Genetics can provide two broad perspectives on dog biology. The first is a historical perspective on breed development and diversification. The available evidence demonstrates the unique phylogenetic basis of dog populations, which have been crafted by selective breeding that has drawn upon standing variation. Breeds are intentionally admixed populations. Consequently, conventional approaches to phylogenetics are not appropriate in dogs -- breeds are not Linnaean species, but polyphyletic constructs. Understanding the ways in which breeds have been developed using custom phylogenetic approaches will shed light on the natural history of dogs. This historical perspective can, in turn, be applied to the mapping of traits and diseases that are shared among breeds, with a priori evidence for common descent.

Mapping traits and diseases is a definitive genetic approach. One can prove that a DNA variant contributes to (or determines) the difference in a characteristic. This can be affected versus unaffected status, as in clinical genetics. Or it can be pointing versus non-pointing, as in behavioral genetics. There are several goals of definitively identifying causative genes. The genetic information that results can be translated into DNA tests that enable breeders to make more informed decisions in managing their bloodlines. The identification of genes also provides molecular access to cellular, biochemical, and physiological pathways governing the general biological process of interest.