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Archive for the ‘wolves’ Category

Wolves and coyotes working as sled dogs in Ontario in 1923. 

The world of dogs is full of ideas, and over the years, those ideas and their expositors have created several camps.  I have learned to keep my head down in most of these discussions about dog ideology, and yes, I learned it the hard way. But I know there are several idea with which I will lay out my own views, or at least critique what I think is an error.

It is hard to overestimate the work of Raymond Coppinger in forming the main ideas around modern dog science.  Coppinger was a biology professor at Massachusetts’s Hampshire College, and he proposed a particular dog domestication hypothesis. This is the model that lots of dog experts believe is correct, and this model also informs how they view the essential biology of dogs.

Coppinger’s domestication model relies heavily upon the work of a Soviet geneticist named Dmitri Belyaev. Belyaev was a Mendelian at the time of Lysenkoism, and he was banished a research facility in Novosibirsk, where he conducted domestication experiments upon silver-phase red foxes that were from fur farm populations. Belyaev selected for tameness using several criteria, and after so many generations, he produced foxes that had drop ears, less sexual dimorphism, large areas of white on their coats, curled tails,  and even multiple estrus cycles per year.

This suite of features very strongly resembles the traits we see in domestic dogs, and Belyaev thought of his experiments as a sort of controlled analogy to dog domestication. 

Coppinger took Belyaev’s ideas a bit further. Instead of seeing humans as actively domesticating wolves, Coppinger believed the whole process came from wolves scavenging near dumps near what became Neolithic settlements. These wolves evolved to become smaller and evolved smaller brains so they could live more easily on wastes, and these animals became the village dogs. Later, people would select for working and hunting behaviors in village, but dogs themselves were not domesticated for any purpose. They evolved from scavenging wolves.

The analogy that Coppinger saw in Belyaev is that he assumed that all wolves through all history had been the very timid paranoid wolves that are known in the lower latitudes of North America and Eurasia, and he thought that for wolves to become successful scavengers in such close proximity to humans that they would have undergone something similar to Belyaev’s selection.  Those that were less afraid of humans would be more likely to stand in dumps while humans were nearby, eating more of the easily procured food.

When I first started this blog, you can see echoes of Coppinger in what I wrote on dog domestication. I loved his 2001 book, but as I’ve read more about wolves and new studies on dog cognition. I’ve come to doubt many of his ideas. 

One of the biggest problems with Coppinger’s model is that the earliest dog remains that are not in contention as belonging to a dog are those of the Bonn-Oberkassel dog. It dates to 14,000 years ago in what is now Germany, and recent analysis showed that was actually a seven-month-old puppy that died of distemper. This dog existed in Europe thousands of years before the Neolithic cultural exchanges hit the region. That means the dog was created by hunter-gatherers of the Paleolithic, not in the Neolithic middens.

The other problem I have with Coppinger’s model is the assumption that all wolves through history are these fearful and often paranoid wolves that exist in much of North America and Eurasia. However, when one reads accounts of early explorers and settlers to North America, there are many accounts of curious and often socially open wolves approaching humans. Lewis and Clark’s diaries tell of luring a wolf in very close with a piece of meat and then killing it with a spear, and various other authors talk of wolves living very near native people’s camps and settlements, often crossing with the dogs. It is likely that our widespread persecution of wolves has culled out all this curiosity and tolerance of people in most extant wolves. Through our hunting, trapping, and poisoning campaigns, we have selected for wolves that are timid and shy, if not totally paranoid.

Further, we have wolves on Ellesmere and Baffin Island that have never been extensively hunted by humans, and these wolves are quite curious and tolerant of humans. (See Jim Brandenburg’s “White Wolf” and Gordon Buchanan’s “Snow Wolf Family and Me” to get an idea of how tolerant and curious these wolves are.) These wolves, though certainly adapted for life in polar conditions, are potentially a good model for what the original wolves of Eurasia were like when they first encountered our species. They were likely quite curious and socially tolerant as these wolves are, and it would have been easy for hunter-gatherers to form a relationship with them.

