For better or worse, Homo sapiens has become the most abundant large mammal ever to roam the planet. We have spread into nearly every conceivable terrestrial habitat. We have increased our fertility and decreased our mortality. We have reengineered ecosystems and food webs and disinterred fossil stores to produce our calories and condition our dwellings. We are seven billion strong, growing at a rate of 70 million people a year.
As E.O. Wilson, both an entomologist and a conservationist, put it, “When Homo sapiens passed the six-billion mark we had already exceeded by perhaps as much as 100 times the biomass [i.e., the mass of the living organism] of any large animal species that ever existed on the land.” He was talking about wild animals. We are only about five times more numerous and probably a little less massive than our livestock—herded, fattened, and medically dosed just for us. Or, as David Quammen puts it in his masterful new book Spillover: Animal Infections and the Next Human Pandemic: we are an “outbreak,” a species that has undergone a “vast, sudden population increase.” “And here’s the thing about outbreaks,” warns Quammen: “They end…. In some cases they end gradually, in other cases they end with a crash.”
If this sounds alarming, it’s meant to. Undergirding his book’s structure, and right there in the subtitle, is the prospect of another major pandemic, what he and various epidemiologists he has consulted call the Next Big One. What will cause it? Most likely, a virus. What kind of virus? A brand new one, or new, at least, to humans. It will likely be a coronavirus. These, like HIV, have genes written in RNA, not DNA. This means it will be quickly mutating and elusive to treat. Where will it come from? Another animal. When a virus from an animal host “spills over” onto us, this is called zoonosis. Quammen estimates that roughly 60 percent of human infectious diseases have originated with animals, including Lyme disease, West Nile fever, the bubonic plague, and all influenzas. Zoonosis is “a word of the future,” he writes, “destined for heavy use in the twenty-first century.”
This insight, of course, is not really new for anyone who has read such books as Laurie Garrett’s The Coming Plague (1994) or Richard Preston’s The Hot Zone (1994) or seen Steven Soderbergh’s film Contagion (2011), in which a virus found in pigs and bats rapidly spreads around the world. Peter Heller’s 2012 novel The Dog Stars takes place after an influenza strain has killed 99.9 percent of humanity. In the films 28 Days Later (2002) and I Am Legend (2007), a rabies-like infection has turned the civilized world into the eaters and the eaten, plus a small band of survivors.
The problem with…
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