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Posts Tagged ‘Chihuahua origins’

Fennec foxes are not the ancestors of Chihuahuas. If you believe this, you’ll believe anything.

As we’ve looked more closely at dog DNA and compared it to other Canid species, a very consistent fact has been confirmed time and again.

Domestic dogs are very closely related to Eurasian wolves.

Most of the genetic literature on dog origins is hotly contested.

But the ancestral species is not.

Dog DNA is wolf DNA.

It may be  that the wolf is the sole ancestor of the domestic dog.

However, there are four species that are chemically interfertile with each other.

The dog and wolf species, Canis lupus, has produced fertile hybrids with Ethiopian wolves (Canis simensis), golden jackals (Canis aureus), and the coyote (Canis latrans).  Dingoes and New Guinea singing dogs (which should be called “New Guinea dingoes”) are feral landraces of domestic dogs and belong to the dog and wolf species.   We know that all of these animals are chemically interfertile only thorugh circumstantial evidence. Because dogs are derived from wolves and have mated with Ethiopian wolves and produced fertile offspring, we know they all can. Ethiopian wolves are the most distantly related species of the interfertile Canis from the dog and wolf species. If they can interbreed and produce fertile offspring, then they all can.

Thus far, no one has found any genetic markers in domestic dogs from any of these other interfertile species. They might be there. In fact, they likely are.

But any genetic material found from these species is very likely to be trivial.

The only dogs that are known to have the blood of species other than wolves in them are things like the Sulimov dogs, which have golden jackal blood in them, and the intentionally and accidentally bred coydogs.

We might even find genetic material dire wolf or other extinct Canis species in domestic dogs, especially if we’re looking at DNA samples from ancient dogs. (There is some evidence that dire wolves were domesticated by the Clovis people.)

But none of these facts would change what the primary ancestor of the domestic dog is.

Their DNA is overwhelming the same as Eurasian wolves.

Thus, we should think of dogs as being domesticated wolves.

That’s what the evidence shows. One can split hairs and say that dogs have a different ecological niche than wolves and classify them as their own species– which is classically Canis familiaris. But the phylogeny of Canis familiaris stems so closely and so directly from Canis lupus that it makes more sense to call them Canis lupus familiaris.

But for whatever reason, these facts are rejected everywhere.

And not just in fringe publications or on e-mail lists where lots of lunatic “experts” like to hang out.

Perhaps the most recent author of any authority to make claims that domestic dogs are derived from multiple species is Stanley Coren.

In The Intelligence of Dogs, Coren contends that a wide variety of species played a role in developing the domestic dog.   He repeats the falsehood that basenjis and Rhodesian ridgebacks are derived from the African wild dog (Lycaon pictus), even though this animal has never interbred with a domestic dog and probably cannot.  And even if it could, the offspring would likely be sterile, as we’ve seen when silver phase red foxes have been bred to blue phase arctic foxes.

Coren’s book came out in the mid-90’s, and we’ve since learned many thing about dog origins since then. However, Coren repeated the same claim that basenjis were derived from African wild dog in How to Speak Dog, which came out in 2001.

By that time, I don’t think anyone was seriously considering the African wild dog as a potential ancestor to any domestic dog breed. In fact, by that time, there were moves among conservationists working to save this species to change the common name for this species. Calling them “African wild dogs” was causing lots of confusion. People were considering them feral dogs, and in some areas, they were being killed as an invasive species.  The truth is that they are likely a descendant of an early wolf-like Canis relative– Xenocyon lycaonoides–  that once roamed over most of Africa and Eurasia.  The African wild dog and the dhole maybe the surviving descendants of this early wolf-like species.

Coren also claims that jackals are an ancestor of domestic dogs. But the phylogenetic tree that was drawn from sequencing the dog genome revealed that jackals are not monophyletic. Golden jackals are in a clade with wolves/dogs, coyotes, and Ethiopian wolves. The other two species of jackal– the black-backed jackal (Canis mesomelas) and side-striped jackal (Canis adustus)– are even more distantly related to the clade that includes wolves/dogs, coyotes, and golden jackals than the dhole and African wild dog are.

These two jackals cannot cross with dogs. Lots of people claim they can and will often point to domestic dogs in Africa with jackal-like features. Those dogs are not evidence of cross-breeding. No one has confirmed a black-backed jackal/dog hybrid with any DNA test.

These hybrids exist only in urban legends.