Several attempts to counter some of Copponger’s shortcomings have come to the fore in recent years. Darcy Morey and Rujana Jeger have posited shifting trophic strategies between wolves and hunter-gatherers, such that dogs evolved from wolves in hunter-gatherer societies and became apex predators with people, later becoming apex consumers with humans in the Holocene. Raymond Pierotti and Brandy Fogg have made a similar attempt in their First Domestication: How Humans and Wolves Coevolved. These two authors rely heavily upon ethnography of hunter-gatherer peoples or partially hunter-gatherer peoples and their complex relationship with hunting dogs and wolves.  The authors contend that these societies have the best framework for understanding how wolves might have been domesticated within a hunting symbiosis.

Recently, though, I came across a new model, one that offers a critique of Coppinger and encapsulates many of the ideas of Morey and Jeger and Pierotti and Fogg. It also posits a new theory of dog domestication called the Active Social Model of dog domestication. 

The authors of this model are Christoph Jung and Daniela Pörtl, and they posit a model that sees wolves and people in the late Pleistocene operating as predators that often worked together and showed each other some mutual respect. In this model, emotional bonds that existed between wolves and people were a major driving force behind the domestication of dogs, and this is the missing piece that explains why wolves were domesticated. Foxes, jackals, and hyenas have all been noted as scavenging near human settlements, but they have never attempted to form emotional bonds with people, unlike the aforementioned wolves of Ellesmere. 

I really like this model, because it actually does mention many things I’ve discussed on this blog. It allows for the less-than-timid, more socially open wolves of the High Arctic as a better model for Pleistocene wolf behavior than those from other more persecuted populations. It also allows for the concept of a potential hunting partnership between wolves and humans as the catalyst for domestication. 

As I noted before, I think the way humans capitalized upon wolves as hunting partners is that humans figured out that a very good way to kill fat healthy game was to follow wolves.  Wolves constantly test game.  If the quarry runs, it is usually unhealthy and will be easily run down, so the wolves’ instinct is to give chase. If game is healthy, it will stand and fight the wolves. 

The stand and fight behavior would give ancient hunter-gatherers a relatively stationary target for their spears, so wolves and humans learned that they could both easily bring down healthy prey if they made it stand and fight.

It is precisely how elkhounds, Karelian bear dogs, and big game laiki bay up moose and wild boar for the rifle shot.  The only difference is these dogs bark while the prey stands at bay.

Humans are big-brained, and our nutritional needs when living on a meat-based diet require quite a bit of fat. Being able to kill healthy prey in this way was a great way to get the fat we needed to power our large brains.

And it would have been to our advantage to hook up with wolves, and wolves would have had an easier job getting meat. They wouldn’t have to grapple so much with big dangerous prey. Our spears would do much of the work, and they would get some meat for their troubles.

This new active social domestication model allows for this sort of relationship to have been the process whereby humans and wolves hooked up. This relationship is far beyond the simple scavenger at the dump. Wolves were not the trash pandas of the Pleistocene. Instead, we had humans and wolves interacting with each other, and over time, these interactions led to the development of the dog.

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dholes

We know that hybridization is a big thing in the genus Canis.  Indeed, scientists are still debating about the validity of certain species because some of the extant forms of wolf could very well be hybrids between gray wolves and closely related species. Everyone thinks that the large coyotes we see in the East are all coywolves, even though they don’t have that much wolf ancestry. but then we have very good genomic data that shows that coyotes and gray wolves really aren’t that different genetically.  We know that Ethiopian wolves were threatened with and still could be threatened with hybridization from domestic dogs, but we also know that getting dog genes into a wild canid isn’t always a bad thing. Wild gray wolves in North America got their black color variant from a single Pre-Columbian black dog that crossed into the population between 1,500 and 7,250 years ago in the Yukon or the Northwest Territories.

