Neolithic Revolution as irrigation and deforestation which allowed the production of surplus food. Other developments found very widely are the domestication of animals, pottery, polished stone tools, and rectangular houses. These developments, sometimes called the Neolithic package, provided the basis for centralized administrations and political structures, hierarchical ideologies, depersonalized systems of knowledge (e.g. writing), densely populated settlements, specialization and division of labour, more trade, the development of non-portable art and architecture, and property ownership. The earliest known civilization developed in Sumer in southern Mesopotamia (); its emergence also heralded the beginning of the Bronze Age. The relationship of the above-mentioned Neolithic characteristics
Neolithic Europe and family trees with estimates of dating of splits, in particular theories on the relationship between speakers of Indo-European languages and Neolithic peoples. Some archaeologists believe that the expansion of Neolithic peoples from southwest Asia into Europe, marking the eclipse of Mesolithic culture, coincided with the introduction of Indo-European speakers, whereas other archaeologists and many linguists believe the Indo-European languages were introduced from the Pontic-Caspian steppe during the succeeding Bronze Age. Archeologists believe that food-producing societies first emerged in the Levantine region of southwest Asia at the close of the last glacial period around 12,000 BCE, and developed into a