Alan A. Berryman, "The Theory and Classification of Outbreaks," in Pedro Barbosa and Jack C. Schultz, edd., Insect Outbreaks
(New York: Academic Press, 1987), quoted by David Quammen, Wild Thoughts from Wild Places
(New York: Scribner, 1998), p.120:
From the ecological point of view an outbreak can be defined as an explosive increase in the abundance of a particular species that occurs over a relatively short period of time. From this perspective, the most serious outbreak on the planet earth is that of the species Homo sapiens.