I have often wondered if we could detect hybridization that went on long before all these wolf-like canids truly diverged, and a recent paper in The Journal Cell reveals that hybridization has always been a feature of these wolf-like canids. Gopalakrishnan et al. compared the genomes of gray wolves, coyotes, domestic dogs, golden jackals, the African golden wolf, the Ethiopian wolf, the dhole, and the African wild dog to see if there was any evidence of hybridization in the lineages.

The authors found that the African golden wolf was actually a hybrid species that developed from gene flow between the gray wolf and the Ethiopian wolf, which likely had a much more extensive range in Africa than it does now.  The authors also found that the clade (which I think is actually a single species) that includes the dog, wolf, and coyote received genes from an unknown species of canid. The dhole and African wild dog have also hybridized in the past, probably because both the dhole and African wild dog once had ranges that overlapped in the Middle East or in North Africa.

The discovery of this unknown species is perhaps the most intriguing. The authors speculate that it might have been the dire wolf or the extinct North American dhole, but seeing that this species fairly close to the division between the dhole and African wild dog, I think a more likely candidate is Xenocyon lycaonoides.  This animal has been posited as an ancestor the dhole and the African wild dog, but a more convincing argument is that the African wild dog derived from Lycaon sekowei.  It is not clear yet what the dhole derives from, but it could have derived from Xenocyon or shared a common ancestor with it.

Xenocyon was the dominant wolf-like canid in Eurasia and Africa during the early part of the Pleistocene, but by the mid-Pleistocene, it began to become less common, and as its numbers dwindled, the diminutive wolf, Canis mosbachensis, began to fill its niche, eventually evolving into the modern gray wolf, which also led to the coyote and domestic dog lineages, as well as the hybrid African golden wolf.

Maybe, as the Xenocyon’s numbers dwindled, a few remaining ones hybridized with C. mosbachensis, perhaps introducing some genes from better pack cooperation and larger size that helped the smaller wolf fill the bigger canid’s niche.

The authors are clear that we need lots of ancient DNA from these extinct canids before we can engage in flights of speculative fancy, but seeing that this unknown canid was so close to the dhole, I think that this animal is a better place to look. Xenocyon might be a bit too old to find viable DNA in fossil remains, but it is certainly possible that we could find some.

So yes, hybridization has greatly affected the evolution of wolf-like canids in the modern era, but hybridization always has. Similar findings have been discovered in bears and various members of the cat family.  My guess is that virtually every clade will have had some of this going on, even if the current species do not hybridize.  Speciation happens, but chemical interfertility isn’t lost for quite some time after speciation. Gene flow continues on with related species, which continues to affect their evolution.

Yeah, evolution is a tangled bush that also has vines that reach out and grab adjacent and not so adjacent twigs.

 

 

 

 

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dire wolf skeleton

I am not big on popular culture these days. I have not watched one second of Game of Thrones, but I do know that dire wolves have something to do with that series.  I am not into that genre of television. Give me an actual documentary about dire wolves, and I’ll be happy.

But I know that dire wolves are thing from that series only because I do sometimes get asked about them. I don’t know how they are portrayed in that series, but most people think of them as just super large gray wolves that went extinct at the end of the Pleistocene.

The funny thing is that there actually was a super large gray wolf that specialized in hunting large game that also went extinct at the end of the Pleistocene. This animal has been called the Beringian wolf, and although no one has dared to give it a subspecies status, it was essentially a form of gray wolf that hunted megafauna in much the same way that the dire wolf did. The two species were contemporaries, but the Beringian gray wolf did not live in the same parts of North America as the dire wolf, which was found through most of the Lower 48 of the United States and ranged down into northern South America.  This Beringian wolf apparently ranged from Alaska to Wyoming, while the dire wolf was found in mid-latitude North America and ranged south from there.

No one really pays that much attention the Beringian wolf, but it is very likely that everything we know about modern wolves would have applied to that animal. The only difference would be that this wolf was much more specialized in hunting large prey such as bison than modern big-game hunting wolves are.

