Tag Archives: evolution

Birthing season for harp seals in Labrador Sea just in time to feed hungry polar bears

The main birthing period for NW Atlantic harp seals has arrived. Local populations of ringed and bearded seal pups will soon follow but in the Gulf of St. Lawrence in eastern Canada, the pupping season for harp seals that is usually in progress by this time has likely been redirected north due to lack of suitable ice conditions. Sea ice off Labrador and Newfoundland is in good condition and this is where the vast majority of the global population go to give birth (ca. 7.6 million vs. 1.5 million in the White Sea and 434,000 in east Greenland).

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Polar bear evolution book is progressing well

Just a short update regarding progress on the book. I am deciding on a cover design while addressing suggested changes as they come back from the editor, and preparing marketing material. If all goes to plan, I am on track for a March publication date–thanks to your support.

In the early 1960s paleontologist Bjorn Kurtén thought that polar bears likely arose from a brown bear ancestor based on fossil evidence alone, and his estimate of when this happened was determined by the age of fossil remains of both species. As I will show in the chapters that follow, despite more fossil evidence being available and additional evidence from molecular genetic studies, his estimate is still the most likely time frame for when the polar bear came to be.

Five years ago today, activist scientists tried to silence me: I’m still here but I need your help

On 29 November 2017, I awoke to find derogatory articles featuring me and my work splashed across newspapers worldwide, part of a coordinated effort to promote a paper published in the journal BioScience. More followed. The paper was a vile attempt by 14 activist scientists to silence me and others, assisted in their unethical attack by an enthusiastic media. But it didn’t work.

I’m still here, in part because of your support, both intellectual and financial. I’ve continued to effectively challenge the baseless rhetoric that polar bears are helpless victims of human-caused global warming by providing fully referenced information without climate fear-mongering. I’ve run this blog for ten years, written numerous scientific reports, a peer-reviewed paper, and a raft of entertaining and informative books.

Now I need a bit more help.

I’ve decided to use this occasion to kick-start a donation drive to help cover production costs of my new polar bear evolution book. In many ways, your enthusiastic support over the years has led me to write this book: the complete story of polar bear evolution, including the role of hybridization, but without the baffling scientific jargon. It will put everything we know about polar bears into evolutionary context–not just the when and where but the why and how.

Nothing like this exists and I don’t think you’ll be disappointed. I’m on track for publication in early 2023.

I’m asking those of you with the means to help, to assist me in getting this important book across the finish line. Details below.

UPDATE 1 December 2022: GOAL REACHED! What an amazing community this is–$5210 raised in two days. I am truly grateful for your generosity and moral support. Your donations will ensure that this polar bear evolution book gets published quickly and looks professional. Heartfelt thanks to all who participated. I will announce the winners of the special incentive (see below) next Tuesday, 6 December.

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Polar bear evolution and recent genetic papers

Two scientific papers in June on polar bear evolution got a bit of media attention but not what the topic deserves. I’ve not written about them because I am currently working on a larger piece putting this conflicting genetic information into full context. Have patience, it’s coming.

Photographer’s claims that Inuit hunting is unsustainable are not supported

A campaign by an anti-hunting Norwegian photographer to destroy the market for legally-hunted polar bears in Canada makes a few disturbingly false claims and an article at National Geographic in which he is quoted further distorts the picture of polar bear conservation. I understand that some people object to hunting and wish more people felt like they do – but this sort of argument is unlikely to sway any but the most gullible.

Cover photo Ole J Liodden small web

Norwegian photographer Ole Liodden apparently has a master’s degree in “nature management and environmental policy“. He takes fabulous polar bear pictures (I purchased one of them, above, for the cover of my novel, EATEN) but his crusade to ban hunting and trade in polar bear products world-wide has lead him to misrepresent essential facts, which is no way to win an argument. A National Geographic writer and several polar bear specialists have provided additional spin and used it as an excuse to promote their failed prophesies that polar bears are doomed: “Should polar bear hunting be legal? It’s complicated” (28 May 2019).

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New genetics paper is not about whether climate change causes polar bear hybrids

A new paper on the evolutionary history of bears (Bears breed across species borders: Kumar et al. 2017) has concluded that hybridization is common and natural among all species of ursids. And while some media outlets (e.g. DailyMail) have framed this as surprisingly convincing proof that experts were wrong to claim that climate change is the cause of recent polar bear X grizzly hybrids, definitive evidence against that interpretation has been available for years to anyone who bothered to look: see my recent “Five facts that challenge hybridization nonsense.”

This genetic evidence is just a cherry on top of the rest but will help get the paper the media attention the authors crave.

Polar bear X grizzly hybrids were known long before climate change and sea ice decline became an issue. See also previous posts here, here, and here. In fact, as I’ve pointed out, “most polar bear hybrids said to exist have not been confirmed by DNA testing” (including virtually all of the bears specialist Andrew Derocher claimed were hybrids, including the latest one from 2016 that prompted such gems as “Love in the time of climate change”).

pizzly_andrewderocher_300dpi_2017 paper

A polar bear X grizzly hybrid, see Kumar et al. 2017. Photo by A. Derocher.

