Dog Genome Project Reveals Secrets of Canine Family Tree
Researchers have been barking up the same tree for over 20 years
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Researchers from the Dog Genome Project at the National Institutes of Health have released the most detailed canine family tree to date, creating a timeline of when and where dogs from 161 breeds emerged, reports Maggie Fox at NBC News. The researchers compiled the data by sequencing and comparing the genomes of 1,346 individual dogs over 20 years.
The new family tree isn’t just a factoid for the kennel club. According to a press release, it has implications for archeology and human health as well. The study, published this week in the journal Cell Reports, suggests that the oldest dog breeds are varieties that served a specific function like herding dogs and pointers.
According to the results, herding dogs were bred independently in various parts of Europe with lineages tracing to the United Kingdom, northern Europe and southern Europe. In the past, reports Erin Ross at Nature, researchers had trouble mapping out the lineages of herding dogs, believing they came from a single source. “In retrospect, that makes sense,” says Elaine Ostrander, an author of the study. “What qualities you’d want in a dog that herds bison are different from mountain goats, which are different from sheep, and so on.”
One of the most interesting finds was that some breeds from Central and South America like the Peruvian Hairless Dog and the Xoloitzcuintle possibly descended from canines that crossed the Bering land bridge with humans thousands of years ago. While there is some archeological evidence that dogs first entered the New World at that time, the study offers potential genetic confirmation. “What we noticed is that there are groups of American dogs that separated somewhat from the European breeds,” study co-author Heidi Parker of the NIH says in the press release. “We’ve been looking for some kind of signature of the New World Dog, and these dogs have New World Dogs hidden in their genome.”
The study will also give researchers insight into which genes and mutations are associated with human diseases. As Fox reports for NBC, all domesticated dogs are part of the same species, Canis familiaris, and have the same genetic material. There are just a tiny fraction of changes in the genome that separate a Chihuahua from a Great Dane. “We have a yellow brick road for figuring out how mutations move around the dog world. We recognize that everything humans get, dogs get—epilepsy, cancer, diabetes, heart disease,” Ostrander tells Fox. She points out that some diseases are more prevalent in certain breeds, like epilepsy in beagles. “We can actually trace diseases as they move around the dog breed population.”
The study suggests there were likely two intensive periods of dog breed diversification, writes Ross. The first happened in hunter-gatherer times when dogs were bred for their skills. During the second period, dogs were bred more frequently for their looks. Known as the "Victorian Explosion," this period was when most modern breeds developed.
The canine family tree, however, is not finished. The team has sequenced less than half of the 400 or so recognized dog breeds in the world. The researchers tell Fox they haunt dog shows and Frisbee dog competitions looking for breeds they have not yet sampled. A list of hard-to-find breeds they are currently searching for is on the Dog Genome Project website. It's worth taking a look, perhaps your pup could be one of the missing branches on the canine family tree.