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
Bronze Age other metals available at the time, allowing Bronze Age civilizations to gain a technological advantage. Copper-tin ores are rare, as reflected in the fact that there were no tin bronzes in Western Asia before trading in bronze began in the third millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition. Although the Iron Age generally followed the Bronze Age, in some areas (such as Sub-Saharan Africa), the Iron Age intruded directly on the Neolithic. Bronze Age cultures differed in their development of the first writing. According to archaeological evidence, cultures in