2012-03-03 04:54:39Simply Wrong! Bob Carter on Polar Bears
Rob Honeycutt

robhon@mac...
98.207.62.223

Here's a trial run on the idea of a Simply Wrong! series.  Let me know what you think.

http://www.skepticalscience.com/simply-wrong-1-bob-carter-on-polar-bears.html

2012-03-03 05:30:43
logicman

logicman_alf@yahoo.co...
109.150.152.138

This is the start of a new series at Skeptical Science called Simply Wrong! where were will address very simple errors that are being propagated in on the internet and explain what science actually says.

 

Nice!

2012-03-03 05:44:16
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Might be good somewhere in the intro to note Carter's general lack of climate expertise, linking to my post on the subject.

2012-03-03 05:50:03
Rob Honeycutt

robhon@mac...
98.207.62.223

Dana... How about we keep the message simple but add your piece to the notes below?

2012-03-03 05:53:38
Rob Honeycutt

robhon@mac...
98.207.62.223

Hmmm.... Why don't the notes show up?  I thought when you posted stuff in the notes section it showed up below the article in a separate box.  

2012-03-03 07:21:04Gap created by this debunking
John Cook

john@skepticalscience...
121.222.175.176
When I read fact 1, it creates the following gap or question that needs answering. In the last interglacial, temperatures were 1 to 2 degrees warmer than now. Sea levels were at least 6 metres higher, meaning plenty of ice loss from Greenland. Presumably Arctic sea ice would've also been either greatly diminished or all gone in these conditions. If polar bears has emerged before that interglacial, how did they survive those conditions?

Notes are only available to SkS authors.

2012-03-03 07:48:57
Andy S

skucea@telus...
209.121.15.232

There's a very good thingsbreak blog article on polar bears that may help answer some questions.

The Eemian change was much slower, so the there was more time for bears (and their prey) to adapt and the other pressures bears (and the whole ecosytem) face now from other human interference weren't present then.

2012-03-03 08:00:28
Glenn Tamblyn

glenn@thefoodgallery.com...
121.212.9.21

JC

 

I disagree with your point here because of the context in which the Simply Wrong idea will, hopefully be applied. A easily transmissable little package on a single point. 99.9% of people know nothing about the details of each Ice Age. Only the more knowledgable will have enough knowledge for there to be a gap. The idea of this is almost sound bites that could be used by he media. So the more we elaborate for the sort of reason you have identified, the more we dilute the concentrated nature of these news bites.

Similar response to Dana's point.

Rob, some suggestions. Try editing the text down a bit and move references to the science to the bottom. Even without access to the Notes section still have a separate notes area at the bottom, below the concluding line to keep the main text tighter. And there also link to any SkS rebuttals as well. Possibly add to the concluding line something like 'We don't know whether Polar Bears can survive the coming changes. They haven't been around long enough to have had to face this before'. This is the reinforcement of why Carter is Wrong!

2012-03-03 08:13:58
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Maybe the Simply Wrong series posts should have 'further reading' links at the bottom so that people who so desire can read about the issues in more detail.  You could link to my post and thingsbreak's there.

2012-03-03 08:51:01
Brian Purdue

bnpurdue@bigpond.net...
138.130.140.206

Recently there was a very active discussion about not putting videos on SkS that reinforce denier’s myths – Carter’s video is full of them so why is it OK this time because people may watch the whole video.

I would take the video out but leave the single frame in and put in full transcript of what Carter said about polar bears.

The introduction by Jennifer Marohasy is enough to turn your stomach but bring joy to denier’s hearts (assuming they have one)

2012-03-03 08:56:31
Rob Honeycutt

robhon@mac...
98.207.62.223

Okay, did an update.  I added a further reading section at the bottom.  Pulled the video link.  I agree with Glenn that we should keep each point simple.  One-liners when possible.  Then if there are gaps like John C pointed out we can add references at the bottom.

2012-03-03 09:14:48
Brian Purdue

bnpurdue@bigpond.net...
138.130.140.206

This first installment starts with a video lecture on Youtube by Dr. Bob Carter, which has now been viewed over 350,000 times. At minute 9:00 Carter makes the tongue-in-cheek claim that the images you see of polar bears on television can't be real

Rob- Assume you are going to rewrite these words because they don’t make sense now video is removed.

