In the preceding chapter we have traced the physical and cultural evolution of the hominids from their emergence in East Africa to their penetration of the frigid tundra of Siberia. We have thus brought man to the very threshold of the New World.

You may recall that, as early as 1590, Fray Jose de Acosta suggested that the ancestors of the American Indians had come from northern Asia. Today, there is virtually unanimous support for this theory among anthropologists. However, the date of the arrival of the earliest Asian immigrants remains a matter of heated dispute. The most convincing evidence for the Asian origin of the Native Americans comes not from archaeology but from physical anthropology and geology.

THE EVIDENCE OF PHYSICAL ANTHROPOLOGY

When we compare Native Americans with the other living races of mankind, we find them to be most similar to the Mongoloid peoples of Asia. Among the visible physical characteristics that these groups share are coarse, straight black hair, relatively hairless faces and bodies, light brown skin, brown eyes, epicanthic eye folds (only occasionally present in American populations), high cheekbones, and a high frequency of shovel-shaped incisor teeth. Both in Asia and the Americas, infants sometimes develop a purplish discoloration of the lower back, known as a “Mongoloid spot.” The distribution patterns of invisible, genetically determined traits offer less clear-cut evidence of relationship. In the Americas, blood type O is predominant; in South and Central American populations, no other blood type exists.