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It's a fact that polar bears and grizzly bears have bred together. Which means either the polar bear or the grizzly migrated into the other's territory. If the polar bear moved further south to find the grizz, then it must have found enough food to survive there. Although it may take awhile, and yes, we could loose many polar bears, but I pray that before they're all gone they will adapt and find a way to survive. I write this because I'm curious how many of you believe that the polar bear will adapt and survive climate change?
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Sheep hunting...... the pain goes away, but the stupidity remains...!!! -
As long as they don't migrate down here.......Originally posted by 4merguide View PostHunt Ethically. Respect the Environment. -
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There's always been overlap between polar and brown bear habitat. Brown bears aren't new to the northern coasts of Alaska and Canada, and that's where polar bears spend the late summer before the ice starts to re-form. Granted, that time has stretched considerably in recent years, but polar bears along the coast isn't a new phenomenon. I wouldn't read too much into a few hybridization events - that doesn't really suggest that polar bears will be able to adapt their way out of a warming climate and the loss of sea ice.Originally posted by 4merguide View PostComment
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But it doesn't suggest they won't either....correct? I am a believer in that mother nature often finds a way for it's creatures to survive. Look at the alligators...a prehistoric creature that is still here today. How many climate changes has it seen?Originally posted by Brian M View Post
Sheep hunting...... the pain goes away, but the stupidity remains...!!!Comment
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Excellent article! Thanks for sharing. Again, lends at least some credence to them possibly adapting to new environments..Originally posted by Daveinthebush View PostSheep hunting...... the pain goes away, but the stupidity remains...!!!Comment
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Oh hell no. Not a hybrid polar bear/aligator. Polargator?Originally posted by 4merguide View PostHunt Ethically. Respect the Environment.Comment
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The ABC bears of Admiralty, Baranof, and Chichagof Islands are a brown and polar bear hybrid. The theory is that during the last ice age a group of female polar bears had relations with male brown bears, when the earth once again warmed and the glaciers receded the ABC bears with hybrid brown and polar bear genes were left stranded on Admiralty, Baranof, and Chichagof Islands.
"We present an analysis of genome-wide sequence data for seven polar bears, one ABC Islands brown bear, one mainland Alaskan brown bear, and a black bear (U. americanus), plus recently published datasets from other bears. Surprisingly, we find clear evidence for gene flow from polar bears into ABC Islands brown bears but no evidence of gene flow from brown bears into polar bears. Importantly, while polar bears contributed <1% of the autosomal genome of the ABC Islands brown bear, they contributed 6.5% of the X chromosome. The magnitude of sex-biased polar bear ancestry and the clear direction of gene flow suggest a model wherein the enigmatic ABC Island brown bears are the descendants of a polar bear population that was gradually converted into brown bears via male-dominated brown bear admixture."
"During the peak of the last ice age, brown bears were likely absent from the region that now comprises the ABC Islands. Although fossil remains dating to this period are abundant on the more southerly islands of the Alexander Archipelago, brown bears are not among the species present during the period spanning 26-12kya, when glacial conditions were at their peak. Geological and climatological data suggest that if any habitat suitable for brown bears persisted on the ABC Islands during the LGM it would have been limited to the western part of Baranof Island, the most distant of the ABC Islands from the Alaskan mainland. By itself, however, this potential refugium would have been too small to support viable populations of brown bears.
Polar bears, alternately, would likely have colonized the sea ice adjacent to the ABC Islands as the ice advanced southward. Notably, marine mammals dominate the fossil remains dating to this interval, including ringed seals, an ideal food source for polar bears. As the climate warmed and ice retreated, polar bears may have been stranded on or near the ABC Islands. As the habitat became increasingly hospitable to brown bears, the early colonizers from the mainland would have been predominantly the more peripatetic sub-adult males. Admixture involving an influx of mostly or exclusively male brown bears with the stranded polar bears would have resulted in a gradual erosion of the polar bear genome within the isolated population. The sex bias of admixing brown bears would have made genomic erosion more rapid in the autosomes, confining the vestiges of polar bear ancestry in extant ABC Islands bears primarily to matrilineal-biased genetic loci."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3597504/
Numerous studies suggest that polar bears diverged from the brown bear lineage about 4 to 5 million years ago.“I would rather have questions that can't be answered than answers that can't be questioned.” Physicist ― Richard FeynmanComment
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Interesting topic 4merguide. The fact of the matter is that no matter how much we debate this topic and however many computer models we use, the future is always uncertain. IMO, the polar bear will adapt because I believe like most bears, the polar bear is an opportunist and therefore can and will adapt. That doesn't mean that along the way the gene pool doesn't change and natural selection may cause the polar bear populations to change. One might even make the argument that polar bears and brown bears are really separate subspecies and not separate species. Not only can they hybridize, but the hybrids are fertile. By definition, that means that they could be in fact improperly classified as a separate species. Taxonomy is a very subjective science that has a lot of vague rules that are unclear.Comment
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Indeed, I totally agree. And thank you for actually giving your opinion towards answering the question I asked. I feel the same.Originally posted by Bushwhack Jack View Post
Sheep hunting...... the pain goes away, but the stupidity remains...!!!Comment
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These kind of questions strike me as akin to saying, "gee I hope the bears will be able to properly rearrange the deck chairs"...while in the background the band can be heard playing Nearer My God to Thee. The premise seems false. My question would be: When was the last time in all of geologic history that our global ecosystem changed as fast as it's currently changing, and what happened to life on the planet that time around?...he who knows nothing is nearer to truth than he whose mind is filled with falsehoods & errors. ~Thomas Jefferson
I would rather have a mind opened by wonder than one closed by belief. ~Gerry Spence
The last thing Alaska needs is another bigot. ~member Catch ItComment
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Dansgaard-Oeschger events or D-O events show that extremely rapid climatic changes occurred and have done so frequently in the recent past. D-O events have shown a rise of temperature on the Greenland Ice Sheet of up to 8 degrees Centigrade in 40 years time. What happened to life on the planet at the time, it adapted or it died. In fact the 8 degrees Centigrade in 40 years time was somewhere around 12,000 years ago...the end of the last Ice Age and a time when numerous large land animals either went extinct or started the rapid decline to extinction. Rapid warming of the earths climate is nothing new, humans being able to witness and attempt to understand it is.Originally posted by iofthetaiga View Post
“I would rather have questions that can't be answered than answers that can't be questioned.” Physicist ― Richard FeynmanComment
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LOL. Well, certainly can't argue at least the second half of that. This will certainly be the first time the human species gets to witness its own extinction, and attempt to understand it.Originally posted by Patsfan54 View Post
...he who knows nothing is nearer to truth than he whose mind is filled with falsehoods & errors. ~Thomas Jefferson
I would rather have a mind opened by wonder than one closed by belief. ~Gerry Spence
The last thing Alaska needs is another bigot. ~member Catch ItComment
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Fair point Taiga, but respectfully, you really have no idea how fast or how slow the environment has changed in the past. You weren't there man and neither was I. Case in point, back prior to the 1964 earthquake there was a species of saltwater stickleback in the Prince William Sound. After the earthquake, there is a new species of freshwater stickleback that was the result of uplift that occurred during the earthquake. I'd say that was a pretty quick adaptation, wouldn't you agree? Nature is pretty resilient. And we really have no idea what is going to happen. Just my 2 cents.Originally posted by iofthetaiga View PostComment
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SticklebacksOriginally posted by iofthetaiga View Post
https://www.adn.com/science/article/...ys/2016/01/23/Comment
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