In my opinion, the most important conclusion of this paper is that occasional but widespread hybridization among bears is why it has been so hard to say with confidence when polar bears arose (which I addressed years ago, in my Polar bear evolution series: Part 1, Part 2, and Part 3). You cannot use traditional methods of pinpointing the timing of speciation events from genetic data if one or more of the species have hybridized (traded genes). See the long, fuzzy “divergence times” for bears in the image below from the Kumar paper.

Kumar et al 2017 hybridization in bear evolution_fig 5

From Kumar et al. 2017, Fig. 5: “The scale bar shows divergence times in million years and 95% confidence intervals for divergence times [speciation events] are shown as shadings.”

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Paleoclimate + genetic study confirms: Arctic species adapted to sea ice changes

A new paper that combines paleoclimatology data for the last 56 million years with molecular genetic evidence concludes there were no biological extinctions [of Arctic marine animals] over the last 1.5M years despite profound Arctic sea ice changes that included ice-free summers: polar bears, seals, walrus and other species successfully adapted to habitat changes that exceeded those predicted by USGS and US Fish and Wildlife polar bear biologists over the next 100 years.

Healy Aug  24 2015 Polar-Bear V Tim Kenna

Cronin, T. M. and Cronin, M.A. 2015. Biological response to climate change in the Arctic Ocean: the view from the past. Arktos 1:1-18 [Open access] http://link.springer.com/article/10.1007/s41063-015-0019-3

Thomas Cronin is a USGS paleoclimatologist at the Eastern Geology and Paleoclimate Science Center, and Matthew Cronin is a molecular geneticist at the University of Alaska Fairbanks (see previous posts here and here about Matt’s work on the genetics of polar bear evolution).

From the Abstract:

Arctic climatic extremes include 25°C hyperthermal periods during the Paleocene-Eocene (56–46 million years ago, Ma), Quaternary glacial periods when thick ice shelves and sea ice cover rendered the Arctic Ocean nearly uninhabitable, seasonally sea-ice-free interglacials and abrupt climate reversals.

The final discussion and two summary graphics from this paper (copied below) are especially useful:

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Long underwater stalk by polar bear shows how hard it is to catch seals in summer

The longest-ever-recorded underwater dive by a polar bear, stalking three bearded seals, shows in striking fashion how truly difficult it is for a polar bear to catch a seal from summer sea ice. After the long dive, the bear (see below screen capture) erupts from the water to try and take the seal resting on the ice but it escapes.

Underwater stalk_01

The paper reporting this dive, by Ian Stirling and photographer and Arctic expedition organizer Rinie van Meurs, has hit the news again in a big way, as it finally appeared in print. I wrote about it in June here, when it came out in press. The video was shot on 19 August 2014, at the height of the Arctic summer (July, August, September).

CBC Radio posted the video and interviewed  van Meurs yesterday (“As It Happens” 4 August), in which he reportedly made this astonishing statement:

“…after 27 years working, I have seen clearly changes in the sea ice. I don’t need to see the NASA records and graphs and all that.”

Indeed, who needs science and all that? You just have to look out the window of your ship! Anecdotal reports are what count as evidence to people who are not scientists. Van Meurs, who is not a scientist, is who the media gets to interview. Where’s co-author Stirling, the scientist?

More stills from the van Meurs video below – too bad, so sad, the bear gets no seal. Why polar bears eat little in the summer even if they are out on the ice hunting, as I discussed here.

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Polar bear behaviour gets the animal tragedy porn treatment – two new papers

Recently, several polar bear biologists have teamed up with photographers to get pictures of starving bears into the scientific literature – and picked up by the media, with mixed results.

doi:10.3402/polar.v34.26612
For the second time in five years, polar bear biologist Ian Stirling has teamed up with a photographer to give unwarranted scientific credence to an anecdotal account of polar bear behaviour. It included a picture of a pitifully thin animal  (classic animal tragedy porn) and was framed to increase alarm over predicted effects of global warming. It got little media attention.

His Norwegian colleagues Jon Aars and Magnus Andersen have just done the same with a bear caught eating a white-beaked dolphin (photo above) – but this time the media took the bait.

Update 13 June 2015 – Information added on white-beaked dolphin distribution, sea ice conditions in 2014 and a correction. See below.
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On being a polar bear expert, among other things

As an interdisciplinary scientist, my recent work reviewing and summarizing polar bear science fits cohesively into my career. In this essay, my 300th blog post, I explain in some detail why ‘polar bear expert’ describes me just as well as ‘dog evolution expert.’ In fact, I have world-renowned expertise in other specialties as well, which will amaze and confuse those who think that a scientist can only ever be knowledgeable about one topic in their lifetime.

Polar bears Stanley park zoo_Crockford 1970s_web

My photo of the polar bears at the Stanley Park Zoo, 1970s.

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