I. THE NATURAL, EARLY POSTGLACIAL ENVIRONMENT
The elements of the physical geography of the Near East and the Middle East are characterized by considerable regional diversity and colour no less rich and varied than the present cultures and peoples of this area. Whether we contrast the warm, parched plains of the Libyan Desert with the cool, foggy slopes of the high Caucasus, or the humid, fertile tract of riverain Mesopotamia with the bleak shores of the northern Caspian, the manifold variations in the natural environment are ever obvious. In the course of millennia races of diverse religions and cultures have modified the physical landscape of plain and mountain, steppe and forest, impressing upon it the features of a cultural landscape. This new pattern has in places obscured the basic physical features; elsewhere it has emphasized more vividly the preexisting distinctions and distributions.
The Near and Middle East presented a somewhat different aspect in pre-Neolithic times from that of today. Topography and landforms, it is true to say, have not changed perceptibly, but vegetation and soils have suffered severely at the hand of man. Forests have given way to fields, or have been reduced to barren scrub by fuel-gatherers and browsing goats. Extensive grasslands have been ploughed up or impoverished by overgrazing. Desolate steppe or the few isolated pines or oaks preserved in a Muslim cemetery may be the only evidence of a once luxuriant forest. These are changes due to the intervention of man. Climatic changes have also taken place which, by reason of their effect on the composition and character of natural vegetation, have significantly modified conditions of human habitation.
The following sketch of the major physical aspects of the natural environment before the advent of villages and farming communities, of towns and cities, must necessarily be incomplete; it need not, however, be either speculative or hypothetical. Prehistoric geography is essentially a physical science founded on factual evidence which is provided by such studies as geology, geography, botany, zoology, meteorology and archaeology, no attempt will be made to discuss or evaluate here the various methods of research and classes of evidence employed.
Topography and terrain are fundamental factors in biological distribution. The Eurasian and the Afrasian steppes, the broad intervening expanse of mountain systems and the intermontane valleys or plateaux constitute three zones of climatic and biological phenomena.