So-called "charismatic megafauna" (large animal species with widespread popular appeal) have in recent years, gotten more than their fair share of media exposure. Polar Bears, especially, have become the go-to "poster species" for a host of hot-button issues related to global warming and wildlife protection. They certainly deserve mention in DB's weekly Arts, Music and Science column.
The spotlights began to shine brightly on the polar bears (both figuratively and literally) in 2007, when a photograph of polar bears stranded on rapidly melting ice caps (above left) made the mainstream media rounds, appearing in the Sunday Telegraph, the New York Times and the International Herald Tribune, among other newspapers.
That photograph was in fact taken by an Australian marine biology student, Amanda Byrd, in August 2004, at a time of the year when the arctic ice is thinnest. The picture was then passed on to Environment Canada, which eventually distributed it to seven media agencies, including Associated Press.
Strangely, it was only in March 2007 that the picture was released by Associated Press, two and a half years after it was taken and, coincidentally, on the very same day that the International Panel on Climate Change (IPCC) released a major report, now somewhat discredited, which stated that global warming was "unequivocal" and "very likely due to the observed increase and anthropogenic greenhouse gas concentrations."
The emotional impact of the picture of stranded polar bears struggling to survive in a rapidly warming Arctic environment was thus vividly associated, in the minds of millions, with alarmist claims about global warming, allegedly based on sound scientific evidence, from the IPCC and the UN. However, Byrd, as well as biologist Denis Simard from Environment Canada, mentioned in 2007 that the bears did not appear to be stranded or endangered in the least; in fact, the bears photographed in August 2004 were, according to Simard, still alive and kicking in 2007.
This turned out to be only the first chapter of an ongoing saga for polar bears.
On May 14, 2008, the polar bear became the first animal added to the endangered species list on account of the phony global warming meme, after the US government officially declared polar bears to be threatened with extinction because of shrinking sea ice.
At the same time, conflicting reports regarding the allegedly declining population numbers of polar bears were being issued. On the one hand, scientists predicted, using computer models, that polar bears would be extinct by 2030 if nothing was done to curb global warming.
On the other hand, the US Fish and Wildlife Service estimated, in 2008, the polar bear population at around 25,000 bears, compared to 10,000 bears in the 1950s and 1960s. Moreover, on-the-ground reports by local hunters and residents in 2010 hinted at bears living as far south as James Bay, and increasing observations of litters of three cubs.
More recently, the polar bear saga took an unexpected twist, on the heels of some startling findings by paleontologists and biologists.
In 2010, a Scandinavian research team found a jawbone of an animal that died 130,000 years ago on an Arctic island to the north of Norway. It was identified as the oldest polar bear fossil. Further research suggested that polar bears had evolved from brown bears forced to adapt to ice age conditions that lasted from 190,000 to 130,000 years ago.
However, these results also led to the conclusion that polar bears had survived the subsequent warm period lasting from 130,000 to 115,000 years ago, which was somewhat inconvenient for global warming advocates. But scientists such as Chris Stringer of the Natural History Museum in London were quick to retort that the fact that polar bears survived a warm period thousands of years ago does not mean that they could do so now.
The polar bear evolution timeline got more complicated in 2011 when an article published in Current Biology claimed that all modern polar bears descended from a subpopulation of polar bears that interbred some 50,000 to 20,000 years ago with now-extinct Irish brown bears. More intriguingly, scientists suggested that polar bears had interbred several times with brown bears during the last 150,000 years, and that the genetic sequences of modern polar bears were in fact closer to those of the Irish brown bears than to those of ancient polar bears.
At this point, some readers may wonder about the relevance of the evolutionary past of polar bears to current concerns about global warming and wildlife protection. The relevance is twofold: The research findings have implications for evolutionary accounts and for the status of the polar bear as an endangered species, because they suggest that polar bears and brown bears may, in fact, be members of the same species (more on this later).
