Roughly 9,000 years ago, humans had mastered farming to the point where food was plentiful. Populations boomed, and people began moving into large settlements full of thousands of people. And then, abruptly, these proto-cities were abandoned for millennia. It's one of the greatest mysteries of early human civilization. The dawn of the age of agriculture falls during the "Neolithic," also known as the late stone age. At that time, about 12,000 years ago, people had already developed incredibly sophisticated stone tools, weapons, and clay vessels for cooking and storage. And when they found seeds that grew into particularly delicious plants, they took them along on their treks, planting them in river valleys on their route, so that they would have a tasty harvest the following year. Earth Shots: Must-See Planet Pics Once these informal farms had gotten a little bigger, it started to seem less advantageous to keep roaming when there was so much food in one place. In the Levant area along the eastern Mediterranean, nomadic groups who had once lived by hunting and gathering began settling down in small villages for part of the year. The Rise and Fall of the Mega-Village As people accumulated more food stores, women began giving birth to more children. Nomadic groups of 20 or 30 people became villages of 200. And some of those villages, like Çatalhöyük in the region today known as central Turkey, grew to a few thousand people. It's hard to say what, exactly, Çatalhöyük was. Was it a city or just some kind of bizarre, outsized village? We know it lasted for millennia, with thousands of people living there continuously from about 7500 BCE to 5700 BCE. Perhaps we might say that was the closest thing to a city in the Neolithic, since hundreds more people lived there than in typical villages nearby. But it had none of the features we associate with the grand, walled cities that emerged thousands of years later in Africa, Asia and the Middle East. There were no palaces, no massive ziggurats or pyramids dedicated to the gods, and no signs of class distinction. Every family had a small, slightly rectangular one-room home with a hearth. Each home was roughly the same size. Streets didn't exist in Çatalhöyük — homes were erected next to each other, honeycomb-style, and people just walked over each other's roofs to get home through doors in their ceilings. Though there was art, there was no writing. And there was little in the way of specialized labor. Unlike in ancient Uruk or Mohenjo-Daro, there were no cottage industries in bead-making or weapons production. Families lived by hunting, but mostly by keeping farms and small herds of animals like goats in the nearby hills. PHOTOS: Gourmet Astronauts: Favorite Space Food Maybe Çatalhöyük didn't look much like cities as we know them, but it and other mega-sites were the most developed forms of settlement anywhere in the world at that time. They were the urban developments of their age, sheltering huge populations and fostering technological progress like cooking with dairy and making fired pottery (both were major high tech inventions in the Neolithic). Here's where things get weird. In the mid-5000s BCE, Çatalhöyük was suddenly abandoned. The same thing happened to several other outsized village-cities in the Levant. Their populations drained away, and people returned to small village life for thousands of years. Below, you can see a graph showing how the size of settlements dropped dramatically about 7,000 years ago (5000 BCE). Even more mysterious is the fact that we see a similar pattern — intensification of farming, booming population, growing settlements, and abandonment — elsewhere in the world. Farming came later to Western Europe and England, so we see this cycle starting roughly 5,000 years ago (around 3,000 BCE) in many European regions and in England. What happened? http://news.discovery.com/human/life/how-farming-almost-destroyed-ancient-human-civilization-141118.htm#mkcpgn=rssnws1