Elements of the surname structure of Austria

The isonymy structure of Austria was studied using the surname distribution s in 1 081 002 private telephone users selected from about 4 000 000 regist ered in a 1996 commercial CD-ROM, which contains all Austrian users. The sa mple was distributed in 120 towns representing an approximately uniform dis tribution over the country. The number Of different surnames found in the w hole analysis was 140 766. Lasker's distance, the negative value of the log arithm of isonymy between localities, was found to be linearly and signific antly correlated with the log of geographic distance, with r = 0.565 +/- 0. 011. A dendrogram was built with the matrix of isonymy distance, using the Unweighted Pair-Group Method using Arithmetic averages, UPGMA. It separates the Austrian towns in five main clusters, one along the central portion of the country, another one which occupies the northern region of central Aus tria; then comes a third cluster at the north-eastern part, a fourth cluste r in the western region, and finally a small cluster towards the border wit h Slovenia. Within each, small subclusters with specific geographic distrib utions could be delimited. The main clusters correspond fairly well to the classic regions of Austria. The results were compared with those obtained i n similar analyses of Switzerland, Germany. Italy and Venezuela. From the p resent analysis, isolation by distance emerges clearly, and it is stronger than in Germany but smaller than that observed in Italy, Switzerland and Ve nezuela. The random component of inbreeding estimated from isonymy, at the level of resolution used here, indicates that the inbreeding level in Austr ia is rather uniform.