But that raises other questions. If dogs were bred from a wild yellow dog rather than from a wolf, then where is/was that wild yellow dog population? Were they all domesticated? Were they driven to extinction in the wild? How? We never came close to driving any other canid to extinction until we invented gunpowder.
The most plausible explanation is that it is extinct for the same reason that dingo as a breed is very soon going to be extinct, and the banteng is soon going to be extinct, and a great many other species/subspecies are soon going to be extinct. When you have a huge pool of domestic animals living in close quarters to the wild form, they interbreed and very rapidly the wild form ceases to exist at all. It just becomes a population of feral domestics. So while Australia will always have wild dogs, and Java will always have wild cattle, they will very soon just be feral dometics. The dingo and the banteng will cease to be. The fact that the wolf does still exist despite constant interbreeding with domestic dogs is actually fairly strong evidence that it isn’t the same species/subspecies as the domestic dog.
And as for the claim that we never came close to driving any other wild canid to extinction, I suggest that you look at the history of the Dire Wolf in North America, or grey wolves in western Europe or India, or the history of the Ethiopian and Nepalese wolves. We actually have no idea how many other canids we have exterminated, because skulls alone won’t allow us to separate most species. There may have been hundreds of species/subspecies of canids in Eurasia 40, 000 years ago, but the skulls would just be classified as variant grey wolves.
In fact the only canids that we didn’t drive to the brink of extinction were the tiny foxes and those living in remote areas. If the ancestor of the domestic dog lived only in the grasslands of the Indus or Tigris valleys then it would have been lucky to survive past the bronze age even without the problems of hybridisation with domestic strains.
Do you have a cite for this?
My experience is that about 10 lbs is the average size of (non-fat) house cats. A quick Google search confirms this is a typical size of a house cat.
This is from 2 years ago, but still pretty current. The oldest fossil dog is sort of like a husky, only bigger. It’s not like modern feral dogs:
You left out the key phrase in my post “before the invention of gunpowder.”
However, I will grant you the Dire Wolf. We may have driven that one to extinction indirectly by wiping out its prey.
But in general, canids are a pretty adaptable bunch. Witness the coyote’s current expansion of its range and numbers. (And that is in spite of the invention of gunpowder.)
Maybe we managed to wipe out this hypothetical wild yellow dog in an age before gunpowder, but it is difficult to imagine that we did so by force of arms. Possibly if they existed in a narrow geographical range we might have wiped out their prey species, and they might have been foreclosed by existing wolf populations from expanding into other regions.
Anyway, don’t get your hackles up, I’m not arguing with you so much as trying to think this thing through. 
From wikipedia:
Seems like 5kg is pretty normal.
I am sorry but I still cannot see why it would be surprising.
Free breeding wild and feral dogs should converge on a form that is quickest to get to from where they are with the genetic material they have that is most “fit” for living in today’s “wild” (including suburban and even urban) environments in which they all similarly find themselves. The wolf form is not very fit for that task, as evidenced by the difficulty of sustaining wild wolf populations in large numbers; a smaller form is. The smaller form will continue to be selected for, sized not too far off from coyotes and foxes. And btw dingos are often much larger than wolves.
But it is (except for the curled tail) an awful lot like the Asian dhole.
Do you have cite for that?
I can’t speak for Blake, but it a little surprising to see an intensively bred grey wolf revert to a form so different. It’s also surprising to see such a change in behavior through breeding as well. Even though dog breeding has occurred over thousands of years (not always intensive), dogs have mixed their genes with wolves repeatedly over that time, so it is unlikely that wolf genes have been eradicated from dogs. Environmental factors do have an effect, and smaller size fits into that pattern, but if dogs have the same basic genetic composition as wolves, wolf characteristics should emerge with a certain predictable probability.
The problem I see in drawing a conclusion about the level of genetic change to expect from breeding. All other domesticated animals have been taken from the wild in a much shorter time frame.
I’m not sure that’s a meaningful idea-- that there are things called "wolf genes’ that are separate from “dog genes”. And keep in mind that some of the genetic changes making a wolf into a dog would be changes to regulatory genes that affect other genes that are identical in the two populations
I’m not convinced that evolution is reversible in the way that the “dogs aren’t descended from wolves” folks seem to think it is. In the words of Louis Dollo:
Throwing a bunch of random dog breeds together isn’t going to “undo” all the previous generations of breeding and selection; it’s going to result in new variation and selection! Further, any given population of feral dogs is composed of only a partial sample of dog variability, so, again, it is unreasonable to expect a full reversion to the ancestral type. I don’t think the “little yellow dog” is any more representative of the ancestor of domestic dogs than is any given breed, really.