But if these memes won’t die even with experts like Stanley Coren, they have a lot of legs among the laypeople.

If you want to see what I mean, check out the comments on my post about why Chihuahuas can’t be derived from fennec foxes (Vulpes zerda).  No, they can’t be– even though they look so much alike!

Here are some gems:

I’d be interested to know what kind of “research” Claire was engaged in. My guess is she was playing with Google, and looking up romantic breed origin myths. That’s not really research.

I answered Claire that Chihuahuas and other small breeds have a gene that makes them small, which is very closely related to a smallness gene that is found in Middle Eastern wolves. One subspecies of Middle Eastern wolf, the Arabian wolf (C. l. arabs) is often quite small, sometimes weighing only 25 pounds.

As I noted earlier in this post, no one has found any genetic markers or genes from other species in domestic dogs, and what’s more, they’d have to come from species with which dogs can interbreed.  Dogs cannot interbreed with any kind of fox in the genus Vulpes.  If arctic and red foxes produce only sterile offspring when hybridized, the chances of them ever being able to breed with anything as distantly related as a dog have to be a zero percent.

Then comes Phoebe. Phoebe tries to through God at me.

Phoebe appears to be functionally illiterate. The study I quoted came out in 2010, not 1993.

There are no proven facts that Chihuahuas are derived from anything other than wolves. All the evidence shows they are toy dogs, and at least with AKC Chihuahuas, they are primarily derived from European dogs.

The origin and ancestry of Chihuahuas is not a theological question. It is not a matter of belief or opinion. It is a hypothesis that we can test empirically. And when we test these hypotheses, their results are not determined by the belief of the majority.

If the majority of Chihuahua owners think their dogs are derived from fennec foxes, this does not make them correct.

If the evidence shows them to be derived from wolves, then the majority Chihuahua owners are wrong.

And then there is Cindy, who just quotes some website. Everything on the internet is true, right?

Yeah. That website totally falsifies all the peer-reviewed papers that show that Chihuahuas are derived from wolves!

But the final one is the best one!

Murray Richardson seems to think lots of bizarre things about dog taxonomy!

Almost everything he claims to be fact in that comment is false.

Chihuahuas have unusual teeth because they are brachycephalic. They don’t have rooms in their mouths for all their teeth. They would have normal dog dentition if they had normal mouths. Strike one!

Chihuahuas and all dogs have round pupils, as do wolves. Vulpine foxes, like fennec foxes, have cat-like pupils. Swing and a miss!

No North American wild fox has any dog DNA. That “fact” was entirely rectally derived. Strike three! You’re out!

And Chihuahuas don’t need to drink water? WTF?!

When was the last time anyone crossed a fennec with a maltese?  I don’t know, but people do keep fennecs and dogs togehter. Fennecs are a relatively common exotic pet in the United States. I’ve never heard of any crossbreeding or if dogs even respond to a fennec vixen in heat. Domestic dogs don’t respond to red foxes in heat, so why would they respond to the fennec?

I hoped that Murray Richardson was just pulling my leg.

But I was wrong.

Because he came back with this canard.

Facepalm.

Murray seems to believe that all wolves are very large animals, probably because the only ones he’s seen on TV have been of the several subspecies that are native to Canada, Alaska, and parts of the Northern US.

There actually are wolves that are much smaller than these rather famous subspecies. Arabian wolves, which have a similar smallness gene to small domestic dogs, aren’t like these animals at all. A 25-pound wolf can easily become a 3-pound Chihuahua through selective breeding.

After all, we’ve bred tiny horses through selective breeding, along with very small pigs. I don’t know of anyone making claims that these little animals have to have been derived from different ancestors.

Why can’t selective breeding produce super-small dogs?

I wonder what it is about Chihuahuas that makes people believe something so patently absurd.

But I think the unfortunate thing is that so many experts have given license to this nonsense.

Charles Darwin thought that several species begat the dog.

Charles Darwin lived long before we looked at DNA or even knew what it was.

He didn’t know everything.

He was not a religious prophet.

He was a scientist who was constrained to his time and place.

Konrad Lorenz also believed that most dogs were derived from jackals (which he called “aureus dogs”) and that others were derived from wolves (“lupus dogs.”)  He later dropped all of this nonsense after listening to the vocalizations of dogs, wolves, and golden jackals.

