Thomas Malthus greatly influenced Charles Darwin.
Charles Darwin was influence by Thomas Malthus's idea that the population of organism shouldn´t grow indefinitely but only up to a level that can be supported by the available resources. Darwin applied that theory to all the species so that he introduced Malthus's thoughts into the concept of survival of fittest.
Thomas Robert Malthus was an English cleric and scholar, influential in the fields of political economy and demography.