The same cannot be said for dire wolves.  Dire wolves evolved solely in North America. The general consensus is that it evolved from Armbruster’s wolf, but the exact origin of Armbruster’s wolf is a bit of debate. One well-known hypothesis is that the common ancestor of the modern gray wolf and the Armbruster’s wolf-dire wolf lineage is Canis chihliensis, a Pliocene wolf-like canid. This is the hypothesis suggested by Tedford and Wang, who are leading authorities on North American canid evolution.

However, there is a whole host literature in Eurasian wolves that posits Canis mosbachsensis as the ancestor the modern wolf. This literature, I think, is a bit more robust, for the large numbers of samples of both archaic Canis lupus and Canis mosbachensis show how the wolves of Eurasia went from being small and gracile to larger and more robust over time.

It is possible that this Armbruster’s wolf/dire wolf lineage evolved from an entirely different grouping of the wolf-like canids. It also would place the common ancestor of the dire wolf and modern Canis lupus back millions of years, even to the point where dire wolves were at least as genetically divergent from modern wolves as modern wolves are from African wild dogs.

If that is true, then we cannot make many wild assumptions about dire wolf behavior by comparing them to modern wolves at.  We don’t have any preserved dire wolves in permafrost. They never lived where there are currently big stands of permafrost, so we will never have dire wolf pelts.

Attempts have been made to get DNA from the many Rancho La Brea tarpit dire wolf remains, but they have not been successful. It was found that it was just too difficult to separate the bone from the tar.

So we really don’t know exactly how closely related dire wolves are to modern wolves, but I would be surprised if they turned out to be as closely related to modern wolves as modern wolves are to coyotes.

Indeed, the real problem with all of this is much of Canis taxonomy and systematics is not entirely resolved. The real issue I have now is we have good genome comparison literature that shows a much closer relationship between wolves and coyotes than we previously believed. Much of our understanding of Canis evolution is that we have tended to think of a linear evolution from jackal-like forms to wolf-like form, when the truth of the matter is we have had jackal and wolf-like forms evolve independently of each other within different lineages of the wolf-like canids.

So we are taken aback with the findings that the two endemic African jackals, the black-backed and side-striped jackal, are the two most basal and divergent forms of the wolf-like canid clade, and we are even more taken aback that the dhole and African wild dog are not as distinct from the rest of the clade as these two African jackals. This finding has led to the rise of the genus Lupullela for these two jackals.

In addition, the creatures formerly known as African golden jackals were revealed to be much closer to wolves and coyotes than to the Eurasian golden jackal, which has led to a bit of a taxonomy war on what exactly to call these creatures, though the popular press likes to use the term “African golden wolf,” which was the name suggested in one of the papers documenting their discovery.

None of these discoveries would have been indicated through morphological analysis alone. One would think that black-backed jackals and coyotes were particularly close relatives, for they look and behave pretty similarly to each other. At one time, we would have classified both as primitive or basal Canis.  Today, I think the best description is that the black-backed jackal is a basal Canis, but that the coyote is actually a very derived but diminutive one.

So we have these problems with extant Canis species, and it is very likely that we’re missing the full picture on how dire wolves relate and compare to modern ones.

One thing that should be noted is that dire wolves had very odd bacula.  The baculum is the penis bone that exists in all but a few mammals, and you, if you are a male human being, are among these few mammals without one.

Dire wolves had longer bacula than gray wolves of the same size and they were kinked upward at an odd angle. This bone is probably indicative of a larger penis in a dire wolf than the modern one, and it also might give us some interesting clues about how dire wolves might have behaved.

I have suggested that having this male anatomy might have meant that dire wolves had more competition with sperm penetration than actual male on male conflict during the mating season. We know that within primates, those species that are better endowed tend to be less aggressive with other males of the same species. Those with smaller genitals tend to be more aggressive, and the reason posited for this difference is those with larger genitalia have given up on intermale aggression and the real competition is how far and how much sperm the male can produce.

