You can’t fight off Ebola the way you fight off a cold. Ebola does in ten days what it takes AIDS ten years to accomplish.

Occasionally they came to villages, and at each village they encountered a roadblock of fallen trees. Having had centuries of experience with the smallpox virus, the village elders had instituted their own methods for controlling the virus, according to their received wisdom, which was to cut their villages off from the world, to protect their people from a raging plague. It was reverse quarantine, an ancient practice in Africa, where a village bars itself from strangers during a time of disease, and drives away outsiders who appear. (94)

If equations are trains threading the landscape of numbers, then no train stops at pi.

Humans in space suits make monkeys nervous.

Once the cells in a biological machine stop working, it can never be started again. It goes into a cascade of decay, falling toward disorder and randomness. Except in the case of viruses. They can turn off and go dead. Then, if they come in contact with a living system, they switch on and multiply. (194)

The earth is attempting to rid itself of an infection by human parasite.

During climbs into taller trees, I was occasionally able to look down on the backs of birds, which shine with reflected sunlight as they move through the green depths of the canopy, like schools of fish.