Ecology 5th Edition by Manuel Molles

Exercise 1

Ecological succession has been compared to the development of an organism and the climax community to a kind of super-organism. F. E. Clements (1916, 1936) was the best-known pro­ponent of this idea, and H. A. Gleason (1926, 1939) the best-known early opponent of the idea of a community as a kind of superorganism. Gleason proposed that species are distributed independently of each other and that most overlaps in distrib­utions are the result of coincidence, not mutual interdepen­dence. Most modern ecologists hold a view more similar to that of Gleason. Which of the following graphs showing hypothet­ical distributions of species along an environmental gradient supports the superorganismic view of communities? How does the other graph support the individualistic view of species held by Gleason? ( A , B, C, and D represent the distributions of species along an environmental gradient.)