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Posts Tagged ‘wolves’

Charles Darwin was an early proponent of humans belonging to a single species. The concept was not popular in Darwin’s imperialist nation, where many of the best and brightest were dead certain that “lesser peoples” of the empire were entirely different species. Monogenists versus the polygenists this was the debate by even those who accepted Darwin’s controversial thesis that species evolved through natural selection and that humans evolved from African great apes.

We know now that the monogenists won out. Only the basest racist frauds believe that humans represent multiple species deriving from distinct evolutionary lineages. The only exceptions are that we do have evidence that humans have trace amounts of other extinct humans in their DNA, such as Neanderthals and the Denisovan hominin.

The monophyly of a species is a concept that should be axiomatic. Much of the “rewriting” of taxonomy and systematics comes from us discovering that a clade is either paraphyletic or polyphyletic, but what does sometimes happen is we do run into situations where we have thought species were really distinct but now we think of them as being subspecies. Black-tailed and mule deer come to mind, as do Cape and African forest buffalo. We have to combine them in a single species to retain its monophyly.

I think something now must be done with gray wolves and their closest kin. In recent years, it has become difficult to retain that domestic dogs and dingoes remain distinct species from the Holarctic gray wolf, especially if we wish to keep the species monophyletic. But I think now a good case can be made that coyotes belong to the same species as Canis lupus. They diverged from a common ancestor only recently, around 50,000 years ago, and the much debated Eastern and red wolf “species,” which appear to be hybrids between coyotes and gray wolves can also similarly be folded into Canis lupus. Whether there was a coyote sister population in the Eastern forest that gave rise to red and Eastern wolves is a moot point. That “forest coyote” population is no more distinct from gray wolves than those of the West are.

Further, we do have evidence of continued gene flow between gray wolves and coyotes. Eastern coyotes have wolf ancestry, and many also have wolf ancestry that comes from domestic dogs.

This new way of describing Canis lupus forms has some benefits. One is that we can come up with a strong legal foundation for the protection of red and Eastern wolves without them being distinct species. Their hybrid status is no longer problematic. We no longer must strain credibility talking about them being ancient North American wolves. Instead, we just go the Endangered Species Act’s statute language which defines an “endangered species” as being a “subspecies” that requires conservation action. We currently protect the Florida panther as an endangered species using this definition, and what is more, the Florida panther was given genetic rescue when Texas cougars were released into its range. The Florida panther exists as a hybrid that holds onto alleles of a population that no longer exists in its pure form, and in the case of red and Eastern wolves, one can very easily make this case.

The problem with going this route is that coyotes themselves do not experience many protections in the United States or Canada. Most states have a very open hunting season on them year-round, and some places have bounties on them. Eastern coyotes are hard to tell apart from what are called Eastern wolves and are even harder to tell apart from red wolves. There is an overlap in phenotype that comes from both forms having similar hybrid origins.

Further, because red wolves living in the North Carolina recovery range are all derived from 19 individuals, and wild wolf-like canids have inbreeding avoidance behavior, it is quite common for red wolves to pair up with Eastern coyotes. Much energy has been devoted to killing off and removing coyotes in red wolf recovery zones, including the euthanasia of crossbred puppies, but it seems that this won’t work long-term.

Recently, researchers at Princeton discovered that the coyotes of Galveston Island are quite closely related to the red wolves in the recovery program. The authors think that many southeastern coyotes might hold the alleles of these red wolves, but I think a better explanation is that we simply under-estimated what the coyote’s range was in the United States at the time of contact. John Smith described the “wolues” of Jamestown as not being much larger than English foxes, and I initially thought he was talking about gray foxes. But then I read original text, and the gray fox is described in complete detail, including the fact that it lacks the red fox’s odor. Henry Wharton Shoemaker, the naturalist and folklorist who chronicled much of the lore of Pennsylvania’s wildlife, wrote about a “small brown wolf” that lived along the Susquehanna River, which made a yipping howl that resembled that of the prairie wolf or coyote. Shoemaker postulated that these small brown wolves were the same species as the coyote, but very few scholars have taken his speculations seriously.

Perhaps, there were coyotes living in the forest alongside Eastern wolves and a endemic Southeastern form of wolf that was very often melanistic. All three exchanged genes, and all three were killed off for their furs and for bounties without any regard to what they were. It was only when settlers in Indiana noticed that some of the wolves in their area were quite small that they began to wonder if they were a distinct species. Later explorers into the West began to call them prairie wolves, which was their name until Americans adopted the Nahuatl-derived name for them.

The most important bit of text I’ve read in any of these North American wolf taxonomy papers is one in a response paper to another one that still argues for multiple species of wolf in North America. The authors write that “[the] genetic differentiation between red wolves and other North American [wolf-like] canids is comparable to the amount of genetic differentiation found between different continental human groups, which of course are not considered to be distinct evolutionary lineages.”

And at that moment, we are back to Mr. Darwin’s debate with the polygenists. He was right to oppose their claims back then, and maybe when it comes to North American and Eurasians wolves, dogs, dingoes, and coyotes, one should be a monogenists.

