The “unparalleled” discovery of dozens of ancient human skeletal remains found in a Central American rock shelter is helping piece together the life histories of North America’s earliest inhabitants, including their transition from hunter-gatherers to sedentary farmers who dined primarily on maize.
Maize, or corn, is one of the most important plants domesticated in human history with more than 1 billion tons estimated for production this year, according to the World Agricultural Production. Until now, little was known about when humans living in Central America transitioned to agricultural producers that helped pave the way for major human settlements seen today.
To determine how Central Americans adapted over time to changing environments and lifestyles, researchers spent five years of fieldwork in two “very remote” rock shelters located in the Maya Mountains of Belize – a two-day walk from the nearest road – home to 52 male, female, and child skeletons laid to rest between 1,000 and 9,600 years ago. The Ocampo Caves are one of the only burial sites in the Neotropics that have been repeatedly used for 10,000 years, providing a unique window into the lives of those buried here.
Different foods have different isotopes, which are influenced by ingested nutrients, and leave an imprint on their host. Carbon isotopes found in the bones and teeth of the individuals were measured in the individuals in order to test for the consumption of maize.
Maize was less than 30 percent of people’s diets in the region 4,700 years ago and yet 700 years later, it accounted for 70 percent. The oldest remains showed evidence of eating wild plants, palms, fruits, and nuts found in tropical forests and savannahs as well as meat from land-based animals. Then 4,700 years ago, diets became more diverse when some individuals began eating maize, with evidence suggesting an increase in consumption over the next 1,000 years as the population shifted to become more sedentary farmers.
"Today, much of the popularity of maize has to do with its high carbohydrate and protein value in animal feed and sugar content which makes it the preferred ingredient of many processed foods including sugary drinks,” said the University of New Mexico Anthropology professor Keith Prufer in a statement. “Traditionally it has also been used as fermented drink in Mesoamerica. Given its humble beginnings 9,000 years ago in Mexico, understanding how it came to be the most dominant plant in the world benefits from deciphering what attracted people to this crop to begin with. Our paper is the first direct measure of the adoption of maize as a dietary staple in humans.”
Around 9,600 years ago, researchers believe that maize was domesticated from a Central Mexican wild grass known as teosinte. Evidence suggests that its stalk juice may have been in the Maya lowlands 6,500 years ago and may have been used for an early form of liquor. The spread of agricultural maize production across the Americas is linked to the spread of distinct cultures, technologies, and languages as people were able to stay in one place for longer periods of time. Additionally, maize was considered a central part of life in Mayan civilization and likely set the beginning stages for humanity as we know it today.