If you turn the clock forward to the point at which this equilibrium has been reached, you will find that the number of species that will survive human habitat destruction is a simple percentage of the amount of habitat we leave undisturbed, a 1:1 correspondence. For example, if we take 50 percent of the land in the United States for our own use, we will end up with 50 percent of the species that originally inhabited this country. If we usurp 80 percent of the land, we will lose 80 percent of the species.
