Researchers were recently able to use modern genetic processes to determine the primary origin of small dog breeds. These canine companions are a long way away from the wild wolves that became domesticated a long time ago, and learned how to live cooperatively with our ancestors. Smaller dogs, however, share roughly the same genetic material as other breeds. In a new investigation published in the latest issue of the respected, open-access journal BMC Biology, experts show that small breeds appeared in the Middle East, around 12,000 years ago, ScienceDaily
The scientists believe that these animals are direct descendants of the Middle Eastern gray wolf, which was domesticated in the same region. The research was conducted by tracing the evolutionary history of the IGF1 gene, which geneticists say plays a huge role in the actual size of dogs. The investigation was led by scientists at the University of California in Los Angeles (UCLA), who were in turn led by experts Melissa Gray and Robert Wayne. The group followed a large sample of a gray wolf population closely, in order to gain some insight into how genetic variations appear.
“The mutation for small body size post-dates the domestication of dogs. However, because all small dogs possess this variant of IGF1, it probably arose early in their history. Our results show that the version of the IGF1 gene found in small dogs is closely related to that found in Middle Eastern wolves and is consistent with an ancient origin in this region of small domestic dogs,” the experts write in the journal entry. According to archaeological accounts, the first small domestic dogs appeared in the Middle East no earlier than 12 millennia ago.
Other investigations, at sites including Western Russia, Belgium and Germany, revealed that larger dogs existed in these regions between 13 and 31 millennia ago. However, these investigations could not establish the presence of small dog breeds anywhere else except the Middle East. Gray reveals that a decrease in stature is oftentimes associated with domestication. Records indicate that pigs, goats and cattle were also reduced in size when they started living together with humans. “Small size could have been more desirable in more densely packed agricultural societies, in which dogs may have lived partly indoors or in confined outdoor spaces,” Gray says.