Origins and spread of agriculture in Italy: a nonmetric dental analysis.

Dental morphological traits were employed in this study as direct indicators of biological affinities among the populations that inhabited the Italian peninsula from the Upper Paleolithic-Mesolithic to Medieval times. Our analysis aims at contributing to the ongoing debate regarding the origin and spread of agriculture in the peninsula by contrasting the dental evidence of archaeological and modern molecular samples. It is not possible to generalize given the complex and dynamic nature of these populations. However, the results from the principal component analysis, maximum likelihood, mean measure of divergence, and multidimensional scaling do indicate a net separation of the Paleo-Mesolithic sample from the other groups that is not related to dental reduction. This suggests that the shift in dental morphology was the product of Neolithic populations migrating into the peninsula from other areas. Nonetheless, the Paleo-Mesolithic populations share several discriminative traits with the Neolithic group. The biological relevance of such evidence suggests that, to some minor extent, the spread of agriculture did not occur by total population replacement. Because of regional small sample sizes, this hypothesis cannot be tested on a micro-regional scale. It is, however, feasible to depict a scenario where processes of genetic mixture or replacement probably took place at different rates on a macro-regional level.