A re-post from January 2012. |
A reader writes to ask about the putative origin of dogs.
It seems she was listening to Science Friday and they referenced this story from PlosOne: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum
She wonders how the transformation from wolf to dog could have occurred in so many diverse geographical areas. If one wolf pup was taken in by humans in Nome, Alaska another in Brittany, France, and another in the Fertile Crescent of Iraq, wouldn't they have a lot of genetic differences?
Here's an interesting question!
Let's start with a simple point: DNA and mDNA are not as good as a license plate. DNA can tell you if this blood or hair came from that animal, but population DNA is a little more complex and a little less clear, and that is especially true for animals that routinely make 1,000 mile migrations and which can jump human-constructed taxonomic fences as if they were little more than chalk lines on a black board.
So what are all these papers about that are proclaiming some scientist or another has just discovered "the first dog"?
Mostly, nonsense.
What is going on here, is that some underfunded and overlooked dirt scraper in some God-forsaken location has come across a canid skull in a cave.
That's it.
But, of course, there has to be more, and so measurements are taken, tests are run, and speculation runs rampant as people desperate for more funding look for a headline, a first, a discovery, a whole new way of looking at the world.
Carbon dating will be done, of course, and in the paper they will note the presence of a possible fire pit nearby, the bones of dozens of other animals, and maybe a few cut marks on a few bones. The scientists will measure the teeth and claim the animal they found has teeth ever so slightly different from some putative "norm" for wolves, and they may also say the muzzle was ever so slightly shorter than some other putative norm.
This "study" has been done again and again, all over the world, with only slightly different wording. So far scientists have boldly proclaimed that the first dogs came from China, the Middle East, France, Ethiopia, Oregon, and ... wherever.
It is all nonsense. They have no idea, and in fact the folks making these claims have no real understanding of wolves, dogs, species or even evolution. Hard to believe, but absolutely true.
Let's start with the basics: The differences between wolves, dogs, Coyotes, and Golden Jackals are so slight that they can ALL interbreed and produce fertile young.
Let's take a look at a few pictures:
Coyote |
Tibetan wolf |
New Guinea Singing Dog |
Red Wolf |
Negev Desert wolf |
Italian wolf |
Arctic wolf |
Australian Dingo |
Golden Jackal |
Egyptian stray dogs |
Greenland sled dogs |
Ethopian wolf |
Romanian wolf |
Chinese village dog |
Philippines Village Dog |
Coyote |
French wolves |
Shave these animals down to account for coat differences due to climate variance, and color them all the same, and there is not a biologist in the world that can reliably say which is dog, wolf, jackal or coyote based on simply looking at them. There are differences in size, but those differences are arrayed on a continuum and there is no obvious break moving from one animal to another.
This is not to say dogs, Coyotes, Golden Jackals, and wolves are not different.
Wolves and coyotes howl and almost never bark, while dogs bark and almost never howl.
Male and female alpha wolves lift their legs to pee, while all other wolf pack members squat to pee. With dogs, almost all males lift their legs, and almost all females squat.
With wolves, estrus occurs only once a year in January or February, while with most non-primitive dogs, estrus occurs twice a year, and can occur at any time.
There are other differences too -- physical differences. Wolves have a pre-caudal gland while dogs do not, and there is also a very small bone difference in the feet of one wolf sub-species.
But can a scientist, anywhere, pick up the skull of an ancient canid and definitely and reliably say this one is a coyote, and this one is a red wolf, and this one is an Arabian wolf, and this one is a dog, and this one is a Golden Jackal and nothing has ever been crossed?
No.
The morphology and biology of dogs, wolves, coyotes, and Golden Jackals is simply too plastic for that kind of facile work based on single skull samples.
In fact, the very nature of the claim being made is flawed at its core.
The assumption is that dogs were created from wolves. It's far more accurate to say dogs ARE being created from wolves. The world of canids is one in which speciation is occurring and has not yet fully occurred. It is still a process, not an event.
And it is a process in which man is still very much stirring the pot.
In Alaska, Kazakhstan, Spain and Romania, there are still wolf pups being snatched from the wild and raised as dogs. These animals are so unreliable as pets that there are laws in almost every country prohibiting their ownership, but their ownership is so common that there's also a entire lexicon of language where the dogs are described as "Malamutes." In fact, many of the animals bought as wolves are Malamutes! Such is the plastic nature of dogs and wolves.
