This document summarizes key concepts in population ecology, including factors that influence population size and distribution patterns. Populations can exhibit clumping, uniform, or random dispersion patterns depending on resource availability and other factors. A population's size is determined by the balance between birth and death rates, which are influenced by biotic potential and environmental resistance. Humans can impact ecosystems through activities like habitat degradation and overharvesting. Sustainable practices can be informed by principles seen in nature, such as nutrient recycling and population control.