What is the specific Subspecies classification for the domestic dog including the Yorkshire Terrier?

C. l. familiaris

The scientific classification of the domestic dog, which encompasses the Yorkshire Terrier, utilizes a hierarchical structure established by Linnaeus. At the level of Subspecies, the correct designation is *C. l. familiaris*. This nomenclature specifically acknowledges the domestic dog as a specialized variant of the broader species, *Canis lupus*. The use of the *familiaris* subspecies designation is preferred in modern taxonomy because it directly reflects the dog’s genetic lineage tracing back to the gray wolf, *C. lupus*. The older classification, *Canis familiaris*, is sometimes encountered but does not explicitly link the dog to its immediate wild ancestor as effectively as the subspecies designation under *C. lupus* does. This detail confirms that despite domestication, the breed remains genetically intertwined with the larger *Canis* structure.