Advertisements
Feeds:
Posts
Comments

Archive for the ‘dog domestication’ Category

new guinea dingo

One of the most annoying things about “dog people” is the constant jockeying for the prize of the “most ancient breed of dog.”  If you watch Westminster on television, I would say a third of the breeds are described as “ancient.”

Most of them aren’t that old, and even if they do resemble ancient forms of domestic dog, the modern day representative often has very little genetic connection to them.

So it was with jaundiced eyes when I saw the latest headline that “The world’s rarest and most ancient dog was discovered in the wild.”  The headline is clickbait, of course, because most people don’t have a clue about what was actually found.

Some camera traps caught images of a type of dingo called the “New Guinea Highland Dog,” which is a new name for the “New Guinea Singing Dog.”  It is a dingo that lives a semi-feral existence in the highlands of New Guinea. Note that I said “semi-feral,” because different indigenous groups in New Guinea have used these dogs and their descendants for hunting.  It lives in the wild, but it can be tamed.

Genetically, these animals are not vastly different from Australian dingoes, which lived in much the same way.  They could breed in the wild, but indigenous people used them to hunt things like tree kangaroos.

These dogs exist where there are no wolves and are found in cultures that are mostly involved in hunter-gatherer societies. These animals might give us a window into how hunter-gatherer people in the Paleolithic may have related toward wolves and perhaps give us an insight onto how domestication may have occurred.

But the problem with these dogs is that there are fantastical claims about them. When someone says this is “the most ancient breed of dog” one needs to understand something. The most complete genetic studies we have on dogs have revealed that this type of thinking is quite flawed. One of the big problems is that no domestic dog is more closely related to wolves than any other. The only exception are dogs that have actual modern wolf ancestry.

Dogs are derived from an extinct population of wolves, and yes, a recent genome comparison study says we have to call this ancestor “a wolf” if we are to adhere to cladistic classification.  The reason is that dogs split off from Eurasian wolves at about the same time Eurasian wolves split from North American wolves.

genome comparis fan wolves and dogs

Arbitrarily declaring dogs and dingoes a species makes the entire Canis lupus species paraphyletic, according to Fan et al.

Dingoes are commonly used in genetic studies about dogs and wolves. When compared to a large number of samples of different breeds and different wolves, they almost always group with East Asian domestic dogs, as this dingo did with a Chinese street dog.

Another study, which found initially reported dogs originating the Middle East (but has since been retracted in light of more recent evidence), also found that dingoes fit with East Asian domestic dogs.

dingoes fit with domestic dogs wayne

It is well-known that New Guinea dingo-type dogs can be recognized as dingoes using a genetic test that looks for only certain dingo markers.

So the animal that was found in the New Guinea Highlands is a dingo, and a dingo is an East Asian domestic dog that has gone feral.

Now, about the question of this dog being “the most ancient.”

One of the problems with saying a breed is the most ancient, as I pointed out before,  is that no breed of dog is more close to modern wolves than any other, and the other major problem with saying a breed is ancient using genetic studies is that many of these so-called “ancient breeds” are actually just populations of domestic dog that have been isolated from the main swarm of dogs. This gives a “breed-like” isolation that confers upon it some antiquity that really doesn’t exist.

Thus, we really can’t say that a breed is the “most ancient,” even with genetic studies.

What I think is more interesting in regard to dingoes and New Guinea singing dogs is that they represent a different permutation of domestication than the bulk of domestic dogs.

Domestication is a cultural process as well as biological. The vast majority of dogs in the world today are street and village dogs, which are very easily tamed if captured at the right age. This is the permutation of dog domestication that arose after the Neolithic Revolution, and it is still the rule when dealing with societies that have not engaged in extensive selective breeding for working characteristics in domestic dogs.  We also have a permutation in which free-roaming and freely breeding livestock guardian dogs accompany herds across grazing lands. Any dogs that show aggression towards stock are driven off or killed. Another permutation, which is older than either of these two, are the people who actually rely upon their dogs as hunters. Here, I am thinking of the laikas of Russia, which are used to bay up boar and moose and tree gamebirds and furbearers in much the same way the Jōmon relied upon their hunting dogs for survival.

