A few weeks ago I mentioned that there is some debate as to the taxonomy of the Polar Bear; specifically, as to whether it was simply a clade of the Brown Bear species. Interesting, I note that today a Polar Bear-Grizzly hybrid was shot in Canada:
There have long been stories of oddly coloured bears living in regions where the two territories overlap. But until now, grizzly-polar hybrids, dubbed "grolar bears" or "pizzlies", have been found only in zoos. The hybrid bear was shot last month by an American big game hunter on Banks Island, Northwest Territories, Canada. His guide, Roger Kuptana, noticed the creature had the long claws and slightly humped back of a grizzly bear and thought it might be a hybrid. The body was seized by officials, who sent a DNA sample for tests which confirmed its unusual origins.
If this is not a "one-off" or sterile hybrid that leaves the opening for gene flow between these populations.