Across the Irish Sea: Dental Affinities between Irish and British Populations from the Neolithic to Medieval Periods

Migrations into and between Britain and Ireland have been attested to throughout history such as those of the Anglo-Saxons and Vikings, and the Scotti of Dál Riata in Early Medieval times. Archaeological material also shows patterns of shared material culture across Ireland and western Britain throughout the Neolithic to the medieval period. This thesis improves the understanding of the biological diversity in these regions and explore the causes. Following the Arizona State University Dental Anthropology System (ASUDAS), dental non-metric trait data were collected for 36 traits in 570 individuals from 17 British and Irish samples that ranged from the Neolithic to the medieval period in date. The data were analysed using Principal Components Analysis (PCA), Kendall’s tau-b correlation coefficient and mean measure of divergence (MMD) to compare the samples and determine the biological similarity and dissimilarity among populations. Multidimensional Scaling (MDS) was used to graphically illustrate the inter-sample relationships. MMD and geographic distance matrices were compared using Mantel test. Results revealed a degree of homogeneity among the samples (36-trait MMD range 0.000-0.127; 17-trait MMD range 0.000-0.390) while MDS revealed regional grouping among the samples. It was found that there is no significant difference between British and Irish populations, although phenetic patterns may differ to patterns in the archaeological record. The MMD distances align with the archaeological record to suggest close relationships between Ireland and Scotland. The findings, while suggesting Anglo-Saxon migration contributed to the gene-pool in the English samples to some degree, are consistent with population continuity in England. There is no strong positive relationship between MMD and geographic distances suggesting that patterns of gene flow and migration are more complex than a linear “stepping-stone” model.