The Western permutation of dog domestication has been to breed many specialized dog breeds and types. We’ve selected for much higher levels of biddability in some of our dogs. We’ve bred out quite a bit of aggression and predatory behavior. We’ve accentuated certain predatory behaviors, like pointing and retrieving, and we’ve produced dogs that look you right in the eye for approval.

Western dogs have been removed very much from wolves, and from our perspective, it looks like the dogs of different cultures are more ancient than our own. But that’s from our perspective. Our own Eurocentric perspective.

For example, the indigenous people of the Americas were very much involved in producing specialized dog breeds. The Salish bred their own wool dogs.  The Tahltan bear dog actually was used to hunt bears, even though it was quite small.  The hairless trait that exists in most hairless dogs actually originated in Pre-Columbian Mexico.

The truth is people all over the world have produced dog breeds and types that are distinct. The various forms of dingo that exist in Australasia are exactly the sort of dogs that would occur in hunter-gatherer societies that were not engaged in the selective breeding of working animals. Instead, they are societies that relied upon feral dogs to provide their own hunting dogs, which often reverted back to the feral existence once they hit breeding age.

This is not the permutation of Western dog domestication at all, and because it resembles the ancient way man may have related to wolves, a lot gets read into these dogs.

These dogs aren’t more or less ancient than any other dog on the planet, but they are dogs that give us a glimpse of what might have been.

That is the amazing story.

But, of course, dog people can’t leave an amazing story to be told on its own, so claims about these dogs are made that simply aren’t backed up by serious inquiry and scholarship.

Unfortunately, we’re always going to be dealing with these sorts of clickbait stories about ancient feral dogs, but that’s not what the genetic studies are revealing. And it is quite sad that we’re still dealing with the erroneous Canis hallstromi classification for the New Guinea dingo, as well as its attendant “dogs are not wolves” hypothesis, which has been as thoroughly debunked as the “birds are not dinosaurs” hypothesis.

So it is interesting that the New Guinea dingo still roams in the Highlands,  but I wish peole would be very careful of clickbait canid taxonomy.

 

 

 

 

 

Advertisements

Read Full Post »

chow-chow

Dog breed origins are often shrouded in a “creation myth.”  If you ever read an all-breed dog book, the official breed origins come across as awfully fanciful. Virtually every breed is regarded as ancient or derived from some private stock belonging to some notable:  Afghan hounds were the dogs Noah took on the Ark.  Beagles appear on the Bayeux Tapestry. Pharaoh hounds were the hunting  dogs of the Ancient Egyptian dynasties.

These stories posit the breed as being part of something deep in the past and maintaining the breeds is magnified as a way of paying homage to the past.

Some breeds are, however, pretty old, or at least genetically distinct from the rest of dogdom to be seen as something unique. Chow chows are a good example. They retain a lot of unique, primitive characters, and as East Asian primitive dogs, they may be among the oldest of strains still in existence.

Konrad Lorenz deeply admired the breed’s wolf-like attributes, believing they represented the best of the so-called “Lupus dogs.” Lorenz believed that most dogs were actually the descendants of golden jackals, and the dogs were friendly to most people and easily broken to fit the will of man. These were the “Aureus dogs.” But the dogs that were more aloof and more independent of the wishes of their masters were seen as the direct descendants of wolves. Lorenz preferred this type of dog, and he kept many chows and chow crosses in crosses as his own personal dogs and “study subjects.”

Lorenz later rejected the dichotomy between the jackal and wolf dogs, but the idea is still worth exploring. What Lorenz actually discovered was a profound division that exists in domestic dogs:  the primitive versus the derived.

In terms of evolution, an organism is considered primitive if it retains characters and behavior that are very like the ancestral form.  For example, lemurs are considered more primitive than other primates because they have the long muzzles and wet noses of the ancestral primates.

Primitive dogs are those that retain many features in common with the wolf. These features include erect ears, pointed muzzles, howling rather than barking, bitches having only one heat cycle per year,  pair-bonding behavior, and general tendency not to be obedient.  Many primitive dogs bond with only a single person, and in the most extreme cases, allow only that person to touch them.

Lots of “Nordic” breeds fall into this category, but this list also includes many of the drop-eared sighthounds from Central Asia, the Middle East, North Africa, and the Indian Subcontinent. It also includes many of the village dogs from undeveloped countries, as well as the semi-domesticated pariah dogs and dingoes.