Maybe something like this was going on with dire wolves. Maybe mating season with dire wolves was just a big ol’ wolf orgy, and the male that could penetrate the female deepest and with the most sperm wound up siring the offspring.

Even calling Canis dirus a “wolf” may not be accurate at all. If it truly is a more distant relative to the gray wolf than we currently assume, then we really need to be careful what we assumptions we are making.

A few years ago, there was a bit of fun speculation on the internet that the dire wolf was actually of South American wild dog clade. A few scholars had toyed with the idea, because there was these two odd species wolfish like canids that were known from the fossil record in South America, called Canis nehringi and Canis gezi. The former was always thought of as being very similar to the dire wolf, and the latter appeared to be somewhat similar to both.

This speculation led to this wonderful image, a depiction of the dire wolf as being an overgrown bush dog.  (The one on the right speculates a South American origin, while the one on the left just turns it into a wolf).

dire wolf bush dog

Of course, serious scholarship performed a phylogenetic analysis of these canids and revealed that Canis nehringi was actually a dire wolf offshoot. Canis gezi was found to be a South American clade wild dog.

So yes, this was a fun bit of speculation, but it’s not much more absurd than assuming that the dire wolf was that fundamentally similar to the modern gray wolf.

We just don’t know. I’m sure that we’ll get a good ancient DNA sample from a dire wolf soon, and we’ll be able to answer some of these questions.

But right now, we need to be very careful in assuming that the dire wolf was just an odd Pleistocene gray wolf.

We’re missing a lot of information, and a lot of the research on dire wolves was performed before we had all these “molecular surprises” with extant Canis species.

There is just so much we don’t know, and it might be a good idea to be careful about making assumptions about dire wolves by comparing them to their supposed modern equivalents.

Those equivalents might not be any more equivalent than those equivalents are to modern African wild dogs and dholes. Yes, there are some similarities, but African wild dogs and dholes are very different from wolves in terms of the exact dynamics of their pack behavior and hunting styles.

So we’re assuming a lot now about dire wolves, but it’s best to wait for me evidence before we play around with speculation. Hollywood will never take this cue, but maybe we should hold back a bit.

We just don’t know.

 

 

 

 

 

 

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tazi mating with wolf

This image appeared on a Kazakh instagram account. 

The wolf appears to be a steppe wolf (Canis lupus campestris). In Kazakhstan, people keep wolves as pets and “guard dogs” fairly often, and according to Stephen Bodio, they are obsessed with wolves.

The dog is a tazi, a sighthound of the general saluki breed complex, that has quite a few wolf-like characteristics. The breed is usually monestrus, like a wolf, coyote, or a basenji, and females engage in social suppression of estrus and sometimes kill puppies that are born to lower ranking bitches.

I wonder if the wolf-like traits of this breed are somehow reinforced by occasionally crossings with captive and wandering wolves like this. As far as I know, no one has really looked into the genetics of the Kazakh tazi, but it is an unusual dog that lives in a society with a very strong tradition of keeping captive wolves.

We know that gene flows between Eurasian wolves and dogs is much higher than we initially imagined, but I don’t know if anyone is looking at breeds like these for signs of hybridization. The only study I’ve seen looked at livestock guardian dogs from the Caucasus, and it found quite a bit of gene flow-– and it was mostly unintentional.

It would be interesting to know exactly how much wolf is in Kazakh tazis. I would be shocked to learn that they had no wolf ancestry.

I seriously doubt that this is the only time a captive steppe wolf and a tazi were found in this position.

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golden wolf vs. black backed jackal

Not the best photo, but this is golden wolf on the left and a black-backed jackal on the right. I screen-captured this image from this documentary, which was made before the big golden jackal revision that happened a few years ago.

There is still a big debate on how classify the creature formerly known as the African golden jackal. It is clearly closer to gray wolves and coyote than to the Eurasian golden jackal, but the exact closeness requires further research.

The black-backed jackal on the right is a much older species. It has been known from the fossil record in Africa for over two million years, and the wolf-coyote-golden wolf lineage last shared a common ancestor with it around 4.5 million years ago.

