Excerpts: from the Sunday Times: Polar bear is a ‘new’ species
by Jonathan Leake
Polar bears may have come into existence only 150,000 years ago, when trapped brown bears had to adapt to an ice age
Polar bears may have come into existence only 150,000 years ago, when brown bears were trapped by an ice age and had to adapt quickly to survive, scientists have found.
The suggestion follows the discovery of the jawbone of an animal that died up to 130,000 years ago, making it the oldest polar bear fossil found. The bone has yielded new insights into the origins of Earth’s largest land predator.
One is the possibility that polar bears owe their existence not only to past climate change, including ice ages, but have also survived at least one long period of global warming.
The bone was discovered at Poolepynten on the Arctic island of Svalbard by Professors Olafur Ingolfsson, of the University of Iceland, and Oystein Wiig, of the University of Oslo.
…
In a paper they said: “Brown bears of the ABC islands may be descendants of ancient ursids [bears] that diverged from other lineages of brown bears and subsequently founded the polar bear lineage.” This view is expected to get support from new research, out this week, based on DNA extracted from the Poolepynten jawbone.
It means polar bears have already survived a global warming that affected the northern hemisphere from 130,000 to 115,000 years ago, when the Greenland ice sheet and the Arctic ice cap were smaller than now. Professor Chris Stringer, of the Natural History Museum in London, an expert in ice ages, said: “Early polar bears would not have had all the specialisations of modern animals and we know nothing about their behaviour.
“Living through a warm period back then does not mean they are resilient to climate change now.”
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Just in case you thought in my last post was necessarily global warming in angle the National Geographic says:
“The preliminary report notes an increase in grizzly bear sightings in Wapusk National Park, just south of Churchill, Manitoba.”
“Experts also aren’t sure what’s causing the influx of bears, but it’s more likely due to reduced hunting pressure than global warming.”
http://news.nationalgeographic.com/news/2010/02/100226-grizzly-bears-polar-bears-hybrid-canada/
One jaw bone..one Yamal tree. What an imagination!
“Biologists from the American Museum of Natural History in New York found grizzly bears are increasingly being spotted in the Canadian province of Manitoba, even though they are officially extinct in that particular region.”>>
Since they are officialy extinct, the science is in and it is settled. There’s no grizzlies in Manitoba. You can prove this by counting all the bears and rounding off to zero.
I thought the most strange information in this whole debacle is that apparently got so much historical information that they could draw such absolute conclusions from one single jawbone that they couldn’t accurately date to even a +/- 100 years.
Talk about a flare for the dramatic fantastical fictive story telling.
Although I now understand how grandpa could have lived in ancient Rome, but he must have been somewhat conservative since he then kept himself within a +/- 2000 years. Now but by using the hobnobs flare for fantastical accuracy I myself might, a hundred thousand years from now, have lived ten thousand years ago, perhaps having surfed the slopes of the last great ice.
Jimbo
Look at the “adaptations” in a all our domesticated animals in the last 6,000 to 8,000 yrs. Better yet look what the American Kennel Club can produce in dogs in a few decades. (And if we use body features – the polar bear and brown bear have more right to claim single species than do St. Bernards and beagles)
If we want to look at animals uninfluenced by farming/husbandry techniques- take something they are calling the new wolf in New Jersey- a coyote X wolf (approx12%) that is now breeding true—-a new species.
Salmon are perhaps the fastest of all vertebrates to adapt (being tetraploids helps) with adaptations becoming apparent in as little as 2 generations. Salmon are the ultimate climate change warrior- as these fast adaptations are necessary to follow the changing ice fronts north and south over time.
Species is an artificial construct necessary to aid in biology. Nothing more. Species definition has evolved more as a result of Endangered Species Act legal proceeding and court tactics than it has for any need in the biological community.
The interesting point Stringer made is that the polar bears of a 100,000 yrs ago may not have been as specialized. This guy should lose his job- animals don’t become specialized as if it is a goal or worse if it implies the bears have become better- animals adapt to the conditions at hand to survive and adaptation is a full time job. Animals can’t become specialized in the human trade sense because this would require a world where nothing changed. Yes the polar bears (or whitish brown bears because a fertile hybrid says by the old species definition they are the same species) were somewhat different 100,000 years ago. The bears 100K yrs ago were specialized to 100k years ago- the bears now are specialized to now and the bears of the future will be specialized to the future. Evolution is the eternal quest to adapt to an ever changing world. Species are a continuum they are not hard lines.