Sorry, I thought I did but I must’ve misread it. They aren’t far off though. Per wikipedia articles Dingoes average 13-20kg and wolves vary greatly in size with Asian and Indian varieties at 25kg, to bigger in North America and Europe. Wiki also states that the prehistoric wolf was very similar in size and form to the smaller Asiatic/Indian wolf (per the fossil record).
Here is a picture of the Indian Wolf which is often more reddish. And here of an Asain variety.
Honestly these look like any generic wild dog to me.
I do happen to have an expert in dog evolution as one of my supervisors (she studies dog bones and bone pathology). I could ask her a lot of questions about this topic, but I don’t really want to be trapped in her office for 3 hours while she goes on and on and on and on.
She has given us some lectures though, that include some of the links that Darwin’s Finch posted in the first page, with specific emphasis on the gene shared with Asian wolves found in smaller dog breeds.
That said, she teaches that the majority of modern dog breeds are recent, as breeding for strict comformations and standards did not start until the late 19th century. Working breeds may have longer lineage, but even they were not strictly bred as the show lines are now.
In her view, the “little yellow dog” is the standard, but that does not mean it did not come from wolves.
Certainly thisvicious-looking creature must be descended from the might wolf?
Reversion of the type discussed isn’t about reverse evolution, but the elimination of breeding and allowing a natural distribution of genes.
The sample of wild dogs and their unknown origins makes it impossible to draw absolute conclusions on this subject. But wild dogs tend to retain dog characteristics even though they share so much genetic structure with wolves. That’s a strong indicator that of a major divergence somewhere along the line. When exactly may be impossible to determine. The little yellow dog doesn’t have to be the ancestor of all dogs at all. It could easily be the product of breeding and a limited gene pool. But smaller head, brain, and jaw of a dog remains across the wild species, along with a brain that functions in some distinctly different way.
No, I didn’t.
No, they aren’t. Some are. Many, such as the Ethiopian and Neplaese wolves or the African Hunting Dog, can not tolerate even the most modest contact with humans.
Coyotes are expanding currently because of three factors;
- It is illegal to shoot them in many areas.
- Introduction of artificial food sources.
- The extermination of wolves.
Exactly the same way that we actually exterminated the grey wolf in England before we invented firearms. And the way we came within hair’s breadth of wiping out the Ethiopian and Nepalese wolves and numerous grey wolf populations. Where human population are high the larger canids rapidly vanish. If the canid in question is a grassland rather than forest species then it will rapidly lose literally all of its habitat in any agricultural area.
The most serious flaw with this reasoning is, of course, that dingoes existed for 5, 00 years on an entire continent on which there were no cities, but vast areas of habitat identical to that in which wolves evolved. Similarly island or rural feral dog populations don’t live in urban environments. We have to accept that the wolf is the most suitable phenotype that can be produced from wolf genes for a large canid living in wolf environments. Yet dogs *never *revert to wolf phenoptype ender any environmental conditions.
The second flaw with the reasoning is one that has been brought up multiple times already. If dogs were simply evolving along the most rapid route to a form suited to survival with the genetic material they have, we should expect them to evolve in all sorts of directions based upon environment and genetics. A dog descended from sheepdogs living on a cold, treeless island with only rabbits for food surely has a completely different set of genes and environmental pressures from a dog living in a hot savanna preying upon fast moving 100 kg kangaroos. So according to your reasoning they should end up looking very different as they take the most rapid course towards fitness. Heck, by your argument some dogs should end up looking like wolves just by chance.
But that isn’t what we see. Feral dogs on freezing, treeless islands in the southern ocean, dogs in villages in the steamy Congo jungles, dogs in the West Virginia woods, dogs in cities in India. They all rapidly converge on the same body type. And they do that regardless of genetic ancestry or the apparent selective pressures.
Isn’t that exactly the *opposite *of what we would expect if these dogs were all evolving towards a form that is quickest to get to from where they are with the genetic material they have that is most “fit” for living in today’s “wild”?
Not often, no.
