Relationships estimated by isonymy among the Italo-Greco villages of southern Italy.

Surnames of parents and grandparents were collected from 1993 children in the primary schools of the thirteen Italo-Greco communes that lie in two areas, four communes in Reggio Calabria in the "toe" of Italy and nine in Lecce in the "heel." The coefficients of relationship by isonymy show almost no relationship between the two areas. The smaller area in Reggio Calabria Province has consistently larger coefficients of relationship between communes than the larger area in Lecce Province. The difference can be ascribed to greater accumulated random isonymy in the smaller area. These populations are not genetic isolates, but each area shows a degree of cohesiveness with respect to surnames that suggests that they are genetically somewhat distinct. Contiguous pairs of communes tend to have higher coefficients of relationship than pairs of communes separated by intervening communes.