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isle royale wolves

One of the classic studies in wildlife management happened on island in Lake Superior. Isle Royale, part of the state of Michigan but much closer to the state of Minnesota and Northwest Ontario, is home to a population of moose. These moose either swam across from Minnesota or were stocked there in the early 1900, and they found themselves in a paradise. No predators existed on the island, and the island was full of birch trees and aspen colonies.

Over time, the moose denuded the aspens and the birches, and they were forced to eat balsam fir. In 1949, when Lake Superior was frozen over, a pair of wolves crossed to Isle Royale, and they were the foundation for a wolf population that specialized in hunting moose.

This island became of interest to ecologists early on.  It had been made a national park in 1940, and as a national park, it has no permanent residents. Because wolves and moose live on the island without any chance of humans hunting them,  early predator-prey researchers went to the island to see if Paul Errington was right.

Paul Errington was professor of zoology at Iowa State University. He had studied bobwhite quail population dynamics while a student at the University of Wisconsin, during which time he became close friends with Aldo Leopold. Leopold was not faculty member, but Errington learned so much from him during his time at the university. Errington was

Errington’s most famous research was performed in the marshes of Iowa. There, he studied the population dynamics of muskrats and American mink. Muskrats, which are giant water voles, are a major prey source for the mink, and one would think that mink would severely reduce muskrat population. However, Errington’s research found that mink predation had no real depressive influence on muskrat numbers.  He found that the mink tended to take young and infirm. Most healthy muskrats  were generally left alone.

This research, which was published in 1943, was the hottest idea in the nascent science of ecology, and researchers were looking for places where this hypothesis could be tested on a grander scale.  Isle Royale fit the bill, and the first studies of wolf and moose dynamics on the island started in 1958.

Initially, the research found similar findings to Errington’s muskrat and mink study.  Moose and wolf populations fluctuated over the years. When the moose became too numerous, they were forced to eat more and more balsam fir. The fir is not nutritious, and the moose gradually become emaciated. Because the moose require lots of nutrition from their bones to grow their antlers, they also wind up suffering from arthritis.  Emaciated, arthritic moose are easy prey for wolves, and wolf numbers increased when the moose hit this stage.  The wolf population would then increase, and after a few years, it would begin to pare back the moose population to allow birches and aspen to recover.

But at the same time, there weren’t enough weak moose for the wolves to hunt, and the wolf population would crash. The moose would find themselves in a situation with more limited predation and better forage, and their numbers would increase again. And the cycle would start again

When I think of Isle Royale’s wolf and moose dynamics, I think of the work of Rolf Peterson, who made a career out of studying the wolf and moose population fluctuations.  He began to notice that the balsam firs on the island were not regenerating through each moose and wolf fluctuation.

These findings meant that Isle Royale would not be able to continue on through constant moose and wolf fluctuations as one might have hoped, and this problem became worse when the wolf population really crashed.

Lots of debate exists about how well wolves can withstand inbreeding. Climate change has meant that ice bridges that connect the island to Minnesota and Ontario no longer form, and those that do form aren’t around very long. So the wolves have been inbreeding on the island for decades. They were able to withstand this inbreeding for decades, but in the 1990s, the population really began to suffer from this inbreeding depression.

In 1997, a lone male wolf, “Old Gray Guy,” wandered onto the island, there was hope that his genes would be a genetic rescue on the island.  He apparently did introduce some much needed genetic diversity to the island, because by the 2010s, 56 percent of all wolf genes on the island could be traced to him. Wolf fertility did not increase as the result of his arrival, and although a debate exists as to whether there was anything like a genetic rescue on the island, it should be noted that Old Gray Guy was very much like a popular sire in a purebred dog. The population was already quite inbred, and the influx of only a single male that winds up contributing that many genes to the population isn’t going to save the population

By the first decade of this century, a genetic disorder of the wolves’ spines became rampant in the population.  The wolves began to die at early ages, simply because they were unable to walk or because movement was painful for them.