Ursus arctos is the apex terrestrial predator of the far northern hemisphere. Until some extinction event far more severe than Al’s climate change (since the brown bear has seen many) U. arctos will continue to spin off brown bear variants to fill and make efficient use of all available niches.
The North American Black Bear, Ursus Americanus is known to develop white patches on its fur, and in rarer cases, all white pelts. In folklore they are known as ‘spirit bears’ and more prosaicly as ‘Kermode Bears’.
Also worth noting that Polar Bears Ursus Maritimus have been known to interbreed with Grizzlies Ursus Arctos Horribilis (I kid you not). Rather reminds me how differing breeds of dog can crossbreed. Perhaps the species concerned are more resilient than the ‘experts’ suggest.
Kermode Bear: http://en.wikipedia.org/wiki/Kermode_bear
Grizzly-Polar Hybrid: http://en.wikipedia.org/wiki/Grizzly%E2%80%93polar_bear_hybrid
The extinction threat to worry about is not polar bears but to polar bear researchers like Dr. Taylor. Dr Taylor is now ostracized for not seeing the climate threat to continued polar bear survival.
Makes the claims made in this story seem all the nuttier:
http://news.discovery.com/animals/grizzly-bears-enter-polar-bear-territory.html
I couldn’t believe that it was listed as a “top story” a few days ago.
Neither the writer, nor her sad little handful of comment authors bothered to consider that these bears had any chance of meeting or living in the same areas at any time in the past.
I did a little research (very little; <2 minutes) and found that polar bear hybrids have been suspected since the 1800's (although only recently confirmed by DNA evidence), which just goes to show that when Grizzly Bears meet polar bears the same possibilities exist as when polar bears meet polar, and it has been so many times before.
From a WWF site – “How do you figure out a bear’s age?
As a bear grows, a thin layer of bone, called cementum, is deposited each year in the teeth. By examining a thin slice of tooth under a microscope and counting the layers of cementum, the polar bear’s age can be estimated in much the same way that tree rings reveal the age of a forest. To do this, a small tooth, located just behind the large canine teeth and of no use to the bear, is pulled. This information is vital for monitoring the health and condition of polar bears over time.”
Maybe Mann & The Team can include this method in their next reconstruction!
rbateman (10:21:59) : “So, do humans revert back to neanderthals in an ice-age?”
No, just when they’re appointed head of the EPA.
Jimbo, I seem to remember watching some show, maybe suzuki, where this GW factoid was presented. My BS radar went to full.
rbateman (10:21:59) :
So, do humans revert back to neanderthals in an ice-age?
Seems to me I’ve read a lot of articles about the sprouting popularity of paleo diets and caveman lifestyles recently. Coincidence?
Don’t know about the polars or grizzlies but there is one black bear who has developed his resiliency at breaking into my ski cabin at Tahoe. For two years running each Spring he has entered it through windows which he manages to rip out of their soffits. This spring when he emerges from hibernation and pays a visit he will be greeted by an electric wire fencing that will require immediate adaptation to lots of free ampheres seeking mother gaia. I hope that will retrain his somewhat animal brain and I won’t find another refrigerator ripped open in the search for his vittles.
DeNihilist
Your BS radar should go up anytime you hear WWF or IUCN. Both NGOs were set up by Julian Huxley the first UN director of UNESCO. WWF and IUCN maintain a “special status” designation within the UN framework…It should come as no surprise we find them as champions of AGW. They are the UN- just with nicer ofices.
The way they define species, if the polar bear lived on salmon in streams emptying to the Arctic back then, and now live on seals, the polar bears who live on seals are a “different species”, because species is defined by genetics, habitat, and diet.
I am not making this up. This means that virtually any change causes extinctions, by their definition.
I doubt polar bears would find killing whatever brown bears eat a great challenge, btw.
A biologist’s definition of species is that which maintains interfertility in reproductive isolation, meaning that recognizable species can exist and evolve where individual members are interfertile, and as long as reproductive isolation occurs, the species taxon can remain valid.
