Covid-19 is not the only story right now, but it’s so big that it threatens to push everything else aside. And there are a million ways of seeing it, touching upon it, suffering it, writing about it. Since my own book-in-progress (on cancer as an evolutionary phenomenon) is one thing that’s been pushed aside, I’m now spending all my time on the pandemic story too. I’ve committed to do a book on the subject for Simon & Schuster, over the next two years, and meanwhile have been offering thoughts, and trying to offer perspective, in some shorter pieces, such as these:

An article in The New Yorker, May 11, 2020:
An OpEd in The New York Times, January 28, 2020:



Twenty-five years ago, I got interested in Ebola virus from reading a few articles and books. Twenty years ago, while walking through a certain Central African forest, on assignment for National Geographic, I recognized that the mysteries of Ebola fall into the category of ecology and evolutionary biology. Where did the virus live—in what animal, what reservoir host—when it wasn’t killing people? Ecology. How did it pass from that animal into its first human victim? Ecology. How did it adapt to transmission among humans? Evolution. Since ecology and evolutionary biology were my wheelhouse topics, I became very curious about the dynamics of Ebola and, more broadly, about the entire subject of scary viruses that emerge from animals and take hold in people.

coronavirus200Those viruses fall into a category called zoonoses—meaning animal infections transmissible to humans. In 2007 I wrote about zoonoses, again for National Geographic. Soon after that, I began work toward a book on the subject, and that book was published in 2012 as Spillover: Animal Infections and the Next Human Pandemic. It was a decent publishing success—good reviews, one week on the Times bestseller list—but it came and went. Eight years later, journalists and other people from around the world have rediscovered the book and been asking me: How did you predict the pandemic of COVID-19?

Of course I didn’t predict this pandemic. What I did was listen to the right scientists, travel with some of them to hunt for dangerous viruses, then describe their work and their thinking, as they predicted this pandemic.

What follows below is my original descriptive introduction to Spillover, from 2012. On the right, under “The Latest,” is my update. And to you readers: Stay safe, stay sane, ask for evidence.


Spillover cover250The next big and murderous human pandemic, the one that kills us in millions, will be caused by a new disease--new to humans, anyway.  The bug that's responsible will be strange, unfamiliar, but it won't come from outer space.  Odds are that the killer pathogen--most likely a virus--will spill over into humans from a nonhuman animal.

Spillover is a work of science reporting, history, and travel, tracking this subject around the world.  For five years, I shadowed scientists into the field--a rooftop in Bangladesh, a forest in the Congo, a Chinese rat farm, a suburban woodland in Duchess County, New York-and through their high-biosecurity laboratories.  I interviewed survivors and gathered stories of the dead.  I found surprises in the latest research, alarm among public health officials, and deep concern in the eyes of researchers. I tried hard to deliver the science, the history, the mystery, and the human anguish as page-turning drama.

From what innocent creature, in what remote landscape, will the Next Big One emerge?  A rodent in southern China?  A monkey in West Africa?  A bat in Malaysia that happens to roost above a pig farm, from which hogs are exported to Singapore?  In this age of speedy travel between dense human populations, an emerging disease can go global in hours.  But where and how will it start?  Recent outbreaks offer some guidance, and so I traced the origins of Ebola, Marburg, SARS, avian influenza, Lyme disease, and other bizarre cases of spillover, including the grim, unexpected story of how AIDS began from a single Cameroonian chimpanzee.

The subject raises urgent questions.  Are these events independent misfortunes, or linked?  Are they merely happening to us, or are we somehow causing them?  What can be done?   But this book is intended to be more than a work of reportage.  It's also the tale of a quest, through time and landscape, for a new understanding of how the world works.


franzJosephLand2Quammen makes his way across a basaltic scree field in Franz Joseph Land in the Russian Arctic. Read his blog post about the 2013 Pristine Seas Expedition sponsored by National Geographic. Photograph by Andy Mann.