At that time, a real debate existed about bringing in wolves from the mainland, but caution was exercised. There was a hope that natural selection would purge the spinal deformities, but this purge never came. When the ice bridge formed during a polar vortex collapse in 2014, there was also real hope that wolves would walk over to the island. However, all that happened was that two Isle Royale wolves left the island, and one was found dead on the Minnesota mainland.

Further, because the purpose of the studies on wolves and moose on Isle Royale was to see what predator and prey relations are like without the use of human intervention, there was very real resistance to introducing more mainland wolves.

However by December 2017, only one wolf was thought to be living on the island, and the moose population exploded.   However, the moose themselves were physically smaller and would very likely eat themselves out of forage in short order.

This past September, a plan was hatched to restore the wolf population to Isle Royale.  Wolves from the UP of Michigan and northeastern Minnesota would be released upon the island.  Yes, after decades of allowing nature to take its course, man would finally intervene in these predator-prey dynamics.

Things are not off to a good start, however.  One of the first three wolves released on the island has already used the formation of an ice bridge in the most recent polar vortex collapse to escape back to the Minnesota mainland.

However, wildlife managers aren’t giving up. Currently, there are plans to release six wolves from Ontario’s Michipicoten Island onto Isle Royale.  These wolves, which also live on an island in Lake Superior, have a bit of a storied reputation.

On their island, there was once a thriving population of woodland caribou, but the wolves have reduced their number from over 900 to just 30 individuals.  The  caribou were not native to the island, however.  A bull just happened to pop up on the island, and other woodland caribou were stocked to create a population, which thrived until the winter of 2014-2015.

That is when wolves walked across an ice bridge n Michipicoten, and they found it a paradise for wolves. Finding a vast horde of ungulates was a boon for their numbers, but by it took them just a few years to drop the caribou numbers. The caribou are now being taken off the island, but the wolves have had virtually no options. the wolves have had virtually no options.

These Michipicoten wolves are large-bodied creatures that definitely have the ability to hunt large ungulates, so there are very real hopes that these wolves will be able to reduce Isle Royale’s moose population.  New studies on their population dynamics can begin, and this experiment continues on.

That is the hope, anyway.  Whatever happens in the next few months, it should be noted that Isle Royale and the related Michipicoten experiences is that both are studies in a really controlled environments that no longer exist in North America, if they ever did at all.

Moose, caribou, and wolves are all at the mercy of a human-dominated world.  These islands give us an idea of what the world would be like if predator and prey dynamics were left alone, but they aren’t necessarily indicative of how these dynamics would exist on a continent in which human interests have great knock-off effects upon ecology.

After all, the Isle Royale moose and wolves are not directly affected by human hunting. They are still controlled by climate change.  Warmer than normal winters mean that the ice bridges don’t form, and the collapse of the polar vortex, which is also caused by climate change, means that the inbred wolves just don’t want to stay on the island. Moose are getting weaker and weaker as the ticks spread through the populations, and without long periods of cold, the ticks are able to infest the moose, weakening them in greater numbers every year.

The Isle Royale studies are the studies of an island where hunting isn’t allowed, but virtually every place where wolves and ungulates exist on this continent, hunting is a major point of human interest. Humans want more ungulates on the ground, and if their numbers ever drop, wolves will be blamed.  Wolves certainly can have an effect upon prey numbers, and even more than that, they have an effect upon prey behavior. Trophy cervids are just harder to kill if they spend much of the year being harried and herded by wolves.

Maybe what we can know from Isle Royale is limited, but in those limitations, we might get an idea of how to mitigate all these competing interests and have some way of keeping large predators as part of our North American wildlife heritage.

If wolves are not restored to Isle Royale, the landscape will likely be denuded of trees, and all that will be left is a population of tick-invested, diminutive moose.  They will always be on the edge of famine.

Restoring wolves gives a potential hope, but nothing is guaranteed.

But the saga goes on. Maybe for just a bit longer, or maybe new, bright future exists for this most storied of predator and prey studies.

 

 

 

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smithsonian wolf

The Smithsonian Magazine has an interesting article with the very simple title “Should the Himalayan Wolf  Be Classified as a New Species?”

