Rise of Ancient Peruvian Civilization Was Powered by Agriculture

de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception

A new research by an international team of archaeologists provides convincing evidence that the earliest civilization of South America relied heavily on agriculture – specifically the large-scale production of maize (Zea mays).

Zea mays (Franz Eugen Köhler)

For decades, researchers have debated whether the people who lived on or near the Pacific coast of Peru during the Late Archaic period (3000-1800 BC). subsisted primarily on fish or whether maize was cultivated and used as a regular part of their diets.
The new study, published in the Proceedings of the National Academy of Sciences, uses microscopic evidence from pollen records, coprolites and stone-tool residues to demonstrate that maize was widely grown, intensively processed and constituted a primary component of the early Peruvians’ diet.
“This new body of evidence demonstrates quite clearly that the very earliest emergence of civilization in South America was indeed based on agriculture as in the other great civilizations of Mesopotamia, Egypt, India, and China,” said study lead author Dr Jonathan Haas of the Field Museum.
The team focused on sites in the desert valleys of Pativilca and Fortaleza north of Lima where broad botanical evidence pointed to the extensive production, processing and consumption of maize. They studied a total of 13 sites. The two most extensively studied sites were Caballete and the site of Huaricanga.
The archaeologists targeted several areas at the sites including residences, trash pits, ceremonial rooms, and campsites. A total of 212 radiocarbon dates were obtained in the course of all the excavations. Macroscopic remains of maize (kernels, leaves, stalks, and cobs) were rare.
However, the team looked deeper and found an abundance of microscopic evidence of maize in various forms in the excavations. One of the clearest markers was the abundance of maize pollen in the prehistoric soil samples. While maize is grown in the area today, they were able to rule out modern day contamination because modern maize pollen grains are larger and turn dark red when stain is applied. Also, modern soil samples consistently contain pollen from the Australian Pine (Casuarinaceae Casuarina), a plant which is an invasive species from Australia never found in prehistoric samples.
Of the 126 soil samples analyzed, 61 contained Z. mays pollen. This is consistent with the percentage of maize pollen found in pollen analyses from sites in other parts of the world where maize is a major crop and constitutes the primary source of calories in the diet.
The team also analyzed residues on stone tools used for cutting, scraping, pounding, and grinding. The tools were examined for evidence of plant residues, particularly starch grains and phytoliths (plant silica bodies). Of the 14 stone tools analyzed, 11 had maize starch grains on the working surfaces and two had maize phytoliths.
The researchers concluded that the prevalence of maize in multiple contexts and in multiple sites indicates this domesticated food crop was grown widely in the area and constituted a major portion of the local diet, and it was not used just on ceremonial occasions. The study ultimately confirms the importance of agriculture in providing a strong economic base for the rise of complex, centralized societies in the emergence of the world’s civilizations.