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A black Italian wolf. The black trait originated in dogs and was transferred to Italian and North American wolves through introgression.

As long-time readers of this blog know, I consider dogs to be a form of gray wolf.  I do not consider Canis familiaris to be a valid taxon, because of cladistics and because of the gene flow between domestic dogs and wolves.

The extent of this gene flow was largely denied in much of the literature on wolves.  But last year, it was discovered that the majority of Eurasian wolves have recent dog ancestry. This gene flow has been going on for a while, and although people do get a bit worked up about domestic animal genes filtering into a wild species, it has been shown that the melanism in wolves that is conferred by a dominant allele originated in a Native American dog that was living in the Yukon or the Northwest Terrtories thousands of years before Columbus. Further, this melanistic allele is associated with higher immune responses, and there is evidence for natural selection favoring black individuals following a distemper outbreak.

In a paper released this week in the European Journal of Wildlife Research found extensive crossbreeding between dogs and wolves in agricultural landscapes in Central Italy.  The authors estimate that about half of all wolves in this region have recent dog ancestry, and they think it is because humans have disturbed wolf habitat to have agriculture.

Of course, humans, wolves, and dogs have been living in Italy alongside agriculture for thousands of years. Dogs and wolves have been mating ever since there was a population of somewhat domesticated wolves.

Further, European wolves are much better adapted than North American wolves to living in agricultural areas.  It may simply be that North Americans are much more likely to kill wolves that appear in agricultural areas and that this is what has created this asymmetry. But North American wolves tend to be in remote areas, where they rarely encounter dogs. Thus, there is not as much gene flow between dogs and North American wolves as there is between dogs and Eurasian wolves.

There is a lot of gene flow between dogs and coyotes in North America, and this finding does make sense. Coyotes do live in agricultural and urban areas much more easily than large wolves do.

I don’t think it worth becoming alarmed that dogs and wolves are mating in the wild.  Dogs have lots of interesting mutations that could be of great use to wolves as they adapt to more and more human-dominated planet. If the dog alleles are deleterious, nature will select against them, but if they are advantageous, they will help wolves thrive into the future.

So it is quite short-sighted to think of wolves as being a some sort of pure entity that must be kept free of “foreign” alleles.  If it were more widely accepted that dogs were just a domestic form of gray wolf, we would have a much easier time accepting a more holistic understanding to how these populations can continue exchange genes and adapt to new challenges.

 

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dare 4 months

When you get a dog of this caliber, you want to do it right.  You want to do her bloodline justice. You want to ensure that you’re doing all the right socialization and training that will allow her genetic potential to be realized.

It means, though, that I must remember that she is but a child. She must be allowed to be a puppy. She must  be able to play and be silly. Every day, she looks more and more like a majestic German shepherd dog. Yes, she’s going through the floppy, “Gumby wolf” stage, but the elegance is there, burning through like an ember in the ashes.

The way this puppy looks at me is utter trust and adoration. She wishes to be with me, to do things with me, and I am taken aback by this responsibility.

I am the most important being she knows. She will even leave another puppy she is playing with if she hears my call.

I don’t want to mess this up.  I want to do it right. There is pressure here. There is tension.

But I have to remember to enjoy her in her salad days. She is raw puppy, trying to make sense of her drives and her teeth.

I cannot let the desire to do it right rob me of this joy. I must take time enjoy her puppy-hood. It is so fleeting.

Just like everything in a dog’s life.

 

Pretty Girl

dare pretty girl

dare pretty

pretty dare.jpg

black squrrel

As long-time readers of this blog know, the black coloration seen in North America and Italian wolves and in coyotes originated in domestic dogs. Indeed, the black coloration in North American wolves originated from a single introgression of a black domestic dog in the Northwest Territories or the Yukon between 1,598 and 7,248 years ago.  Of course, we now know that there is significant gene flow between dogs and certain populations of gray wolf and that this gene flow has been going on for some time.

I have often wondered about color genetics and gene flow between species. One species that is particularly beguiling for speculation for me was always the origin of melanism in Eastern gray squirrels. Melanistic Eastern gray squirrels are more common in Ontario, Quebec, and Michigan, but there are isolated populations south of these locations.

A new paper just published in BMC Biology revealed that melanism in Eastern gray squirrels most likely had its origins from hybridization with the fox squirrel.

Melanism has evolved twice in fox squirrels. The melanistic ones in the Southeast have a mutation called ASIP A3.  Melanistic Western fox squirrels have a mutation that causes a deletion in the MC1R. This allele is called MC1R∆24.

What is interesting is that melanistic Eastern gray squirrel have the same mutation.

The authors contend that the most likely explanation for this shared mutation is hybridization between fox and Eastern gray squirrels, although ancestral polymorphisms and earlier hybridization between gray squirrels and fox squirrels cannot be ruled out as possible origins either. However, The authors think it originated in fox squirrels because it resembles other fox squirrel MC1R haplotypes.

This finding is pretty interesting because I live where both species are common, and I use to live where there were lots of black gray squirrels.  I had read accounts of fox squirrels mating with gray ones, but the accounts I read said that no offspring resulted from the mating.