The article details the work of scientists who have gone around Nepal collecting DNA samples from wolf scat.  This is a difficult project, for wolves in this region have experienced quite a bit of persecution from man. Further, where they live is quite inaccessible.

The researchers have found that these wolves have some uniqueness in their mitochondrial DNA, and they have also found that they share some genetic markers with the African golden wolf.

This is all interesting stuff, but I would caution going out on a limb and creating a new species called Canis himalayensis.

The big reason is the studies that have  attempted to figure out where these wolves fit have base part of their calculations on an assumption that gray wolves and coyotes last shared a common ancestor about a million years ago. We know that from full genome comparisons that this assumption is faulty, and the most divergence between gray wolves and coyotes happened about 50,000 years ago.  The DNA studies have shown that the Himalayan wolf is closer to Holarctic wolf, as is the African golden wolf, which means that Himalayan wolves aren’t as divergent from Holarctic gray wolves as coyotes are.

I have argued many times on this blog that the best way to think of coyotes in light of the evidence of this recent divergence between gray wolves is to think of coyotes as a form of gray wolf, and I think the name for coyotes should be Canis lupus latrans.  It makes at least as much sense as Canis lupus familiaris for pugs and Yorkshire terriers.

Because of the coyote’s position in light of full-genome comparisons, I think that we really shouldn’t think of the Himalayan wolf as a distinct species. I have no problem with Canis lupus himalayensis.

I am quite open to the African golden wolf being recognized as a subspecies of Canis lupus. In light of the work performed on Himalayan wolves and the recent discovery that African golden wolves are almost entirely gray wolf in ancestry, I think this might be correct.

And if you use this species model for gray wolves, you wind up with amazingly phenotypically and behaviorally diverse species, which is reflected in both wild and domestic forms.

I find this a lot easier to deal with than this model that has all these different species described that wind up exchanging genes all the time, and then, because we have declared one form endangered, we get into culling all the hybrids.

We need full genome comparisons between African golden wolves, coyotes, Holarctic gray wolves, and Himalayan wolves to suss out fully what these exact relationships are, but it seems that all of these animals are much more closely related to each other than we initially assumed. We also need more comparisons of ancient wolf DNA, including DNA from the remains of the ancestral Mosbach wolves (Canis mosbachensis).

So there might be a new species of wolf in the Himalayas, but I don’t think the evidence is all there yet. And there are lots of reasons to be skeptical.

But I do think that a unique high altitude subspecies of wolf does exist in the Himalayas. It is very likely that African golden wolves and Himalayan wolves are genetic relics of what was once a more genetically diverse Canis lupus. These lineages have since been lost in the main Holarctic wolf populations, just as we have lost the lineage that led directly to the domestic dog in these wolf populations.

After going through the red and Eastern wolf taxonomic mess, we should be careful in assigning new species status for unique wolf populations, particularly when we are using only very limited DNA assays.

 

 

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loggerhead sea turtle hatching

Recently, I’ve been using this space to play around with the fuzziness of “species.” Hundreds of species concepts exist, and because different researchers have somewhat different perspectives, you will sometimes get real conflicts about whether something is a species or a mere subspecies.

In canids, we get caught up in species discussions that are about what really amounts to very little genetic variation. For example, red wolves, Eastern wolves, gray wolves, dogs, dingoes and coyotes are all lineages that have only radiated in the past 50,000 or so years.

By contrast Old World and North American red foxes, including the ones allegedly derived by those set out by English colonists in the seventeenth and eighteenth, last shared a common ancestor 400,000 years ago.  This finding means that we probably should regard the red fox of North America as Vulpes fulva.

But 400,000 years of divergence is nothing compared to the 3 million years estimated for the Indo-Pacifica and Atlantic-Mediterranean populations of loggerhead sea turtle. There has been some gene flow between the populations. Matrilines have flipped around South Africa, once 250,000 years ago and an once 12,000 years ago.

