This program lets you play with some basic ecology models. The included models are exponential and logistic growth, lotka-volterra competition between two species, lotka- volterra predator-prey, a four species lotka-volterra type system, and a predator / two competing prey system. The last of these is done in a separate program with a different interface. For all the others, you can change the parameters associated with each model using a novel but intuitive control on the screen. As each model runs, PopDyn shows the population sizes in one window, and a phase-portrait in a second window. The lines are color-coded for the different species, and in addition there are cute icons of each species which draw the curves. There are several options for controlling the look of the graphs, the speed and so on. You can also make parameters in the models change stochastically over time. The accompanying manual includes some exercises for students to do with the program.

This is a very nice portrayal of these basic ecology models. The program is very visually appealing and easy to use, with lots of cute pictures and rudimentary but effective online help. There are a few features missing that would be nice, such as being able to scroll and change the scales on the graphs, and the ability to print. A more substantial missing feature is the ability to change the initial population sizes. But these are minor complaints, and will not bother most students. This program should be very well suited for use in an introductory ecology class where the included models are introduced to the students, especially for students without the math background to understand the equations analytically.

Computer: Macintosh

Source: Ron J. Etter,
Biology Department,
University of Massachusetts,
100 Morrissey Blvd.,
Boston, MA 02125.
Phone: 617 -287-6613,
email: etter@umbsky.cc.umb.edu

Cost: Free

Last update 22nd of January 1996