forms of political organization have in fact prevailed for all of the prehistory and much of human history and civilization. The primary competing organizational forms to the state were religious organizations (such as the Church), and city republics. Since the late 19th century, virtually the entirety of the world's inhabitable land has been parcelled up into areas with more or less definite borders claimed by various states. Earlier, quite large land areas had been either unclaimed or uninhabited, or inhabited by nomadic peoples who were not organised as states. However, even within present-day states there are vast areas of wilderness, like the Amazon rainforest, which are uninhabited or inhabited solely or mostly by indigenous people (and some of them remain uncontacted). Also, there are so-called "failed states" which do not hold de facto control over all of their claimed territory or where this control is challenged. Currently the international community comprises around 200 sovereign states, the vast majority of which are represented in the United Nations. Pre-historic stateless societies For most of human history, people have lived in stateless societies, characterized by a lack of concentrated authority, and the absence of large inequalities in economic and political power. The anthropologist Tim Ingold writes: Neolithic period During the Neolithic period, human societies underwent major cultural and economic changes, including the development of agriculture, the formation of sedentary societies and fixed settlements, increasing population densities, and the use of pottery and more complex tools. Sedentary agriculture led to the development of property rights, domestication of plants and animals, and larger family sizes. It also provided the basis for the centralized state form by producing a large surplus of food, which created a more complex division of labor by enabling people to specialize in tasks other than food production. Early states were characterized by highly stratified societies, with a privileged and wealthy ruling class that was subordinate to a monarch. The ruling classes began to differentiate themselves through forms of architecture and other cultural practices that were different from those of the subordinate laboring classes. In the past, it was suggested that the centralized state was developed to administer large public works systems (such as irrigation systems) and to regulate complex economies. However, modern archaeological and anthropological evidence does not support this thesis, pointing to the existence of several non-stratified and politically decentralized complex societies. Ancient Eurasia Mesopotamia is generally considered to be