So researchers who specialize in wolf-like canids are debating over very small genetic differences and relatively recent divergence times.  Red fox researchers are only just now realizing that there are likely two species in what was once thought to be a Holarctic species. And those specializing in loggerhead sea turtles don’t really care that their species has such a deep genetic difference.  The occasional gene flows between populations are enough for them to recognize only one species of loggerhead sea turtle.

This problem gets more interesting when we start talking about “living fossil species.” Take this article on Futurity.org, which is entitled “Evolution Hasn’t Revamped Alligators in 8 Million Years.” This article discusses the findings of some paleontologists at the University of Florida, who have found 8-million-year-old alligator fossils in North America, and they are remarkably similar to the ones we have today.

One of the researchers is quoted in the article says,”We were surprised to find fossil alligators from this deep in time that actually belong to the living species, rather than an extinct one.”

I would be just a hair more careful in my language. Although one can certainly see that these ancient alligators looked and probably behaved very much like the current species, 8 million years is a long time. I doubt that current alligators and those from that time could even interbreed if they encountered each other today. From a biological species perspective, it makes little sense to call them the same species, but from a paleontological perspective, it makes more sense, simply because paleontology is more interested in morphology and ecology over the entire time a population has existed.

So yes, “species” is a nebulous concept, and that is a good thing.  It makes some legal aspects with conservation difficult, because we have an Endangered Species Act that is about a hard and fast definition of a taxonomic entity.  In reality, the whole nebulous side makes for interesting levels of inquiry. If the Neo-Darwinian synthesis correctly describes the origin of biodiversity, then we would expect these discussions and debates to be commonplace.

They certainly are quite common in taxonomy and systematics. They probably always will be. Part of what defines a species are the biases of the classifier, which can often be contradictory.

For example, I have no problem with the new taxonomy of wildcats that posits the European wildcat into a different species than the Near Eastern/North African species. However, I disagree with the position of the domestic cat, which derives fro the Near Eastern/North African species, as its own unique species.

That bias may come from the simple fact that I am more familiar with domestic dog taxonomy, and I have come to accept that domestic dogs are best classified as a divergent form of gray wolf. If the domestic cat derived from its wild ancestor much more recently than the dog derived from its wild ancestor, why would it make any sense to classify the domestic cat as its own species?

So in zoology, we have all these different perspectives on how to classify species. Specialists in sea turtles are able to tolerate a genetically quite divergent species, while experts in wolf-like canids will debate over much more recently divergent lineages. These researchers really don’t talk to each about their ideas.  Indeed, the only time loggerhead sea turtle researchers worry about what specialists on the wolf-like canid side are doing is when they need to figure out how to stop coyotes from destroying the turtles’ nests. But they don’t need to know the complexity of the systematics to find an answer.

However, it is amazing how different specialists come to tolerate variation within one species. That nebulous nature of the various species concepts makes for some interesting variations on what specialists accept as normal.

Specialists often have very different ideas in mind, depending upon what they are used to, and I find it beautiful, even if it a bit confusing at times.

 

 

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Sicily once had a coyote-sized wolf

sicilian wolf

Italian wolf (Canis lupus italicus) at left and the newly described Sicilian wolf (Canis lupus cristaldi).

The Mediterranean islands of Sicily, Sardinia, and Corsica are quite interesting from a natural history perspective.  Insular endemics have occurred on these islands throughout their history, and over the years, one species has captured my imagination, the so-called Sardinian dhole, which was found on both Sardinia and Corsica.  I’ve been trying to trace down exactly what this species was for quite some time, but so much is contentious about this animal that I’ve left it alone, still awaiting that paper that will elucidate it in all its glory

But recently, I’ve become aware of something more tangible: an insular dwarf form of gray wolf that was found in the island of Sicily.  This wolf existed well into the twentieth century, and we have many specimens of them from which we can make measurements and take DNA samples.

In 2018, a paper was published that described the Sicilian wolf’s morphology and contained some initial mitochondrial DNA analysis. The wolf is described as standing on average 21 inches (54.6 cm) at the shoulder, which is about the same height as a coyote.

sicilian wolf taxidermy

These small wolves ranged throughout Sicily and were persecuted as lamb killers. The last documented taking of a wolf on Sicily was in 1924, but reports of hunters killing wolves persisted until 1938.  Sightings were reported from 1960s into the 1970s, but since then, the reports of the Sicilian wolf have largely gone dry. The subspecies is almost certainly extinct.