The chow chow sort of fit between both Nordic breed type and the village dog type.  It has many of the features of the Nordic breeds– curled tail and prick ears– but it also has had a long history as a village dog in China, where it had periods in which it freely bred.

One would think that chow chow fanciers would be into celebrating their dogs as primitives, like owning something between wild and domestic.

But dog people being dog people are more than willing to add embellishments.

Westerners have done a lot to add to the bear-like features of the chow chow, which Konrad Lorenz actually castigated.

However, dog breeders will often go to great lengths to justify breeding decisions, including putting out absolute science fiction as scientific fact.

A few years ago, I heard an acquaintance mention that a well-educated chow owner she knew firmly believed that chow chow were derived from bears.

I laughed at it.  I did not think there was a serious discussion that chow chows were derived from bears.

And then I received notice of this website, which purports to have the full history of the chow chow. The history begins as follows:

It´s assumed that during the Miocene period (between 28 to 12 million years back), the evolution of the Hemicyon, an intermediary between the Cynoelesmus [sic], “father” of all the canine ones, and the Daphoneus [sic] – from which the bears descend as we know them today, – originated the Simocyon, an animal that varied between a fox and a small bear that inhabited in the sub-Arctic regions Siberia and the Northwest of Mongolia and of which it is known had 44 teeth.

I don’t know where this actually comes from, but it is entirely in ignorance of what we now know about the evolution of bears and dogs.  Dogs and bears are indeed closely related, but the division between the two is much deeper than the dates proposed here. Their most recent common ancestor was the ancestral stem-caniform miacid, which lived about 40 million years ago.  Most of the “ancestors” mention here are actually evolutionary dead ends that have little to do with modern bears or dogs.

First of all Hemicyon was not an intermediary between dogs and bears. The Hemicyon family was actually a branch of the bear lineage. Unlike the true bears, it was digitigrade and was probably a cursorial predator like wolves are today. The Hemicyon family lived between 11 and 17 million years ago, and it has left no living descendants.  That is, it is in no way an intermediary form between dogs and bears.

The author mentions “Cynoelesmus,” probably meaning Cynodesmus. My guess is this discrepancy comes from a poor cut-and-paste job, but although Cynodesmus was a primitive dog. It is not the ancestor of all living dogs. The ancestor of all living dogs was Leptocyon. Leptocyon was once considered part of Cynodesmus, but it is no longer.

The other two ancient creatures mentioned in the opening have nothing to do with bears or dogs.

“Daphoneus,” which refers to Daphoenus, a type of Amphicyonid. Amphicyonids were are really spectacular sister family to the canids, which had traits in common with both bears and dogs but really behaved more like big cats. This family has nothing to do with evolution of dogs, except that this is a sister lineage that went extinct.

Simocyon was actually something even a little bit cooler. It was not a dog. It was not a bear. It wasn’t even in the lineage of either family. Instead, it was a genus of leopard-sized animals much more closely related to the red panda. In case you were wondering, red pandas are not closely related to giant pandas. Giant pandas are actually a primitive form of bear. Red pandas are their own thing. Modern red pandas are the only species in their family known as Ailuridae. Millions of years ago, there were several species of red panda, and Simocyon was actually a large predatory red panda. Like the modern red panda, Simocyon had a thumb formed out of its sesamoid bone.  Giant pandas have this thumb, and it was thought to connect both modern species of panda.  Now, we know that the giant panda, which is a true bear, actually evolved its sesamoid thumb in parallel to the red panda. The red panda lineage evolved this trait so they could more easily climb in trees, while the giant panda evolved it to hold bamboo.

So that entire introduction to chow chow history is simply wrong. It may have been correct carnivoran paleontology at one point, but it also seems that the originators of this theory just went around looking for creatures that sounded like they might be fossil dogs that could be found in Asia.  “Cyon” does mean dog, but it doesn’t always refer to dogs in scientific names. Remember that there is a primitive whale the unfortunate name of “Basilosaurus,” which is in no way related to any lizard or dinosaur, and the raccoon family is called “Procyonids,” even though they aren’t that closely related to dogs.

Again, I don’t know why this theory is so popular, except that it can be used as a defense for breeding more and more bear-like features into chow chows than they had when they first came into the West. It’s also a way of making chows so much more super-special than the were before.

But it really makes chow fanciers look silly to anyone who has ever looked closely at carnivoran evolution.

