Educational Model: Allen’s Rule

This model is a component of the IUMC (Innovative Educational and Methodological Complex) "Ecology: Constructing the Biosphere", developed in 2008 by D. A. Shabanov, A. G. Kozlenko, and M. A. Kravchenko by order of the NTFP (National Training Foundation) of the Russian Federation (more about this project is in the article "Innovation and Reality"; reasons why this complex is not used are briefly described in the column "Textbooks: Straight into the Day After Tomorrow"). This model is posted here for educational use. The model explains the zoogeographic Allen’s rule. The theoretical material related to the model is in the section "Clinal Variability and Some Ecological Rules" of the manual "Ecology: Biology of Interactions." A similar model covers Bergmann’s rule. Allen’s rule shows the dependence between habitat conditions and the relative size of protruding body parts in homeothermic organisms. The mathematical model allows estimating the ratio of heat production to heat loss and concluding which organism more effectively maintains constant body temperature under low-temperature conditions. Instructions for working with the model are located at the bottom of its window; if they do not fit, they can be scrolled with the arrows on the right. The first page explains the essence of Allen’s rule. Investigate the mathematical model by choosing two animals for comparison. Compare their body surface areas and volumes; use the gridded figures shown in the corresponding model windows for calculations. Using the volume-to-surface-area ratio (proportional to the heat-production/heat-loss ratio), choose which organism is better adapted to low-temperature conditions.