Tracking dogs across the Pacific: an archaeological and ancient DNA study

The dispersal of dogs across the Pacific region is inseparably linked to the relationships between dogs and people. Unlike movement across continental landmasses, dogs must have been transported by people across the waters that separate islands. The purpose of this PhD research is to investigate the introduction and dispersal of dogs throughout the Pacific. The approach uses dog remains from archaeological sites to generate ancient mitochondrial genomes using next generation sequencing technology. This molecular data is interpreted in relation to regional archaeological models for human and animal movements and human-dog interactions. In order to understand as fully as possible what the nature of the dog-human relationship may have been like, ecological, ethnographic and historical information about dog populations and their interactions with people in the region are also considered. The outcomes of the ancient DNA analyses of dog specimens from colonisation era archaeological sites in New Zealand demonstrates the impact that the interactions between people and dogs can have on mitochondrial molecular diversity, and hence the usefulness of studies using only maternal markers. The results, nonetheless, are informative about the Pacific dogs brought to New Zealand and the colonisation process. The homogeneity of mtDNA lineages from this first introduction suggests a single, closely-related founding population, and supports the current archaeological model of rapid and strategic colonisation. Complete and partial ancient mitogenomes were generated from archaeological specimens throughout Southeast Asia and the wider Pacific to investigate the place of dogs in the Lapita migrations. These results indicate the introduction of at least three different dog lineages to the Pacific region, each with a different dispersal history. An association between Late Lapita dogs and modern Taiwanese dogs was found that suggests the possibility that dogs may have been part of the expansion of Austronesian language speakers associated with the Lapita Cultural Complex, but were not successfully transported by groups moving beyond the Bismarck Archipelago. A major Pacific dog clade was observed, which was a relatively late but highly successful introduction. This lineage was found in archaeological specimens across the Pacific, including several islands in Polynesia. There appears to be a discontinuity between Lapita era mtDNA lineages and later East Polynesian lineages. This research has resulted in new data generated from ancient DNA analyses of complete mitochondrial genomes of dogs from archaeological samples from Island Southeast Asia and the Pacific. The results demonstrate the complexity of dog introductions and dispersals in the region, with implications for understanding human colonisation processes and the ways in which dogs may have been moved around the Pacific