At a time when the Stone Age gripped Europe and the Sumerians ruled Mesopotamia, a group of people half a world away built a city whose remains are about to rewrite a key chapter in the history of the New World.
Archaeologists in Peru's Supe Valley have found evidence that pushes back by a thousand years the emergence of complex urban societies in the Americas.
Researchers have been studying the site - known as Caral - on and off for years. More-systematic work began in 1996. But only recently have scientists been able to precisely date material unearthed from the site's apartments, public structures, and enormous ceremonial mounds.
The new dates indicate that Caral's structures were built during a 693-year period from 2670 BC to 1977 BC. Previous work had attributed such "monumental" architecture in the New World to societies dating back no further than about 1,500 years BC.
"Our findings show that a very large, complex society had arisen on the coast of Peru centuries earlier than anyone thought," says Jonathan Haas, curator of anthropology at the Field Museum of Natural History in Chicago and one of the team conducting the study. "What we're learning from Caral is going to rewrite the way we think about the development of early Andean civilization."
By the standards of its day, Caral was enormous. Its central area covers 160 acres and contains six large, flat-topped platform mounds. The largest measures roughly 500 feet on each side and rises 60 feet. The smallest of the six is still larger than any third-millennium mound found elsewhere in the Andes, the researchers say. Caral may include another 110 acres of mainly residential structures, although this "suburb" may prove to be a separate site.
Even at 160 acres, Caral is as large as any other site in the world during the third millennium, except Sumeria, Dr. Haas says. Indeed, he adds, one can see cultural threads emerging from the Supe Valley that ultimately lead to the emergence of the Inca empire to the south and the Moche and Chimu empires to the north.
Moreover, the site is exceptionally well-preserved because it falls in a time period before pottery was developed in the region. No pots, Hass says, means no looting.
Caral's founders built it on a terrace of land above the Supe River, which winds down from the Andes through a narrow, arid valley and empties into the Pacific Ocean some 13 miles downstream of the city.
Moving away from the sea
The location is critical to unraveling the city's role, researchers say, because the only previously-known third-millennium sites along Peru's coast have been near-shore settlements that appear to have relied exclusively on the sea for food.
Indeed, it was all early Americans could rely on as they moved into the area, because the coastline from Ecuador to northern Chile is desert.
"You've got the juxtaposition of the desert with the New World's richest fishing grounds," says University of Florida anthropologist Michael Moseley. The newcomers "had to get their calories from the sea." These groups engaged in some agriculture, experts say, but their crops typically were "for industrial use only."
"Crops were grown for cordage for nets and lines and for containers and floats," says Clark Erickson, associate curator at the University of Pennsylvania'a Museum of Archaeology and Anthropology in Philadelphia. That meant cultivating cotton and gourds, along with some spices.
By contrast, Caral's ancient trash heaps have yielded foods such as squash and beans, as well as industrial crops such as cotton. Crops relied on irrigation from the river. Yet the city also retained links to the coast, since fish remained the residents' major source of protein.
Caral, along with 17 similar, smaller sites in the valley, appears to mark a transition from communities that relied on sea-based harvests to those built around irrigated agriculture, according to the research team, which was led by Ruth Shady Solis, with the Museum of Archaeology at the Universidad Nacional Mayor de San Marcos in Lima, Peru.
Highly organized - but how?
The researchers also note that to build an irrigation system as well as Caral's monumental structures, the society must have been highly organized.
The question is: What form did that organization take?
"So far, we have not found evidence of kings or dynasties in the archaeological record," says Penn's Dr. Erickson. The lack of gaudy baubles at burial sites suggests that these were simple folk.
Yet if there was no dynastic hierarchy, he continues, there could have been a political hierarchy similar to IBM's: The management jobs are there; people just rotate through them. "It's a form of government the Spanish found when they arrived in the 16th century," Erickson says.
Building huge mounds or irrigation canals may have been akin to mandatory public service, or perhaps a form of tax that substitutes time for tithes.
As Dr. Solis and her team continue to probe Caral, Haas says he expects more stunning revelations. Already, he says, "it's clear Peru's central coast was very precocious."
(c) Copyright 2001. The Christian Science Monitor