Analysis of the mitochondrial DNA from two museum specimens revealed that these wolves had a slightly different signature from the mainland Italian wolf. The authors attribute to the Sicilian wolf’s evolution in isolation, which likely started between 20,000 and 21,500 years ago, when the last known land bridge connecting Sicily and mainland Italy was around.

In about 20,000 years or so, insular dwarfism selection pressures produced a small wolf on Sicily in much the same way we might understand how an earlier Pleistocene radiation of wolves into North America could have created another form of small gray wolf that we call coyotes.

The coyote didn’t evolve its smaller size to fit the ecological needs of living on an island. It had to evolve its smaller size to fit a more generalist niche than try to compete as an apex predator on a continent already dominated by dire wolves.

So we have this sort of evolution of coyote-like wolves in parallel in the Old World, which is entirely within our understanding of the gray wolf as a phenotypically and behaviorally plastic species that has had great success adapting to new ecosystems throughout Eurasia and North America.

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red wolf

So I’ve been sent this story a couple of times: apparently, a genetic analysis of Galveston Island coyotes found a relationship between these coyotes and what are called red wolves that are part of the US Fish and Wildlife Service’s endangered species recovery program.

I found it interesting that Bridgett vonHoldt was part of the study that found this genetic link between Galveston Island coyotes and red wolves. VonHoldt is one of the leading canid molecular geneticists who was part of a team of researchers that have found that the red wolf is of hybrid origin. She was also an author of the paper that shows the biggest problem that the red wolf has in claiming species status.

This problem is that it really doesn’t matter whether red wolves are hybrids or not. The question is whether they are hybrids between two entities that are best described as distinct species or not.

A comparisons of full genomes of gray wolves, Eastern wolves, red wolves, and coyotes revealed that Eastern wolves and red wolves are hybrids between coyotes and gray wolves. This finding has been revealed in three papers, one in 2011, one in 2016, and one in 2018. This hybrid discussion is tiresome, though, because we can get into a sea-lioning contest about how there might very well be a hidden unique red wolf species hidden somewhere in the coyote.

This paper would appear to have found such a thing, but it needs to be understood within the full context of the literature.

Yes, the genome-wide and full genome comparisons reveal a hybrid origin of red and Eastern wolves, but the problem that no one seems to be willing to deal with is how recently gray wolves and coyotes split.

When it seemed like gray wolves and coyotes had a common ancestor 800,000 to a million years ago, debates about hybrid origin made some sense. But in the 2016 study, the authors did some comparisons of gray wolf and coyote DNA to see if they could find when the two forms of canid split. The most statistically valid date for that common ancestor was alive around 50,000 years ago:

If we assume a generation time of 3 years, and an effective population size of 45,000 (24, 25), then this corresponds to a divergence time of 50.8 to 52.1 thousand years ago (ka), roughly the same as previous estimates of the divergence time of extant gray wolves (26–28). Thus, the amount of genetic differentiation between gray wolves and coyotes is low and not much greater than the amount of differentiation within each species (for example, Eurasian versus North American gray wolf, FST = 0.099; Table 2 and fig. S1).  This result contradicts molecular clock calculations based on short mitochondrial control region sequences, which were calibrated using a 1-Ma (million years ago) divergence time between gray wolves and coyotes (10). Despite body size and other phenotypic differences between the two species [for example, (1)] and a long history of coyote- and wolf-like forms in North America (1, 29), the genomic data suggest that modern coyotes and gray wolves are very close relatives with a recent common ancestry. (Italics mine).

This paper shows that what we call a coyote could best be described as a form of gray wolf, a smaller and more jackal-like form of gray wolf to be sure but a gray wolf nonetheless. I don’t know why the authors didn’t make this suggestion, because a similar way of thinking clearly puts pugs and Newfoundlands in the gray wolf species as well. This classification is controversial, but it’s not that controversial if you understand systematics based upon clade-based thinking.

