Science: Researchers map history of dog breeds

May 10, 2017

From the delicate, minuscule Yorkie to the powerful, hulking Great Dane, dog breeds are as diverse as they are beloved as household pets and companions.

Now, researchers have pieced together the largest family tree of dogs ever compiled.

In a study published in Cell Reports, researchers have explained how over two decades, they used gene sequences from 161 breeds (less than half of commonly recognized breeds) to trace the evolutionary and breeding history of modern dogs. In addition, the team studied wolves and jackals. As a result, they identified 23 categories, called “clades,” of breeds that share traits.

With this information, certain breeds can be traced back to a geographic location and a point in time. For example, many hunting dogs can be pinned back to Victorian England.

“All of the spaniels, the pointers, the setters and the retrievers are actually pretty closely-related, and they group into one overarching clade of sporting breeds,” said Dr. Heidi Parker, a co-researcher who worked on the study, in a BBC article. Other clades center on dogs bred for strength or herding, for example.

Over the past 15,000-30,000 years, dogs have been bred for practical purposes, like hunting, herding or guarding. Only within the past few centuries have dogs been bred for aesthetic reasons, like cuteness or cuddliness.

Creating new breeds of dogs often involves crossbreeding existing breeds. In the 16th century, breeders used pugs, for instance, to shrink working dog breeds. Because of this, many toy dogs possess some pug DNA.

Information gained from the study could prove beneficial to understanding dog health.

“We now know where various disease mutations or disease alleles come from,” said Dr. Elaine Ostrander, another co-researcher who worked on the study, in the BBC article.

One area that might be improved by this new information is the identification of genetic problems in dogs. One genetic disease, collie eye anomaly, can be better identified by veterinarians if they understand which dogs belong to the most commonly affected clade.

In the future, the researchers intend to continue their work, filling out their information with the many breeds they have not yet analyzed.