It’s a fun story, but it’s not based in reality.

And when you get the paleontology this wrong, then virtually nothing of value can be trusted until the error is corrected.

Chows are cool as primitive dogs. They don’t need all the malarkey.

 

 

 

Read Full Post »

015

I keep running into this female Eastern box turtle when I am out and about. She is usually out looking for a place to lay her eggs, and because I know that her particular subspecies could become threatened in the near future, I don’t even touch her.

At one time in my life, I would have taken her home. Most rural children in my part of the world collect box turtles during the early summer and try to make pets out of them.

The truth is that this subspecies, the Eastern box turtle (Terrapene carolina carolina), actually makes a terrible pet. They become deeply attached to their home range, and taking them from their home ranges stresses them so much that they become susceptible to disease and parasites.

The Eastern box turtle is a subspecies of the common North American box turtle, which used to range up into Eastern Canada as well as most of the Midwestern and Eastern US.  We know only about its range in Canada from remains that have been dated to the sixteenth century, but now it is experiencing lots of problems in its range in the US. In the neighboring state of Ohio, it is a “Species of Concern,” but it is still pretty common here. I’ve seen little, tiny hatchling box turtles that aren’t much bigger than a quarter, but these little turtles aren’t maturing many parts of their range.

So I don’t recommend that anyone keep pet Eastern box turtles, especially those from wild populations. Many states ban the practice now.

Even if you have a box turtle as a pet, it requires a large enclosure, a high protein diet, and relatively high humidity.

But not all box turtles subspecies have the same problem with attachment to their home ranges than the Eastern subspecies has.

In the South-Central US. there is another subspecies of the common North American box turtle, which is called the three-toed box turtle (Terrapene carolina triunguis). I first saw these turtles at a pet store in Vienna, West Virginia, and I was amazed at how much they looked like the native subspecies. The main difference was they were mostly chocolate-brown in color and had three-toes on their back feet.

three-toed box turtle

I didn’t know at the time, but these three-toed box turtles were being offered as pets simply because they were found to be much better suited to captivity than the Eastern subspecies. They still require the humidity, the large enclosure, and the high protein diet.

However, they aren’t as greatly stressed from being removed from their native ranges, and as a result they are much better able to adapt to captive conditions.

When a three-toed box turtle is released into my part of the world, they often cross with Eastern box turtles. I have often suspected that the Eastern one at the top of this page might be a hybrid, simply because she lacks the extensive yellow markings on the head.

But that could simply be a variation in the Eastern subspecies.

Whatever the story of these two box turtles is I think they can tell us a lot about how to think of wolves and dogs.

Modern wolves are very difficult to domesticate, and they make terrible pets. Dogs, of course, do very well in the human environment.

Just like the box turtles, there are minor morphological differences between wolves and the less exaggerated breeds of domestic dog.

And when given the opportunity, dogs and wolves exchange genes.

I do not know how much DNA Eastern and three-toed box turtles share. My guess is they share far less than dogs and wolves do, simply because dogs and wolves are a highly mobile, relatively large species and species with those characteristics tend to have less diversity as a species. Regional box turtle populations are going to show greater distinctiveness than a wolf or dog population when compared to the entire species.

My guess is that the split between the two subspecies happened earlier than the split between dogs and wolves, too. T

But it’s not controversial that Eastern and three-toed box turtles are just separate subspecies. However, saying the same about dogs and wolves tends to launch people. That’s because there are political and sociological reasons for classifying dogs as a separate species from the wolf, which you can’t say about the two subspecies of box turtle.

But if we’re willing to say that these two box turtles are part of a single species, what level of mental gymnastics are we willing to engage in to keep wolves and dogs separate species?

I know the answer to that question, I’m afraid.

Read Full Post »

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.

Read Full Post »

The Promise

Source.

Read Full Post »

pekin duck

One of the more bizarre fights that happens in the world of dogs is how to classify them. Within these debate is always a background of what it actually means to care for a dog “naturally” and what their “natural” life should be.

It actually shouldn’t be this way. Whether one considers a dog to be its own species or a subspecies of Canis lupus, there is no natural way to care for them or natural life for them. That’s because a dog is a domestic animal, the oldest of domestic animals, and there is very little that is natural about them. Over the thousands of years that have been part of human societies, they have adapted very nicely to our needs. Dogs have even developed cognitive short-cuts that have made them better readers of human body language than virtually any other animal, wild or domestic.

