Remember when I said that polar bears should be considered a subspecies of brown bear?
I was wrong.
I then broke my own rule about believing mtDNA studies and accepted these findings.
I did not report, as some places did, that polar bears evolved in Ireland.
The fossil record shows that polar bears have been around for at least 110,000 to 130,000 years.
What happened was that a male polar bear mated with a female Irish brown bear, and it turned out that all living polar bears descend from that coupling. The crossbred bears bread back into polar bears, and the only thing they have that is brown bear is that mtDNA.
Now, based upon that evidence, I suggested that polar bears ought to be considered a specialized subspecies of brown bear.
Well, a nuclear DNA study came out yesterday that shot that possibility down.
This study revealed that polar and brown bears split about 600,000 years ago. There was some cross-breeding between the two over that time period, but the two lineages have been distinct for a long time.
Instead of polar bears being a subspecies of brown bear, we have a species complex that exists between Ursus arctos and Ursus maritimus.
The two species can and do interbreed when they wind up sharing territory, which isn’t often.
However, it is possible hybridization has affected the evolution of both species.
In addition to that finding about Irish brown bears, another mtDNA study found that brown bears living in Alaska’s Alexander Archipelago have mtDNA that is very similar to that of a polar bear. It is possible that a female polar bear wound up on the islands. She mated with brown bears, and her offspring then bred back into the brown bear population. For what ever reason– perhaps inbreeding– all the brown bears of that island descend from that female polar bear.
I know of know studies that have looked at these bears from this perspective.
Mitochondrial DNA studies don’t tell us everything.
We need to be careful when citing them as absolute fact.
They can really skew results.
Are the studies that put dog domestication in SE asia based on mtDNA?
Yes, they are, but there’s more to that than meets the eye. Jan Koler-Maznick did a study that argued on morphological grounds that the dingo originated from a small far-eastern wolf, C. chanco or C. variabilis. You can find that study on the website of the New Guinea Singing Dog Conservation Society (NGSDCS). Also, the CS has a discussion group on Yahoo. It’s the one called NGSD Discussion Group. There you can talk to Jan.
It’s bullshit.
Her whole paper has been falsified.
I don’t waste my time her crap.
Dogs are derived from wolves. Dogs are wolves.
Dogs are derived from various populations of wolves in Eurasia, but the current dogs we have now are derived mostly from Middle Eastern wolves.
Her stuff is generally loved by people who don’t read the other literature to know how full of crap she is.
She also thinks singing dogs are different species. And they aren’t.
They are dingoes, which are dogs.
I thought of including a warning. Or of just not mentioning that study, so I wouldn’t have to post this. However, I know Kate is interested in origins, including science, history and folklore. So, I mentioned that study for the sake of completeness. BTW, who shot it down? And how?
The separate species stuff is in response to requirements of conservation organizations. Seems you can’t conserve a “sub-species”, never mind whatever the singer is. Nobody in singerland bats an eye when unique taxonomic status is claimed. Everybody knows the singer and the other dingoes are dogs.
What is known about the dingo is that it is descended from domestic dogs and that it has been living as a wild animal for about 3500 years. Last year a study (Savolainen) traced its origins to southern China. Also, it is not descended from Austronesian dogs (same study by Savolainen, I believe).
I don’t take sides in the China vs Middle East question. Wake me up when we know for certain. Could have happened twice. In neither place – genes get around. I find it disturbing that people feel so strongly about this question.
This latest post about the polar bear is terrific. I wonder whether their taste in food is inherited or whether they just learn to hunt and eat whatever mother teaches them.
Savolainen has been falsified.
I’ve written this post: https://retrieverman.wordpress.com/2011/12/19/twigs-versus-logs-and-the-origin-of-the-domestic-dog/
And Mark Derr wrote this one: http://mbdog.markderr.com/2011/12/dog-is-from-where.html
UCLA used a much more sophisticate analysis of the genome than the y-chromosome and mtDNA studies, which, by definition, looked at only a tiny part of the genome.
The study that says the Middle East is the place of domestication doesn’t say that. What it actually says is that dogs were domesticated throughout Eurasia over a long period of time from several different wolf populations. There was no single domestication event, and dogs and wolves have exchanged genes through most of that time.
That’s what the data shows.
I can go throught Koler-Matznick’s paper and show you where she’s wrong, where she’s misrepresenting things (especially about leopards and jaguars), and where the current data totally falsifies what she’s looking at.
She’s one of those who is promoting the New Guinea singing dog, which is a dingo, as a separate species. Dingoes are actually East Asian domestic dogs that have gone feral. They are not a missing link between wolves and dogs, and they are not a separate species from wolves or dogs, which are the same species.
There are wolf mtDNA lineages that are as distinct from each other as dog mtDNA lineages are to certain wolves. There are plenty of wolves with coyote mtDNA, but when their nuclear DNA has been examined, they have been overwhelmingly wolf.
This is why you need to be careful of mtDNA or y-chromosome studies.
BTW, Savolainen’s big complaint is that the UCLA team didn’t look at any dogs originating in Southeast Asia.
Wrong.
They looked at dingoes.
That’s what a dingo is.
Dingoes have Middle Eastern wolf and East Asian wolf ancestry.
If you wish to be educated on the real origins of dogs, please refer to this book:
http://www.amazon.com/How-Dog-Became-Wolves-Friends/dp/B005V933HM
Good book. He rambles a lot, but if you are interested in dogs before Victorian Toilet Science takes over, it’s a must read.
Can we forget the dingos for awhile? I have a question about bears. Do you think their taste in food/hunting strategy/life on the ice are inherited? Because, if they are, that might explain why so few maternal or paternal lineages survive: if a hybrid does not inherit a whole package, it would be less fit than either of its parents. Similarly for the retrievers, the water dogs not only loved the water, but it sounds as if they could dive. Whatever the recipe for producing a retriever, does it ever produce a dog that dives? Or has something been irretrievably (no pun intended) lost?
Diving is a learned behavior. I had a golden retriever that dived.
Polar bears have specialized adaptations to life on the ice. Their heads are smaller so they can go into seal holes better. They have grappling hook claws, while brown bears have very dexterous claws.
A hybrid would have fewer of the features that would make it a good polar bear.
Most of what bears do is learned behavior. They learn it from their mothers, which is why they remain with their parents for so long.
Thank you. My neighbor has a beautiful new lab. Now, if I had some dog treats that sink….
More seriously, while we’re trying to save things by cross-breeding, it’s much safer where behavior is learned.
What do you think of conservation breeding? It has its limitations, I know, but while you were criticizing that fellow in Russia, I was thinking why not include all the people who want exotic pets in conservation breeding programs? That is being done with the singing dog, but could be done with other species. Just supply the owner with breeding stock and facilities for breeding. The owner could foot the bill for food, housing, medicine and the breeding program could take the babies. Just a thought.