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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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They aren’t the most genetically distant canids from wolves. That would be the Urocyon species.

Reproductive technologies in domestic dogs will lead the way.

I have this bizarre fantasy of someone setting up a ranch in the Southwest for the purpose of rewilding maned wolves. The oldest fossil remains of maned wolves actually do come from the Southwestern US,but the species is now confined to South America.

 

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Arctic hare vs. wolves

Quite a chase!

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Yep. This has to have been the first documentary about wolves I ever watched. Jim Brandenburg and David Mech hanging out with a wolf pack from a population that has never experienced persecution:

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dire-wolf-baculum

Dire wolves are one of those creatures from the past that has captured the public imagination. They are conventionally dreamed of as being massive wolves, and Hollywood has created fictional ones the size of horses.

The truth of the matter is they were only slightly larger than the largest of modern North American wolves.

We know that they were closely related to modern wolves, but their exact position in the wolf family tree is still a bit contested.  The two species are close enough in appearance that it often takes a specialist to figure out whether one is looking at the skeletal remains dire or modern wolf the measurement of the skull features and limb proportions.

One feature, though, that is diagnostic of the dire wolf is its  robust and “perky” baculum.

If you don’t know what a baculum is, that’s because you’re human. In virtually ever other species, the males have a “penis bone” or os penis.  Where I grew up in West Virginia, it was not unusual for men to wear a raccoon’s baculum as talisman of both one’s virility and redneck bona fides.

The dire wolf is one of those ancient animals for which we have a lot of skeletal remains to examine.  In the famous La Brea Tar Pits, where the remains of over a million Pleistocene creatures have been found, dire wolves are the most common species to have been recovered.

The tar pits were a death trap for all sort of large herbivorous mammals, and when they became stuck in the natural asphalt tar, they were easy pickings for scavengers.  Dire wolves came to the tar pits to eat, but many, many of them died. Over 200,000 of them have been taken out of the site.

With such a big sample of dire wolf skeletal remains, paleontologists have been able to figure out quite a bit about their growth patterns, but of particular interest are the bacula of the male dire wolves.  They are shaped not the bacula of any extant canid. They are curved and robust, and when compared to modern wolves of the roughly the same size, they are 44 percent longer.

That is a unusual find, and it suggests something about dire wolf behavior that isn’t true of modern wolves.

Modern wolves generally reproduce through a mated pair. In most wolf packs living in most situations in the wild, only a single pair in a pack gets to mate and produce pups. Other wolves in the pack might mate, but their pups will either be killed or abandoned.

This doesn’t happen every time. If there is abundant prey, these young females are sometimes allowed to raise their pups alongside their mother’s litter.

But in most cases, they don’t get to raise pups.

Modern wolves spend a lot of energy making sure that the mated pair, who are usually parents of the other wolves in the pack, get to mate and get to mate with each other.  The other females in the pack might become pregnant, but they will be attacked if they try to mate with the main breeding male.  The only way they ever get pregnant is by wandering interlopers who haven’t yet formed a pair bond with a female.

During the mating season is when young wolves typically leave their parents’ pack.  They typically don’t have any mating opportunities, and the constant bickering wears on them.

The big and strangely shaped bacula of dire wolves suggests they might not have been quite like modern wolves.  These bacula are suggestive that dire wolves were “better endowed” than modern wolves, and larger genitalia is usually associated with a less physically competitive reproductive strategy.

This phenomenon is well-known in primates. Generally, if a monkey or ape has bigger testes or penis, there is going to be less physical confrontation when it comes to mating.

The competition for well-endowed monkeys is how much semen a male can produce and how far up in the female he can penetrate it. If you can produce more semen and get it deeper into the female’s reproductive tract, then you’re more likely to pass on your genes.

In less-endowed species, there is much more physical confrontation to get one’s genes passed on.

My guess is that this applied to dire wolves. They may not have even had a proper pair-bonding system, and a dire wolf bitch may have mated with many partners in much the same way female domestic dogs do.  The male dire wolves may have had very little competition for mating. They just mated and got along with each other.

