> Pre-civilization there was a very strict limit on human populations based on the natural resources they could extract via labor. Anybody who didn't work starv

> Pre-civilization there was a very strict limit on human populations based on the natural resources they could extract via labor. Anybody who didn't work starved in short order. Labor is a product of civilization. Hunter-gatherer lifestyle was much less labor intensive than the agrarian lifestyle that followed. Instead of doing the hard work of making the land produce more than it naturally did, hunter-gatherers harvested whatever was naturally available. In a sense, a hunter-gatherer tribe was like a pre-industrial army. Its size was primarily limited by the amount of food it could steal from the surrounding lands.