Let a bear robbed of her whelps meet a man,
rather than a fool in his folly.
Proverbs 17:12
"Brown bears—some of which are called grizzlies—and polar bears are closely related and are even able to interbreed. In the past few years, researchers have used genetic
information to sort out this relationship and to understand how polar bears thrive in the frigid Arctic, feeding primarily on seals and other marine life captured from holes in the ice. This work has included sequencing the animals’ genomes, which has indicated that polar bears are truly a distinct species that at times lived apart from brown bears and at times intermingled and interbred with them. The most distinctive polar bear genes include many related to fat processing and to the development of the heart and circulatory system. Indeed, nine of the 16 most distinctive genes are ones that in humans are associated with heart disease, Willerslev says. One that stood out was a gene called APOB, which helps transfer fat from blood into cells.
In brown bears, the sequence of this gene varies from one bear to another, but all the polar bears surveyed have an identical version, with the exact same genetic code at nine variable spots in the gene, about half of which should change the function of the APOB protein.
That all polar bears have the same version indicates that it is very beneficial, perhaps enabling the animals to eat lots of fat without developing artery-clogging plaques that can plague humans who eat high-fat diets, says study co-author Eline Lorenzen, a molecular ecologist at the University of California (UC), Berkeley." ScienceNow
In other words, the bears come from a common ancestor going back to the creation. Along the way, apparently brown bears lost some of this genetic info (since some have the genes & some don't). So it would seem logical that the polar bear may be a step closer to the original "bears" at the creation than brown bears.