The Neolithic revolution led to people living in permanent or semi-permanent settlements. Because of this fewer people led a nomadic lifestyle. To be able to know who the crops grown belonged to, the concept of land ownership was developed. The natural environment was changed, population sizes grew, and people ate more vegetable and cereal foods in their diet. Hierarchies developed in society. Grain was stored, and could be traded. Surplus production from good crop yields helped societies survive bad years.