If such traits were diffused from one American area to the other, they left no trace between. When we add this to the fact that from Alaska to Middle America there are no traces of even the simplest beginnings of the cultures of the central area, the advocate of independent invention has a pretty good case. In answer, the diffusionist has been tempted to argue that when men are moving rather steadily across an area, they do not leave evidence that is easy to find some millenniums later. Only a hundred years have passed since Brigham Young led his people from Independence, Missouri, to Salt Lake City, and yet there is a singular paucity of spinning wheels and first editions of The Book of Mormon along their trail.
The Trap of Time
Gladwin has a better answer, which is also an attack on a basic weakness of his opponents. Through many years he has been pointing out that friends of the inventive Indian have been getting squeezed tighter and tighter in a trap of their own independent invention. It is the trap of time.
When the Spaniards found the New World, they found it full of inventions and discoveries. There were cities of stone, painted temples, great pyramids. Metal workers smelted ores, made alloys, and cast elaborate ornaments of gold by a most intricate process. There was a complex despotism in Mexico and as complex and despotic a communism in Peru. The Maya had a calendar more accurate than the one Columbus used. They had devised a hieroglyphic writing and knew how to make cement. The Indians of both continents had developed an extensive agriculture, with potatoes and fertilizers in Peru and corn and beans and tomatoes all over the place.
As soon as the archaeologists decided that all this had been invented in the New World with no help to speak of from the Old, they had to recognize that it would take quite a little time. At first this posed a difficulty, for there was no very early evidence of man in Mexico. In 1917, however, came the discovery of skeletons and pottery under a lava flow at Copilco near Mexico City and of a primitive pyramid half buried under the same flow at near-by Cuicuilco; and the archaeologists promptly dated the eruption of the lava at 4000 B.C.
Then, unfortunately, new evidence narrowed the trap of time once more. George C. Vaillant and his wife dated other sites with the same kind of pottery as Copilco considerably later than the birth of Christ. A radiocarbon date based upon charcoal within the pottery level below the Cuicuilco lava falls between these guesses; it is 2422 ± 250 years.[15] The Basket Makers advanced from an estimated 2000 B.C. to a tree-ring date about A.D. 217. And all this time nobody could find any really primitive beginnings of pottery in Middle America, and nothing that seemed earlier than the birth of Christ. The trap of time was growing tighter and tighter. A very elaborate civilization would have to develop in 1,500 years, without any roots. Gladwin pointed out this difficulty and urged the theory that man came into the Americas not only as a paleolithic primitive 15,000 or 25,000 years ago, but as a fairly civilized and perfected neolithic close to the beginning of the Christian era.
Escape from the Trap
The similarity between the traits of the north and the south which Nordenskiöld points out, and the fact that a different lot of traits were dropped in between the others are grist to Gladwin’s diffusion mill. In 1937, when he wrote Excavations at Snaketown, he was only beginning to see an answer. By 1947, when Men Out of Asia appeared, he had a fairly complete and certainly an ingenious explanation.
His first proposition is that the Mongoloids came late—very late—and that they brought not much more than the brawn and brains which someone else would later direct. His fifteenth chapter begins with the following parody of a baseball score:
Score at the End of the Fourth Inning