Quotes from David Quammen

A high jeopardy of extinction comes with territory. Islands are where species go to die.

The Towner paper contained a very interesting statement, as an aside, concerning the five ebolaviruses: "Viruses of each species have genomes that are at least 30–40% divergent from one another, a level of diversity that presumably reflects differences in the ecologic niche they occupy and in their evolutionary history.

Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications." There's a nice word: ramifications. It's especially good in this context because, while the literal definition is "a structure formed of branches," from the Latin ramus, of course the looser definition is "implications." Darwin's tree certainly had implications.

An amplifier host is a creature in which a virus or other pathogen replicates—and from which it spews—with extraordinary abundance. Some aspect of the host's physiology, or its immune system, or its particular history of interaction with the bug, or who knows what, accounts for this especially hospitable role.

With influenza and many other diseases the order is reversed, high infectivity preceding symptoms by a matter of days. A perverse pattern: the danger, then the warning. That probably helped account for the scale of worldwide misery and death during the 1918–1919 influenza: high infectivity among cases before they experienced the most obvious and debilitating stages of illness.

Mad cow disease is caused by a prion, a weirdly folded protein molecule that triggers weird folding in other molecules, like Kurt Vonnegut's infectious form of water, ice-nine, in his great early novel Cat's Cradle.

Identifying the new virus was only step one in solving the immediate mystery of Hendra, let alone understanding the disease in a wider context. Step two would involve tracking that virus to its hiding place. Where did it exist when it wasn't killing horses and people? Step three would entail asking a further cluster of questions: How did the virus emerge from its secret refuge, and why here, and why now?

Advisory: If your husband catches an ebolavirus, give him food and water and love and maybe prayers but keep your distance, wait patiently, hope for the best-- and, if he dies, don't clean out his bowels by hand. Better to step back, blow a kiss, and burn the hut.

The first rule of a successful parasite? Myxoma's success in Australia suggests something different from that nugget of conventional wisdom I mentioned above. It's not Don't kill your host. It's Don't burn your bridges until after you've crossed them.

Will the Next Big One be caused by a virus? Will the Next Big One come out of a rainforest or a market in southern China? Will the Next Big One kill 30 or 40 million people?

A zoonosis is an animal infection transmissible to humans. There are more such diseases than you might expect. AIDS is one. Influenza is a whole category of others. Pondering them as a group tends to reaffirm the old Darwinian truth (the darkest of his truths, well known and persistently forgotten) that humanity is a kind of animal, inextricably connected with other animals: in origin and in descent, in sickness and in health.

The fossil record shows that no other species of large-bodied beast—above the size of an ant, say, or of an Antarctic krill—has ever achieved anything like such abundance as the abundance of humans on Earth right now.

When the Next Big One comes, we can guess, it will likely conform to the same perverse pattern, high infectivity preceding notable symptoms. That will help it to move through cities and airports like an angel of death.

Ecological disturbance causes diseases to emerge. Shake a tree, and things fall out.

It comes and it goes. But epidemiologists have recognized that, with measles virus, as with other pathogens, there's a critical minimum size of the host population, below which it can't persist indefinitely as an endemic, circulating infection. This is known as the critical community size (CCS), an important parameter in disease dynamics.

Each outbreak, by this view, represents a local event primarily explicable by a larger cause—the arrival of the wave. The main proponent of the wave idea is Peter D. Walsh, an American ecologist who has worked often in Central Africa and specializes in mathematical theory about ecological facts. "I think it's spreading from host to host in a reservoir host

Identity is such a crucial affair that one shouldn't rush into it

The downside was that hospital staff took the first big blasts of secondary infection; the upside was that those blasts generally weren't emitted by people still feeling healthy enough to ride a bus or a subway to work. This was an enormously consequential factor in the SARS episode—

Then there was a new epidemic—of fear," said Dr. Sam Okware, Commissioner of Health Services, when I visited him in Kampala a month later. Among Dr. Okware's other duties, he served as chairman of the national Ebola virus task force. "That was the most difficult to contain," he said. "There was a new epidemic—of panic.

Vast areas of old forest have been cut, or chained down with bulldozers, to make way for cattle ranching and urban sprawl. People have planted orchards, established urban parks, landscaped their yards with blossoming trees, and created other unintended enticements amid the cities and suburbs. 'So bats have decided that, as their native habitat is disappearing, as climate is becoming more variable, and their food source is becoming less diverse, it's easier to live in an urban area.

In some zoonotic pathogens, efficient transmissibility among humans seems to be inherent from the start, a sort of accidental preadaptedness for spreading through the human population, despite a long history of residence within some other host. SARS-CoV had it, from the earliest days of its 2002–2003 emergence in Guangdong and Hong Kong. SARS-CoV has it, no matter where or why SARS-CoV may be hiding since then.

Spillover" is the term used by disease ecologists (it has a different use for economists) to denote the moment when a pathogen passes from members of one species, as host, into members of another. It's a focused event.

As we besiege them, as we corner them, as we exterminate them and eat them, we're getting their diseases.

Humanity badly needs things that are big and fearsome and homicidally wild. Counterintuitive as it may seem, we need to preserve those few remaining beasts, places, and forces of nature capable of murdering us with sublime indifference.