For taxonomic purposes, cohorts meeting these criteria generally are known as species. However, a great many species are defined solely on their reproductive isolation or their phenotype or niche utilization. The line of interfertility is not a hard line. Some species are interfertile with low reproductive success, undergoing a process usually described as incipient speciation, meaning they are on their way to fully independent speciation whose reproductive isolation is biological, not geographic (or temporal, or a number of mechanisms).
There are species, such as leopard frogs, that are interfertile across their range but members from the extemes are not co-fertile. This is the Rassenkreis of Ernst Mayr.
The brown bears and their cousins, like the the coyotes, wolves, coy-dogs etc, are not true species (depending on your definition, of course), but really are subspecies of a complex genus. This is partly why animals’ taxa get changed from time to time – they’re found to be interfertile, the mechanism for reproductive isolation breaks down, have significant anatomical differences or some group is redefining the definitions of the taxa. DNA sequencing is muddying the waters.
The true test of speciation is interfertility, which is also sometimes extended to include a requirement for the hybrid to be able form a stable interfertile population without reverting to type (biologically , ie. phenotypically distinct from either parent). Note again, this starts to re-assert the continuum nature of speciation.
Speculation on successful and future niche utilization of allied species based on phenotypic variation without a rigorous analysis of the interfertility is pretty meaningless, and even with such analysis, is probably pretty meaningless as to species’ survival. Most extinctions are extinctions of subspecies, not species. Subspecies are inherently “experiments” in niche utilization; sometimes they’re successful, often, they’re not.
TJA
Now you understand the great power of the Endangered Species Act– the answer to what is an endangered species is anything we want it to be. The report listing the Maine Atlantic Salmon declared any salmon in a river more than 2 generations to be wild and open to protection. So salmon can spin off endangered stocks in less than 8 years.
Another paper shifting the center of gravity of climate change away from the agw settled science. Where were these guys prior to the climategate tsunami. I’m sure they must have found their fossil and the status of greenland and svalbaard glaciers data before svalbaard’s winter set in last fall. I guess academic institutions are removing the shackles from researchers and we are enjoying a surge of pent-up papers either kept in wraps Or stuck in peer review.
Incidentally, I’ve proposed in a much earler post that when the arctic ice melted in earlier warm periods, it was the seals that were at risk. The polar bears actually had a field day with a linearly distributed seal pop. Along the shorelines.
There was no science that polar bears were in trouble until WWF decided to use them as their poster animal.
Polar Bear Population Status in the Southern Beaufort SeaOpen-
SeaOpen-File Report 2006–1337USGS
“In our analysis of the 2001–06 data, we did not find clear evidence for a relationship between sea ice coverage in the SBS region (i.e., the covariate ice) and survival. ”
They could not find a relationship between sea ice and survival—- but despite finding no relationship it is now declared a fact.
Bears are the prototypical omnivores, and survive on meat, vegetation, berries, or whatever’s going. In warm periods, there are more of all of the above. Polar bears are unique in their ability to cope also with very cold environments; that gives them local dominance as the peak predators. But they do fine (better, actually) when there’s LOTS of food available. Such as when it warms up.
P.S.
The only threat to polar bears’ survival is rifles. Their population surged after the ’70s when hunting them was forbidden.
The thing about evolution by natural selection is that POPULATIONS remain constant. SPECIES change through time (a long time) through the deaths of individuals that cannot survive an environmental change and the reproduction and success of individuals with very subtle mutations better suited to the environment. This mechanism for evolution requires very long time periods (15,000 years in this case) for significant changes to occur. If a significant environmental change occurs over a short time period (200 years for example) the species will simply die out rather than evolve.
Climate change today is much more rapid than the change described above. Too rapid for real evolutionary changes, as opposed to adaptions, to take place. That is why the polar bear is threatened by the melting of the polar ice caps.
another note-
“Brian H (17:43:06) :
P.S.
The only threat to polar bears’ survival is rifles. Their population surged after the ’70s when hunting them was forbidden.”
If Polar bears are pushed into human population centers by climate change for whatever reason, for instance because food sources have died out, this becomes a real problem, both for the bears as well as for people.
land (21:01:24):
“Climate change today is much more rapid than the change described above.”
No, it’s not. But thanx for playing.
Oreo? Is that like brown on the outside and white in the middle?