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What a Dog Geneticist Wants You to Know about Dog Genetics

What dog lovers get right, and wrong, about dog genetics

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Dog lovers talk a big game when it comes to genetics. Who hasn’t heard someone claim to know which breeds reside within a beloved mutt simply by appearance? And who hasn’t heard claims about a dog’s underlying “nature” even though geneticists acknowledge nature and nurture work together? DNA is undeniably instrumental to all living beings, but casual beliefs about genetics — particularly dog genetics — aren’t always on point.

Not being a geneticist myself and wanting to know what dog lovers tend to get right and wrong about dog genetics, I reached out to an actual geneticist! After completing her PhD in genomics, Jessica Perry Hekman (FB, Twitter) joined the Karlsson Lab at The Broad Institute of MIT and Harvard as a post-doctoral associate. You may be familiar with their citizen science project, Darwin’s Dogs, which is sequencing dog DNA for free. It’s quite an undertaking that’s dependent on grant funding, and they have a particular interest in dog behavioral genetics and its applications for dogs and people. In addition to working as a researcher, Hekman has created widely available online webinars and classes relating to genetics, and she also maintains the thoughtful and informative blog, The Dog Zombie.

Here’s what Hekman, the dog geneticist, wishes dog lovers knew about genetics:


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What do dog lovers seem to get wrong about dog genetics? “Thinking that genetics are destiny — that if a problem is ‘genetic,’ it can't be changed. Sometimes that's true, but very rarely in the case of behavior problems. A dog's personality is inextricably made up both of genetics and experience, and if you're seeing problem behaviors, it's always worth exploring what it might take to fix them. (On the other hand, if you're trying to get your retriever to be less interested in balls, this is likely to be an uphill battle.)”

What do you wish purebred dog owners knew about dog genetics? Inbreeding is real and is a serious problem in many, if not most, pure breeds.”

[Hekman has previously weighed in on this topic. In the post ‘How to Make the World Better for Dogs’ at Companion Animal Psychology, Hekman describes a number of well-known challenges that purebred dogs face. Here’s Hekman: “We can make the world better for dogs by making dogs who fit into the world better. I would love to see dog owners draw a line in the sand and insist on dogs with muzzles long enough to let them breathe normally, or dogs who are not born with a 60% chance of developing cancer at some point in their lives due to their breed, or dogs whose heads are too big for them to be born without a C-section. I'd love to see more breeders taking matters into their own hands and starting to experiment with how we breed dogs instead of continuing to use dogs from within breeds lacking in genetic diversity. I'd love to see more breed clubs supporting outcrossing projects to bring an influx of genetic diversity and healthy alleles into their breed. I'd love more dog lovers to become aware of the problems with how we breed dogs — how even the most responsible breeders breed dogs! This year, it is time for change.”]

What do you wish mixed-breed dog owners knew about dog genetics? “Finding out the breeds that make up your mixed breed dog is unlikely to be helpful in predicting your dog's behavior or future health problems. It's just fun!”

[Speaking of mutts, MuttMix is a new, online, citizen science survey by Darwin’s Dogs and the International Association of Animal Behavior Consultants (IAABC) exploring if people can visually identify the predominant breed in mutts. Based on earlier studies, this might be more difficult than you’d think. Give it a try!]

In the study of heritability (particularly regarding dog behavior traits) is there an area that has the most potential for advancing the field? “Sample size! This is why I am throwing my lot in with Darwin's Dogs. Elinor Karlsson, the head of the project, firmly believes that the way to crack the problem of ‘which genes affect behavior’ is to look at lots and lots and lots of dogs. She has me convinced. We have succeeded in building a base of people who have given us access to their dogs’ DNA and answered so many questions about their dogs, for which we are extremely grateful. Now we just need the funding to sequence all those dogs!”