The natural way of keeping a dog is that a dog lives with people. It’s an oddball among domestic animals in that is derived from a very old domestication, and it is also the only large carnivoran that has ever been domesticated. Almost all other domestic animals are herbivores, and the other domestic carnivorans–the Near Eastern wildcat, the European ferret, and the red fox– are all small species. Most large carnivorans consider humans to be prey, so there is something very unusual about domestic dogs.

I get that.

But I am not among those who thinks that there is a species called Canis familiaris. I think dogs are most correctly classified as a subspecies of Canis lupus. 

As soon as I say this, people just lose it. That’s because when you say this, it is almost like justifying abusive dog training methods that are based upon dominance. It also might be justifying raw feeding, which is also contentious issue in the world of dogs.

Those are implications that I soundly reject. There is nothing inherent in a classification of an organism that tells you how to feed it or train it, especially when you’re dealing with the real oddball among domestic animals.

Note that it is never controversial to say that a pekin duck is a mallard. In the photo at the top of the page, you can see the old pekin drake that used to rule the pond. His mate was that Rouen-cross hen, which was sold at a feed store as a mallard. They were both of the same species. Her ancestors were some kind of Western Europe mallard, while his were wild mallards living around Nanjing that were later transplanted to the area around Beijing, where they were selected for larger size and white plumage.

Both of these animals were quite different from the true wild mallard that I see swimming in rivers here in West Virginia. She was twice the size of a wild mallard hen and much darker in color, and he was three times the size of wild drake. Neither of them could fly very well. The Khaki Campbell crosses in the photo were actually much better fliers than either of them.

Performance-strain Rouens are not far removed from the wild mallard. Although they are larger and cannot fly, they still produce the large amounts of oil in their plumage that keep them warm and dry even when they swim the coldest water. Female Rouens also retain the brooding instinct and can hatch out their offspring.

Pekins don’t produce as much oil and aren’t as cold tolerant, and if incubators didn’t exist, there would be far fewer pekin ducks in this world. Most pekin hens have no broody instinct. Further, they also grow so much more rapidly the either Rouens or wild mallards that they are prone to growth disorders.

Even though it is so far removed from the wild mallard, the pekin duck is still a mallard. It is as much a modification on a mallard as a St. Bernard is on a wolf.

The only difference is that no one is going to launch into a culture war tirade over the classification of a pekin duck, but if you say a St. Bernard is a wolf, then you will be asking for it.

It is certainly true that dog domestication happened a lot longer than mallard duck domestication. I cannot find any good literature on dates for mallard domestication, but it’s pretty clear that ducks have been kept in Southeast Asia for thousands of years.  Dog domestication dates and locations are still quite contentious, but the best evidence I’ve seen suggests that they were domesticated from an extinct wolf population between 15,000 and 32,000 years ago.

Some will argue that this extinct wolf population actually is a different species from modern Canis lupus, but I’m quite skeptical. Wolves themselves are among the most varied species in the wild. If we were to go back in time  see that ancestral wolf population that gave rise to domestic dogs, I think it would be hard to say that they weren’t within the diversity of phenotype that we see in current Canis lupus populations.

I think the big difference is that these wolves had far fewer reasons to fear people and were actually quite curious about our kind and were actually fairly easy to habituate to living near us. Over time, these wolves became incorporated into our society.

Much has been made that dogs and wolves have different reproductive strategies, but the truth is wolves actually have two reproductive strategies. One of these is the pair bond, where a male and female become partners and their grown offspring help care for the puppies. This is the most successful strategy for wolf reproduction because all the resources and attention of the pack can be devoted to a single litter. Another strategy goes on in parallel. Young male wolves leave their natal packs, but they often cannot find a mate or suitable territory. So they often try to mate with the grown daughters that are part of an established pack. These daughters cannot mate with their father, who is pair-bonded to their mother, who will attack them if she catches them in the act. So these females do often mate with these roaming male wolves. They often become pregnant and even have puppies, but in the wild, they almost never get a chance to raise those pups.  In the early years of wolf reintroduction to Yellowstone, prey was so abundant that many packs raised multiple litters every year. One would be born to the mated pair, while others would be born to these unpaired daughters and the roaming males. The way dog genes get into wolf populations is almost always when one of these non-paired females in a pack hooks up with a roaming male dog, which is why dog hybridization in European wolves went unnoticed. Most studies on wolf DNA looked at mitochondrial DNA alone, and if a wolf had dog ancestry coming from a male dog, it simply never would have been noticed.