That’s where I am planting my flag. I think that is where it will all end up once we’ve sorted it all out.

I find the idea of gray wolves representing a phenotypically and behaviorally diverse species awfully intriguing. This diversity is greatly exaggerated in the domestic form, but this diversity is also reflected in the wild, where we have 15-pound coyotes and wolves that weigh 130 pounds.

It may even be that the African golden wolf, which is derived from the ancestor of the gray wolf and coyote mating with the ancestor of the Ethiopian wolf, may be close enough to extant gray wolves that we might also regard it as part of this very diverse species. It would be a coyote-evolved in parallel out of the gray wolf lineage, for the coyote likely evolved in its smaller and more generalist form from the ancestral Eurasian gray wolf because it could not compete as a pack hunter in a North America dominated by dire wolves. African wild dogs once ranged over almost the whole continent of Africa, and they could have provided competition for that niche that would force these ancestral gray wolves to evolve in something like an African coyote.

The recalibration of the evolution of Canis needs to be done with light of the knowledge that gray wolves and coyotes aren’t so genetically distinct from each other. We need new papers that look at he full genomes of golden and Himalayan wolves to get an idea of when they may have split from the rest of the gray wolf swarm. It may be very well be that they all belong to this wide-ranging phenotypically diverse species that over parts of four continents

Yes, this is controversial, but I think it is parsimonious. So many scientists now have no problem thinking that pugs and Yorkshire terriers are Canis lupus familiaris, so why is it so difficult to think of coyotes as being Canis lupus latrans?

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We don’t really think of antlers as being practical weapons. No species of deer that has them has them year round, and in only one species, caribou/reindeer, do both sexes have antlers.

We tend to think of antlers as being used to attract the opposite sex and for ritualized combat between conspecifics, usually just competing males during the rut in all species but caribou/reindeer. In that species, the females retain antlers well into the winter, which they use fight for preferential feeding areas, a great asset in feeding the calves they carry through the long northern winters.

But we don’t normally think of them as weapons to be used against predators. After all, predators are a problem that plagues deer all year, not just during the rut, and if they were widely used in fighting off predators, one would think they would evolve to hold onto them permanently or at least for longer periods of the year.

Well, a recent paper in the journal Nature examined how these factors work with regard to elk living in Yellowstone, where wolf predation is a significant factor in elk survival.

The authors found that bull elk that lose their antlers relatively early tend to be in better physical condition than those that retain them, and those that lose their antlers early tend to grow larger antlers than those that retain them, simply because they have more time to grow their new antlers in the coming year.

The authors found that there is a massive trade-off for how long elk hold onto their antlers. Those bull elk that lose their antlers are preferentially targeted by wolves. Yes, even though they are in better physical condition than those that retain them, the wolves go for elk that lack antlers as weapons.

Predation from wolves could be driving elk in Yellowstone to hold onto their antlers longer, and it could explain why elk in general hold onto their antlers long after their breeding season.

This study has some interesting implications, because wolves could indirectly be selecting for smaller antler size in elk, simply because the elk that lose their antlers sooner tend to have bigger racks in the following year. Further, because the elk hold onto their antlers longer when they are in poorer physical condition, the wolves could be selecting for weaker elk that are much poorer foragers than they might otherwise be.

These questions were not addressed in the paper, but I’m sure the questions did arise as the researchers looked at their data. More work is going to have to be done, but it is clear that wolf predation is a lot more complex in how it selects for fitness in the elk population than we might have assumed.

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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 machairodonts, 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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I’m so glad these taxonomy issues are being raised on a popular science Youtube series:

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This is “Mr. Ethiopian wolf,” pretty much the world’s leading expert on the species:

There is a very interesting discussion in the Q and A portion about the introgression of dog genes into Ethiopian wolves and why that’s not necessarily always a bad thing.

The current research is working toward a full genome sequence of the Ethiopian wolf, and if they are like coyotes and “Holarctic” wolves, I bet there will be some surprises in store.

 

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dire wolf mesomelas

Yep. This was an April Fools’ prank.

That’s okay. I had one pulled on me last night at the cabin where we were fishing. About 10 o’clock last night, my dad shouts “Oh my God! There is a bear in the trash!”

By the time everyone had rushed to the windows to see– and I had just been roused from slumber– it was soon revealed there was no bear.

Yes, and just as there was no bear, all that was in the post about the dire wolf’s genome being closely allied to black-backed jackals is utter nonsense.

But I have always imagined that this was a possibility, because I think our assumption that dire wolves were very closely related to modern wolves really hasn’t been tested out empirically.  We have some phylogenetic trees drawn from paleontological analysis, but one must be very careful of these studies. Parallel evolution is a very common occurrence in canids, and I’ve come to the conclusion that everything one reads about paleontology and canids needs to be taken with a grain of salt.

So yes, it’s an April Fool, but it is a definite possibility.

Oh, and please don’t hate on my dodgy “photoshop.”

