Ethnicity and evolution of the biodemographic structure of arbereshe and italian populations of the Pollino area, southern Italy (1820-1984)

In the present study, we show how, through time, an ethnic mosaic and a changing social and economic context translated into intrapopulation differentiation and a change in genetic barriers between populations. Surname analysis was applied to a sample drawn from two centuries of marriage records in ten Arb ¨ ereshe and nine Italian villages of southern Italy to evaluate the evolution of internal differentiation and changes in genetic relationships between populations. Marital isonymy and subdivision into subpopulations was higher in the Arb ¨ ereshe. Genetic barriers coinciding with ethnic boundaries characterized the 1800s. In the second half of the 1900s, ethnic differentiation disappeared. We hypothesize that socioeconomic changes, such as increased outmigration and regional mobility, were the forces that progressively eliminated the ethnic-related genetic differentiation in the region. This study has important implications for an understanding of the relationship between genetic evolution and the cultural milieu involving enforcement of ethnic differences.