What Did Chihuahuas Evolve From?

Long-haired Chihuahuas get their locks courtesy of a recessive genetic mutation.
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Modern Chihuahuas originated in Mexico. Like all modern dogs breeds, Chihuahuas trace their evolutionary roots to the gray wolf (Canis lupus). Like their Labrador, Pekinese and Rottweiler relatives, Chihuahuas reflect the cultural, materialistic and labor needs of the humans who molded them from an ancient stock into the modern breeds they are today.

Ancient Dog Evolution

Scientists have long suspected that dogs originated from selectively bred wolves, and that domestication occurred around the same time that humans began settling down and inventing agriculture. However, a 1997 study, published in the journal “Science,” presented DNA evidence demonstrating that dogs were much older than previously thought. According to the data, dogs evolved over 100,000 years ago, when humans were still nomadic. While scientists are not yet sure whether dogs resulted from one domestication event or two such events around the same time, it is clear that domestic dogs (Canis familiaris) are the direct progeny of gray wolves. PBS explains that most of the 150 or so living dog breeds are the product of the past 150 years of human-guided evolution of the species, but Chihuahuas predate this period of relatively rapid breed development.

Modern History of the Breed

Chihuahuas are an old breed that was first registered with the American Kennel Club in 1904. However, Chihuahuas have been barking at strangers and looking at their owners with vulnerable, loving eyes for much longer than that. Chihuahuas are known to have been popular in Mexico prior to European settlement, and some records exist that indicate that Columbus met the endearing little dogs and may have had a hand in bringing them back to the Old World.

Mysterious Beginnings

According to the AKC, the early dog breeders probably developed the Chihuahua from a dog called the Techichi. The Techichi was a dog of the Toltec people, who inhabited Mexico from the early 900s to the mid-1100s. However, the Techichi’s roots may be even deeper than that: They likely inhabited Mexico prior to the rise of the Mayan culture. Nevertheless, the transition from the Techichi to the Chihuahua remains murky. Archaeologists working in the Yucatan Peninsula have found the oldest Chihuahua-like dogs ever recorded, in sites that date to the mid-16th century.

Developmental Downsizing

Modern Chihuahuas are dainty dogs who usually weigh about 6 pounds, some smaller. However, their ancestors were much larger. This reduction in size may be the result of breeding between early Chihuahuas and Chinese crested dogs.