On the biological affinity between the populations of Iron Age and Roman central southern England, using dental non-metrics as evidence

Abstract

This study examines the impact of the Roman invasion and occupation of central southern England on the genetic variation of the local Iron Age population. Three models are examined that purport to explain the relationship between the populations of the Iron Age and Roman periods. The first, biological continuity, sees no discemable change in the genetic variation of the population from the Iron Age to the end of the Roman occupation. The second model, biological replacement, proposes that the Roman occupation of Britain brought with it such high levels of immigration that the local Iron Age population was replaced by a new population from other parts of the Roman Empire. The third proposed model is increased genetic diversity. Under this model, the population of central southern England during the Roman occupation is seen to consist of the descendents of the local Iron Age population with the addition of a significant number of immigrants. The levels of immigration expected under this model are such that the total Iron Age and Romano-British populations were biologically distinct. Dental non-metric data from the skeletal populations of Iron Age and Romano-British central southern England are used as a source of evidence with which to examine the validity of these three models. Various statistical analyses and computer applications are used to generate information on the relatedness of the subpopulations from the area, including principle component analysis, canonical variant analysis, mean measure of divergence, and PAUP (Phylogenetic Analysis Using Parsimony). Very strong support for a model of increased diversity is observed. A lower level of support for a model of no discemable change is revealed. A lack of support for a model of replacement is also observed. This study concludes that an examination of the dental non-metrics of the skeletal populations of Iron Age and Roman central southern England demonstrates a relationship of strong biological affinity. This correlation signifies a close relationship between the living populations of Iron Age and Roman central southern England. That a statistically significant difference between the skeletal populations was observed, however, implies that the Roman occupation resulted in a discemable impact on the genetic variation of the local Iron Age population. The increased genetic diversity of the population in central southern England during the Roman occupation most likely resulted from a significant level of immigration from other regions of the Roman Empire.