First Step: Find A Solver And Play - I always start with Lotka-Volterra.

Predator-Prey - A Propos, Don’t You think?

It’s been a while, so don’t trust my parameters - just learning the software. Another day, another software package.

A Remarkable Tool For Assessing Your Level Of Ignorance, Especially With Respect To System Dynamics

This is a place holder, while I attempt to collect the data I need to model the toxicology lab rat populations from birth to death, to locate the most effective throttle points, to reduce animal use if I can.

There is a tendency, which comes from the physical sciences, I suspect, to think that a mathematical model has to accurately predict or describe the behavior of a system in order to be useful. I am not of this opinion. I consider the creation of the state diagram of the model to be a very valuable first step, followed by thoughts on the nature of key variables and how they are influenced by the parameters of the model. Take foxes and rabbits - clearly, as the fox population grows, rabbits will fall, until foxes begin starving, and on it goes. So, why is this simple model useful to a biologist? It makes you think - what value should we give to the birth or death rate of foxes, for instance. You have to consider all the things that permit foxes to proliferate and those that take foxes out of the equation. A little thought will soon make you realize that this is a highly complex situation, but you still need to insert values for ‘b’ and ‘d.’ So you approximate, and watch the behavior, and refine the model as you go along, each time understanding the limits of your understanding of the system dynamics a little better. For me, mathematical modeling of biological systems is about challenging my understanding - not accurate prediction!

“Essentially, all models are wrong, but some are useful.”