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Can DNA Decipher the Mix?
Unraveling the genetic tapestry provides clues to breeds and their mixes
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A mongrel dog is like a box of chocolates: You never know what you’re going to get. And therein lies the appeal. What’s more fun than serendipitous unpredictability all bundled up in puppy fur? But when that puppy grows up, we inevitably make assumptions about her ancestry based on how she looks and behaves. Our logic goes like this: “If my pooch is long and low to the ground, and she never barks, she must be a Corgi/Basenji mix.”

But it’s much more complicated. The genes—and there may be hundreds—that work together to make a Corgi look like a short-legged Shepherd may be completely different than those responsible for a Basset Hound’s low-slung carriage. With some exceptions, scientists cannot yet connect genetic dots to specific traits. But they have discovered something tangible that measures some of the differences between breeds: genetic patterns of organization displayed on a scatter graph that answer the question, “What’s the same and what’s different?”

A scatter graph provides a symbolic visualization of DNA, wherein each individual dog contributes one point. The resulting pattern indicates the type and strength of the relationship between individuals. The more the points cluster around each other, the more alike they are.

 

Breakthrough
Until only a few years ago, scientists couldn’t identify the differences in genetic material that might explain profound variations in the Canidae clan. From wolf to West Highland White Terrier—they all looked the same under the microscope. Then, in 2004, Elaine Ostrander and her colleagues at the Washington-based Fred Hutchinson Cancer Research Center published data indicating that as much as 30 percent of the dog’s genetic material accounts for breed variation (Science, May 2004).

In addition to simplifying methods used to find markers for breed-related disease, the researchers identified patterns of “breedness” and tracked the history of breed DNA. At the same time, by following mitochondrial DNA, genetic material passed down from mother to offspring without changing, they traced the breed’s journey.

Depending on how much time is attributed to a generation and how many generations are involved, scientists can estimate how much time has passed. Based on this tracking, it has been suggested that it took 5,000 years to develop and refine a handful of the world’s 350-plus breeds, and about 400 years to create the rest.

Research indicates that four distinct breed groups are ancient: (1) Middle Eastern Saluki and Afghan, (2) Tibetan Terrier and Lhasa Apso, (3) Chinese Chow Chow, Pekingese, Shar-Pei and Shih Tzu; Japanese Akita and Shiba Inu, (4) Arctic Alaskan Malamute, Siberian Husky and Samoyed. Although the 13 breeds look different, they are so closely related that they are represented by a single genetic cluster. It’s likely they all originated from the same stem-parent—proto-breed, if you will—who roamed the Asian continent.

As humans migrated from one place to another, this ubiquitous proto-breed trotted along, bringing with her the ingredients needed to cook up all the breeds we’re familiar with today. Her offspring performed work unique to each geographical region, such as hunting, hauling or guarding. Isolated and mating only with each other, “accidental” breed types exhibiting consistent shape, color and behavior emerged.

No matter what historians might claim—scent hound to sight hound, bird dog to bad dog—evidence produced through genetic research indicates that all remaining breeds have been concocted in the last 400 years. Although closely related to one another, they can be identified as distinct based on the way their DNA separates.

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Submitted by Anonymous | August 4 2011 |

Fascinating. So are DNA tests accurate enough to be useful in identifying the breeds in your mutt?

Submitted by Dave Strack | February 5 2013 |

I am still a skeptic as to the accuracy of these tests. There have been results that have been documented in which the same dog's sample was submitted to the same lab twice with entirely different results, dogs with color patterns and coat types that have been studied to identify the specific genes needed to produce them but the DNA test did not identify any breeds in the test result that could have produced the dog being tested, and an unscientific report of a test on ans 8 pound dog that listed only large breeds in its ancestry (a little white Rottweiler?).
The DNA testing is not one where a sample is put into a machine that spits out the answers. A human still has to interpret the raw result to come up with the answers - can you say human error. If you are just curious go ahead and have your dog tested. I would not like to think of a situation where my dog's life depended on these test results.

Submitted by Jane Brackman | March 28 2014 |

Read a more recent article I wrote about DNA tests, published in Bark in December 2012. http://thebark.com/content/do-dna-tests-reveal-genetic-secrets
You still may be a skeptic, but you'll have more knowledge about why the tests are accurate but appear contrary to what we see in our mixes.

Submitted by Lorri | October 20 2011 |

Thank you Jane Brackman for this article. It was very informative and interesting. I'd love to know what has transpired, since it's been three years since the article was published in The Bark.

Submitted by Jane | March 1 2012 |

That's the same thing I've been asking myself Lorri. And yes, I'm working on an updated piece. I've been sending my mixed breed pooches DNA into two companies to see if the results are the same.

Submitted by Kathi | July 30 2012 |

Jane,

I have been doing my own research on the various DNA tests plus DNA breed identification. This is because my city has a breed ban on certain breeds of dogs. I am not a scientist:( which makes this difficult. Mars Wisdom Panel is the only test that is available now to my knowledge. The shelter at our city has been testing questionable mixed breeds since 2009 with the Wisdom Panel Professional. We've done 20+ dogs so far. We have even done both test(Insight & Professional)on the same dog to see if we received the same results (we did). Our city does not acknowledge DNA testing but the city council is open on us gathering information (with the city) to determine if DNA testing can determine the banned breeds. Our city will accept the banned breeds if they are less than 50% of the banned breeds. This is currently determined by animal control officers visual identification. When will your updated piece be out? I'll be looking forward to it.

Submitted by Mia | November 17 2012 |

It is completely cruel and just plain wrong to ban an entire breed of dog. The dog is what you bring it up to be. PEOPLE are the ones that should be punished for TEACHING the dog to fight or be cruel or purposely inbreeding....Jail time and permanently keeping animal cruelty on their records should be put into law!

I have recently gotten a pitt bull mix (weimeraner we think) but he has fit right in! And is the most loving dog....I have six dogs and the lab/labradoodles that we have are more aggressive than he is - Especially with strangers walking in front of the house or people coming in....

Banned breeds should be banned people - people are the ones that are cruel.

Submitted by Anonymous | February 4 2013 |

I agreed to watch a friend's pitbull for one night and he moved out of state. So I had this huge brendle 11 year old pit bull, and I was scared of him. I had him for 3 years, and he was one of the most sweetest dogs I ever owned. At first I thought he was mute, he never barked for 3 months until I had him tied up outside and I walked out of his line of sight, that was the first time I ever heard him bark. A drunk friend of mine climbed through my window in the middle of the night and the dog just tackled him and licked him to death. I thought "what a lousy guard dog." But I would take him with me on runs, and a creepy guy approached me and he sensed my unease and went after the guy. He would let babies ride him like a horse. He was a great dog. But I couldn't get renter's insurance because of him.

Submitted by Anonymous | October 27 2011 |

So the "groups" are: Two hounds, MULTIPLE Spitz dogs, and a few small breeds... I think these groupings are messed up. At the very least, Asian Spitz dogs should have been one group (with the exception of the Chow Chow the visual and behavioral similarities are striking.)

Submitted by Erin | April 18 2012 |

Thanks for the interesting article! I had my dog's DNA tested recently and it was an interesting experience to say the least! She came back with about nine different breeds detected! The Humane Society believed her to be an Australian Cattle Dog/mix, however none was detected. They came up with boxer/miniature schnauzer mixed with a keeshond/chow chow. We really just did it for fun and it was affordable (around $60), but it might be interesting to see if the other companies that offer this service would come up with similar results. I am looking forward to reading your follow-up article regarding this. Of course, we love her no matter what the results are!

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