Changes in diet lead to changes in morphology and behavior:
These are precisely the same changes that have happened between wild and domestic Canis lupus populations.
Domestic variants are called Canis lupus familiaris.
In the same way that these lizards have evolved to eat vegetation, domestic dogs have new digestive adaptations to consume carbohydrates.
But these does not mean that new species have been created.
In the case of dogs and wolves, there has continued to be a small but not insignificant gene flow between wild and domestic populations. Black wolves in North America obtain their melanism from a mutation that was introduced into their population through breeding with domestic dogs, and now melanistic Italian wolves have been found to have exactly the same mutation that was also introduced in exactly the same way.
I don’t think dogs and wolves will ever become divergent enough to become distinct species, but I do think that smaller dogs, which are genetically isolated from the larger ones, could eventually evolve into a new species.
If there is no gene flow between the lizards on these two islands, they will also eventually become so genetically distinct as to lose chemical infertility.
I should also note that Dawkins hits the nail right on the head when he makes the caveat that we should not automatically assume that the lizards of Pod Kopiste haven’t also experienced rapid evolution as the ones on Pod Mrcaru. They could have indeed experienced similar rapid evolution, but the two would have derived from a common ancestor.
I think some of the problems in doing comparison research on dogs and wolves is that people are unwilling or unable to understand that this possibility exists.
There is an assumption that the wolves we are studying in captive situations are truly reflective of the ancestral population that gave rise to domestic dogs.
Most of these wolves are large wolves from northern Eurasia or northern North America.
It’s very unlikely that any of these wolves has contributed much genetic material to modern dog populations. North American wolves haven’t contributed much at all.
Further, most wolves in captivity descend from ancestors that were heavily persecuted by man.
What we’ve done is something like the Belyaev experiment in reverse. Whereas Belyaev selected for lack of fear in foxes, man has selected for something akin to paranoia in wolves.
We’ve trapped and poisoned them across the northern hemisphere.
The only ones that have survived, with the exception of some populations in the high arctic, have been those that have been most overly cautious. It’s well-known that many wolves won’t even cross highways, which stymies their recolonization of much of their former range, and in Yellowstone, at least one “Casanova wolf,” a bachelor wolf that mated only with the non pair-bonded wolves in established packs, used the highway as a buffer zone to keep from being killed by the main breeding male in the pack.
The wolf that once ranged over the northern hemisphere couldn’t be like these animals. It had to have been much more adaptable and less timorous than these very reactive and fearful animals.
The ancient wolf had to have been an animal that was very easy to domesticate.
I’ve occasionally stolen from an insurance company’s advertisements when I’ve written about these issues, but I do think that dog domestication had to have been so easy a caveman could do it.
Modern wolves, in general, are difficult animals to tame. There are exceptions, and I’ve written about them at length on this blog.
But they are exceptions.
And just because some modern wolves have proven to be quite like dogs when socialized to humans doesn’t mean they are all appropriate pets.
You’ll never find a chimp that can do all the things that a human can do, but occasionally, you’ll find a wolf that is as tractable as any retriever or a dog that is as obstinate and reactive as any wolf.
Because some wolves are quite like dogs when they are imprinted and socialized with humans, I think it’s actually much more important to tell people not to keep them as pets.
Just because one tame wolf is as nice as a golden retriever doesn’t mean they all are. In fact, most are not.
But it’s not like the difference between humans and chimps.
It’s really the difference between wild and domestic.
I don’t know why it is that with this one domestic species very intelligent species spend hour after hour trying to deny the proper classification with its wild ancestor.
It’s almost creationist in a way.
***
I should also note the wall lizards have been introduced to southwestern Ohio. One of the members of the Lazarus department store family introduced a few lizards to the Cincinnati suburbs from Italy, and the wall lizards have expanded their range into adjacent Kentucky and Indiana.
Because they were introduced by a member of the Lazarus family, they are called “Lazarus lizards.”
I wonder if these lizards have any unique adaptations that separate them from the ones in Italy.
What I talk to people back in Idaho, I tell them wolves and most wolfdogs generally make lousy guard dogs and somewhat crappy house-dogs. After all, I think a typical wolf is more ‘dog’ than many people can handle. Same goes for coyotes and some ‘primitive’ breeds like the dingo, certain sled dog breeds and the New Guinea Singers.
