In Chapter III ("Struggle for Existence") of The Origin of Species Charles Darwin offers a violent metaphor for the constant strife between creatures, the deadly competition that prevents exponential growth for any one species:

In looking at Nature, it is most necessary to keep the foregoing considerations always in mind — never to forget that every single organic being around us may be said to be striving to the utmost to increase in numbers; that each lives by a struggle at some period of its life; that heavy destruction inevitably falls either on the young or old, during each generation or at recurrent intervals. Lighten any check, mitigate the destruction ever so little, and the number of the species will almost instantaneously increase to any amount. The face of Nature may be compared to a yielding surface, with ten thousand sharp wedges packed close together and driven inwards by incessant blows, sometimes one wedge being struck, and then another with greater force.

TopicScience - TopicLiterature - 2006-09-01

(correlates: DarwinOnTheStruggleForExistence, WeHappyFew, HopefulRejoinders, ...)