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Posts Tagged ‘dog domestication’

kenya black-backed jackal

We think of interactions between predators as always antagonistic.  Meat is hard to come by, and if one comes by meat on the hoof, it is unlikely that the owner-operator of said flesh will give it up willingly.   Meat is a prized food source, and it is little wonder that most predators spend quite a bit of energy driving out competitors from hunting grounds.

Because of this antagonism, the domestication of wolves by ancient hunter-gatherers is difficult to explain. Indeed, the general way of getting wolves associated with people is see them as scavengers that gradually evolved to fear our species less.

This idea is pretty heavily promoted in the dog domestication literature, for it is difficult for experts to see how wolves could have been brought into the human fold any other way.

But there are still writers out there who posit a somewhat different course for dog domestication.  Their main contentions are that scavengers don’t typically endear themselves to those from which they are robbing, and further, the hunter-gatherers of the Pleistocene did not produce enough waste to maintain a scavenging population of wolves.

It is virtually impossible to recreate the conditions in which some wolves hooked up with people. With the exception of those living on the some the Queen Elizabeth Islands, every extant wolf population has been persecuted heavily by man. Wolves generally avoid people, and there has been a selection pressure through our centuries of heavy hunting for wolves to have extreme fear and reactivity. It is unlikely that the wolves that were first encountered on the Mammoth Steppe were shy and retiring creatures. They would have been like the unpersecuted wolves of Ellesmere, often approaching humans with bold curiosity.

As I have noted in an earlier post, those Ellesmere wolves are an important population that have important clues to how dog domestication might have happened, but the truth of the matter is that no analogous population of wolves or other wild canids exists in which cooperation with humans is a major part of the survival strategy. The wolves on Ellesmere are not fed by anyone, but they don’t rely upon people for anything.

But they are still curious about our species, and their behavior is so tantalizing. Yet it is missing that cooperative analogy that might help us understand more.

I’ve searched the literature for this analogy. I’ve come up short every time. The much-celebrated cooperation between American badgers and coyotes is still quite controversial, and most experts now don’t believe the two species cooperate.  Instead, they think the badger goes digging for ground squirrels, and the coyote stand outside the burrow entrance waiting for the prey to bolt out as the badger’s digging approaches its innermost hiding place in the den. The coyote gets the squirrel, and the badger wastes energy on its digging.

But there is a story that is hard to dispute. It has only been recorded once, but it is so tantalizing that I cannot ignore it.

Randall Eaton observed some rather unusual behavior between black-backed jackals and cheetahs in Nairobi National Park in 1966.

Both of these species do engage in cooperative hunting behavior. Black-backed jackals often work together to hunt gazelles and other small antelope, and they are well-known to work together to kill Cape fur seal pups on Namibia’s Skeleton Coast. Male cheetahs form coalitions that work together to defend territory and to hunt cooperatively.

However, the two species generally have a hostile relationship. Cheetahs do occasionally prey upon black-backed jackals, and black-backed jackals will often mob a cheetah after it has made a kill, in hopes of forcing the cat to abandon all that meat.

So these animals usually cannot stand each other, and their interactions are not roseate in the least. Eaton described the “normal interaction” as follows:

The normal interaction between these two predators occurs when the jackals hunt in the late afternoon and come into a group of cheetahs. The jackals, often four or five, are normally spread out over several hundred yards and maintain contact by barking as they move. When cheetahs are encountered by one of the jackals, it barks to the others and they all come to the cheetahs, sniffing the air as they approach apparently looking for a kill. If the cheetahs are not on a kill, the jackals search the immediate area looking for a carcass that might have just been left by the cheetahs. If nothing is found, they remain near the cheetahs for some time, following them as they move ; and when a kill is made the jackals feed on the leftover carcass. If the cheetahs have already fed and are inactive and if a carcass is not found nearby, the jackals move on.