The pair bond strategy exists because it about the only way to raise wolf pups. It is very common in all other dog species. In fact, a study of Chicago coyotes revealed that they are almost 100 percent monogamous, and similar findings have been discovered in golden jackals. However, in a wolf pack, preference toward the bonded pair during the mating season means lots of stress. They mated pair has to spend lots of time making sure no one mates with the wrong wolf, and they also will try to kill any of the roaming males that come near the unpaired females, which is also why the roaming male strategy isn’t as successful with wolves.  Natural selection would favor pair-bonding over roaming male mating strategies.

Domestication changed this equation. When wolves began to hook up with people, people began to provide food.  These wolves may have pair-bonded and mated in that fashion, but the chances of these secondary females to raise litters to maturity were much greater. Over time, pups born to roamers and unpaired females would start to outnumber those that were born to the pair-bonded wolves, and thus, a relaxation of selection pressures for pair bonding would become ubiquitous in these wolves. When pair-bonding became broken, then it became easier to selectively breed them. One could have a stud that mates with many females, and this promiscuous behavior could have been heavily selected for. Dogs are able to reproduce at much faster rates than wolves do, and one of the weird effects of domestication has been that female dogs are no longer monestrus and become sexually mature at younger ages than wolves or virtually any other wild dog.

Dogs and wolves have continued to exchange genes since the initial split. Black wolves in North America derive from domestic dogs that mated with wolves, as do black Italian wolves.  Wolves in Italy also can have dewclaws on their hind legs, which also originated from dog and wolf matings. Historians ranging form Pliny the Elder to the Plott hound historian Bob Plott have documented cases of hunters breeding their dogs with wolves, a practice that still goes in parts of Russia. It was just recently revealed that the livestock guardian dogs of Georgia have a rather significant amount of gene flow with the wolves of the same region.

So yes, I do recognize there are differences between wolves and dogs, but dog is a modification on the original wolf template.

The final important reason why I classify dogs as being part of the wolf species is that evolution has within it a nested law. This is the law of common descent. One can never evolve out of one’s ancestry. Humans are always going to be great apes, and humans are always going to be primates, not matter how different we become from our ancestors. A whale will always be a mammal, even if it somehow evolved gills.

A dog is always going to be a wolf. We change them through selective breeding, as we have with all our other domestic animals, but we are never going to change their fundamental ancestry.

All that I’m doing when I use Canis lupus familiaris is that I’m putting dogs where they fit on the tree of life. I’m showing my respect to their evolutionary heritage. I am paying homage to their phylogeny.

I’m not making excuses for Cesar Millan or anyone else.

Many people who promote science in our understanding of dogs are actually engaging in what I call “phylogeny denial.”  Many people bend over backwards to show how dogs aren’t like wolves, which I supposed is harmless, but I think it gives people a false impression of what a dog actually is in terms of its evolutionary history. It’s not a domesticated golden jackal or coyote or African wild dog. It is a domesticated ancient wolf, but that wolf was just an older form of the modern Canis lupus.

When you classify an animal according to its phylogeny, you aren’t doing anything else but classifying it. If a whale is a mammal, it does not automatically follow that it is a land mammal, does it? And classifying a dog a subspecies of wolf doesn’t mean that it evolved to hunt moose in Alaska.

I really wish people were taught to think about natural history in this fashion more often. It clarifies a lot of misconceptions people have about evolution. If I had a nickel for every time I get asked about humans evolving from modern chimpanzees, then I’d be a pretty wealthy individual. The last common ancestor between humans and chimps was not a chimpanzee. It may have looked more like a chimpanzee, because chimpanzees retain a lot more of the original African ape’s features than humans do, but it was not a chimpanzee like we have today.

By contrast, the wolves that gave rise to domestic dogs were probably indistinguishable from Eurasian wolves living today. Further, dogs and wolves continue to affect each other’s evolution through a rather significant gene flow. Humans affect chimpanzee evolution only through hunting them for bushmeat, destroying their forest habitats, and spreading disease. There is no gene flow between the two species, and because we have a different chromosome number, any “humanzees” would likely be sterile.

