Studies of modern Italian dog populations reveal multiple patterns for domestic breed evolution

Through thousands of years of breeding and strong human selection, the dog (Canis lupus familiaris) exists today within hundreds of closed populations throughout the world, each with defined phenotypes. A singular geographic region with broad diversity in dog breeds presents an interesting opportunity to observe potential mechanisms of breed formation. Italy claims 14 internationally recognized dog breeds, with numerous additional local varieties. To determine the relationship among Italian dog populations, we integrated genetic data from 263 dogs representing 23 closed dog populations from Italy, seven Apennine gray wolves. Using 142,840 genome-wide SNPs, this dataset was used in the identification of breed development routes for the Italian breeds that included divergence from common populations for a specific purpose, admixture of regional stock with that from other regions, and isolated selection of local stock with specific attributes. 273 canid samples representing 21 Italian breeds and seven Apennine gray wolves