However, Eaton discovered that one particular group of jackals and one female cheetah had developed a different strategy:

At the time I was there in November, 1966, one area of the park was often frequented by a female cheetah with four cubs and was also the territory of a pair of jackals with three pups. The jackal young remained at the den while the adults hunted either singly or together. Upon encountering the cheetah family, the jackals approached to about 20 yards and barked but were ignored except for an occasional chase by the cubs. The jackals ran back and forth barking between the cheetahs and a herd of Grant’s gazelles (Gazella granti) feeding nearby. The two jackals had gone on to hunt and were almost out of sight by the time the adult cheetah attacked two male Grant’s gazelles that had grazed away from the herd. The hunt was not successful. The jackals took notice of the chase and returned to look for a kill ; it appeared that they associated food with the presence of the cheetahs and perhaps with the chase.

One month later, while observing the same cheetah family, I noticed that the entire jackal family was hunting as a group. The cheetah and her cubs were about 300 yards from a herd of mixed species. This same herd had earlier spotted the cheetahs and given alarm calls. The adult cheetah was too far away for an attack,there was little or no stalking cover and the herd was aware of her presence. The cheetahs had been lying in the shade for about one-half an hour since the herd spotted them when the jackals arrived. Upon discovering the cheetahs lying under an Acacia tree, one of the adult jackals barked until the others were congregated around the cheetah family. The jackal that had found the cheetahs crawled to within ten feet of the adult cheetah which did not respond. The jackal then stood up and made a very pneumatic sound by forcing air out of the lungs in short staccato bursts. This same jackal turned towards the game herd, ran to it and, upon reaching it, ran back and forth barking. The individuals of the herd watched the jackal intently. The cheetah sat up and watched the herd as soon as it became preoccupied with the activity of the jackal. Then the cheetah quickly got up and ran at half-speed toward the herd, getting to within 100 yards before being seen by the herd. The prey animals then took flight while the cheetah pursued an impala at full speed.

Upon catching the impala and making the kill, the cheetah called to its cubs to come and eat. After the cheetahs had eaten their fill and moved away from the carcass, the waiting jackals then fed on the remains.

Eaton made several observations of this jackal family working with this female cheetah, and by his calculations, the cheetah was twice as successful when the jackals harassed the herds to aid her stalk.

Eaton made note of this behavior and speculated that this sort of cooperative hunting could have been what facilitated dog domestication:

If cheetah and jackal can learn to hunt mutually then it is to be expected that man’s presence for hundreds, of thousands of years in areas with scavenging canines would have led to cooperative hunting between the two. In fact, it is hard to believe otherwise. It is equally possible that it was man who scavenged the canid and thereby established a symbiosis. Perhaps this symbiosis facilitated the learning of effective social hunting by hominids. Selection may have favored just such an inter-specific cooperation.

Agriculture probably ended the importance of hunting as the binding force between man and dog and sponsored the more intensive artificial selection of breeds for various uses. It is possible that until this period men lived closely with canids that in fossil form are indistinguishable from wild stock (Zeuner, 1954).

Domestication may have occurred through both hunting symbiosis and agricultural life; however, a hunting relationship probably led to the first domestication. Fossil evidence may eventually reconstruct behavioral associations between early man and canids.

Wolves are much more social and much more skilled as cooperative hunters than black-backed jackals are. Humans have a complex language and a culture through which techniques and technology can be passed from generation to generation.

So it is possible that a hunting relationship between man and wolf in the Paleolithic could have been maintained over many generations.

The cheetah had no way of teaching her cubs to let the jackals aid their stalks, and one family of jackals is just not enough to create a population of cheetah assistants.

But humans and these unpersecuted Eurasian wolves of the Pleistocene certainly could create these conditions.

I imagine that the earliest wolf-assisted hunts went much like these jackal-cheetah hunts. Wolves are always testing prey to assess weakness. If a large deer species or wild horse is not weak, it will stand and confront the wolves, and in doing so, it would be exposing itself to a spear being thrown in its direction.

If you’ve ever tried a low-carbohydrate diet, you will know that your body will crave fat. Our brains require quite a bit of caloric intake from fat to keep us going, which is one of those very real costs of having such a large brain. Killing ungulates that stood to fight off wolves meant that would target healthy animals in the herds, and healthy animals have more fat for our big brains.

Thus, working together with wolves would give those humans an advantage, and the wolves would be able to get meat with less effort.

So maybe working together with these Ellesmere-like wolves that lived in Eurasia during the Paleolithic made us both more effective predators, and unlike with the cheetah and the black-backed jackals, human intelligence, language, and cultural transmission allowed this cooperation to go on over generations.

