Ancestry-inclusive Dog Genomics Challenges Popular Breed Stereotypes

Abstract

Behavioral genetics in dogs has focused on modern breeds, which are isolated subgroups with distinctivephysical and, purportedly, behavioral characteristics. We interrogated breed stereotypes by surveyingowners of 18,385 purebred and mixed-breed dogs and genotyping 2155 dogs. Most behavioral traitsare heritable [heritability (h2) > 25%], and admixture patterns in mixed-breed dogs reveal breedpropensities. Breed explains just 9% of behavioral variation in individuals. Genome-wide associationanalyses identify 11 loci that are significantly associated with behavior, and characteristic breedbehaviors exhibit genetic complexity. Behavioral loci are not unusually differentiated in breeds, but breedpropensities align, albeit weakly, with ancestral function. We propose that behaviors perceived ascharacteristic of modern breeds derive from thousands of years of polygenic adaptation that predatesbreed formation, with modern breeds distinguished primarily by aesthetic traits.