Doctoral Dissertation Improvement Grant: Hunter-Gatherers, Archaeogenomics, and the Evolutionary History of the Foxes of California's Channel Islands

University Of Maryland, College Park, College Park MD

Investigators

Abstract

One of the greatest environmental impacts of ancient people was the introduction of both domestic and wild species to non-native habitats. Globalization has led to the rapid spread of exotic and invasive species, but the movement of species through trade networks and human migration extends back at least 20,000 years and intensifies during the last 10,000 years. The analysis of ancient DNA and genomic data permits one to investigate the possible prehistoric introduction or movement of the now endangered island fox (Urocyon littoralis) by Native Americans across the California Channel Islands. The Channel Islands contain some of the earliest human occupations in coastal North America at 13,000 cal BP and some of the most populous hunter-gather groups in the world with extensive trade networks between the islands and mainland. The endemic island fox of California's Channel Islands is a federally listed endangered species and has been the subject of considerable conservation research, including a captive breeding program. Despite decades of research, significant questions remain about when foxes colonized the Channel Islands and the role that Native Americans may have played in their introduction and dispersal to six islands. Most researchers agree that Native Americans deliberately introduced island foxes from the northern to the southern Channel Islands by 5,000 years ago, and recent research raises the possibility that Native Americans may have first introduced foxes from the mainland to the northern Channel Islands. This is supported by their widespread distribution on six islands, their absence in fossil deposits or in very early archaeological contexts, and the significance of foxes in Native American religion and ceremony. Using archaeological, historic (19-20th century), and extant island foxes samples, C. Hofman is characterizing genetic variation of thousands of loci across the island fox genome to test the hypothesis that foxes were first introduced to the Channel Islands by Native Americans during the Holocene. By dating dispersal/introduction events and placing them in the context of the archeological/fossil records using high throughput sequencing, this study will investigate the role of anthropogenic, biotic (introduction and dispersal of other species), and environmental factors (e.g. climate change) in shaping island fox genetic variation across several millennia. These data will allow a better understanding of how humans have interacted with and influenced animals by introducing them to new environments, obscuring the distinction between nature and culture. This study will form Hofman's PhD dissertation and will be published in peer-reviewed archaeological, biological, and interdisciplinary journals, synthesized in a technical report, and summarized in a brief educational document for the Channel Islands National Park (CHIS). This project will demonstrate the importance of integrating archaeology and genomics for understanding ancient and modern human environmental relationships and modern conservation biology. Archaeological investigations of human-animal relationships through time can help document the influence of Native Americans on species distribution, abundance, and ecology. Understanding how species and humans adapted to and influenced changing environments in the past will inform decisions about protecting, preserving, and restoring biodiversity in the future.