2012-03-03 09:32:18
Rob Honeycutt

robhon@mac...
98.207.62.223

Being that this whole thing is in response to Carter's video I'm not sure we can NOT provide a link.  On one hand, most news sites regularly neglect to create links to source material.  But if we want to give the reader a chance to see what we're talking about we probably should.  Otherwise I'm not sure how I could rewrite that sentence to reference material that we aren't referencing. :-/

2012-03-03 10:32:20John Cook is right
Tom Curtis

t.r.curtis@gmail...
101.118.12.27

The gap created by this debunking is the Eemian, with the seperation of Polar Bears  from Brown bears preceding the Eemian by 20 thousand years, and with a fossil jaw having a modern morphology, and a modern polar bear diet found just 4 thousand years after the end of the Eemian, most readers will understand this to mean that:

1)  Polar bears evolved into their modern form 150 thousand years ago; and

2)  They survived a period in which there was no Arctic ice.

From which they will draw the conclusion that 

3)  Polar bears are not threatened by loss of ice.

 

(1) and (3) are false, but you do not have space to explain that in this format.  

 

In fact, the Eemian would have been an ideal time for brown bears to invade the high arctic.  The lack of summer sea ice would have forced seal populations to breed on the shores of Arctic islands, and in particular the Canadian Archipelago.  Brown bears could have taken advantage of the summer warmth to move into the archipelago to access an easilly accessible and highly concentrated food source that was not used to predation.  Distances between islands in the Archipelago are sufficiently large to favour specialist adaptions for long distance swimming, but not so large as to be beyond the swimming range of a brown bear.

Brown bears taking this opportunity would probably have migrated north within the archipelago in summer, and south during the winter, and probably developed a winter coat.  With the onset of glaciation, the winter coat would have become permanent, and the maritime archipelago habit been easilly adapted to expansion onto the sea ice as the bear's prey dispersed.

 

The problem with this scenario for combating the myth is that we do not have any specific evidence that that is what occurred.  What is more, people continue to assume that time of seperation equals time of development of modern features.  Once deniers attack this point, you will have a hard time establishing that they are incorrect.  

 

Consequently, although I like the format, and think this myth should be taken on, it is the wrong format for this myth.

2012-03-03 10:32:33
Brian Purdue

bnpurdue@bigpond.net...
138.130.140.206

Post is just about polar bears so add the single frame of polar bears with Carter’s tongue-in cheek words at bottom. And add to the existing frame a talk bubble with Carter saying "Look! They all died out here and here and here and here! There's none there today. There couldn't be." and a few words of explanation – anything but the entire video!

2012-03-03 10:58:11
Rob Honeycutt

robhon@mac...
98.207.62.223

Does anyone have a full copy of Lindqvist 2010?  If it's supported in the paper perhaps there is a way to word this more accurately.  Clearly it wasn't just one day when suddenly we had both brown bears and polar bears as we know them today.  I would speculate that it was the following glaciation that drove them apart genetically as one adapted to the northern glacial climate and the other migrated south and adapted to a different climate.

Again, if the paper supports it, I could say that the polar bear began to diverge from brown bears some 130,000 years ago just prior to the Eemian interglacial.  It was clearly not modern polar bears that survived that interglacial.  

Ultimately to make these Simply Wrong! pieces be effective we need to keep them as short as possible.  The minutia should be contained in the further reading.

2012-03-03 11:00:52
Rob Honeycutt

robhon@mac...
98.207.62.223

Note that the first and last "further reading" links explain all the details of polar bears in the Eemian and the Holocene.

2012-03-03 11:24:36
Tom Curtis

t.r.curtis@gmail...
101.118.12.27

Rob, http://www.pnas.org/content/107/11/5053.full

 

"Fig. 3. 

Phylogenetic and chronographic reconstruction of polar bear evolution. (A) Maximum clade probability tree inferred from a BEAST analysis of complete mt genome sequences excluding the VNTR repeat in the D loop (Table S2). Numbers at selected nodes indicate mean ages in million years. The red bars at nodes illustrate the age width of the 95% highest posterior density interval. The posterior probability values of each clade are indicated in orange. An identical tree topology was obtained using maximum parsimony and maximum likelihood (bootstrap support values in green and yellow, respectively). For details on voucher information for the mtDNA genome sequences included in this study, see Table S1 and Figs. S3 and S4. The 2009 Geologic Time Scale with major relevant epochs is shown above the tree. (B) Phylogenetic network of complete mt genomes (excluding the VNTR repeat) of 11 polar and brown bears based on Neighbor-Net analysis with LogDet distances (see scale bar)."

