Communality of surnames: a measures of biological interrelationships among thirty-one settlements in upper Val Varaita in the Italian alps.
The upper part of the Alpine valley of the Varaita (population about 1,596) has three communities situated in a triangle about 6 km on a side but divided into frazioni (clusters of houses) that form a "Y" along the road and river in the valley floor. The coefficient of relationship (Ri) based on the communality of surnames between pairs of frazioni and between pairs of the communities shows very high levels of interrelationship (up to 0.26 compared with 0.5 for brothers). It tends to be higher between frazioni of the same community than between communities. It is highest among five pairs of contiguous frazioni within 1 km of each other. It tends to be highest between frazioni of the community least influenced by tourism and migration. It is not dmonstrably affected by the division of one community into two parishes. It is about twice as high between contiguous communities as between the two communities with an intervening one. The high values represent the long history of the same surnames in the valley and the accumulation of relationship through high levels of valley endogamy.
D005826:Genetics, Medical; D006801:Humans; D007558:Italy; D009275:Names; D010375:Pedigree