Population dynamics is the study of marginal and long-term changes in the numbers, individual weights and age composition of individuals in one or several populations, and biological and environmental processes influencing those changes.
Population dynamics is the dominant branch of mathematical biology, which has a history of more than 200 years. The early period was dominated by demographic studies such as the work of Benjamin Gompertz and Pierre François Verhulst in the early 19th century, who refined and adjusted the Malthusian demograhical model.
A more general model formulation was proposed by F.J. Richards in 1959, by which the models of Gompertz, Verhulst and also Ludwig von Bertalanffy are covered as special cases of the general formulation. The computer game SimCity tries to simulate some of these population dynamics. Population dynamics also attempts to study topics such as aging populations or population decline.