 

Key sections:

 

"Timing estimates for the divergence of polar bears from brown bears have differed considerably. In addition to the hypothesis of a very recent split, a divergence time of 250–200 kya has also been proposed (6), whereas based on comparisons of complete mitochondrial (mt) genomes the cladogenesis has been estimated to be as distant as 1,320 kya (9). Recently, using an extended dataset of 10 mt genomes, the split of brown and polar bears was estimated to be 1,170–660 kya (2). Sources of these inconsistent estimates may have included inappropriate, deep fossil calibrations as well as limited sampling, and in particular lack of data on brown bears from the ABC islands. Recognizing these shortcomings, internally calibrated substitution rates have been calculated from a dataset of short stretches of mt control-region sequences, including several radiocarbon-dated individuals, with the result that the divergence time between polar and ABC island bears was estimated to be as recent as 72–48 kya (10). However, the limited polymorphic characters within these very short stretches may contribute to erroneous dating in this case.

Fossil remains of the polar bear are very rare (41113), because the animals mostly live and die over vast areas of sea ice, and when they die their remains are likely to be scavenged by other animals and disappear into the ocean. In light of this paucity of fossil finds, every new specimen is of interest. Recently, a lower jawbone (left mandible) was excavated in situ at Poolepynten on Prins Karls Forland, a narrow strip of land on the far western edge of the Svalbard Archipelago, Norway (11). Diagnostic polar bear traits and morphometric measurements of this well-preserved mandible, comparing it to brown bear and other available subfossil polar bear remains as well as a large collection of extant polar bears from Svalbard, proved that it falls within the range of modern polar bears and suggested that it belonged to an adult male (11). Accelerator mass spectrometry 14C age determination from a canine tooth attached to the jawbone dated it to older than 45 thousand years (ky) old (11). Based on long-term studies of the stratigraphy and depositional history of the Poolepynten area and infrared-stimulated luminescence of the sediments (14), the specimen was estimated to be 130–110 ky old, which is significantly older than any other known polar bear subfossils (i.e., partly fossilized specimens), none of which are older than possibly ∼70 ky (and most younger than 10 ky) (11). The discovery of this jawbone confirms that the polar bear was already a distinct species at least 110 kya, and as such any findings from genetic research based on this specimen could contribute to answering key questions on the evolutionary history of this species."

And:

"The robust phylogeny and the close position of the subfossil polar bear specimen to the polar/brown bear split offer an ideal opportunity to ultimately settle a time of origin for the polar bear. Our Bayesian analyses with different datasets returned a divergence date for the entire brown bear/polar bear lineage to a mean of less than 500 ky (Fig. 3A; see also Table S2), which is consistent with recent estimates using deeper fossil calibration in the Ursidae (3). Within this clade, we estimated the mean age of the split between the ABC bears and the polar bears to be 152 ky, and the mean age for all polar bears as 134 ky, near the beginning of the Eemian interglacial period and completely in line with the stratigraphically determined age of the Poolepynten subfossil (11). Analyses of an extended dataset of 39 mtDNA control-region sequence fragments from a number of carbon-dated brown bears (26) and modern polar bears, importantly including four from Svalbard, provided comparable, although slightly older (190 ky for the ABC/polar bear split), divergence time estimates (Fig. S5). Although mtDNA capture cannot be excluded to have happened between ABC bears and polar bears, these estimates nevertheless affirm with strong support a very recent divergence of polar bears from brown bears. Even more surprising, the age of the modern polar bear crown group (the clade containing the last common ancestor of all extant members) is estimated to be less than 45 ky, slightly older than the age of the ABC bears (Fig. 3A), a date that is also found with the expanded dataset of control-region sequence fragments (Fig. S5). These estimates suggest a very recent and rapid expansion of modern polar bear populations throughout the Arctic since the Late Pleistocene, perhaps following a climate-related population bottleneck, although data from more modern and Holocene polar bear specimens will be required to establish this."

And

"Stable isotope analyses of carbon and nitrogen have been used as a tool to evaluate trophic relationships, both in past and present environments (2627). Modern polar bears prey mainly on ringed seals and bearded seals (28), and stable isotopes have confirmed that they are marine predators that make little use of terrestrial food sources (2931). To investigate the trophic relationships of the ancient Poolepynten specimen as compared with present-day polar bears from Svalbard, we analyzed the stable isotope content in the canine tooth. The stable isotope values for the ancient tooth (δ13C = −13.9‰ and δ15n = 19.4‰) were within the range found from extant polar bear teeth and other tissues and were reflective of marine feeding (262931). Importantly, these isotope values are distinct from those found in Late Pleistocene brown bears, including from the ABC brown bear lineage (26), as well as present-day coastal Alaskan brown bears (32). Thus, our results clearly demonstrate that the jaw is from an individual that had a feeding ecology similar to present-day polar bears, at the top of the Arctic marine food chain. Furthermore, analyses of the stratum containing the subfossil jawbone uncovered a bivalve and foraminifera fauna reflecting an arctic, open marine environment influenced by glacier input and advection of warm North Atlantic water as today (1114).

