I explore the relationships between the ancient city of Teotihuacan and the animals used in ritual sacrificial events using aDNA methods. Specifically, I study how the Teotihuacános were acquiring and managing the sacrificed animals. My research focuses on three species of sacrificial animals: golden eagles (Aquilla chrysaetos), pumas (Puma concolor), and jaguars (Panthera onca). While each species comes with its own slightly different questions and objectives, I am reconstructing evidence of long-term captivity through genetic relationships between sacrificed animals. I hypothesize that if there are groups of full siblings within a burial, then they were likely collected together as juveniles and raised by the Teotihuacános. This would suggest widescale management of highly dangerous animals that predates Montezuma’s zoo by 1000 years. Many animal remains already excavated from ritual sites show skeletal and isotopic evidence for captivity, such as lesions on the limbs of eagles and felids—suggesting they were bound—and isotopic evidence for maize-based diets. Genomic approaches allow us to get a more detailed look into why and how the Teotihuacános managed sacrificial animals by determining the relationship between sacrificed animals. Date generated by this project can also inform questions about sex bias within animal sacrifices, which could also have cultural significance. Aside from the anthropological significance of this work, I have also made methodological improvements that will further the field. Over the course of my work with the golden eagle remains, I dramatically increased the on-target DNA recovered from samples, making poorly preserved samples useable.
I am studying archaeological rockfish diversity on the California coast. Rockfish are found from the Bering Sea through Southern California and are a diverse clade of species. Different species of rockfish live in distinct habitats and are visually unique, but their skeletons are very similar, making it nearly impossible to identify species in archaeological contexts. By identifying what species people were fishing, we can learn about technologies and practices that that do not leave material remains for archaeologists to find. For example, if we find that some of the fish from these archaeological sites are only found in deep water, they must have had fishing technologies such as long, sturdy fishing lines. Genetic analyses of archaeological rockfish also give us a glimpse into ocean conditions in the distant past, as specific species prefer different water temperatures and habitats. Finally, we can compare these archaeological samples to modern ones to see how rockfish have changed over time, giving us a picture of rockfish evolution that help assess modern populations.
I have attempted to recover DNA from ancient samples excavated at Rancho La Brea (RLB), asphaltic seeps in Los Angeles. Over the last 50,000 years, millions of plants and animals were trapped in the sticky tar and fossilized, leading to one of the richest late Pleistocene fossil collections in the world. Currently their collections house over 3.5 million fossils, and excavations are still ongoing. Despite numerous attempts, DNA recovery from asphalt-covered remains has thus far been unsuccessful, potentially due to the chemicals used to clean the asphalt from remains. In collaboration with the Brea Tar Pits Museum, we attempted to recover DNA from untreated remains, instead removing the asphalt mechanically. We used the latest and most efficient ways to recover DNA but were not able to definitively identify ancient DNA suggesting that asphalt may impair DNA preservation and/or recovery. Without significant technological advances in DNA recovery, it is unlikely that other researchers will be able to recover DNA from asphaltic samples.