Population dynamics is the branch of life sciences that studies the size and age composition of populations as dynamic systems

Population dynamics is the branch of life sciences that studies the size and age composition of populations as dynamic systems, and the biological and environmental processes that drive them (such as birth and death rates, and immigration and emigration). The example scenarios are the aging of the population, the growth of the population or the decline of the population.
Population dynamics have traditionally been the dominant branch of mathematical biology, which has a history of more than 210 years, although more recently the reach of mathematical biology has greatly expanded. The first principle of population dynamics is widely regarded as the exponential law of Malthus, according to Malthus’s growth model