Eaton may have stumbled onto the secret of dog domestication. It takes more than the odd population of scavenging canids to lay the foundations for this unusual domestication. Human agency and foresight joined with the simple cooperative nature of the beasts to make it happen.

 

 

 

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atila and the wolf

Photo by Tanja Askani.

In paleontology, a group of scholars exists largely on the fringe of the discipline. No matter what evidence is provided, they find some way to pump out a paper that says that birds cannot be dinosaurs. An established scholar or two will the publish and beat them down, but there is still an idea in the public mind that there is a debate between dinosaur experts about whether birds are a specific type of theropod dinosaur.

These scholars are known as BAND (“birds are not dinosaurs”), and they do get the attention of the popular press, even if ignored by the mainstream scholarship.

I’ve noticed in that in all my years writing about dogs and their taxonomy that there is a similar group in this sphere as well.  The difference is this group had the backing of one of the leading authorities on dogs in the world, Raymond Coppinger.

Coppinger was certain that dogs had to be classified as Canis familiaris, based upon a very crude ecological species concept. Village dogs that scavenge off human civilization hold a different niche than pack-hunting wolves, ergo, they are different species. Never mind that if we applied that same standard strictly, Arabian wolves, which scavenge a lot and don’t often hunt large prey, would be a different species from arctic wolves or any of the moose, elk, or bison-hunting wolves we have in North America.

If we are to adhere to cladistic classification, though, it is virtually impossible to create arbitrary species for dogs. The reason is best summed up in this paper that compared genomes of many wolves and a few dogs that have origins on different continents. The authors concluded:

 [W]ithin the Old World clade, wolf and dog represent sister taxa. Therefore, suggestions that the dog or dingo are a separate species (Canis familiaris) (e.g., Crowther et al. 2014) would cause gray wolves to be a polyphetic taxon; and consequently, our results support dogs as a divergent subspecies of the wolf. This result has societal significance as legislation in some countries and regional governments consider wolves and dogs as distinct species restricting the possession, interbreeding, or the use of vaccines and medications in wolves or dog–wolf hybrids if they have only been approved for use in dogs. In this sense, analysis of evolutionary history informs law and veterinary practice, as dog lineages are nearly as distinct from one another as wolves are from dogs, and the justification for treating dogs and wolves differently is questionable.

That pretty much should end this discussion. What these authors found and has been discovered in other papers is that dogs descend from a ghost population of gray wolves, Eurasian gray wolves, to be exact.

Lots of other experts agree with this assessment. Darcy Morey, an archaeologist with a great expertise in the study of Pleistocene wolves and early domestic dogs, has the address for his website as “dogsarewolves.com.” He and Rujana Jeger have formulated a conceptual framework of dog domestication that is quite unique. Basing their model upon trophic strategies on behalf of the wolves and shifting perceptions of humans, the authors contend that wolves that became dogs attached themselves to people. These early humans were often already acting as the apex predators in the ecosystem of the Pleistocene, and the wolves that did join up with people were able to take advantage of this niche.  Pleistocene wolves were not operating as apex predators in a faunal guild that included machairiodonts, cave lions, cave bears, and Pleistocene spotted hyenas, but when those animals became extinct, the wild wolves became the apex predators of Eurasia.  The wolves that hooked up to people joined humanity in agricultural societies and joined us as apex consumers. When humans began to domesticate other livestock,  wild wolves were seen as competitors and killed off.

The idea that dogs are not wolves does have some currency, especially if you’re quite stuck on Southeast Asian origins for domestic dogs. Vladimir Dinets believes that wild Canis familiaris was some kind tropical Southeast Asian canid that was related to but not descended from Canis lupus.  There is still a massive debate as to where dogs originated, and it should be noted that there are as many good papers that have concluded European or Central Asian origins as have suggested as Southeast Asian origins.

The reason you would go for wild Canis familiaris in Southeast Asia as the ancestor is that Southeast Asia is one of the few places in Eurasia that never has had gray wolves living there. In these schools of thought, much emphasis is placed upon Canis variabilis a possibly being the wild ancestor. Of course, Canis variabilis disappeared from the fossil record 300,000 years ago, and no serious scholar thinks dogs diverged from wolves that early.

