Impact of agriculture
The impact of agriculture has been profound on humanity, most clearly in terms of population. This is because breeding plants and animals has significantly increased the availability of human consumable calories per square kilometer. One way to think about it is that we replaced things that weren’t consumable by humans with things that were. Through techniques like irrigation, we were also able to make things grow where they might not have before.To put this in perspective, before the agricultural revolution experts estimate that there were six to ten million people, which is about how many hunter-foragers the Earth could sustain. By the time of the Roman Empire, about 10,000 years later, the world population had grown over 25-fold to 250 million. Fast forward 2000 years to the present, and the population has grown another 28-fold to seven billion. In roughly 10,000 to 15,000 years, advances in agriculture have allowed the human population to become roughly 1000 times larger!