Chihuahuas carry small fragments of coyote genetic material, scientists from Stanford University have found. The traces were discovered while testing a new algorithm designed to provide a detailed analysis of the origins of different species. The study was published in the journal Nature Communications.
The genetic segments probably entered the breed’s lineage long before the arrival of Europeans in the Americas. The Chihuahua’s ancestry is linked to the Techichi – a small companion dog bred in pre-Columbian Mexico by representatives of the Toltec civilization around the beginning of the first millennium.
Modern Chihuahuas have retained around 4% genetic material from ancient dogs that lived before European colonization. Within this inherited portion, researchers have found even smaller fragments suggesting ancient interbreeding between native dogs and coyotes.
Traces of Ancient Contacts in Mexico
Identical DNA segments have also been found in Chinese Crested dogs. According to the scientists, this supports the assumption that the fragments are linked to an older common lineage rather than to relatively recent interbreeding.
“I assume that these coyote DNA fragments originated from ancient contacts between dogs and coyotes in Mexico. They may have appeared in animals that later gave rise to both modern breeds,” said Stanford University geneticist Alexander Ioannidis.According to him, all domestic dogs trace their origins to wolves from the Old World, while coyotes belong to a different evolutionary lineage. Historical evidence suggests that interbreeding between coyotes and native dogs in pre-Columbian Mexico may have been deliberate rather than accidental.
Does Not Explain the Breed’s Behavior
Coyote DNA accounts for approximately one-tenth of one percent of the Chihuahua genome. Therefore, scientists do not directly link the discovery to the small dogs’ characteristic courage or to their behavior toward larger animals.
“Since coyote DNA makes up only one-tenth of one percent of the Chihuahua genome, its influence on behavior, if it exists at all, is probably negligible,” Ioannidis explained.
The same applies to the breed’s small size. It is probably the result of genetic changes associated with delayed growth and prolonged artificial selection, in which humans bred the smallest animals. Thus, the genetic heritage from coyotes remains a curious trace in the breed’s history, but not a proven explanation for its temperament.
Sources: unian.net, sciencealert.com