>>374860none of the bears are different species, they can all intermate. they're all subspecies (races/breeds/etc) of the same thing, who have either been isolated long enough to accentuate specific traits or a certain population has survived better through genetic mutation/evolution.
brown bears, grizzlies, and kodiaks are basically all the same thing (99.9%), polars and blackies are like 99.8% the same thing.