Thomas Malthus made significant contributions to the study of population dynamics through his theories on population growth and resources. In his work, *An Essay on the Principle of Population*, he posited that populations grow exponentially while resources grow arithmetically, leading to potential crises. Malthus argued that without checks such as famine, disease, and war, overpopulation would result in societal collapse. His ideas have influenced fields like economics, environmental science, and demography, prompting discussions about sustainable development and resource management that remain relevant today.