
Description:If a population of microbes grows on a constantpressure source, it increases exponentially. But the death rate is also increased because of more interactions and crowding, so the population levels off. When the deaths equal the births, the population reaches a steady state. Examples: 

Variables:E = constantpressure energy sourceQ = stored quantity (population) K1 = increasing factor K4 = decreasing factor Equations:DQ = K1*E*Q  K4*Q*QSimulation:The graph shows the changes of Q over a time period.Source code: Logistic.java 

"What if" Experiments:Think about a population of mice: 