"An epic, hilarious, and heartfelt adventure into the idea of family--where it begins and how far it goes--and what it has to tell us about our biology and our genetics, our tribes and our traditions, and our history and our future. A.J. Jacobs has received some strange emails over the years, but this note was perhaps the strangest: "You don't know me, but my wife is your eighth cousin. And we have over 80,000 relatives of yours in our database." That's enough family members to fill Madison Square Garden four times over. Who are these people, A.J. wondered, and how do I find them? So began Jacobs's three-year adventure along the branches of the world's family tree. Spanning both the globe and the genome, Jacobs's quest joyously upends what we think about when we think about family. He drinks beer with a U.S. president. He visits Salt Lake City--and the genealogical database of the Mormon Church (where, every year, more data is added than is contained in the entire Library of Congress). He meets scientists and computer programmers working to chart and understand the world's genetic links. He attempts to convene the biggest family reunion in recorded history. He contemplates black sheep and bad apples. He unearths his own genealogical connections to Hollywood actresses, Civil War soldiers, and real-life scoundrels. Ultimately, this extraordinary book is a profound exploration of the realms of what binds us all. "We are family" Sister Sledge famously sang. This book proves it." -- From the dust jacket flap.

Introduction -- The eighth cousin -- The world family tree -- DNA sharing is caring -- A great (or possibly terrible) idea -- A pandemonium of genealogists -- Historical voyeurism -- Genetic jambalaya -- Groundhog Sam and my 2,585 southern cousins -- Embracing failure -- Should family be abolished? -- The good cousin -- Adam and Eve -- Kissing cousins -- The Greatest Generation (and the upside of cigarettes) -- Thank you for having sex -- Biological and logical families -- Ellis Island -- Our Neanderthal cousins -- Family feuds -- Who's your father? -- Son-in-law of the American Revolution -- The mega-tree revolution -- Our animal cousins -- Big love -- The other side of the dash -- Privacy -- The genius of Isaac Newton -- Fathers and sons -- Twins and twins. Also more twins -- Five mothers -- Black sheep -- My presidential cousin -- Tradition! -- The Kevin Bacon delusion -- The pilgrimage -- An ocean of cousins -- Cheers to the dead -- My celebrity cousins -- 51 percent of the family tree -- The melting pot -- The FBI and my grandpa -- The great surname challenge -- Awkward family photos -- Brother versus brother -- The global family reunion -- We are, without a doubt, irrefutably, family -- A brief and subjective guide to getting started on your family tree.