Natural History

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It’s very popular for people to deny dogs their proper classification according to molecular cladistics.

It’s popular because to accept that dogs are a type of wolf and actually belong to Canis lupus means that one has to deal with all sorts of political baggage that goes along with it.

Does it mean that Cesar Millan is right? Not at all.

Does it mean that I can go out and keep pet wolves? I wouldn’t recommend it.

But just because those two concepts are bogus doesn’t mean that the classification of dogs as part of Canis lupus is invalid.

This idea of dogs not being wolves was popular in the era of pre-cladistic classification. Cladistic classification is a way of organizing taxonomy to reflect evolutionary relationships. Paleontologists and anatomists spend hours classifying creatures using morphological characters, and there is a lot of debate, especially in paleontology, about how extinct organisms should be classified.

Currently, most taxonomists who use cladistic classification pay much more attention to molecular data. DNA tells us much more about common ancestry than we could ever get from bone or fossils. And yes, there are surprises.

We know now that dogs are nothing more than specialized offshoot of the Holarctic wolf. Canis lupus today exists in four lineages: the Holarctic wolf, the South Indian wolf, the Himalayan wolf, and the African wolf (which had previously been recognized as a form of golden jackal). We also know that dogs were domesticated in Palearctic somewhere, so they actually do derive from some form of Eurasian wolf.

This form is probably extinct, because the best nuclear DNA studies have shown that dogs are not derived from any extant wolf population.

If we are to adhere to cladistic classifiation, Canis familiaris is an invalid taxon.

So is Canis dingo. In fact, because dingoes fit within East Asian domestic dogs, the common scientific name Canis lupus dingo is also invalid. They are also Canis lupus familiaris, though definitely distinct ecomorph.

Some people get really worked up with this classification stuff, because the world of dogs inherently political. If you say a dog is a wolf, people jump to conclusions about some endorsement about feeding or training.

Politics be damned. Classifying organisms according to how they evolved is a much more important exercise than these tempests in a teapot that constantly swirl around the world of dogs.

I’m not saying that a golden retriever is the same thing as a large Alaskan wolf, but those two animals share more characters and more DNA than either shares with a coyote or a black walnut. If a golden retriever came in heat in the Alaskan bush and she ran into an unattached male wolf, they would breed and produce fertile offspring.

Indeed, many dog breeds have documented wolf ancestry. These include many arctic and boreal breeds like West Siberian laikas and Alaskan malamutes, but wolves have also been crossed into such unlupine breeds as Plott hounds, otterhounds, and griffon Nivernais.

Similarly, the black coloration in North American and Italian wolves originated from crossing with domestic dogs. It’s also not unusual for people to come across Italian wolves with dewclaws on the hind legs, which also is a diagnostic trait for crossbreeding.

When someone denies the phylogeny of domestic dogs, they usually do so rocking back on their heels as if they were somehow the most super-rational person in the world.  Only a fool would deny that a dog isn’t a wolf!

But it is these people who are in denial. Most of the ones I’ve seen either own little dogs that really don’t look or act much like wolves or they cannot think skeptically about Raymond Coppinger’s work.

Most people, I’ve discovered, have a very hard time thinking of organisms according to their clades. Part of that problem  is that it’s very hard to think of humanity as the last survivor what was once a diverse lineage that came out of same stock that gave us chimps and bonobos. If we were to adhere to cladistic classification, chimps and bonobos would have to be placed within our genus. We would either have to become part of Pan, or they would become part of Homo. The only reason this isn’t done is that this sort of classification would mess up the scientific names of all the transitional forms between our last common ancestor with chimps and bonobos and ourselves, and there actually are pretty big differences between the Australopithecines and Homo erectus.  Dogs and Holarctic wolves differ no more than 0.01 percent in their nuclear DNA sequences. Humans and chimps differ about 5 percent.

Of course, a dog is much more a wolf than a human is a chimpanzee. A dog is also much more a wolf than a human is the last common ape ancestor between humans and chimps. Dogs and wolves still exchange genes over the vast spaces of Eurasia and North America. They once did so far more often, when far more wolves lived near far more people and domestic dogs.

We live in a time when dogs are bred in closed registries, and too many dog people think of their favorite breeds as almost being distinct species unto themselves. Most dogs never see wolves. Most wolves never get to see free-roaming domestic dogs.

They could become separate species, but it would take a while. Even now, full reproductive isolation doesn’t exist in certain species in the genus Canis. Wolves mate with coyotes, which has caused some taxonomic wars with North American admixed canids like the so-called red wolf, and African wolves in Senegal have been known to breed with golden jackals.

Our species once existed with other human species. We could cross with neanderthals. We could cross with the Denisovan people. We are now alone, but dogs and wolves are still around with other species with which they can hybridize.

We are the species that does the classification, but we are the last survivors of our lineage. We used to think of Africans and indigenous Australians as distinct species from Caucasians. We did the same with people from Asia and indigenous Americans. We now know that, even though some of us are admixed with other extinct human species, we are all actually the same species and that the vast majority of our ancestry– no matter who we are– came from a single origin in East Africa.

We really aren’t that diverse. We’re really common, but when compared to chimps, we’re not that diverse at all.

But Canis lupus is a pretty diverse species, especially when you include African, South Indian, and Himalayan wolves to the species. Wolves are quite diverse in phenotype, ranging from 25-40-pound Arabian wolves that live on carrion and small game to 130-pound Alaskan wolves that live on moose. When you add domestic dogs to that classification, phenotypical diversity becomes even more explosive.

When you start thinking about wolves this way, they become something quite amazing. It’s really hard for us to think of pugs and arctic wolves as being the same species, but when you realize they are, it’s stunning what can happen through the forces of evolution through natural and artificial selection.

And when you put it into the context of the rest of life on this planet, it becomes humbling.

It all comes from these same processes.

That’s what amazed Charles Darwin.

And that’s what should amaze us.

So stop the cheap phylogeny denial.