Competition for Resources Among Consumers
In the previous chapter, we examined the mechanics of growth of populations. In nature, these rates of population growth very often vary. If r varies randomly, a population may become extinct or, alternatively, suffer enormous increases in abundance, since the reproductive potential of any species is capable of producing very large numbers of new individuals. Since few environments are completely overwhelmed by the species with highest growth rates, there must be mechanisms that inhibit increase in abundance as density increases. This, in brief, is the theory behind the description of population growth, known as the logistic equation, first suggested by P. F. Verhulst in 1838 and later derived independently by R. Pearl and L. J. Reed in 1920.