This activity will allow students to develop a model of the mathematical nature of population growth. The investigation provides an excellent opportunity for consideration of the population growth of plant and animal species and the resultant stresses that contribute to natural selection. Students will discover that populations grow or decline through the combined effects of births and deaths and through emigration and immigration into specific areas, increase through linear or exponential growth, with effects on resource use and on environmental pollution, and reach limits to growth. They will realize that carrying capacity is limited and although living organisms have the capacity to produce populations of arbitrarily large size, environments and resources are finite and this fundamental tension has profound effects on the interactions between organisms. This site has a list of materials and all other information required to complete this activity.