.J. Jacobs, which confirms that the beguiling promise of all this ancestry hunting is not so much to have scientific proof of your genetic heritage, but instead to construct a narrative for yourself that is more interesting than the one you’ve got. Or, at the very least, to identify in the family tree a strain of talent you can claim heir to, even if only at a molecular level. 

Even the author agrees: “Genealogy is the most self-aggrandizing hobby ever. Look at all these thousands of ancestors who all teamed up to create their ultimate masterpiece: Me!”

Mr. Jacobs, whose parents have a house in East Hampton, is a talented writer, an editor at large of Esquire magazine, and the author of other humorous “quest” books such as “Drop Dead Healthy: One Man’s Humble Quest for Bodily Perfection” and “The Year of Living Biblically: One Man’s Humble Quest to Follow the Bible as Literally as Possible.” 

“It’s All Relative” follows his rather neurotic journey from becoming piqued by the family chain to attempting to throw a Global Family Reunion for over 3,000 relatives, which, if successful, would make it into the Guinness Book of Records.

“Relatives” are, in fact, relative. Apparently, Barack Obama is his fifth great-aunt’s husband’s father’s wife’s seventh great-nephew. He’s 13 steps away from Einstein, 24 from Halle Berry. Daniel Radcliffe is a cousin and so is his wife. The point is that we’re all related. But that also makes every one of us special, which ultimately means none of us are.

Mr. Jacobs gave himself 51 weeks to plan the mega-reunion and, although there’s a countdown report at the end of each chapter reminding us of the event, most of the book delves into an array of related topics like our animal cousins — we share 98.8 percent of DNA with bonobos — Ellis Island, Neanderthals, surnames, alternative families, inbreeding, and more — all told in offhanded humor that The New York Times described as “often-effortful wit.”

But humor is also relative, and while this reader was mostly unmoved by his effortful attempts to be self-deprecating and snappy, his loyal fans, who have turned him into a best-selling author, will surely appreciate this book too. And if not, at least his family will. All seven billion of them.

The strength of Mr. Jacobs’s storytelling is his anecdotal sharing, but only when he allows the reader to enjoy the inherent comedy in the situation presented rather than interjecting his attempts at amusing commentary. 

One of my favorites is toward the end of the book, about 15 weeks away from the reunion, when the author is frantically trying to recruit celebrity “cousins” to help market the big bash and, he hopes, bring in sponsors. So far, he’s got the likes of Donny Osmond (Mormons are big into genealogy), Ricky Gervais, Olivia Wilde, and Dr. Oz to hold up signs that read, “I Am a Cousin.” But he decides to go even bigger and hops on a plane to Houston to meet with the older President Bush and his wife, Barbara, whom Mr. Jacobs had interviewed a few years ago for Esquire.

“There’s the president, sitting in a wheelchair, wearing a blazer, khakis, and pink-and-yellow argyle socks. Mrs. Bush and her Maltese dog are by his side.”

“I explain to them why I’m here. ‘I’m helping to put together a family tree of all seven billion humans. And you’re on this tree. Because you’re humans.’ ”

“ ‘Well, thank you,’ the former first lady says dryly. ‘That’s very flattering.’ ”

“I tell them how we are related. ‘I thought we were more closely related than that,’ says the president . . . I tell them about some of their distant cousins, including Bill Clinton, who is President Bush’s 10th cousin once removed.”

“ ‘I always felt that Bill Clinton was my son from another mother, so I suppose that makes sense.’ ”

And then, President and Mrs. Bush held up his “I Am a Cousin” sign and smiled for the camera.

The Global Family Reunion took place on June 5, 2015, at the New York Hall of Science in Queens. It never made it into the record books. Too bad all that energy and time had not been harnessed for something more altruistic.