Origins of Agriculture and the Long-Term Social-Environmental Dynamics in the Tehuacan Valley, Puebla, Mexico

This ongoing research project explores the rich archaeological and environmental record within the Tehuacan Valley of southern Puebla, Mexico, today a UNESCO World Heritage Site. It address several key questions, including: Why did people first transition from hunting-and-gathering to farming ? How did human population levels change in response to environmental and cultural changes? How did changes in subsistence strategies influence social and political organizations?

Funding for this project has been provided by the National Science Foundation (#1901618), the Wenner-Gren Foundation (Gr. 9655), and the UCMEXUS Program.

Project collaborators include: Dr. Isabel Casar (UNAM-Mexico), Pedro Morales (UNAM-Mexico), Joaquin Arroyo-Cabrales (INAH-Mexico)


  • Somerville, Andrew D., Isabel Casar, Joaquin Arroyo-Cabrales (2021) New AMS radiocarbon ages from the Preceramic levels of Coxcatlan Cave, Puebla, Mexico: A Pleistocene occupation of the Tehuacan Valley? Latin American Antiquity Vol. 32(3).

Selected Press

  • Science News: “New clues suggest people reached the Americas around 30,000 years ago: Ancient bones from a Mexican rock-shelter point to humans arriving earlier than often assumed” by Bruce Bower
  • Popular Science: “Humans may have arrived in the Americas 15,000 years earlier than we thought: New animal bones discovered in Coxcatlan Cave may push back the arrival date, but the evidence is still unclear” by Philip Kiefer
  • Science Alert: “Shock Discovery Suggests Humans Were in The Americas 20,000 Years Earlier Than Thought” by Mike Mcrae

The Collapse of Early Urbanism in Central Mexico: Investigating the Classic to Epiclassic Transition at Teotihuacan

Located just north of modern day Mexico City, the ancient metropolis of Teotihuacan was home to approximately 100,000 residents between the years of AD 1-550. Late in the sixth century AD, the city experienced a rapid loss of population and much of the civic ceremonial center was burned. This new project, co-directed with Dr. Marion Forest, explores the factors associated with this rapid collapse of urbanism at Teotihuacan by focusing on the sub-site of Hacienda Metepec, a semi-peripheral neighborhood of Teotihuacan (see picture of the ruins of its central pyramid) that was occupied before and after this period of rapid social transformation.

Funding has been provided by the National Science Foundation (NSF # 2211663, Nature of State Instability), the French Ministry of Foreign Affairs , and Iowa State University and permission for new excavations have been provided by the Mexican government (Instituto Nacional de Antropología e Historia). Research is also being conducted in collaboration with the property owners of the site, the Reino Animal, a wildlife safari park zoo with an explicit mission to promote biodiversity, restoration, and sustainable agriculture.

Selected Press

  • Iowa State, Research News: “Iowa State search for clues may explain collapse of an ancient city in Mexico” by Rachel Cramer

Human-Animal Interactions in Ancient Mesoamerica: Studies of Breeding, Management, and Domestication

Through the use of stable isotope analysis and the study of recovered animal bones, this area of research explores the role and impact of human-animal relationships on the local environment, human nutrition, and social change. Investigated species include rabbits, hares, dogs, turkeys, and scarlet macaws.

Funding for this area of research has been provided by the National Science Foundation (NSF# 1262186), an NSF IGERT Fellowship (NSF# 0903551), the University of California, San Diego, Arizona State University, and Sigma Xi.

Project collaborators include Dr. Nawa Sugiyama (UC Riverside), Dr. Christopher Schwartz (ASU), Dr. Ben Nelson (ASU), Dr. Kelly Knudson (ASU), Dr. Margaret Schoeninger (UCSD), Dr. Linda Manzanilla (UNAM – Mexico), Dr. Cyler Conrad (UNM & Los Alamos national Laboratory)

Illustration on left by Nathan Thrailkill (from Somerville and Sugiyama 2021).