The real problem is the genetic closeness between wolves and dogs, and that same genome comparison study mentioned earlier shows a significant gene flow between wolves and domestic dogs. Up to a quarter of all Eurasian wolf genomes likely have some dog ancestry, and in East Asian wolves, the dog component of their genome can be as high as 20 percent. In European and Middle Eastern wolves, the dog component can be as high as 25 percent.

The only thing that keeps dogs from swamping the Eurasian gray wolf population with dog genes is the reproductive and territorial behavior of wolves. Wolves generally allow only one female to raise her pups. Wolves generally kill dogs that wander onto their territories, and they will kill dogs that are in territories they wish to claim.

But dog genes are getting into the wolf population at pretty high rate in Eurasia, a much higher rate than you would think of for two distinct species.

A lot of the people who have a hard time recognizing dogs as wolves are tired of bad dog training advice that is based upon bad wolf science.  They might also be tired of claims from the raw feeding community that say we must feed dogs like wolves.

But just because people misuse the classification does not infer that the classification is wrong.

Cladistically and genetically, dogs represent a now extinct population of Eurasian gray  wolves.  If these terms mean anything, then dogs are Canis lupus familiaris.

These theorists are always going to have a reason to say that dogs are not wolves, just like the BAND theorists.  Indeed, it may be necessary to refer to them as DANW (Dan-double u), for they are they are coming up with reasons to avoid classifying dogs as wolves, no matter how much genetic or archaeological evidence is presented.

In the grand scheme of things, classifying dogs has little effect on our practical understanding of them, but this continuous phylogeny denial makes the dog world seem oddly out of step.

No one would miss a beat if you called a Hereford a domesticated aurochs.  A pekin duck a domesticated mallard? No problem.

But if you say dogs are wolves, which they clearly are, then you’re anti-science.

I’m not, though. You’re the one rejecting cladistics for your special classification model.

I’m adhering to the same model that would be accepted with any domestic species and its wild ancestor.

You’re just rejecting it because you think that’s what the science says. Maybe, but it’s hard to argue with DNA.

But they do it on Maury Povich every day, so why not?

Update: A more recent study that examined the genomes of gray wolves from across their range revealed that 62 percent of all Eurasian wolves have some dog ancestry. That’s much higher than the genome comparison study mentioned above. 

 

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gordon buchanan wolf

Gordon Buchanan with a wild arctic wolf on Ellsmere. Photo by the BBC.

For really long time, the mystery of human bipedalism vexed us. Our closest relatives, the chimpanzees and the bonobos, are all knuckle-walking apes, and there was an assumption that the common ancestor of all three species was a knuckle-walker. At some point, the lineage that led to our species rose up on its hind legs, perhaps to make it easier to gaze over tall grass, and we became bipedal.

The current thinking, though, is that humans never derived from any knuckle-walking ape. Instead, the common ancestor of humans, chimps, and bonobos was likely a brachiator.  The modern brachiators are the gibbons and siamangs, the so-called “lesser apes.” These animals are highly arboreal, and because they lack tails, they rely upon their long limbs to move swiftly through the trees. When on the ground, brachiators walk bipedally, swinging their long arms to the side for balance.

Humans evolved bipedalism from these brachiators, while the chimps and bonobos became knuckle-walkers. In this scenario, humans never were knuckle-walkers, and it is misleading to think that humans rose up on our hind-legs from creatures that moved like chimpanzees.

What does this have to do with dogs?

Well, there have been quite a few studies that have compared dogs and wolves that have been imprinted on humans from an early age in hopes that we might figure out the domestication process from studying how tamed wolves behave when compared to domestic dogs.

These are interesting studies, but I think they oversell what they can answer.

It should be of no secret that I am very much a skeptic of the Raymond Coppinger model of dog domestication. His model contends that dogs necessarily evolved from scavenging wolves that gradually evolved not to fear people and then became village dogs. Our specialized breeds are thus derived from village dogs that were later selectively bred.

Coppinger thought that wolves were just too hard to domestic without this scavenger-to-village dog step that lies between truly wild wolves and their evolution to domestic dogs.

Modern wolves are hard to tame. They must be bottle-raised from an insanely early age.  Coppinger thought that it would be impossible for people living during the Pleistocene to provide that kind of care for young wolf pups.