But by then, he’d already written several books in which he had posited this theory, and it had already been accepted by so many people that one can still run into people who will parrot this lupus and aureus dog dichotomy.

In the end, I think people still have a hard time accepting that dogs are derived from wolves.

Wolves are the only large predator that we have managed to domesticate.

It’s the only domestic animal that is derived from an ancestor that has occasionally considered humans to be prey.

Paradoxically, it’s also the domestic animal with which we have the most intimate relationships. Even cats don’t open themselves up to us in the profound ways dogs do.

How can we have an intimate relationship with an animal whose wild ancestors occasionally hunted humans?

That’s the cognitive block that keeps people from accepting the lupine origins of domestic dogs.

For much of human history, killing off wolves was seen as a great service to civilization.

It’s only been in the last 40 years that we’ve changed our views about wolves.

At the same time, breeding and training dogs that are useful for humanity has also been considered useful for civilization.

Accepting that the useful dog is derived from the much-maligned wolf is really quite difficult.

And that’s a major reason why people have such a hard time accepting that the wolf is ancestor of  rhe dog.

The other reason– and the one I think is driving these Chihuahua loons– is that owners of a particular dog breed like to believe that their dogs are super special.

Nothing makes them more super special than to say they derive from an entirely different wild ancestor than other dogs.

It becomes almost a theological discussion when trying to convince them of their error.

These sorts of theories and postulates should be severely ridiculed and debunked when one comes across them.

They are as bad as any kind of creationism, and they prevent any sort of rational discussion about what a dog actually is.

These theories are just mythology.

And there are already too many myths about dogs and what they are floating around.

These particular myths are relatively harmless, but accepting these really poorly thought-out theories means that one might be willing to accept ones that do result in lots of harm to the welfare of the animal.

The notion that Chihuahuas don’t need water because they are derived from fennec foxes really would have a welfare consequence.

I can just see all these Chihuahuas dying of hyperthermia or dehydration because their owners buy into that particular cock-and-bull story.

Facts are stubborn.

And just because you believe a falsehood with a lot of fervor doesn’t mean that it stops being a falsehood.

It just means you like to be wrong with a lot of fervor.

And you look like a fool!

 

 

 

 

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Yet another celebrity has passed away.

The Taco Bell Chihuahua has died at the age of 15.

Although voiced by a man, the Taco Bell dog was actually a female named “Gidget.”

Her trainer reports that Gidget had had normal day with nothing to suggest that she was ill in any way.

Then while the trainer was watching television, Gidget  “began making ‘strange noises’ and suffered a stroke.”

Another icon is gone, but I certainly hope we aren’t talking about this a month from now, wondering who will get custody of her pups or whether the vet prescribed too many drugs for her.

***

Now, I’ve always been peeved at the grammar in those commercials. “Yo” means “I.” However, it’s almost never used in Spanish sentences, because “Quiero” is used only as a first person. “Yo” is simply redundant.

***

Now, Gidget was a faulty dog by show dog enthusiasts.

You see, Chihuahuas must have what is called an “apple head.”

apple head chihuahua

Apple heads are very different from Gidget.

I have not seen any studies on this condition, but I think we can at least question whether apple headed dogs might be predisposed to hydrocephaly, which is a bit of a problem in Chihuahuas.

Gidget was what is called a “deer-headed” Chihuahua. They aren’t preferred in the show ring.

But somehow I doubt that the Mexican pariah dogs that are the ancestors of the Chihuahua had these apple heads. Apple heads were very common in “English white terriers,” which I’ve always suspected were a partial ancestor of the modern Chihuahua.

The modern dog is really an invention of the show ring. We have some evidence of what these dogs might have looked like in Mexican and Meso-American Art, but I think the best evidence from which we can infer some idea of what they originally looked like. I think the breed that gives us the best idea isn’t from Mexico but from Western Canada. The Tahlta people kept a small hunting dog called the Tahltan bear dog. (Here’s another photo.)

*Yes, they were used to hunt bears, which explains why so many Chihuahuas have good prey drive. My grandpa even used his little Chihuahua bitch to flush grouse and tree squirrels, which further adds evidence to my theory that the two were related.

And then there is a dog called Techichi, which is probably the Mexican version of this little Native American dog.

Then they were crossed with small terriers, toy spaniels, and toy spitz breeds to produce the modern Chihuahua.

The apple heads look cool in the show ring. I don’t think they are of much use to the dogs or in keeping with their ancestry.

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