Depending upon when we finally determine when the golden wolf diverged from the modern gray wolf, it may have evolved from larger ancient gray wolves that adapted to fit the generalist jackal-like niche, or it may have evolved from a African population of Canis mosbachensis.

The black-backed jackal is derived from the earliest wolf-like canids to have entered the Old World from North America. Those early wolves were all smaller and jackal-like, and its appearance and adaptations are of the primitive type.

So here we have two species that look like they might just be color phases of the same species but actually are divided by millions of years of evolution. One is a truly primitive member of its lineage. So primitive and basal that its now classified in a different genus (Lupullela). The other came from a more derived source that evolved parallel characteristics with the primitive one.

Parallel evolution is a hell of a thing, especially when it comes to canids. So much of this parallel evolution has been missed in paleontology and in the conventional methods of taxonomy that use only morphology. Not recognizing the parallel evolution issues is why we didn’t notice that coyotes and gray wolves were much more closely related than we ever could have imagined. It’s also why we thought bush dog belonged with the dhole and African wild dog, just because their teeth are so similar, and it is also why an affinity has been suggested between crab-eating foxes and raccoon dogs, even though they are in entirely different lineages. It is also why there was a suggestion that red wolves represent an ancient lineage of North American wolves, when they are now probably hybrids between coyotes and gray wolves.

Parallel evolution messes up a lot of things. Our eyes and our measuring instruments can fail us.

But the correction of these failures reveals a much more mysterious world.

That’s the inherent beauty of science. Each correction is a revelation.

 

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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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African golden wolf

What we do know about the origins of Canis species is much more hotly-contested than what we know about the evolution of our own species. The earliest fossils of the genus are roughly 6 million years old, and the oldest species in the “wolf lineage” is Canis lepophagus, which lived in the American Southwest and Northern Mexico 5 million years ago.  This species is often posited as the direct ancestor of the coyote, and it may have been a direct ancestor of all the entire wolf-like canid lineage.

Of course, recent discoveries that have come from full genome comparisons make things a little complicated. With the discovery that coyotes diverged from gray wolves as recently as 50,000 years ago, the linear evolution from Canis lepophagus to Canis latrans is probably invalid.  Further another full genome study that used a single Israeli golden jackal (Canis aureus) as the outgrouping sample to determine when dogs and gray wolves split, revealed that this particular jackal diverged from gray wolves less than 400,000 years ago.

Both of these dates are far more recent that the millions of years that are assumed to separate these wolf-like canids from each other. Of course, more work must be done. We need more studies on coyote genomes, but these researchers have come across what could be the most important discovery in our understanding of the evolution of Canis species. Depending upon the study, coyotes and gray wolves were thought to have diverged between 700,000 to 1 million years ago, and this assumption is used to calculate when other Canis have diverged.

Now, this assumption always did bother me, because if Canis lepophagus leads directly to Canis latrans, where do wolves fit in?  Because in order for that model to work, gray wolves have to evolve from a very small coyote-like ancestor with very few transitions in between. It always just seemed to me like it was unworkable.

Further, there is a whole host of literature on the evolution of gray wolves in Eurasia, and in most European literature, there is a general acceptance of how gray wolves evolved from a smaller wolf called Canis mosbachensis.

Wolfgang Soergel, a German paleontologist at the University of Tübingen, discovered Canis mosbachensis at a site near Jockgrim in 1925. The animal is sometimes called the “Mosbach wolf,” which means it was found in the Mosbach Sands, where many fossils from the Middle Pleistocene have been found.

Mark Derr was particularly interested in this species in his How the Dog Became the Dog.  He points out that the earliest dated fossils of this species are 1.5 million years old and come from the ‘Ubeidiya excavations in Israel.  The most recent Canis mosbachensis remains in Europe are about 400,000 years old, after which time they were replaced by Canis lupus.  Derr speculated about the relationship mosbachensis might have had with early hominin species, which were also well-known from that site, and suggested that they might had some kind of relationship.