It would have been an asset in a dire wolf pack for males to have gotten along with each other. More peace in a dire wolf pack means that more wolves remain in the pack for a longer period of time, and that means they would have had larger packs that would have been much more capable at hunting large prey. They also would have been better able to run off short-faced bears from their kills and to compete with Smilodons and American lions.

It’s likely that the intense competition between huge carnivorans during the dire wolf’s reign forced them into a more cooperative breeding and pack structure.

Again, no scientist has ever seen a dire wolf or observed their pack behavior, but they had this weird adaptation that sort of points to a more peaceful pack existence than exists in the modern species.

My guess is that dire wolves traveled in massive swarms, much like those seen in dholes of today. They were ruthless scavengers and dogged hunters.

When mating tame came, they bred like village dogs. Males would bunch up around a bitch in heat and each would mate with her. There would be no pair bond between the male and female.

The competition was in the semen and the implantation thereof.

 

 

 

 

 

 

 

 

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This is now playing on Netflix:

These wolves really do remind me of coyotes, right down to their consumption of fruit when it’s available.

 

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brush wolf

It cannot be overstated how much the discovery that coyotes are not as distantly related to wolves as we believed ultimately questions our entire understanding of the evolution of the Canis species.

The traditional understanding Canis species evolved from some form of Eucyon dog some six million years ago. Wang and Tedford, who wrote the most important book on the paleontology of the dog family, believe this was Eucyon davisi, which was the first of its genus to enter Eurasia. The genus Eucyon is where the common ancestor of the Canis dogs (including Lycaon and Cuon) and the South American wild dogs would be located. Eucyon dogs were small. Imagine them as being something like a black-backed jackal or a Hoary fox rather than a coyote.

Then, 5 million years later in the Southwestern US and northern Mexico, a coyote-like Canis evolved, which was called Canis lepophagus. This animal is sometimes considered the common ancestor of wolves and coyotes. It may be, but considering how close we now know wolves and coyotes are now, it’s not the most recent common ancestor. Canis lepophagus did migrate into Eurasia, where it either founded or is identical to Canis arnensis.

In Eurasia, several smaller jackal-to-coyote forms evolved. One of these was Canis estruscus,  which then evolved into Canis mosbachensis (which is called Canis variabilis in China).

Ron Nowak believed the red wolf was an offshoot of this wolf that wound up colonizing North America and then becoming isolated from the rest of Canis mobachensis when the ice sheets expanded. There was also a competing view that the red wolf was actually a remnant version of Canis edwardii or Canis priscolatrans (which were probably the same animal). This animal was roughly the size of a red wolf, but Nowak rejected it as a red wolf ancestor because it lived too early for what he thought were red wolf fossils.

The Eurasian wolf species evolved mosbachensis-variabilis, but the two forms of wolf shared habitat and likely exchanged genes, making it very difficult

The coyote’s evolution was never clear. It was thought to have evolved out of Canis lepophagus. It was thought that lepophagus evolved into edwardii, and then it began to become more gracile and smaller, eventually becoming the now coyote.  It’s now pretty clear that it evolved out of the Eurasian Canis lupus and not these endemic North American “wolves.”

It either evolved from the modern wolf, which evolved into roughly its current form 800,000 years ago, or it came from a late surviving mosbachensis-type wolves that were regularly crossing with modern wolves before they came into this continent. Maybe the remains that Nowak had been considering “red wolves,” were actually these ancestral wolves that were evolving into the modern coyote.

Maybe when this wave of wolves came back across from Eurasia, perhaps 50,000-100,000 years ago, it came into a world already dominated by a dire wolves, which already occupied the niche for large, pack hunting canids and this wave of Canis lupus evolved as the American jackal.  After all, the bobcat is just a diminutive Eurasian lynx that found itself in a very similar position when it came into this continent, and it evolved to be a smaller animal that generally hunts smaller quarry than its larger ancestor. Of course, the modern bobcat didn’t reach its current form until about 20,000 years ago, but it still was forced to adapt to a slightly different niche than its Eurasian ancestor.