Like the people who assumed that humans evolved from knuckle-walkers, Coppinger assumed that wolves that exist today are good models for what wolves were like during the Pleistocene. These wolves are reactive and nervous to the point of being paranoid. It is well-known that many wolves won’t even attempt to den near human settlements, and if they catch wind of humans, they soon leave.

These animals would not be easily tamed by anyone, much less people living with Stone Age hunter-gatherer technology.

I generally accepted his arguments, and in the early days of this site, I largely parroted them.

A few years ago, I was watching a documentary about the tigers of the Sundarbans, a vast mangrove forest that straddles the border between India and Bangladesh. These tigers are notorious for their man-eating behavior, and there have been many theories posited about why these tigers so readily hunt man. Among these is the argument that the Sundarbans tigers drink so much salt in their water intake that it destroys their kidneys, which disables them and makes them more likely to hunt man.

But the documentary contended that the real reason these tigers are more likely to hunt man is that all other tigers descend from populations where humans have hunted them heavily. In British India, tiger hunting was a popular activity among the colonial administrators, and this intensive hunting cause tiger populations to drop.  This hunting left behind only tigers that had some genetic basis to fear man more, and thus, man-eating tigers are exceedinlg rare now.

The Sundarbans never received this hunting pressure, so the tigers left behind had the same innate tendencies to hunt humans that the ancestral tiger population possessed.

I found this argument utterly intriguing, and I began to weigh it against what I knew about wolves. Wolves across their range have experienced even more persecution than tigers have.  In North America, we have four hundred years of humans coming up with more and more creative ways to kill them. In Eurasia, this persecution has gone on for thousands of years.

The persecution of wolves surely has had some effect in how wolves behave, including their innate tendency to accept humans and other novel stimuli in their environment.

Wolves are often so fearful that they won’t cross roads.  They just avoid people at all costs, and it just seems that this is an animal that we couldn’t possibly domesticate or even habituate to our presence.

This has led some people to suggest that dogs aren’t derived from wolves, but some Canis x creature that is related to dogs and wolves, but it is ancestral to the former but not the latter.

Genome comparisons have shown that such claims really don’t work. Dogs are derived from an archaic wolf population, and in this way, they are sort of genetic living fossils, holding the genomes of a Pleistocene wolves that no longer exist. But these wolves that became dogs were still part of Canis lupus, and thus, we have to maintain dogs as part of Canis lupus as well in order to retain the monophyly of the species.

Except for dogs that have modern wolf ancestry, no dog is actually derived from a wolf population that exists today.

And the wolf populations that exist today just seem so hard to tame and work with that it makes sense then to consider the need for Coppinger’s scavenging wolf-to-village dog stage between wild wolves and modern dogs.

The thing is, these studies using modern wolves are only using wolves that are derived from these heavily persecuted populations, and it is very unlikely that these animals are representative of the wolves that lived during the Pleistocene.

We know that when wild dogs have never experienced human hunting, they are intensely curious about us. Timothy Treadwell had a pack of tame red foxes that followed him around like dogs while he was off communing with the brown bears. Darwin killed the fox that was named after him by sneaking up on one and hitting it with a geological hammer.

Lewis and Clark came onto the American prairies where there were vast hordes of wolves lying about.  The wolves had no fear of people, and one wolf was actually killed when it was enticed in with meat and speared in the head with a spontoon.

After these wolves experienced the persecution of Western man, the only wolves left in the populations were those that were extremely wary and nervous.

In fact, the only wolves that exist now that have never experienced widespread persecution by man are the white wolves that live in the Canadian High Arctic.

I’ve had the pleasure of watching two documentaries about these wolves. The first was by Jim Brandenburg.  Brandenburg and L. David Mech spent a summer living with and filming wolves on Ellesmere.  These wolves showed no fear of them, and they allowed them to observe their natural behavior in the wild, including allowing them near their den sites.

Virtually the same documentary was recently made by Gordon Buchanan of the BBC. Buchanan came to Ellesmere and became accepted by a wolf pack, which eventually trusted him enough to allow him to babysit their pups while the adults hunted.

These wolves hunt arctic hare and muskox. They live hard lives, but because they have no real history with man, they are oddly curious and trusting of people.