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coyote profile pic

I am a coyote lover. No two ways about it.  I have always been interested in wolves and dogs, but in the past couple of years, I’ve had encounters with Eastern coyotes.  And they are every bit as fascinating. Western man has thrown every single weapon he could contrive at them, and all they have done is spread all over the continent.

So it was with great joy when I got a chance to read Dan Flores’s  Coyote America. I had heard the author interviewed on Steven Rinella’s podcast a while back, and I was really fascinated about what he had to say about Pleistocene megafauna on the North American Great Plains.

I also knew he was writing a book on coyotes, and I wanted get his take on them.

I’ve just started reading the book. I really enjoy his discussion about Native American traditions with coyotes. I am a damned, no-good Easterner, so I know very little about those traditions.

But I do have a quibble. It’s a friendly quibble. In one part of the book he describes coyotes as being as genetically distinct from wolves as humans are from orangutans and that the two species split from a common ancestor some 3.2 million years ago. He uses a lot of the paleontological data from Xiaoming Wang, who is a great canid paleontologist, who posits that coyotes evolved from directly from Canis lepophagus and that they are wholly a North American lineage.

Now, this is paleontology, and it’s not exactly the best way to determine evolution relationships between very closely related canid species. The reason why is that canids have a tendency toward parallel evolution. For example, the bush dog of South America has dentition that is very much like the African wild dog and the dhole, and at one time, it was suggested that the bush dog was actually a species of dwarf dhole. We now know from genetic studies that it is actually a close relative the of the maned wolf, and it is well-nested in the South American canid clade.

It is definitely true that coyotes resemble African golden jackals, but similarities in appearance have led to error here.  Molecular geneticist have recently found that African golden jackal is actually much more closely related to coyotes and wolves than it is to the Eurasian golden jackal. That means that two animals we thought were the same species actually turned out to be two.

And when it comes to the relationship between coyotes and wolves, molecular geneticists had long assumed that the two species split around 1 million years ago.  In countless dog domestication articles, the molecular clock has been calibrated around a 1-million-year-old split between wolves and coyotes. I have always thought that was weird, because the paleontology studies suggested a much older divergence.

Well, a recent comparison of wolf and coyote genomes from across North America revealed that the actual separation time was something more like 50,000 years ago. That means the animals we’re calling coyotes now aren’t the same thing as those million-year-old fossils.  Those animals are of evolutionary dead-ends that just happened to have a very similar morphology to a coyote in much the same way that African and Eurasian jackals do. Of course, we cannot get genetic data from such old fossils, but it could be that some of these dead-end canids might be more closely related to black-backed and side-striped jackals, which really did diverge from the rest of Canis a really long time ago. They are more divergent from the rest of Canis than the African wild dog and dhole are, and the dhole and African wild dog have their own genera.

If coyotes and wolves diverged only 50,000 years ago, then this raises an interesting taxonomic question. All extant wolf lineages diverged in the past 44,400-45,900 years, as a recent study comparing wolf genomes revealed.  These means the genetic difference between a wolf and a coyote is not much more than the greatest genetic variance between wolves. (Generation time are roughly similar in both wolves and coyotes).

This means that the creatures we’re calling coyotes now actually derived from the Eurasian wolf. The reason this animal looks so much like a jackal isn’t because it represents a primitive North American Canis lineage, but because the larger, pack hunting wolf from Eurasia couldn’t live very well at middle latitudes in North America. At the time, dire wolves were occupying this niche. There were also dholes coming into North America, which means that the pack-hunting wolf of Eurasia really had some strong competition. That means that these wolves evolved more toward the generalist jackal body-type and ecological niche. They did so in parallel to the Eurasian and African jackals.

This is very similar to what happened to the first radiation of Eurasian lynx into North America. Eurasian lynx are pretty large, weighing as much as 70 pounds, but they found the mid-sized cat niche already locked up in North America. So they evolved into the smaller bobcat. It just happened millions of years before the wolves that became coyotes came into the continent.

The fact that wolves and coyotes are this closely related and have exchanged genes so much across the continent raises some important questions about what a coyote is. The comparative genome study on wolves and coyotes showed that the animals called the Eastern wolf and the red wolf, which Flores considers valid species in the book, are actually hybrids between wolves and coyotes. I’ve long been a skeptic of the red and Eastern wolf paradigm, but this study actually makes me question coyotes.

One could actually argue that coyotes are a subspecies of wolf. This is a controversial thing to say, but it was once controversial to say that dogs and wolves were the same species– and now there is growing acceptance (at least among scientists) of this fact.

It is certainly true that all wolves, jackals, African wild dogs, and dholes do descend from a coyote-like North American ancestor.  But to assume that coyotes are directly derived from this ancestor is a major error, and one that has been falsified in the molecular studies.

If my interpretation of the genetic studies is correct, the coyote should be called the “thriving wolf.” Unlike the bigger ones, it was able to survive all that we threw at it. The more we persecuted it, the greater its numbers became, as did the vastness of its range. It is an adaptable, resourceful survivor, and that makes it the perfect “American avatar” to use Flores’s construction.

So that is what a coyote is.  It is the wolf that thrives.

 

 

 

 

 

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