Red Queen Simulator

Damuth, John. 2007. A macroevolutionary explanation for energy equivalence in the scaling of body size and population density. The American Naturalist, vol. 169, pp. 621-631.

Abstract: Across a wide array of animal species mean population densities decline with species body mass such that the rate of energy-use of local populations is approximately independent of body size. This “energetic equivalence” is particularly evident when ecological population densities are plotted across several or more orders of magnitude in body mass, and is supported by a considerable body of evidence. Nevertheless, interpretation of the data has remained controversial, largely because of the difficulty of explaining the origin and maintenance of such a size-abundance relationship in terms of purely ecological processes. Here I describe results of a simulation model suggesting that an extremely simple mechanism operating over evolutionary time can explain the major features of the empirical data. The model specifies only the size scaling of metabolism and a process where randomly-chosen species evolve to take resource energy from other species. This process of energy exchange among particular species is distinct from a random walk of species abundances and creates a situation in which species populations using relatively low amounts of energy at any body size have an elevated extinction risk. Selective extinction of such species rapidly drives size-abundance allometry in faunas towards approximate energetic equivalence, and maintains it there.

       If you are interested in the Red Queen Simulator we strongly urge you to read the full version of this article, or at least the basic Scientific Notes. Otherwise, you'll have a hard time figuring out what the application is doing!

       If you cannot obtain a copy of the above article, contact John Damuth at this address.