  • Conrad, Cyler and Andrew D. Somerville (in press) An isotopic perspective on turkey (Meleagris gallopavo spp.) management and domestication from archaeological contexts in North America. Exploring the History of Turkey Domestication and Management. Edited by A. Manin, C. Speller, E. Corona & E. Thornton. Muséum National d’Histoire Naturelle, Paris.
  • Somerville, Andrew D. and Nawa Sugiyama (2021) Why Were New World Rabbits Not Domesticated? Animal Frontiers Special issue: Animal domestications: from distant past to current development. Vol. 11(3): 62-68.
  • Schwartz, Christopher, Andrew D. Somerville, Ben A. Nelson, Kelly J. Knudson (2021) Investigating pre-Hispanic scarlet macaw keeping through radiogenic strontium isotope analysis at Paquimé in Chihuahua, Mexico. Journal of Anthropological Archaeology, 61: 101256.
  • Somerville, Andrew D., Nawa Sugiyama, Linda R. Manzanilla, Margaret J. Schoeninger (2017) Leporid management and specialized food production at Teotihuacan: stable isotope data from cottontail and jackrabbit bone collagen. Journal of Archaeological and Anthropological Sciences, 9(1) 83-97.
  • Somerville, Andrew D., Nawa Sugiyama, Linda R. Manzanilla, Margaret Schoeninger (2016) Animal management at the ancient metropolis of Teotihuacan, Mexico: stable isotope analysis of leporid (cottontail and jackrabbit) bone mineral. PLoS ONE, 11.8: e0159982.
  • Sugiyama, Nawa, Andrew D. Somerville, Margaret J. Schoeninger (2015) Stable isotopes and zooarchaeology reveal ancient management of wild carnivores at Teotihuacan, Mexico 1000 years before the Spanish Conquest. PLoS ONE, 10(9): e0135635.
  • Somerville, Andrew D., Ben A. Nelson, and Kelly J. Knudson (2010) Isotopic investigation of pre-Hispanic macaw breeding in Northwest Mexico. Journal of Anthropological Archaeology, 29(1) 125-135.

Selected Press

  • Forbes: “Why is your pet rabbit of European descent? Researchers have a possible explanation” by Sara Tabin
  • Scientific American: “Ancient Mexican metropolis engaged in hare-raising activity” by Cynthia Graber
  • New Scientist: “Bunnies helped a great civilisation in ancient Mexico thrive” by Conor Gearin
  • Ancient Origins: “Mesoamericans at Teotihuacan kept Ferocious Animals Captive and May Have Fed them with Humans” by Mark Miller

Reconstructing Paleoenvironments with Stable Isotope Analysis of Animal Bones

Human societies both influence and are influenced by changes in the natural environment. Being able to reconstruct past environmental conditions is thus an important task of archaeologists interested in understanding past dynamics of change. This area of research explores the potential of using stable isotope analysis of faunal bones, particularly rabbits and hares (Leporids) to produce paleoenvironmental data relevant to past archaeological settlements. Rabbits and hares are particularly attractive archives of environmental data as they were commonly consumed by ancient human communities in the Americas, and their bones are commonly found in trash middens at archaeological sites.

Project collaborators: Dr. Margaret Schoeninger (UCSD), Dr. Andrew Froehle (Wright State University)


  • Somerville, Andrew D., Ben A. Nelson, Jose Luis Punzo Diaz, Margaret J. Schoeninger (2020) Rabbit bone stable isotope values distinguish desert ecoregions of North America. Journal of Archaeological Science, (113) 105063.
  • Somerville, Andrew D.,Andrew W. Froehle, Margaret J. Schoeninger (2018) Environmental influences on rabbit and hare bone isotope abundances: implications for paleoenvironmental research. Paleogeography, Paleoclimatology, Paleoecology, (497) 91-107.
  • Schoeninger, Margaret J., Corinna A. Most, James Moore, Andrew D. Somerville (2016) Environmental variables across Pan troglodytes sites correspond with the carbon, but not the nitrogen, stable isotope ratios of chimpanzee hair. American Journal of Primatology, 78(10) 1055–1069.