Men lived in small tribes for most of human history, hunting and gathering. As long as that produced sufficient levels of food, there was no incentive to acquire food by the very, very hard work of agriculture. This is the low hanging fruit principle, i.e., we just take what is easiest first and leave the rest for later. Why would a species trade lives of relative leisure for lives of long hours of drudgery when it was not necessary? Look at other species that primarily live by hunting. They lounge around and sleep much of the time, hunting only when the time is ripe and their bellies demand to be fed.
The human population has until the last 400 years grown at a very low rate. Whenever the beginning, whether it was 1.7 million years ago or just 1 million years ago, it took 99.9% that time for the world population to reach the 3/4 of a billion 400 years ago.
Agriculture began about 10,000 years ago, which made it possible to support larger populations. Had it been invented earlier, the rate of population growth would have increased earlier. Had the way to extract and use fossil fuels been discovered earlier than 400 years ago, the exponential, unsustainable explosion in population would have happened earlier.
"Bend over and grab your ankles" should be etched in stone at the entrance to every government building and every government office.
Want DP delivered to your inbox daily? Subscribe here: