New evidence strengthens the argument that maize played an important role in ancient Peruvian civilisation 5,000 years ago. Samples taken from pollen records, stone tool residues and fossilised faeces suggest the food crop was actively grown, processed and eaten, adding weight to the theory that Andean society was agricultural.
     Study co-author Jonathan Haas from The Field Museum, Chicago, says "If you look at the origins of civilisations around the world - from Egypt to China and India - they are all based on agriculture."  Dr Haas said that the pollen record gathered from the study sites was unequalled, with the data being accessed by other scientists in their research projects.
     Other artefacts the team examined included 14 stone tools used for cutting, scraping, pounding, and grinding, which were radiocarbon-dated to between 2090 and 2540 BCE. "Eleven of the 14 tools had predominantly or exclusively maize starch grains on the working surfaces, and two working surfaces had maize phytoliths (mineral excretions by the plant)."
     The researchers also found samples of sweet potato and bean starch grains, and recovered 62 coprolites (fossilised faeces), of which 34 were human specimens. 68% of the specimens contained maize starch grains, the dominant source of starch in the diet at that time.
     Dr Haas observed: "Maritime resources were important as it was their primary source of protein. But in each one of those coprolites, there was, on average, half an anchovy - that is not your diet, that is a condiment. In contrast, finding corn, beans, sweet potato and a number of other things in the diet - that is an agriculturally-based society." He added that a vibrant agriculture system would result in a surplus of food, allowing the societal leaders to attract outsiders to the area and exert power.
     The team wrote: "It was during this time that large permanent communities were settled, monumental architecture first appeared on the landscape, agriculture was more fully developed and indicators of a distinctive Andean religion are manifest in the archaeological record."

Edited from Popular Archaeology (25 February 2013), BBC News (26 February 2013)