A typical dingo is between 10 and 15 kg, though males up to 20 kg are fairly common in some areas. The largest pure strain ever recorded was 25kg.
A typical sub-tropical wolf (the physically smallest populations) weighs 25 kg, with males up to 40kg being fairly common. The largest wolf ever recorded was 80kg.
IOW the absolute largest dingo ever recorded was the same size as a typical tiny wolf. In no way can you say that dingoes are often larger than wolves, much less “much larger”.
Once again though, if dogs were simply evolving novel variation and selection based on the genetic material they have, we should expect them to evolve in all sorts of directions based upon environment and genetics. A dog descended from sheepdogs living on a cold, treeless island with only rabbits for food surely has a completely different set of genes and environmental pressures from a dog living in a hot savanna preying upon fast moving 100 kg kangaroos. So according to your reasoning they should end up looking very different as they take the most rapid course towards fitness. Heck, by your argument some dogs should end up looking like wolves just by chance.
But that isn’t what we see. Feral dogs on freezing, treeless islands in the southern ocean, dogs in villages in the steamy Congo jungles, dogs in the West Virginia woods, dogs in cities in India. They all rapidly converge on the same body type. And they do that regardless of genetic ancestry or the apparent selective pressures.
I’m not going to argue with your expert, but plenty of other people are doing it. As Blake pointed out so well, there is so much sharing of genes between all the canis varieties, there is no definitive way to determine their evolutionary history. The fossil record shows an evolutionary line of ancestors of the grey wolf, which may have been around for more than 1 million years, so there is a great chance that dogs did descend from grey wolves. The big question is when. The great divide in thought is whether humans domesticated grey wolves, or some other closely related animal.
Definite? No. Beyond any reasonable doubt to experts in evolutionary genetics? Apparently yes.
A major mistake being made here is imaging the primal wolf as the big North American Grey Wolf. The prehistoric common wolf/dog ancestor is felt to be much more along the lines of this Arabian wolf, and again, put that next to a picture of a dingo, or a host of other wild or feral dogs, and it would fit right in.
Big Grey Wolves require a very specific habitat and set of competitors and prey to thrive. Most islands, most current environments, do not have that. If reversion occurs as a valid concept (which I question as a concept) then reversion would be to the smaller prehistoric Arabian/Asian phenotype. Which for all we know was yellow, with grey being a more recent adaptation.
Actually my argument is just the opposite: that it would be extraordinarily unlikely for a “wolf” to pop out of the intermixing of feral dogs, even if it is the ultimate wild ancestor.
And while sure, these little yellow dogs may look superficially similar, what studies have been done which actually compare the freezing island variety to the hot savanna variety? As we all know, superficial similarities can be deceiving. Just because they share similar body types doesn’t mean they are all converging on the same ancestral form.
The body type could well be developmentally constrained as a result of generations of selective breeding. Further, we don’t always even know which domestic varieties of dogs are the ancestors to these feral populations, so we can’t really be sure what we are looking at one way or the other. It could be that the “ancestral breed” was a little yellow guy, and that little yellow guy could, in turn, be derived from wolves. Or dingoes. Or dholes. Or whatever. The point is, we can’t really backtrack sufficiently for this to really tell us anything about the ultimate wild ancestor of the dog because there’s an awful lot of shared morphological similarities between dogs and the potential ancestral candidates.
Granted, there have been many studies which start with wolves (or just assume wolves as the ancestor) and examine the genetic similarities between dogs and wolves and, of course, they have been shown to share a good deal of genetic similarities. Have such molecular studies been done with respect to the other potential candidates…? If not, it would seem like that could go far in untangling the phylogenetic mess.
Only to somebody who knew nothing at all about dogs. That’s an animal with a broad snout, low-slung tail, deep abdomen and many other features totally atypical of yellow dogs.
While I could easily post a string of photos of various yellow dogs that you would be unable to assign to their correct breeds (eg you would identify the pariah dog as a dingo), there is no way in hell that anybody would mistake that wolf for one any of them. It looks completely different in posture, body form and skull morphology. It might be mistaken for a coyote in a bad light, but never for a yellow dog.
The problem is that yellow dogs have different posture, different skull dimensions and different size. Colour is the very least of the problems. You could colour that wolf yellow if you like, but nobody who has ever even glimpsed a dingo or a Carolina dogs would would mistake it for one of them.