July 3 (UPI) -- The preference for a maize-centric diet by Mayan elites may have left the ancient civilization more vulnerable to climate change, according to new research.
To better understand the relationship between diet and the collapse of the Maya civilization, researchers analyzed the remains of 50 Maya people from burial sites surrounding an ancient Maya city in Belize. The oldest remains were dated to the Middle Preclassic period, between 735 and 400 B.C., while the youngest remains were dated to the Terminal Classic, between 800 and 850 A.D.
To decipher the dietary habits of the Maya people, scientists analyzed the carbon and nitrogen isotope values in preserved bone collagen. The findings showed the youngest remains had higher levels of carbon isotopes from a group of plants that includes the Maya staple crop maize. The concentration was highest among the remains of elite members of the Maya civilization.
Isotope rations among the remains of both elites and commoners from the Middle Preclassic period revealed a diverse diet. Over time, however, maize became more popular among elites.
As the Maya population grew and social stratification intensified, a dichotomy in eating habits developed during the Terminal Classic period. The remains of people living farther from the city center had lower levels of maize-derived carbon in their bones. People living in the city ate more maize, researchers found.
"Our results show a pattern of highly restricted stable nitrogen and carbon isotopes for elite individuals in the Late and Terminal Classic, which corresponds to a hyper-specialized maize-based diet that persisted through the final abandonment of the site," Claire Ebert, a paleontologist and geochemist at Pennsylvania State University, said in a news release.
Ebert and her colleagues suggest the agricultural practices of the Maya civilization shifted to meet the demands of city elites. Intensified monoculture practices made the civilization less able to adapt to periods of drought and other types of climatic stress.
"Population expansion and anthropogenic environment degradation from agricultural intensification, coupled with socially conditioned food preferences, resulted in a less flexible and less resilient system," Ebert said.
Researchers published their findings this week in the journal Current Anthropology.
"The study speaks to the importance of diet in the resilience and decline of ancient societies and contributes to our understanding of vulnerability to climate change among modern traditional farming communities as well as industrialized nations," Ebert said.