Dog lovers, art lovers and natural historians are fascinated by man’s best friend. There is a long history to the relationship between humans and their dogs.
Over the centuries humans have bred dogs to maximise a particular skill. But we have also bred for what we consider to be a more appealing appearance – often with little regard to the impact of the change on the dog’s health.
Dog breeding: an ancient practice
Humans have shaped dog breeds since wolves first started hanging around settlements. The understanding of evolutionary relationships is part of the intriguing science of taxonomy.
Paolo Viscardi is Keeper of Natural History at the National Museum of Ireland. He says people have shaped dogs to do things they want them to throughout history. We bred bulldogs to fight bulls, now we want them to look cute. So we’ve bred them to have shorter muzzles. This can mean they have breathing difficulties but people don’t seem to care about that, they want cuddly dogs, Paolo points out. Seeing the look on my face, he adds: “that’s not what I want myself, Mum*, don’t worry!” (*If you have privileged access to an expert, use it!)
The term for dogs with flat faces is brachycephalic. There is a range of health issues that arise from a shortened face. Such dogs can find it harder than others to breathe, and that in turn can mean they take in less oxygen. That can lead to long-term effects on the heart. Dogs get rid of excess heat through their tongues by panting. A smaller tongue area means less efficient heat dispersal, putting flat-faced dogs at risk of overheating.
To breed or not to breed?
So why do people find such dogs so attractive? Professor Anjali Goswami is an evolutionary biologist with her own research group at the Natural History Museum in London. I talked to her before her contribution to Ada Lovelace Day, where she gave her presentation arguing that cats are evolutionarily perfect.
Anjali says that when you consider evolution, there are gaps in possible forms that haven’t been realised. Breeding can fill in gaps that would have been unviable in nature. The difficulty is that doing so can produce all sorts of health problems alongside the desired characteristics. That is why ‘mutts’ can be healthier than pedigree dogs.
She suggests dog breeds that aren’t too modified from the ancestral wolf may have fewer problems than those at the extreme, such as dachshunds. I asked her why people want highly modified dogs and she offers a similar opinion to Paolo’s – people like dogs that look like puppies.
Natural evolution
Katrina van Grouw bridges the worlds of science and art, producing sumptuously illustrated books that are also about serious science. In Unnatural Selection she shows how animals are constantly changing. The difference between animals in the wild and their domesticated cousins is that human intervention produces changes quickly enough for us to see differences.
Anjali mentioned the ancestral wolf, and Katrina argues that ancestral wolf may not have been quite the same beast as wolves today. When human populations numbered in the thousands rather than millions, wolves probably behaved very differently from wolves now – “less wary and more enterprising”.
The domestication of wolves probably did not have much to do with them being cute, though. Early dogs were probably developed for reasons such as guarding settlements and flocks, herding, hunting, and, sadly, fighting for entertainment.
Modern standards were failing the dogs
In the UK, the Kennel Club sets the standards against which dogs of each breed must be assessed in dog shows. In 2008 a BBC documentary, Pedigree Dogs Exposed, revealed how breed standards could lead to serious health problems for some breeds. This was already a concern for the veterinary profession but the publicity was important in achieving change. The Advisory Council on the Welfare Issues of Dog Breeding was set up in 2010.
The Kennel Club is now much more concerned about the health and welfare of the breeds it regulates. It is one of the sponsors of Anjali’s research and has set up Breed Watch to serve as an early warning system for potential problems in show dogs. For example, for the pug, judges are warned to be alert for signs of respiratory difficulty or distress.
So not only are dogs evolving, so too are the standards against which they are judged. And it seems the overall direction is good for the health of individual animals.
The Natural History Museum at Tring includes a dog display which shows how domestic dogs have changed shape due to selective breeding. It includes the tiny Russian and Mexican lapdogs as well as famous racing greyhounds.