First, the Current Biology paper led to the idea that rather than separating into distinct branches, evolving species may alternate between episodes of interbreeding and evolving in different directions. Moreover, it forced scientists to reevaluate the impact of interbreeding between polar bears and brown bears, as explained by population geneticist Michael Hofreiter:
"We thought that hybridizations [interbreeding], which seem to have become more common because of climate warming, would be threatening polar bears as a species. However, now it seems that this view could be too simplistic, and limited hybridization during times of climatic change could even help species survive such times."
Second, this interbreeding between polar bears and other bear species has become a legalistic nightmare for hunters and conservation agencies. The case of Jim Martell, a hunter from Idaho, who found and shot a "grolar" (grizzly-polar bear hybrid) in 2006, in the Northwest Territories of Canada, was perhaps the first such instance that was widely reported. Martell had a license to kill polar bears, but not grizzlies, and could have faced a fine and possibly up to a year in jail if the animal had been determined to be a grizzly. The bear was finally returned to Martell, but not before the animal was examined by officials and a DNA test conducted by scientists.
In 2010, a bear shot by an Inuvialuit hunter in the Northwest Territories was determined to be a second-generation grizzly-polar bear hybrid, meaning that the bear's mother was herself a "grolar," while the father was a grizzly. This posed a new and annoying conundrum for scientists, to the extent that even a mainstream magazine such as The Slate felt obliged to address the topic.
The issue is that interbreeding species do not normally produce fertile offspring; the concept of "reproductive isolation" between different species, coined by biologist Ernst Mayr is, in fact, crucial to the modern concept of biological species, and is still accepted today. Thus, animals belonging to species that can produce fertile hybrids should, according to this definition, be treated as being part of the same species.
Of course, the notion that brown bears, grizzlies and polar bears simply would be different variants of the same species has wide-ranging implications that go far beyond evolutionary accounts. It has been known for a long time that, in zoos, brown bears interbreed with polar bears, American black bears and Asiatic black bears. But, while zoos are artificial environments, the natural occurrence of second-generation "grolar" hybrids was a momentous find.
While The Slate tried to brush off the topic by pointing out that polar bears and grizzlies have more recent common ancestry than, say, donkeys and horses, some alternative media and bloggers quickly seized on the potential import of this idea. Here is a savory quote from Jim Beers' blog "Klamath Bucket Brigade," in a blog entry that deals with an LA Times report of the Current Biology article cited above:
Why are we concerned about polar bears moving south to share "bed and habitat" with brown bears if they have done it "many times before"? Are the "various species" of brown bears really "species" or populations or subspecies? When you call later in the article to "protect hybrids" do you mean just crosses between polar bears and all the "various species of brown bears" as well as crosses between each of the "various species of brown bears?"
As Beers notes, the larger issue is whether the Current Biology findings, as well as the reports of naturally occurring hybrids, should lead to a reevaluation of the polar bear protection efforts. This seems reasonable if we interpret these findings to mean that polar bears, brown bears and possibly grizzlies are simply variants of a broadly defined "bear" species and have possibly been interbreeding for tens of thousands of years, and that polar bears seem to have survived prior warm periods.
However, mainstream scientists do not see these discoveries as having any bearing on conservation efforts, and biologist Beth Shapiro claims that "there is no reason that past hybridization and genetic introgression with brown bears should affect at all the conservation status of polar bears. The two species are very different, each adapted to a particular lifestyle, and each playing a crucial role in their ecosystem."
But when taking into account the larger-than-life status of polar bears in the context of the global warming fear-mongering, coupled with conflicting reports about recent population trends, the polar bear saga can be seen as a cautionary tale depicting a situation where political goals and scientific interests are hopelessly intertwined, to the extent that apparently innocuous scientific debates about evolutionary findings and the concept of biological species become heavily charged with potentially significant repercussions on current political and environmental concerns.
DB regularly advocates for a return to a free market of ideas (see Science and the Free Market of Ideas). Regardless of its eventual epilogue, the polar bear saga serves as a reminder that truly independent science is, and will remain, a pipe dream as long as the bulk of research funding, as well as scientific career options, are ultimately controlled by the governmental apparatus, abetted by central banking and the unrestricted power to print fiat currency.