DNA Study Sheds New Light On The Ancient Teotihuacans

Conny Waters - AncientPages.com - One of the most intriguing archaeological pre-Columbian sites is Teotihuacán, which scientists still know relatively little about. Who were the people who built and lived in Teotihuacán?

Established in the northeastern Basin of Mexico, Teotihuacán "was first inhabited in about 150 BC, but the first ceremonial buildings were constructed in the 1^st and 2^nd centuries AD. It is believed that Teotihuacán, most probably the largest city in the New World, had about 150,000 – 200,000 inhabitants at its height." ¹

Teotihuacan was once a very powerful Mesoamerican city. Credit: Adobe Stock - Dmitry Rukhlenko

Teotihuacan was one of the largest metropolitan centers in ancient Mesoamerica in the pre-Columbian era. The ancient city flourished the most in the fourth century AD, exerting a significant cultural influence throughout Mesoamerica.

In a new study, researchers led by Dr. Fuzuki Mizuno at the Toho University School of Medicine have examined six ancient individuals unearthed from the Teotihuacan between the third and seventh centuries AD.

Scientists have determined the entire mitochondrial DNA sequences of these ancient Teotihuacans, revealing their genetic diversity. Additionally, this study demonstrates the dependence of Teotihuacans on maize as their primary food source.

In studying ancient societies, DNA analysis of individuals excavated from archaeological sites has provided critical insights into the lives of those who lived there. However, the success of ancient DNA analysis is highly dependent on preserving the DNA samples. The Teotihuacan region is not favorable for preserving ancient DNA because of the climate, highly fluctuating temperature and humidity, and the properties of volcanic ash soil.

In the analysis of stable isotope ratios (δ13C and δ15N), the six ancient samples from Teotihuacan were mapped to an area indicating the intake of stable isotopes through a staple maze diet. Black circles represent Teotihuacans. Green, Blue, and Orange indicate pre-maize, transitional maize, and staple maize diets, respectively. Reference data for stable isotope analysis of ancient Mesoamericans were obtained from Kennett et al. (2020). Credit: Dr. Fuzuki Mizuno

Therefore, there have been few studies of ancient DNA in this area. Recent developments in next-generation sequencing and technical advances in molecular biology have revolutionized the analysis of ancient DNA. In this study, Dr. Mizuno and colleagues employed this state-of-the-art technology to investigate the Teotihuacan society and its genetic origins.

The research team extracted mitochondrial DNA from the human remains newly unearthed from civilian dwelling areas at the Teotihuacan site, dated to 250–636 cal AD (calibrated AD). They employed target enrichment-coupled next-generation sequencing to successfully determine the entire mitochondrial genome (mitogenome).

The individuals belonged to haplogroups A2, B2, or D1, which are representative haplogroups of present-day Native Americans. Haplogroup A2 was the most common, followed by B2 and D1, a trend similar to that reported in the Central Mesoamerican group. Based on the mitochondrial DNA sequence data, the six individuals were further classified into more specific haplogroups: A2f2, A2ae, A2d1, A2d1, B2c1, and D1i.

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