In literature on the paleontology of Canis, there is a heated debate as to how these animals all fit. The conventional view is that the wolf evolved from Canis mosbachensis/variabilis through Canis etruscus, which may be the same thing as Canis edwardii/ Canis priscolatrans. Wang and Tedford contend that the coyote and wolf split from Eucyon.  The modern wolf evolved from Canis chihliensis, which was a large wolf-like canid. It spread into North America to found Canis armbrusteri, which then evolved into the dire wolf (Canis dirus) in North America and Canis gezi and Canis nehringi in South America.  In the Old World, another offshoot of chihliensis gave rise to Canis falconeri, which the supposedly gave rise to the Xencyon, which is supposed ancestor of the dhole and African wild dog. Another view holds that the Armbruster’s wolf (C armbrusteri) is descended from edwardii/priscolatrans (which may be the same as etruscus). This lineage then gave rise to the dire wolf and the two sister species in South America, thus descending solely from North America wolves.

All of these ideas come from paleontology, and they pretty much are done without looking very deeply into the studies that are examining the DNA of these species. It is pretty obvious from that literature that the notion that coyotes and wolves split at the time of the Eucyon ancestor is quite wrong. For that hypothesis to work, African of  wild dogs and dholes would have to be genetically closer to wolves than coyotes and golden jackals are. They aren’t.

But if the genome-wide analysis shows that coyotes are so much more closely related to wolves is true, then all these fossil and subfossil canids that are said to be the most recent common ancestor of wolves and coyotes simply aren’t.  Instead, all of these species that are classified in Canis are likely a mix of evolutionary dead ends, like the dire and Armbruster’s wolf, or could be hidden ancestors of extant canids that aren’t wolves or coyotes.

For example, black-backed and side-striped jackals diverged from the rest of Canis and its allies at about the same time that Eucyon was diverging from Canis. It is possible that there are many relatives of these particular dogs that are hidden in this vast sea of Canis fossils.

The new discovery about the coyote’s split from the wolf also means that any remains of North American canid that are listed as coyote that date to 1 million years before present are not coyotes. What they actually were is a very good question.

We’ve spent a lot of time assuming that coyotes and wolves were quite divergent. We know now that they really aren’t, but when we look into the past at all the “wolves” and “coyotes” that came before, we see how this genus became so successful. It can easily evolve into big game-hunting forms, but the real success is in its ability to assume the size and shape of the generalist predator. Phenotypic plasticity is a wonderful thing for a lineage to possess.

But the real message of the new discovery about wolves and coyotes should be is a cautionary tale about paleontology. Paleontology is a wonderful science, and it makes amazing discoveries every day, but when its faced with a lineage of animals where phenotypic plasticity and tendencies toward parallel and convergent evolution are commonplace, it is bound to make errors. Paleontologists aren’t examining flesh and blood that can have its molecules tested for relationships. They are measuring anatomical characters and determining phylogenetic relationships based upon the similarities of these characters.

Which works well.

Until you get something like wolves and coyotes, where there are many ancient fossil and subfossil remains that look like they could be ancestors of either.

But the DNA says they aren’t.

And paleontology would have problem catching the inverse. There are many species that we’ve discovered only through DNA testing. African butterfly fish in the Congo and Niger basins look identical to each other, but they have been isolated from each other for 57 million years. I have yet to see this species split into two, but if they were mammals, you could bet they would be placed in distinct species in heartbeat.

Paleontology is missing some really important things we’ve since found out through molecular analyses.

And paleontologists know this.

They are working with the data they have, and by definition, it’s going to be more incomplete than genetic studies.

Science is provisional. Different disciplines and methodologies are going to come up with different answers. It’s pretty amazing that one genome-wide assay study can wipe out so much literature in paleontology.

These debates have been raging for years.

And it turns out that everyone was actually wrong.

Update 21 August 2016:  It turns out that I missed a paper that actually did some limited DNA analysis and found that Canis nehringi was pretty much a South American dire wolf, as in it was likely the same species as the North American dire wolf. Canis gezi, however, was  more closely related to the modern maned wolf and had been incorrectly identified as a wolf. So let this stand as a correction to the error above.

 

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