National Geographic : 1955 Dec
Long before, beyond the seas, the human race apparently had developed from creatures like the ape men of Java and southern Africa to the intellectual and cultural level of the pioneers of civilization. By the time primi tive hunters were spreading over the Americas, men in Europe, Asia, and Africa may have been approaching the earliest stages of agri culture.* Meanwhile, impassable seas separated man from North and South America. He came at last out of northern Asia, perhaps a goalless wanderer, perhaps pushed on by population pressures across Bering Strait to Alaska, the nearest thing to a bridge between the Old and New Worlds.t The possibility that the migrants could have passed dry-footed over such a causeway rests on the geologists' estimate that vast amounts of water were locked in glaciers, lowering the sea level 200 or 300 feet. Even today, Bering Strait can be crossed on waters not more than 150 feet deep. If man came later, after the glaciers re treated, he may have crossed on the ice in winter; it can still be done. The longest distance between the mainland and interven ing islands is little more than 25 miles. The firstcomers brought with them weap- ons, a fact that shows they had developed a considerable degree of skill. The weapons en abled them to pursue and slay some of the fiercest and most powerful animals the world has ever known. Before these earliest immi grants, however, lay a vast, terrifying, and unknown wilderness of ice-covered mountains. For generations many of the wanderers doubt less stayed close to the hospitable sea, which provided much of their food. Nomads Inched Slowly Southward But occasional groups must have ventured inland. Then they moved eastward and north ward, drifting through the mountain passes and river valleys which opened before them, always following the game. Eventually a few may have reached the Arctic coast, perhaps somewhere in the neighborhood of present-day Point Barrow, where traces of ancient camps and weapons have been found. To understand their next move, one should recall that great ice sheets lay over the north ern half of North America when man first entered the continent. These glacial sheets * See Everyday Life in Ancient Times, published by the National Geographic Society, 1951. t See "Exploring Frozen Fragments of American History," by Henry B. Collins, Jr., NATIONAL GEO GRAPHIC MAGAZINE, May, 1939.