Further, there is a growing tendency among paleontologists to group Canis mosbachensis with another wolf that was its contemporary. This wolf, called Canis variabilis, was discovered at the Zhoukoudian Cave System in China in 1934. Its discoverer was Pei Wenzhong, who became respected paleontologist, archaeologist, and anthropologist in the People’s Republic of China. It was a small wolf with a proportionally smaller brain, and it has long been a subject of great speculation.

And this speculation tends to get lots of attention, for this cave system is much more famous for the discovery of a type of Homo erectus called “Peking Man.”  It is particularly popular among the people who insist that dogs are not wolves, which is about as scientifically untenable as the “birds are not dinosaurs” (BAND) clique of scholarship.

Mark Derr and as well as more established scholarship have begun to group variabilis and mosbachensis together. Variablis has also been found in Yakutia, and it may have been that varibablis nothing more than an East Asian variant of mosbachensis.

These wolves were not large animals. They varied from the size of an Eastern coyote to the size of an Indian wolf. They were not the top dogs of the Eurasian predator guild.

Indeed, they played second fiddle to a larger pack-hunting canid called Xenocyon lycaonoides, a large species that is sometimes considered ancestral to the African wild dog and the dhole, but the recent discovery of Lycaon sekoweiwhich was a much more likely ancestor of the African wild dog, suggests that it was more likely a sister species to that lineage.

Although canids resembling Canis lupus have been found in Alaska and Siberia that date to 800,000 years ago, anatomically modern wolves are not confirmed in the Eurasian faunal guild until 300,000-500,000 years before present.

I’m throwing a lot of dates at you right now, because if the modern Canis lupus species is as recent as the current scholarship suggests, then we can sort of begin to piece together how the entire genus evolved.

And we’re helped by the fact that we have an ancient DNA study on a Yakutian “Canis variablis” specimen. This specimen would have been among the latest of its species, for it has been dated to 360,000 years before present. Parts of its ancient mitochondrial DNA has been compared to other sequences from ancient wolves, and it has indeed confirmed that this animal is related to the lineage that leads to wolves and domestic dogs.  The paper detailing its findings suggests that there is a direct linkage between this specimen and modern dog lineages, but one must be careful in interpreting too much from limited mitochondrial DNA studies.

360,000 years ago is not that far from the proposed divergence between gray wolves and the Israel golden jackal in genome comparison study I mentioned at the beginning of the post.

This really could suggest something a bit controversial and bold. It make take some time for all this to be tested, but it is a hypothesis worth considering.

I suggest that all this evidence shows that Canis mosbachensis is the ancestor of all interfertile Canis, with the possible exception of the Ethiopian wolf.

If the Ethiopian wolf is not descended from that species, then it is a sister taxon. It is not really clear how divergent Ethiopian wolves are from the rest of interfertile Canis, but their divergence estimates currently suggest that it diverged from the rest of the wolf-like clade 1.6 million years ago, which is just before Canis mosbachensis appears in the fossil record.

If that more recent date holds for the split for the Eurasian golden jackal, then it is almost certain that this hypothesis is correct.  The Eurasian golden jackal may be nothing more than a sister species to a great species complex that includes the coyote, gray wolf, dingo, and domestic dog that both derived from divergent populations of Canis mosbachensis. 

The exact position of the Himalayan wolf and the African golden wolf are still not clear. We do know, though, that both are more closely related to the coyote and gray wolf than the Eurasian golden jackal is, and if its split from the gray wolf is a recent as less than 400,000 years ago, then it is very likely that all of these animals are more closely related to the main Holarctic population of gray wolves than we have assumed.

The recent divergence of all these Canis species is why there is so much interfertility among them.

And if these animals are as recently divergent as is inferred, their exact species status is going to be questioned.

And really should be, at least from a simple cladistics perspective.

More work does need to be done, but I don’t think my hypothesis is too radical.

It just seems that this is a possibility that could explored.

 

 

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