In Italy, Alaska, Minnesota, Spain, Ethiopia and the Middle East, wolves are occasionally crossing with dogs to create small unstable hybrids with the result being mostly wolf, but with sizable doses of dog coursing through the bloodstream.
Here in the U.S. no one knows what to make of the giant coyotes that have appeared in New York and Maine. They appear to be mostly wolf, but there's a little dog in there too.
And, of course, there is the Red Wolf, which has always been nothing more than a stable and self-replicating hybrid of a wolf and a coyote.
The point here is that the world needs to stop saluting this notion that there was a "magic moment" when a wolf became a dog, or that there is even a bright-line morphological difference between Wolves, Dogs, Coyotes, and Golden Jackals.
Bones, by themselves, do not actually tell us all that that much in this instance.
Malaysian feral dog |
Native Siberian dog |
Leonhard Sepalla and his sled dogs |
Golden Jackal |
Turkish Wolf |
Fantastic collection of primitive dog pictures! It was fun to see so many in one spot.
ReplyDeleteOn another note, if anyone is interested in domesticated dog history, the book "A History of Dogs in the Early Americas" by Marion Schwartz is an awesome read - but most parts are not for the bunny hugger set.
In part of the book, the author presents the thought that there are no primitive domesticated dogs left in North America - that they went the way of the Dodo and the Carrier Pigeon when the Europeans brought their dogs over.
great stuff !!
ReplyDeletewe have run into the coyote hybred up here in Massachusetts many times.
They come in packs and are bold as heck. They have a way of hunting dogs that is prety smart.
A small coyote will show itself and run into the wood line when a dog gives chase...the pack is laying in wait. tricksters are no joke!
Great article.
ReplyDeleteSpottydog, I was walking my Police trained German Shepherd this past week on a farm that overlooks the Connecticut river here in CT. It was just dusk and a lone coyote came out from a thicket. He traveled through an overgrown horse pasture where we lost site of him; then appeared on the gravel road about 120 feet ahead of us. It then took off into the treeline. Something about its actions made me think it was an ambush. Now that I have read your comments, I am glad I didn't yield to the urge for him to give chase! Contrary to popular belief coyotes are cooperative hunters!
Great post. The Turkisk wolf looks like a Basenji in the face...
ReplyDeleteI suspect that all these canids are the "default" matrix that human interference can only temporarily distort for purposes good and bad. Romanticizing or demonizing them is one of those distortions, with -- again -- consequences both good and bad. I just enjoy their raw existence, esp. when spotted by surprise on the prairie. Of course, I don't raise sheep.
ReplyDeletePrairie Mary
Except for his floppy ears my partner's hound mix could pass for one of the desert versions of these canids. Same lean build and natural camouflage.
ReplyDeleteGreat post and interesting pics. I read years ago that our big coyotes were gray wolf - coyote crosses.
ReplyDeleteHaven't seen any near my house luckily since my dog is only 35 lbs. We have lots of Fox even on our street but so far the cats are ok. The dog hates them.
Kathy
A dog's still a wolf more than any other canid. I'm sure I read the same articles you did on google and it clearly states that dog DNA doffers about 1.8% from wolves' while the other canids differ at least 4% from wolves'. I like your take on the morphological differences but if used correctly it's pretty hard to argue with DNA evidence. Eventually the little smarty-pantses working on this will figure out most of the story. All about sub-speciation and various taming evens I bet.
ReplyDeleteLove all the pix, including the red wolf that seems pop up in numerous arguments. And then we have the Belyaev results where selecting for a behavioral trait - short flight distsance - gave a friendly outgoing fox with some different morphological features in just 30-40 generations. That is a "magic moment" in evolution.
ReplyDeleteDogs aren't made from wolves/coyotes/dingo/jackals/etc, even if they can interbreed. they do have a common ancestor though. then they diverged, each into a niche. probably near around the time humans came around.
ReplyDeletedog behavior is actually very different from wolf behavior, with strikingly different inborn rules (that don't rely on socialization or environment, it's genetic) -- though there are many similarities too. and i can back that up with solid experience.
Have you read "How to Tame a Fox (and Build a Dog)"? I enjoyed it, even if I'm not sure about the scientists theory of self domestication. There was a lot of discussion of dog domestication.
ReplyDeleteAnd wow. Finally telling it like it is, a process still going on. Just like each breed is in the process of changing.
ReplyDelete