I assumed that the two species could not hybridize, and I still have not seen any literature that even suggests hybridization could occur until I read this paper.

More work is going to be needed to see exactly how this mutation originated and if there are other traits that originated in one species that now are found in the other.

And yes, there is that old wives’ tail that says that gray squirrels castrate fox squirrels to reduce the competition. What actually happens is that when squirrels are hunted in the early part of the season, the testicles shrink in size, so that they appear to have been castrated.

But I have never heard of these two species hybridizing. Indeed, it may be that the hybridization that transferred that particular mutation onto Eastern gray squirrels happened far back in the evolutionary history of both species, when they were still chemically interfertile.

However, they might still be able to hybridize. It is just that no one has ever documented a true hybrid between the two species.

But I am certainly open to the possibility.

So it is likely that black gray squirrels resulted from introgression, just as black wolves and coyotes do.

The McCaig Delusion

working BC pup

Donald McCaig was a great dog writer. His historical fiction was even better, but he was a sort of founding father of a movement that I now find rather problematic.

McCaig was a border collie sheepdog trials person, and he was part of a group of people who were fanatically anti-American Kennel Club. So much did they hate the idea of border collies becoming a standardized breed that the American Border Collie Association will not cross register AKC border collie puppies, and any dog that earned a conformation championship from any registry would become ineligible for registration. 

McCaig was the intellectual father of this fanaticism. He believed that the border collie should remain solely a sheep herding dog, and if it were used for something else, it would cease to be a true border collie.

He raised sheep and ran border collies in the Allegheny Mountains of Virginia, not far from the West Virginia border.  He thought of himself as a traditional country writer, but as a native to that part of the world, he always seemed like an outsider trying to play country boy.

For example, the traditional sheep herding dog of that part of the world is not the border collie. It is the English shepherd, a loose-eyed herder, that also can tree raccoons and bring in the milk cows. It is the unimproved peasant collie of British Isles,  the one that existed before the Enclosure, where lots of livestock needed to be managed, not just vast folds of sheep. Those vast folds came about when the manors were enclosed and the tenants shipped off to toil in the mills, and the border collie’s existence came about when this sort of dog was needed on the new land.

In the Alleghenies, no one runs vast hordes of sheep over great pastures. The woods have mostly reclaimed the Alleghenies. Bears and coyotes make sheep husbandry harder than before, and with the wool market tied up with Australia and New Zealand’s near monopoly, sheep have been mostly relegated to the few die-hards in the West who fight the battle against wolf depredations and the odd homesteader who keeps a little flock in the back pasture.

So, although McCaig was a successful writer and sheepdog trial enthusiast, he was never the sort of authentic mountain farmer that he hoped he was. If he were, he would have kept a pack of English shepherds and mixed enterprise farm on a little holding.

But leaving behind those problems, McCaig’s idea that the border collie should be maintained solely as a herding dog was at best delusional. The dog itself has traits that would make it well-suited for the 21st century. They are scary smart. They are trainable. They are also beautiful creatures with pleasant temperaments.  These dogs have traits that make them superior sport and working animals.

If this attitude had been applied to the German sheepdogs in 1890s, they would have become just regional dogs of no particular note, but Max von Stephanitz and the other founders of the SV decided to use their nation’s sheepdogs as working animals.

German shepherds are certainly still capable of herding sheep and working as farm dogs, but the 1890s, Germans were finding they had less of a need for a sheepdog. Sheep could be shipped via train now, and private property finally replaced the last vestiges of feudalism. Fences could be used to contain the sheep now.  A tending dog became less of a necessity.

So members of the SV embraced the future. They encouraged members to train their dogs for other disciplines. That move created the most successful working dog ever created, one that is known the world over for its abilities.

And because lots of people ignored the sage counsel that breed be produced solely as a sheepdog, the border collie is seeing great days as a sport and working animal. They dominate agility and flyball. They have done great work as search and rescue dogs. Some have even been used as gun dogs. And yes, many are accomplished show dogs, and those show dogs still have their brains and herding instincts.

But even now, you will see wags harp back with claims that border collies are being ruined because they are being used in these other disciplines.

So honestly, what if they are?

Imagine 10,000 years ago that a group of people had a bunch of dogs that were superb at hunting sheep in the mountains. They had the monopoly on these dogs and the sheep hides and meat they were able to procure.

But one day, they ran into another group of people that had managed to tame some sheep. The attitude of the early Holocene McCaig’s would have said the dogs would have no use if they couldn’t hunt sheep. The Holocene Stephanitzes would have begun working on training the dogs to manage sheep. Those were the people who created the first herding dogs.

This is the problem of this McCaig delusion. I do not wish to pick on the man solely, though, for there are lots of dog people with this delusion. They can only see what once was or what they hope things were, and they cannot embrace the future.

And it is this delusion that I wish we would reject.  We cannot assume that a breed or type of dog can remain employed solely in its original occupation. That assumption is what made the turnspit go extinct and the otterhound roll around in obsolescene  and obscurity.