The stable isotope data, phylogenetic analysis, and the geological and molecular age estimates of the Poolepynten specimen indicate that ancient polar bears adapted extremely rapidly both morphologically and physiologically to their current and unique ecology within only 10–30 ky following their split from a brown bear precursor and, subsequently, within the course of ∼100 ky, spread to the full perimeter of the polar basin. As such, the polar bear is an excellent example of evolutionary opportunism within a widespread mammalian lineage (33). Moreover, the extreme proximity of the Poolepynten specimen to the polar bear ancestor provides a unique case of a morphologically and molecularly validated fossil link between living mammal species."

My emphasis throughout.

2012-03-03 11:41:27
Rob Honeycutt

robhon@mac...
98.207.62.223

So, am I reading this right?  It sounds like modern polar bears are only about 45 ky old, very much post-Eemian, and a product of the last glacial.

2012-03-03 12:59:23
Tom Curtis

t.r.curtis@gmail...
101.118.12.27

Rob, that's not correct.  The date given for the crown group is based on analysis of mitochondrial DNA, which is passed on almost exclusively by the mother.  That means the last female polar bear to which all modern polar bears can be traced through purely maternal lines lived about 45, 000 years ago.  There is almost certainly a more recent bear (of either sex) who is an ancestor of all modern polar bears through  mixed sex lines of descent, and the most recent bear who is a common ancestor through all paternal lines may be about the same age, or more recent.  (In the case of humans the y chromosome adam lived about a third as many years ago as did mitochondrial eve (from memory).  None of this has any bearing on when modern polar bears evolved, except that the relatively recent date of the mitochondrial eve of polar bears (about a quarter of that of the recently evolved and absurdly named species, Homo sapiens sapiens, for example) suggests that their population was was relatively small relatively recently (ie, 50 to 100 kya).

 

The key information here is that the split between the 110 kya polar bear sample from Svarlbad and all modern polar bears occured about 134 kya.  Because that Svarlbad bear had a maritime diet,  came from a population that had obviously migrated extensively over sea ice, and had morphological features in its jaw that clearly group it with modern Svarlbad polar bears, it must be identified as belonging to the current polar bear species.  This does not mean it had all modern polar bear features, but it almost certainly had most of them, although possibly in less evolved form in some areas.

That means polar bears evolved from brown bear stock sometime between 152 kya and 120 kya at the latest, and the most likely time is during the Eemian (IMO), although the mitochondrial evidence would suggest just prior to the Eemian.   It is likely that the bears from which modern polar bears evolved started developing polar bear features after 152 kya, and given the extent of adaption, it is unlikely that they would have been recognizable as polar bears before about 140 kya, so perhaps 134 kya (+/- 10 ky) would be the best estimate.

 

Now, imagine trying to explain that polar bears first evolved around the hottest time in the Eemian when there was no summer Arctic ice, but that the return to no summer Arctic ice is a threat to them.  That is in fact the case, and the relevant difference is that there where no humans in the America's, and certainly none in the Canadian Archipelago, Greenland or Svarlbad  prior to about 12 kya, so that polar bears had no competition for the spot to place them under threat, and all the beaches where available as breeding grounds for seals (their primary diet) - two factors which are not the case today.

 

If it where not for the presence of humans, a similar case of global warming would reduce polar bear populations, but probably not threaten their extinction because they would survive in outposts on high arctic islands, free from other competition.  It is the presence of humans together with global warming that places them under threat, not global warmign alone. 

2012-03-03 15:02:28
Rob Honeycutt

robhon@mac...
98.207.62.223
We may have to stretch this one to two sentences.
2012-03-04 04:11:50
Rob Honeycutt

robhon@mac...
98.207.62.223

Okay gang...   See if this update works better.

2012-03-04 04:42:07
Same Ordinary Fool

chicagoriverturning@gmail...
71.35.29.177

FACT 2*..........isn't true for the most studied polar bears, those in the western Hudson Bay subpopulation.  The ice on Hudson Bay routinely disappears during the summer, so these polar bears spend those months on land.

Evolution makes this possible.  The polar bears are uniquely adapted to endure a summer long fast- since there's not much food available on land.

This population is now in some distress (low weight pregnant females) because global warming has extended their time spent on land.