David Quammen is an author and journalist whose books include The Song of the Dodo (1996), The Reluctant Mr. Darwin (2006), and  Spillover (2014), a work on the science, history, and human impacts of emerging diseases (especially viral diseases), which was short-listed for eight national and international awards and won three.  His shorter books Ebola  (2014) and  The Chimp and the River(2015) were drawn from Spillover, each with a new introduction. His forthcoming book (August 2018) is The Tangled Tree: A Radical New History of Life, which explores the drastic revisions in understanding of life’s history on Earth forced by recent discoveries from genome sequencing, and the story of a scientist named Carl Woese. In the past thirty years Quammen has also published a few hundred pieces of short nonfiction—feature articles, essays, columns—in magazines such as Harper’s, National Geographic, Outside, Esquire, The Atlantic, Powder, and Rolling Stone.  He writes occasional Op Eds for The New York Times and reviews for The New York Times Book Review.  Quammen has been honored with an Academy Award from the American Academy of Arts and Letters, and is a three-time recipient of the National Magazine Award.  He is a Contributing Writer for National Geographic, in whose service he travels often, usually to wild and remote places.  Home is Bozeman, Montana.

Throughout the rest of this website, he will not refer to himself in the third person.






On November 3, 1977, the front page of the New York Times carried an article announcing the discovery of a “third kingdom” of living creatures, entirely distinct from the two kingdoms (bacteria and everything else) thought to exist until that time. Above the article was a photo of a man, seated before a blackboard in a lab at the University of Illinois, with his feet up on a cluttered desk. He was wearing Adidas. His name was Carl R. Woese. He had just triggered a revolution that would change how science understands the history of evolution on Earth.

Woese redrew the tree of life, and it has never been the same.

The “tree of life” was an old phrase, an old idea, going back to the Bible and other sources, but Charles Darwin in The Origin of Species (1859) turned it into the iconic image of evolutionary history. Life arose from a single source, like the trunk of a great oak, and diverged into limbs, branches, smaller branches, and twigs, representing the divergence of lineages through time and the origin of species. Modern genetics later affirmed that image, with the canonical assumption that heredity passes downward from ancestors to offspring (or upward, in the tree image) and never sideways from one limb to another. It turns out that assumption was wrong. Genetic sequencing and comparison of genomes, of the sort pioneered by Woese, has revealed the unimagined phenomenon of sideways inheritance.

Scientists have given this phenomenon some fancy names. One is horizontal gene transfer. Another, slightly more suggestive, is infective heredity. In some cases, these genes travel sideways—from creature to creature, even from species to species—by viral infection. That’s supposed to be impossible. Woese’s successors have shown that it’s not just possible—it’s widespread and vastly consequential.

Carl Woese died in December 2012, just before I picked up this thread about horizontal gene transfer and the radically revised history of life. So I never met him. It’s probably just as well: He was famously gruff and unfriendly to journalists and other nosy writers. But for the past five years I’ve studied him and his work and the revolution he triggered—studied them through the evidence of his publications, his archives at the University of Illinois, and the testimony of his students, his colleagues, his assistants, his friends, many of whom I’ve interviewed. He became my Citizen Kane, and I functioned like the faceless newsreel reporter in the movie, visiting everyone to ask: “Who was Charles Foster Kane, and why did he say ‘Rosebud’ with his dying breath?” (If that reference rings no bells, do yourself a favor and watch Orson Welles’s great film.) What I found was a tangled story, a tangled man, and a new tree of life that is not a tree.

The implications of this Woesean revolution involve more than our understanding of life’s history for the past four billion years. They also challenge some of our most immediate and personal assumptions: What is a species, what is an individual, what is a human? What am I?

The Tangled Tree was published by Simon & Schuster on August 14.  Order now:

Barnes & Noble
Simon & Schuster





Yellowstone: A Journey Through
America's Wild Heart

The Chimp and the River



The Reluctant Mr. Darwin

Monster of God

The Song of the Dodo


Natural Acts

The Boilerplate Rhino

Wild Thoughts from Wild Places

The Flight of the Iguana


Blood Line

The Soul of Viktor Tronko

The Zolta Configuration

To Walk the Line


On the Origin of Species

by Charles Darwin

The Illustrated Edition

The Best American Science

and Nature Writing 2000

Edited with Burkhard Bilger