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Posts Tagged ‘Canis latrans’

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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It’s been so hot lately that long walks can only be accomplished in the early evening.

So Miley and I went out yesterday evening at 7:30.

It didn’t get us out of the heat at all– just the worst part of it.

As we entered the woods, I could tell something had caught Miley’s nose.

She began sniffing the ground and quartering about as virtually all golden retrievers do when they smell something of interest.

As we walked, I noticed that her tail went straight up.

It was then that I knew what she was smelling.

She was smelling where another dog or a coyote had just been.

Because we were pretty far from other houses, I deduced that she had caught the scent of a coyote.

So I began to walk a little slower.  Where Miley sniffed, I checked the somewhat muddy ground for tracks.

And as we moved along, we came across these tracks:

They were small for coyote tracks, but they were the wrong shape for those of a gray fox, which have almost cat-like feet.

I walked on about 20 yards. Miley was quartering about 10 feet ahead of me.

And then she stopped and began sniffing the air.

I scanned around on both sides of the well-tending road we were on, and suddenly, a sandy-colored form began to move on the brush to my left.

My eyes registered upon the form, and it wasn’t long before I knew I was looking at something very much like an unusually-colored German shepherd puppy.

There was no question that I had come across a coyote pup.

Its big, pointed ears were protruding out of the brush, and they were the last things I saw as it trotted out into the tall grass in the middle of the road.

Now I couldn’t see it, even though it was directly in front of me, but it as this time that Miley’s sense of smell began to reveal the pup’s presence to her.

After about twenty seconds after it disappeared into the tall grass before me, Miley let loose one of those terrifying golden retriever growls and charged.

The coyote pup bolted from the grass with the big yellow dog running close behind.

I saw the pup look back as it ran. I could see the terror in its yellowish eyes as checked to see how closely the big blond wolf was following.

It then veered right into the tall timber, and Miley slowed her advance, stopped, turned around, and came back to me.

She gave me a look that said “I sure scared him off good!” And we continued our walk.

Now, I like to make fun of the wolfaboo subculture that has sort of developed in North America.

These are people who have made a sort of sacred deity of the wolf, and they refuse to have any kind of rational discourse about what wolves actually are.

I have to say that after seeing that coyote pup, I can see where they are coming from.

For about an hour afterward, I was a full-blown coyote-boo.

I was just so amazed that I had been able to have this brief encounter with a such a young wild dog.

I was a bit surprised with how large he was. I could tell from his sandy coloration and not entirely bushy tail that he was a juvenile.

And coyote pups are born in late April, which would make him a little over two months old.

It would not be entirely unusual for some enterprising coyote pup of that age to wander away from his parents. Some pups are just that bold and curious.

But I was also a bit surprised with how big he was for being only two-and-half months old.

He was about the size of a golden retriever puppy of the same age.

Now, I am aware that coyotes do have longer legs in proportion to their body size than domestic dogs do, so I bet he didn’t weigh as much as golden retriever pup.

However, he was still pretty big.

There is quite a bit of variance in coyote size in this area. Some of the smallest bitches are only 25-30 pounds in weight, but the dogs can be in the 50-55 pound range. A really big one can be almost 60 pounds.

My guess is this coyote pup, if he manages to survive this summer, will be about that size when he matures, and then if he can pack up with some confederates, he might become a deer hunter.

He learned an important lesson yesterday evening that might improve his chances of survival:  Humans and dogs are dangerous.

Now, Miley probably wouldn’t have known what to do had she caught him.  The chances are pretty high that she wouldn’t have hurt him, but there are plenty of dogs around here that would love to kill a coyote if they had the chance.

So maybe Miley’s little charge might have been that lesson that will keep this little coyote alive.

I sure hope he makes it.

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