Finally, Canis familiaris creates a stumbling block in understanding the natural history of dogs, which is why you still run into people who think dogs derive from any number of different species of wild dog. Canis lupus familiaris neatens up that confusion very nicely.

Classifying a dog as a wolf shouldn’t be any more controversial than classifying a pekin as a mallard, but dog people just have a much harder time thinking in this way. I have never seen an internet flame war erupt between pekin duck owners over the classification of their ducks. In fact, I don’t think many pekin duck owners actually know that their ducks are mallards and do not actually occur anywhere in the wild.

But with dogs, charlatans have used the dog as wolf idea to justify all sorts of bad human behavior towards dog, but scientific facts remain scientific facts, whether charlatans misuse them or not. In terms of their ancestry, as has been revealed through copious analyses of their DNA, dogs are in the Canis lupus lineage.

They simply aren’t anywhere else in the tree of life. This is where they belong. Accept it, and move on.

 

 

 

 

Read Full Post »

skull 1

A recent study of pit bull skulls using 3-D imaging technology has revealed that they have skull measurements that are more similar to the extinct canids in the genus Borophagus. Further analysis involving SNP technology revealed that the average of 24.6 percent ancestry that is from a canid that is neither wolf nor domestic dog.

Abbott Millard, a canid researcher with the Dog Origins Project, has performed the 3-D imaging research, which included 130 pit bull skulls. His a comparison with the measurements of the pit bull skulls with those of several extant and extinct canids.

“Our results show that pit bulls have skull morphology most similar to the extinct dogs of the genus Borophagus. These results were quite shocking because Borophagus has been classified with an extinct group of canids that were thought not be related to modern dogs at all,” said Millard.

However, knowing that canids have a tendency towards convergent evolution in skull morphology, it is quite possible that pit bulls, a breed known for its massive jaw strength, evolved similar jaws to the Borphagus through similar selection pressures.

Which is why the Dog Origins Project decided to do some research on pit bull DNA. The researchers used SNP chip technology, which allows for extensive genome-wide assays. Similar research has been used to disprove East Asian origins for the domestic dog and raised real questions about the taxonomic status of the red wolf.

Otto Klinger, lead geneticist at the Dog Origins Project, compared DNA from 20 pit bulls, 15 boxers, 4 dingoes, 6 wolves from 4 different regions in the Old World, 12 coyotes, and 3 golden jackals. Pit bulls were found to be mostly domestic dog in origin, but a large sample of their genetic material didn’t match any extant canid.

“It is possible that this mystery canid was actually an undocumented wolf subspecies, but the finding that pit bulls have similar skulls to the Borophagus raises intriguing questions. It could mean that the pit bull terrier developed in America was crossed with a relict population of Borophagus,” said Klinger, “There are many mentions of strange wolves in the colonial literature that might be very suggestive of Borophagus, and there are mentions of blocky-headed wolfdogs belonging to the Algonquin peoples of the Northeast. Maybe these dogs and wolves were the relict Borophagus. They certainly would have been great fighting dogs.”

The discovery of the hybrid origin for the pit bull, though, does raise some important questions.

Millard believes that these studies mean that pit bulls deserve their own species status:

“The hybrid origin of the pit bull strongly suggests that we should not be classifying pit bulls as part of the greater dog species. We propose that the scientific name for the new pit bull species be Canis horribilus. Pit bulls are the grizzly bears of the dog world, so we think that we should use the grizzly bear’s name [Ursus arctos horribilus] to define the pit bull.”

With this new definitive DNA research on pit bulls, breed specific legislation will now be much easier to enforce, and the Dog Origin Project plans on donating its findings to law enforcement to develop a definitive pit bull genetic test.

“Our research will now have a positive impact upon society. I can’t tell you how thrilled I am wih the possibilities!” said Klinger.

So we now know why pit bulls are so different from other dogs. They are hybrids with a mystery canid that might be a survivor from the days of the ancient Borophaginae.

*The above is an April Fools’ prank. Not a single word of it is factual. Reposting or quoting this article as if it were fact will make you look extremely stupid.

 

 

 

 

Read Full Post »

Older Posts »

%d bloggers like this: