Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment.
It is the study of how the population sizes of species living together in groups change over time and space. A population is a group of individuals of one species living in one area who have the ability of interbreeding and interacting with each other.
The size of human population and its impact are now among Earth's most significant problems. With a population of more than 6 billion individuals, our species requires vast amounts of materials and space, including places to live, land to grow our food, and places to dump our waste. By rapidly expanding our presence on Earth, we have devastated the environment for many other species and now threaten to make it unfit for ourselves.
To understand human population growth, we must consider the general principles of population ecology. Population ecology is the study of populations in relation to the environment, including environmental influences on population density and distribution, age structure, and variations in population size.