So what the researchers found Galveston Island is a population of coyotes that share some genetics with the red wolf. The population that founded the red wolf population that receives conservation attention came from the East Texas and Louisiana mainland, and if this population is isolated, then you can see how this unique population could have retain its genetics as more coyotes spread through the mainland on their way East.

Even if we were to find that there were once large wolves in Prehistoric North America that had coyote-like mitochondrial DNA, we would still have that problem of the recent coyote origins. The only way that problem might be solved is if these large wolves are significantly older than the date suggested from the gray wolf-coyote split. Because we know that anatomically modern gray wolves already existed in Eurasia well before the coyote-gray wolf split, one would expect to find large wolves with coyote-like DNA in North America. We also should expect to find wolves with coyote-like DNA in the Old World as well.

The real debate should be about the validity of Canis latrans as a species. The problem with going down this road is more political than scientific. Coyotes are the most successful relatively large canid in North America. They are found in 49 states, and the only reason they aren’t in Hawaii is they can’t swim that wall.  They are working their way down through Panama, and I would not be surprised if I read some morning that they had crossed the swamps of Darien into Colombia.  Coyotes receive almost no protections anywhere in their range, while wolves generally are protected via the ESA where their populations have been reduced or extirpated.

But we don’t regard domestic dogs as a species either. One can easily see them as a divergent form of gray wolf without losing perspective that there really ecological distinction between a domestic animal and a top-level predator. We are currently grappling with the evidence that dog genes are introgressed heavily into Eurasian wolf populations, but almost exactly the same thing has been observed with North American wolves and coyotes. Even the wolves of Alaska and Yellowstone have coyote ancestry.  

So one should have a bit of skepticism about what was actually discovered on Galveston Island.  At the very least, we should be very careful about thinking of gray wolves, dogs, and coyotes as hard and fast entities and that all three continue to exchange genes across their respective ranges.

We do have a species problem, a species problem that would make sense only if Darwininan precepts are true. With this clade in Canidae, we have also have the Ethiopian wolf, the African golden wolf, and the Eurasian golden jackal that are capable of exchanging genes with each other and with dogs and Holarctic gray wolves. Indeed, the African golden wolf is derived from either a gray wolf or a gray wolf ancestor interbreeding with the ancestral Ethiopian wolf, which was probably much more widespread in the past. 

I don’t have as much of problem thinking of coyotes as a form a gray wolf, probably because I’ve long since accepted that domestic dogs are also a form of gray wolf, but thinking in this way is disruptive to our concept of hard and fast species. However, we should never think that such thing as a hard and fast species exists in the first place. Evolution is fundamentally about change, but it’s also about fuzziness and questions that harry our concepts of essentialism.  

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One of the great exercises on the internet among those who wish to be taken seriously as “dog people” is to say that dogs are not wolves. In one sense, they are quite right. Dogs are not wild canids, and they are certainly not the mostly fearful and reactive wolves of the middle latitudes of Eurasia and North America.

But in another broader sense, they are dead wrong. I’ve been following this debate for some time. At one time, there was a great emphasis on the so-called Canis variabilis that were contemporaries with Homo erectus at the Zhoukoudian cave system in China. The remains date to 500,000 years ago, and it’s quite a leap to say that Homo erectus began dog domestication.

It should be noted now that Canis variabilis is no longer an accepted scientific name for these early wolves. They have since been reclassified as a subspecies of the Mosbach wolf (Canis mosbachensis). Their new name is Canis mosbachensis variabilis, and although the Mosbach wolf is ancestral to the modern gray wolf, the Chinese subspecies is now not regarded as leading to the modern one.

So this idea that these Chinese specimens are ancestral to the domestic dog is quite faulty. Even if we were to say that Canis mosbachensis were the ancestor of dogs, we would have a real problem on our hands. The Mosbach wolf disappears from the Eurasian fossil record no later than 300,000 years ago, when it was replaced by modern gray wolves. The earliest domestic dog that has been proposed dates to 33,000 years ago in the Altai Mountains.

