Science

The Species Problem

What do you get when you cross a polar bear with a grizzly?

AP Photo/Troy Maben
AP Photo/Troy Maben A mount of a first-generation polar-grizzly bear hybrid in Glenns Ferry, Idaho.

If it was clear to David and Bella Kuptana what had happened to their hunting cabin on Victoria Island in the Arctic Archipelago last spring, it’s because there was a bear-shaped hole in the wall. Tracing the frozen coastline on snow machines, they found five more cabins in a similar state of ruin; behind one that appeared untouched, they spotted the rogue, making a break for the open plain. David, who took down his first polar bear when he was nine years old and has killed as many as three a year since then, felled the animal with his first shot, and immediately knew something was wrong. Its head was unusually wide, and its paws were brown. Except for all that matted white fur, it looked more like a grizzly.

“My wife was yelling at me, ‘Shoot it some more!’” says Kuptana, one of the few Inuvialuit who still lives off his hunting. “So I shot it three more times when it was down, to make sure.” There was something unsettling about not knowing exactly what this creature was. The couple strapped it to a sled and hauled it back home to Ulukhaktok, Northwest Territories, where they called in government wildlife officer Colin Okheena. After a thorough inspection, he sent photographs to his boss in Inuvik, who then asked for a dna sample. About a month later, they got word: this was a hybrid, with both polar bear and grizzly ancestors, perhaps a freak consequence of climate change, which is pushing grizzlies into polar bear territory.

In fact, hybrids are not all that unusual. George Washington is often credited with the invention of the mule, the offspring of a female horse and a male donkey, but the hardy animal has been used to haul cargo for at least 3,000 years. Less practically, nineteenth-century European zookeepers successfully bred the liger, which thanks to a genetic quirk grows to be enormous if not, contra Napoleon Dynamite, magical. Once genetic testing became widely available in the 2000s, biologists started identifying hybrids in the wild, many close to home. We now know that Canada lynxes have been quietly interbreeding with bobcats in Minnesota, while some of the canines preying on livestock in southern Ontario are actually coyote-wolf hybrids, or coywolves.

Motley Cruise

The minivan morphs its way to modernity

Illustration by Joel Kimmel
Joel Kimmel

While it is currently the road’s most ubiquitous mutt, the van has had a long and somewhat checkered history. The first attempt to combine a car and a bus for personal use was met with confusion and fear: the Stout Scarab, produced in 1935, featured a “bug-like” exterior, a table and chairs instead of passenger seats, and a hefty $5,000 price tag; only nine were ever produced. Half a century later, the minivan, sleeker than its predecessor, and roomy enough to accommodate the baby boomers’ expanding families, became an icon for suburban living.

But sales have declined in recent years, perhaps due to the minivan’s milquetoast connotations, and manufacturers have responded by hybridizing the vehicle yet again—this time with a sports car. Last November, Chrysler introduced the “man van,” which boasts heated leather seats with coloured stitching, and a more “athletic” frame. Not to be outdone, Toyota has dubbed its latest offering, the Sienna, the “swagger wagon.” Promotions include a series of viral videos featuring a middle-class family rapping about their wheels—an image as unsettling to modern audiences as one imagines the Scarab was in its time.

Chris Berube

Kuptana’s “grolar bear” (also “pizzly” or “polizzly”) attracted a great deal of attention, considering. “I got phone calls from the farthest places you can get phone calls from,” he says. Some people wanted to hear the story of the hunt, and others were more interested in the condition of the pelt, but everybody was fixated on the fact that tests had indicated that the bear’s mother was also a hybrid, making him a second-generation cross, which runs counter to most people’s idea of what constitutes a species.

High school biology texts generally define the basic taxonomic unit as a group of organisms that can breed and have fertile offspring. The fact that mules are sterile, for example, proves that horses and donkeys are different species. If only it were that simple. Further study reveals at least half a dozen competing definitions of “species” in circulation, the most popular based on physical traits, ecological roles, or geographical range. Ultimately, whether the grolar bear is a grizzly bear, a polar bear, both, or neither depends on which definition you give credence to.

Marc Ereshefsky, a professor of philosophy at the University of Calgary, is one of the world’s experts on the so-called species problem, which can be understood as a subset of what philosophers call the natural kinds problem. Is a category based on some essential, singular characteristic shared among its constituents, or is it an arbitrary human construction? “Consider a substance like gold: all and only pieces of gold have a certain atomic structure,” says Ereshefsky. “But not all and only Canis familiaris share the same DNA.” In other words, every dog—or bear, for that matter—is a little bit different.

“Many people say that if Darwin taught us one thing,” he continues, “it’s that in the biological world the notion of essence doesn’t really fit.” By the process of natural selection, any characteristic that you might argue defines the polar bear—its fur, the size of its paws, the way it hunts—can change over time, due mainly to existing variation between individual specimens. One of the interesting facts about evolutionary biology’s founding volume is that even though the word “species” is right there in the title, Darwin never got around to defining it. Ereshefsky thinks this was deliberate: “In a sense, he really didn’t believe in the category.”

Nevertheless, certain endeavours clearly require some categorization—devising policy to protect threatened populations, for example. In that case, conservationists might be tempted to reach for a restrictive concept—one based on a specific, and therefore more isolated, physical trait—while opponents would be better served by a broader measure. This multiplicity need not lead to chaos, says Ereshefsky. We just have to note which definition we’re using, and why it’s best under the circumstances.

Kuptana, for his part, is sticking with the fertile offspring concept that made his second-generation cross, and him, a star. Collectors from all over the world bid on the pelt, but he eventually sold it to the local government for $15,700, and a promise to mount it in a new community hall as a tourist attraction. “I said okay so my grandkids would know that I was the one who caught it,” he says. And if they tell their grandkids, someday it could be part of his people’s oral tradition.

This appeared in the April 2011 issue.