Our knowledge of the first appearance of Greeks in Asia Minor has undergone radical revision in recent years. Their prehistoric culture can be traced as far back as the Neolithic. The chief interest of modern discovery centers around the now accepted fact that Greek culture originally invaded the region from the south and that the Indo-European element which brought Aryan speech to the land is a later wave which flooded the original Mediterranean stock at some time during the transition from the Age of Bronze to that of Iron.[215] The southwestern coast was first colonized. A northerly extension occurred thence and proceeded mainly along the coast.[216] The sequence of geological events preceding man’s appearance upon the Ægean coast of Asia had imparted features which were destined to favor human development to an exceptional degree. A land-bridge connecting the Balkan and Anatolian peninsulas occupied the site of the Ægean Sea at the dawn of quaternary times. The subsidence of the land during this period was accompanied by heavy fracturing trending in east-west lines. The Ægean archipelago, studded with islands and surrounded by deeply indented coasts, conveys a vivid picture, on the map, of the crustal deformity which occurred. Climate also conferred its share of advantages. The long and narrow valleys are sheltered by mountains on all sides except to seaward. Northerly air currents cannot reach them. Frosts or snows are therefore unusual.[217] The course of moisture-laden winds blowing landward from the seas that wash the three coasts of Asia Minor is arrested by the mountainous rim of the peninsula. Precipitation is almost entirely expended upon the narrow shore lands. Copious rainfall and flowing rivers thus provide this historic Anatolian fringe with patches of luxuriant vegetation and green valleys. The interior plateau, on the other hand, remains parched and barren during the summer months. A splendid stage for Greek history was thus built during the prehuman period. Early Mediterranean oncomers discovered sheltered havens and fertile inlets along the entire development of the fancifully dissected coast. A natural festoon of outlying islands increased their security by providing them with advanced posts for the detection of hostile raids. Erosion along the parallel lines of east-west rifts had carved fair valleys in which the winding rivers of classical literature found a channel. But above all, the sea contributed commerce and cosmopolitanism, both great elements of world power. These in turn favored the growth of tolerance,--a trait which has ever marked the western mind and which, at that particular spot, was to constitute a bastion destined to remain impregnable to the opposing spirit of the east.[218] [Illustration: _The American Geographical Society of New York_ _Frontiers of Language and Nationality in Europe, 1917, Pl. VII_ PART OF ASIATIC TURKEY SHOWING DISTRIBUTION OF PEOPLES]