 

[Edit additions]   "Unlike brown and black bears, polar bears are capable of fasting for up to several months during late summer and early fall, when they cannot hunt for seals because the sea is unfrozen...[Then} some populations live off fat reserves for months at a time...The polar bear's biology is specialized to require large amounts of fat from marine mammals, and it cannot derive sufficient caloric intake from terrestial food."  Wikipedia

* "FACT 2  The polar bear's summer habitat is the sea ice and it relies on this summer sea ice for feeding..."

2012-03-04 05:16:48
Tom Curtis

t.r.curtis@gmail...
101.118.20.115

"... modern polar bears branched off  evolved from brown bears ..."

Technically they branched of from brown bears about 20 thousand years earlier (154 kya).  Further, as noted before I beleive the more appropriate dates for the evolution to polar bears would be 140 -120 kya.  Bear in mind that the Svalbad bear mandible is dated from 110 to 130 kya, and it is distinctly a polar bear.  Having a period of evolution exactly coinciding with the stratigraphic dating would be unusual.

Also, although often speed of change is a factor, I do not think it is in this case.  The difference between loosing the summer ice pack over a century (or half century) vs loosing it over 500 - 1000 years is almost irrelevant in terms of evolutionary adaption.  As it is, polar bears (like nearly all bears) are very adaptable to different conditions, and so the rapid ice loss would not be a problem provided they have refuges which cannot be invaded by brown bears (their primary competitors in a human less, warming arctic).  In the various islands they could reach, they have that.  There would be a population crash to fit into the new constained habitat, but fast or slow again makes little difference in that regard.  So, I recommend that you drop the reference to rapid ice loss.

I still maintain my opinion that the issue is too complex for this format.

2012-03-04 11:53:29
Rob Honeycutt

robhon@mac...
98.207.62.223

Do you think there is ANY climate related issue that can be zipped up tight in simple facts?  Or is this one just particularly complicated?  Is Simply Wrong! just not a good format for explaining climate issues or not a good format for explaining the polar bear situation?

2012-03-04 15:05:24
Same Ordinary Fool

chicagoriverturning@gmail...
71.35.29.177

Rob H,     It's the polar bear situation that is too varied for generalizations.  The Hudson Bay polar bears are already adapted to spend summers on land, because of a lack of summer sea ice.  And ironically, when the Arctic summer sea ice is mostly gone, a new area for seals and polar bears will open up off the Queen Elizabeth Islands, as the now very thick multiyear ice melts to a seal-livability thinness.

Bob Carter IS literally wrong, by 400,000 - 150,000 = 250,000 years.  But as you say, this is a 'tongue-in-cheek claim.'  And you quote his punchline, "There's none there today."  And in the video he's obviously in high humor.  And he tops it all off with a very funny graphic..........We'd be amiss to take his statement seriously.

2012-03-04 17:06:03
Tom Curtis

t.r.curtis@gmail...
101.118.13.232

Rob, any number of false claims by Monckton could be dealt with in the just wrong format.  For example, he is just wrong in implying that Gore's San Francicisco condo is just a few feet above sea level.  The WSJ op-eds would ahve provided plenty of material for this series as well.  Another example from Australia is claims during the Jan 2011 floods that climate scientists had claimed that it would never flood again.  (I've personally read 10 documents, including 2 dealing specifically with Brisbane which state that global warmign will cause longer deeper droughts insterspersed by more intense floods.)

 

More substantively, claims that arctic sea ice is recovering, or that world sea ice isn't declining, or that CO2 in the atmosphere results in a cooler surface (as claimed by Jon Nicol of the Galileo Movement) coul all also be discussed in this format.

 

The difference is not that deniers won't argue.  They will argue anything as witness the 2nd law thread.  The difference is that our counter arguments are fairly straight forward .  Arguing that polar bears evolved in the Eemian, or just before, but that similar conditions today will threaten their continued existence, while correct, is not straight forward.

2012-03-05 04:01:37
Stephen Leahy

writersteve@gmail...
24.239.7.88

Rob - in first reference at bottom its "Ed" not Erik Struzik.

I like it but I would not make it the first of the series, it's not a big enough lie, or big enough issue. Great as the fourth or fifth but not the lead off.

Speaking as a 'professional communicator' I wouldn't embed the video - just link to it in the references.  An 8 min Carter performance is a distraction from the main purpose of short and factual. The video gives Carter more profile than he deserves.  With the video people will remember him as an 'expert', not that he was wrong. That is the power of images over words. 

2012-03-05 14:11:16
Rob Honeycutt

robhon@mac...
98.207.62.223

Thanks guys.  I think I'll keep my eyes peeled for a better first run on the Simply Wrong! idea.  This has been a good exercise though.