Interesting video. Makes me realize that the word ‘evolution’ convolves two (or more) types of change: one from sorting among existing alleles; the other involving mutation. There could be some epigenetic stuff as well. Anyway, I’d bet the lizards evolved that rapidly because there was a lot of genetic variation in the population and the new environment introduced strong selective pressure. Perhaps the species has turned vegetarian in the past due to climatic change or movement into new territory, so the genes for the change were present, but not common.
In thinking of dogs and wolves, you have to consider that both have enormous geographical ranges, and thus huge diversity. Wouldn’t surprise me if some pre-modern wolves were more tame than some of the dogs I’ve met. Balyaev didn’t use a binary classification…he had several levels for degrees of domesticity, and I remember reading that he had to add a level above his original top level because he ended out with foxes that were more tame than he originally thought possible. I think it would be useful to give up the words wild and domesticated and allow shades of grey…or perhaps a range of colors.
The starch digestion argument is frustrating cause the published data could not possibly reflect the range of variation.in wolves, and the dog population showed several fold variation. I wish they had published the breeds for the dog data.
I wonder if ‘Lazarus’ lizards are a weed-type species and we’ll soon be worrying about them outcompeting native species in disturbed habitats (meaning, almost everywhere). Sounds like they are wonderfully adaptive.
It will be species such as this that will be the root stock for the runaway speciation that will inevitably occur once the current man-made extinction event has run its course. Whether our species will be there to see it happen is arguable at best.
Excellent post! I am glad that you noted that North American wolves were not the progenitors of modern dogs. Early dogs evolved from Asian or Middle Eastern small dogs. You seem to think that wolves and dogs are not separate species. That’s debatable, and possibly a topic for another post. I think I’ll make that my next post on my blog:
http://dogsandwolves-smartoldlady.blogspot.com
Actually, I think the answer to the question of speciation would have been much different in the early 20th century than it is now, with the proliferation of deliberate mating of dogs and wolves. But, it is the wolves who are evolving again to be dogs.
The reason why I think dogs and wolves are the same species is that I cannot create a good definition of what’s a wolf and what’s a dog. When I once was a Coppingerite, I tried very hard, but I think the real problem is that there are always doggish wolves and wolfish dogs. And there was a significant gene flow between the population, and in Italy and perhaps other places, there apparently is still some gene flow (black wolves and wolves with dewclaws on the hind legs all derive from dogs mixing into the wolf population.)
I’ve come across so many texts of wolves being tamed and them behaving like normal dogs. The one I link to in this post actually turned into an excellent upland bird dog!
Further, there are breeds of dog–I’m not just talking about Saarlooswolfhond and the Czechoslovakian wolfdog– that have very recent wolf ancestry. In Russia, laikas are still bred with wolves to improve hunting ability.
http://stephenbodio.blogspot.com/2006/12/working-wolf-dogs.html
My taxonomy for the wolf and dog species goes as follows: Canis lupus, which includes all the holarctic wolf subspecies, including the Indian, Himalayan, and African wolf (which is not the same as the Ethiopian wolf), as well as all domestic and feral variants of the domestic dog, including the dingo.
I do think this species is part of a larger species complex that includes the coyote (Canis latrans) and the golden jackal (Canis aureus). The red wolf, the Eastern coyote, some African wolves, and certain Eastern North American wolves are actually hybrids that are difficult to classify. I would argue that red wolves are actually glorified Eastern coyotes and these Eastern North American wolves are just wolves with some coyote in them. The African wolf is still controversial because they do hybridize with golden jackals, but are far more closely related to wolves than golden jackals. They were once classified as golden jackals until very recently.
Quick question
Wolves are protected in some areas and thus not hunted like before. These areas may have humans around that being afraid of is no longer needed. E;g the fearful wolf wastes energy and the less fearful one doesn’t get killed. Will this lead to wolves developing tame traits?
Adam
Assuming that there’s a genetic component to the general skittishness of contemporary wolves, I speculate that ‘genes’ for tameness still reside w/in the species’ genome and if they provide an evolutionary edge would eventually reemerge.