"Two Canadian biologists have reported sighting a handful of grizzly bears and hybrid grizzly/polar bears at unusually high latitudes in the Arctic, indicating that the interbreeding of the two bear species is becoming more common as the climate warms and grizzlies venture farther north."
"The sightings of three grizzly bears and two hybrid bears, made in late April and May, represent an unprecedented cluster of these animals at such high latitudes. The biologists even took DNA samples from a grizzly bear at 74 degrees North latitude.
The report of the sightings comes on the heels of a recently published analysis of newly sequenced polar bear genomes, suggesting that climate change and genetic exchange with brown bears helped create the polar bear as we know it today. The genetic mixing that the Pennsylvania State and University of Buffalo analysis identified happening in the past — in which polar bears would interbreed with grizzly bears as the polar bears’ sea ice habitat shrunk — is now happening again, according to bear biologists."