Consider how time lags can cause population cycles.
Logistic growth is ageneral model in that the basic pattern fits many species fairly well.
For particular species, it can be modified to make it more accurate. We will consider two ways of doing this in today's lecture. First, we will consider time lags. For example, maybe the birthrate in a population depends on the population size when individuals got pregnant, and there is a gestation period so that the growth that depends on this occurs at some time later. The kind of lag we will focus on is in resourse response to population size.