In addition to differentiation of language, there is differentiation of physique. When we in the United States think of the Indian, we think of a tall man with high cheekbones, a hawk-nose, and a bronze-red skin. Actually the American Indian is probably more varied in height, face, and color than the whole White racial stock.[7] More than that, his somatic constitution—the inner man in a physical sense—varies greatly. By 1492 the Indian had adapted himself to eight different climates from arctic to tropic, from arid to humid, from sea level to the 14,000-foot heights of Peru. This would take time, much time. Albrecht Penck, the great European glacialist, thinks 25,000 years hardly long enough.[8]
The civilizations which the Indian developed in the Americas—the Maya, Aztec, and Inca cultures—provide another test of how long man had been in the New World before Columbus came. This test is no more exact than those we have already mentioned, but it suggests quite a long sojourn.
While the physical man was adapting himself to all manner of climates, the mental man dragged himself up from the hunting life of the Old Stone Age to the invention of writing and the perfecting of an accurate calendar. On the way—and as slow, necessary steps in his progress—he developed agriculture, and invented or perfected the arts and crafts of pottery, weaving, dyeing, metallurgy, sculpture, poetry, painting, architecture, city planning. In his agriculture he utilized irrigation, discovered fertilizers, and developed a great many exclusively American plants which now supply more than half of the world’s provender. He was probably the first to write numbers effectively through the use of zero and numerical position. He practiced trepanning—the removal of a piece of skull bone to relieve pressure on the brain—and he discovered how to use certain medicines and narcotics. In his textiles he employed all the weaves known to us today. He contrived efficient methods of government. He proliferated into 368 major tribal groups, and developed fifteen culture centers of distinct individuality.[9] In the United States he left 100,000 mounds as the product of one of his cultures; in Middle America, 4,000 ceremonial cities of stone. He practiced most types of religion except atheism. Certain things that he made resemble things of the Old World; most are peculiar to him and his life. Of Indian culture traits Clark Wissler remarks that “the range in variety and individuality seems even greater in aboriginal America than in the primitive Old World.”[10]