What are the effects of population growth?

Proponents of this theory indicate that every time food production is intensified to feed a growing population, the population responds by increasing even more. Some human populations throughout history support this theory, as consistent population growth began with the Neolithic Revolution, followed by subsequent agricultural revolutions, and thus food supply began consistently increasing and continues to do so in the present. This can be observed in cultural contexts, as populations of hunter-gatherers fluctuate in accordance with the amount of available food and are significantly smaller than populations of agriculturalists, who increase the amount of food available by putting more land under agriculture.