One of the common arguments made for why race supposedly does not exist is that unless there's a race for everyone and everyone in his race, then the entire concept of race is useless and fallacious. An yet many of the same problems exist with the concept of species.
There are approximately 22 different proposed definitions for the species, with the most prestigious being Ernst Mayr's: "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.” And yet, it turns out that this definition has problems (besides not working for asexual species and being useless for paleontological purposes: lots of animals that are reasonably considered separate species can interbreed if they are in the mood.
You can breed lions and tigers together in the zoo to get ligers and tigons, but there is a lack of hard evidence that they've ever existed in the wild.
But now there is interesting news of a formidable wild hybrid. National Geographic reports, with a picture:
DNA analysis has confirmed that a bear shot in the Canadian Arctic last month is a half-polar bear, half-grizzly hybrid. While the two bear species have interbred in zoos, this is the first evidence of a wild polar bear-grizzly offspring.
Jim Martell (pictured at left), a 65-year-old hunter from Idaho, shot the bear April 16 on the southern tip of Banks Island (see Northwest Territories map), the CanWest News Service reports.
Wildlife officials seized the bear after noticing its white fur was interspersed with brown patches. It also had long claws, a concave facial profile, and a humped back, which are characteristic of a grizzly.
Now the genetic tests have confirmed that the hybrid's father was a grizzly and its mother was a polar bear.
"I don't think anyone expected it to actually happen in the wild," said Ian Stirling, a polar bear expert with the Canadian Wildlife Service in Edmonton.
Polar bears and grizzlies require an extended mating ritual to reproduce, Stirling said. Both live by themselves in large, open habitats.
To prevent wasting their eggs, females ovulate only after spending several days with a male, Stirling explained. "Then they mate several times over several days."
In other words, the mating between the polar bear and grizzly was more than a chance encounter. "That's what makes it quite interesting," he added.
Stirling says the hybrid has no official name, though locals have taken to calling it a "pizzly" and a "grolar bear."
These kind of hybrids raise important legal issues under the Endangered Species Act.
These conceptual conundrums with the concept of species are one reason I tossed out the top-down idea of race as "subspecies" and invented the bottom-up concept of a racial group as a "partly inbred extended family." In this framework, then a species is a "virtually wholly inbred extended family," but it's all relative. See my article: "It's All Relative: Putting Race in Its Proper Perspective."