Spillover: the powerful, prescient book that predicted the Covid-19 coronavirus pandemic.

by David Quammen

So we’re unique in the history of mammals. We’re unique in the history of vertebrates. 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. Our total weight amounts to about 750 billion pounds. Ants of all species add up to a greater total mass, krill do too, but not many other groups of organisms. And we are just one species of mammal, not a group. We’re big: big in body size, big in numbers, and big in collective weight. We’re so big, in fact, that the eminent biologist (and ant expert) Edward O. Wilson felt compelled to do some knowledgeable noodling on the matter. Wilson came up with this: “When Homo sapiens passed the six-billion mark2 we had already exceeded by perhaps as much as 100 times the biomass of any large animal species that ever existed on the land.”