In the Western world, the most important job for dogs is to be family pets, and there is nothing wrong with breeding good working dogs that can fit into modern society. Indeed, this is the challenge of working dogs in this century.  We must find ways to keep working drives and instincts alive and to produce dogs that are suitable for family life.

And that’s why we need to be critical of ideas that are so accepted without criticism, even if they are ideas that are popular. These were ideas that I accepted without criticism, and they are ideas that I now think need more careful consideration for the future of our breeds.

 

Snakes are lizards

For most of my life, we have thought of snakes as being closely related to lizards. Both snakes and lizards are squamates (the order Squamata), but all my childhood reptile books placed snakes as being part of a distinct suborder called Serpentes.

However, taxonomy has moved onto a cladistic model, where we group organisms based upon their common ancestry. A clade is defined as including all descendants of a common ancestor, and keeping snakes a specially defined entity distinct from lizards is problematic.

A recently published paper on the Komodo dragon genome reveals why this is a problem for a cladistic classification model.  The authors compared the genomes of komodo dragons with the Burmese python, several species of lizard and lots of other tetrapods.

A phylogenetic tree was drawn from the comparisons.

komodo dragon genome phylogenetic

The Burmese python does not fit outside of the “lizard” clade. It fits within that clade, and if we are to use cladistic classification, then we must place snakes within lizards.

Snakes are a particularly specialized form of lizard, and as it should be noted, they are not the only legless lizards known. There are glass lizards and worm lizards (some of which are not entirely legless) that have a similar sort of body design to the snakes.

Snakes are the most wildly distributed legless lizards, but we probably should recognize them as lizards and not some sort of special grouping distinct from lizards.

xenocyon and cynotherium

Depiction of Xenocyon lycaonoides (in the back) with Cynotherium sardous (in the front).

The “hunting dogs” are sister lineage to the true wolves. They were once widespread across Eurasia, Africa, and into North America. Today, the lineage is survived by two species, the dhole (Cuon alpinus) and the African wild dog or painted dog (Lycaon pictus).

But during the Pleistocene, a third species, much larger than two extant species, was ubiquitous. This species, called Xenocyon lycaonoides, was found all over Africa and all over Eurasia.  It ranged into North America, where its remains have been described as Xenocyon texanus.

It was long accepted in paleontology that the dhole and African wild dog derived from Xenocyon lycaonoides, but new evidence that shows the African wild dog deriving from a Pliocene African species called Lycaon sekowei casts that idea into doubt. Further, because the dhole and African wild dog are so closely related to each other, it is doubtful that either derives from Xenocyon.

My take, based upon simple chronology and the genomic analysis of living species, is that Xenocyon and its offshoots were a sister lineage to that which leads to the dhole and African wild dog.

The best way to think of Xenocyon lycaonoides is that it was the gray wolf before there was a gray wolf. It was a pack-hunting canid that was able to expand its range over a wide range. It was roughly the size of a large northern gray wolf, and it would have been a formidable predator of large game.

On islands, though, Xenocyon evolution went a bit weird. On Java, two descendants of Xenocyon lycaonoides evolved. One was Merriam’s dog (Megacyon merriami). It was even larger than the mainland form, but over time, it was replaced by a smaller form that averaged 22 kg (48.5 pounds) called the Trinil dog (Mececyon trinilensis). A new analysis of these Pleistocene canids places both in the genus Xenocyon (which fits a cladistic classification model) and shows that the smaller Trinil dog derived from the larger Merriam’s dog.  Increased competition from tigers and other large predators forced the larger Merriam’s dog to target smaller prey, and over time, they became smaller.

Anothe even more extreme insular form of Xenocyon evolved on the Pleistocene island of Corsica-Sardinia. This island is now two islands in the Mediterranean, but during the Pleistocene, they were connected to each other. On that Pleistocene island, Xenocyon lycaonoides became isolated on an island that was full of small prey, especially a species endemic pika.  This Corsica-Sardinian canid became a specialist in hunting burrowing prey.  It had the ability to thrust its head out laterally better than any living canid, which would have given it an advantage in catching quick-moving prey that would take refuge in burrow.

This species is called the Sardinian dhole (Cynotherium sardous), but it is not directly related to the modern dhole. It was the size of a golden jackal or a small coyote, and it went extinct after humans colonized Corsica-Sardinia at the very end of the Pleistocene. It was the last of the Xenocyon derivatives to go extinct.

The Mosbach wolf (Canis mosbachensis) was a contemporary of the larger Xenocyon lycaonoides.  It was smaller canid that varied in size from an Eastern coyote to an Indian wolf.  It eventually would evolve into the larger gray wolf, which would have a similar evolutionary trajectory to the Xenocyon. It would spread over much of the world. Many regional forms would evolve.

Domestication, of course, would give the gray wolf lots of opportunities for weirdness to come about. Yes, as weird as the so-called Sardinian dhole was, it was never as bizarrely put together as some of our domestic dog breeds.

These extinct “wolves in parallel” do tell us a lot about how a large canid can radiate across the a broad swathe of the planet and adapt to regional conditions and thrive.

 

 

 

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