Population dynamics

Population increase, stability, or decrease are expressions of social forces and human interaction with the environment. Children's social and economic role varies from class to class and presents potential parents with an inverse proportion quandary: an extra member of the group versus the financial difficulties involved in bringing up an extra child, with a lower impact if this latter is put to work young. Children are always the result of procreational decisions as unwanted pregnancies can be responded to with abortions, abandonment, or infanticide. In our species overall population trends are represented by three successive logistic curves. The first point at which the curve begins the logistic trend, raising population levels, is the shift from hunting and gathering to settled agriculture. The second point is the onset of the Industrial Revolution, namely the large\u2010scale use of fossil fuels, at the origin of modern exponential population growth