It seems to me that these wolves are much more like those described by Lewis and Clark, and they are likely to have behaved much like the ancient Pleistocene wolves did. They had never undergone extensive persecution by man, and thus, they were probably quite curious about man.

If these ancient wolves were more like the Ellesmere wolves, then it seems domestication would have been a pretty easy process. In fact, it appears to me that it is so easy to have happened that the struggle would have been preventing it from happening in the first place.

So if these High Arctic wolves are a better model for the ancient wolves that led to dogs, why aren’t they included in the studies?

Well, these wolves are hard to access, and what is more, because they represent such a special population, it might not be wise to remove any of these wolves from the wild.

So the socialized and imprinted wolf pup studies really can’t be performed on them.

But we could still get DNA samples from them and compare their behavior-linked genes to those of dogs and wolves from persecuted populations.

All these other studies are ever going to do is tell you the difference between dogs and certain wolves from persecuted populations. They aren’t really going to tell you the full story of why dogs came to behave differently from wolves.

So for the sake of science, we need to understand that evolution through artificial selection has affected wolves as well as dogs. Dogs have been bred to be close to man. Wolves have been selected through our persecution to be extremely fearful and reactive.

So as interesting as these studies are, they have a big limitation, and the assumption that these wolves represent what ancient wolves were like is major methodological problem.

 

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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.

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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.

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The Promise

Source.

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Wolves come in many colors. The black ones, as we know, have their origin in domestic dogs, which crossed with wild wolves. The revelation intrigued me when it came out in early 2009, and I am always thinking of what color might mean when it comes to the evolution of wolves and dogs.

I have noticed that there are many photos of wolves from Finland that have an unusual color. Most European wolves (Canis lupus lupus) are dark gray sable, the classic “wolf color,” but in Finland, there seem to be more than a few wolves that appear to be golden in color. The wolves have varying amounts of sabling on their pelts, and some are what we would call “clear sables” if they were domestic dogs, as we can see the photos of “Susi,” the famous Swedish wolf that came from Finland or Russia.

It is possible that this coloration also has its origin in domestic dogs. There are rumors that the Russians turned out wolfdogs on the Finnish border, but there are always rumors about Russians and their deeds.

Of course, the Finns have always owned dogs of this color, and it is now known that some of these hunting and herding spitz breeds are derived from wolf and dog crosses. It is possible that the gene flow has worked both ways between these spitzes and Finnish wolves. Indeed, it is probably quite likely.

However, there is another possibility that is also worth considering.  In late 2013, Olaf Thalmann and Robert Wayne published a paper that compared samples of ancient mitochondrial DNA from the remains wolves, dogs, and possible transitional forms between wolves and dogs from Europe were compared to modern dogs and wolves. In this analysis, samples from dingoes and basenjis were included in order to get samples from dog populations that had long been isolated from the main dog population.  All modern dogs, including dingoes, are very close to these ancient European wolves in terms of their mitochondrial ancestry. Mitochondrial DNA alone can lead people astray when tracing evolution and ancestry, but the fact that dingoes were closest to these European canids really does point to a strong possibility that dogs were domesticated by European hunter-gatherers at some point between 18,800–32,100  years ago.

It is also interesting to me that almost all dingoes and many, many pariah and primitive dogs are red or yellow sables like these wolves. I wonder if these yellow Finnish wolves represent a sort of throwback to the ancestral European wolf population that gave rise to domestic dogs. Perhaps the majority of the ancient European wolves were golden in color.

Yellow wolves do occur in the Middle East, China, and South Asia,  and China and the Middle East have been suggested to be places where dog domestication first happened.  However, none of these wolves have been linked to dogs through ancient DNA samples in the same way the ancient wolves of Europe have been.

Of course, the questions about the yellow wolves of Finland could be answered in much the same way the questions about the origins of the black wolves of North America were.

But there is something to these golden wolves that does need some exploration.

Maybe they are the result of dog and wolf gene flow. Maybe they are just a local unique mutation.

Or maybe they are a flash of gold that tells us a bit about the past.

DNA nalysis on ancient remains has already revealed that dappled and black horses were in the wild Pleistocene horse populations, but no similar studies have been performed on the remains of ancient wolves or dogs.

Maybe there really is something to these yellow Finnish wolves that just a pretty coat.

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