Population history of southern Italy during Greek colonization inferred from dental remains

We are testing competing scenarios regarding the population history of the ancient Greek colonization of southern Italy using dental phenotypic evidence.

We collected dental metric and nonmetric trait data for 481 human skeletons from six archaeological sites along the Gulf of Taranto, dating to pre-colonial (900-700 BC) and post-colonial periods (700-200 BC). We are evaluating scenarios through an individual-level biodistance analysis using a three-pronged approach: (a) by analyzing levels of mobility in pre- and post-colonial periods under a model of isolation-by-distance; (b) by quantifying differences in group means and variances in pre- and post-colonial periods utilizing permutational multivariate analysis of variance and Betadisper analyses; and (c) by identifying ancestries of post-colonial individuals using naïve Bayes classification.

Southern Italy during pre-colonial times was characterized by low levels of mobility and marked differences in group means and variances. During post-colonial times, mobility increased and there were no differences in group means and variances. About 18% of the people in post-colonial times were of Greek ancestry and lived equally distributed across Greek colonies and indigenous villages. Nevertheless, the overall biological composition and variability of southern Italy remained relatively unchanged across pre- and post-colonial periods.

Our results support a scenario in which only few Greek colonists migrated to southern Italy and lived in smaller numbers alongside indigenous people in Greek colonies as well as in indigenous villages. Our results contradict a scenario in which large numbers of Greek invaders founded biologically isolated and substantially homogeneous colonial enclaves within conquered territories.