Somehow, you have to get a species that went extinct hundreds of thousands of years before the formation of the earliest domestic dog to become its ancestor. The chronology makes no sense.

Now, we do have some ancient mitochondrial DNA of a Siberian Canis cf. variabilis that appeared to show a connection with the origins of the domestic dog. This specimen is probably a ate surviving Siberian variant of the Mosbach wolf, and it is possible that the reason for this mitochondrial DNA similarity is that domestic dogs have a mitochondrial DNA lineage that very close to this extinct wolf. The real problem with this study is it is a mitochondrial DNA study, and if we could somehow get a full genome comparison from these remain, which would not be easy, then we could get a better picture of how the Mosbach wolf relates to wolves, domestic dogs, and coyotes. Yes, the discovery that gray wolves and coyotes shared a common ancestor only around 50,000 years ago means that coyotes descend from the Mosbach wolf as well.

So when you see someone claiming that Canis variabilis is wild Canis familiaris, just understand that this person hasn’t looked at the most recent literature on these Middle Pleistocene wolves. But I’ve seen this repeated enough that I do think I need a place on this blog where I can easily link to the problems with this assertion

The real problem with all of this is that in dogs, at least in the English speaking world, there is a real problem with phylogeny denial. So many people are caught up in this “dogs are not wolves” idea that they invest lots of mental gymnastics in trying to create another wild ancestor for the domestic dog.

So many people got worked up with the discovery that no extant population of gray wolf is ancestral to the domestic dog that they had to make it about how dogs were not derived from wolves.

Again, the gray wolf species is at least 300,000 years old, and no one has found a relationship between dogs and wolves that posits their divergence as being greater than 33,000 years. There is an old mitochondrial DNA estimate that is largely not accepted that puts their split between dogs and wolves at something like 135,000 years ago, but that’s still after the gray wolf existed as a species.

So let’s talk about why saying dogs are not wolves is an exercise in phylogeny denial:

One of the implications of our modern Darwinian synthesis is monophyletic descent. All organisms derive from ancestors, and it is impossible to evolve outside one’s ancestry. If we were to go back in time to see when the most recent common ancestor of dogs and gray wolves, you would have a hard time describing that ancestor as anything other than a form of Canis lupus.

Dogs have evolved through their Canis lupus ancestor, just as modern wolves have evolved through theirs. It is accurate to say that domestic dogs are not derived from extant wolves, but it is not accurate to say that dogs did not derive from wolves. It is also not accurate to say that dogs are a different species from Canis lupus, because dogs are still part of a Canis lupus lineage.

Further, we have lots of data about the extensive gene flow between dogs and wolves in Eurasia. We know that livestock guardian dogs in the Republic of Georgia have exchanged genes fairly extensively with wolves. But we now have data that shows an extensive gene flow between domestic dogs and wolves across Eurasia.

So dogs and wolves are continuing to exchange genes. They are not becoming reproductively isolated from each other in a way that would lead to speciation, even now.

I’ve never understood why this line of thinking has ever been popular, except that wolves people have indeed abused dogs under the assumption that their social systems are much like those of captive wolves. Further, it is quackery of the worst order to assume that dogs should be fed only full raw carcasses of meat because that is what wolves eat.

But those problems are not adequately addressed by promoting another scientifically dubious prospect. Dogs do behave somewhat differently from wolves, but that is because dogs are domesticated. Wolves behave differently because they are a wild form, and as a wild form, they have undergone a selection for extreme timidity and wariness as we have tried to wipe wolves off the face of the earth.

The argument that dogs are part of Canis lupus is well-supported by science. Indeed, an analysis of gray wolf, domestic dog, and dingo genomes revealed that creating a separate species for the dog, the dingo, or for both would make the entire species polyphyletic and thus not in keeping with Neo-Darwinian principles.

So it is scientifically correct to say that dogs are wolves, but one should say that dogs are domesticated wolves. And just leave it at that.

And drop the phylogeny denial.

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Coyotes, nature’s sighthounds

Built a lot like a lurcher.

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